Background Despite advances in the understanding of the disease and new treatment strategies, stage IV GC remains a relevant health issue worldwide. So far, treatment in stage IV GC has been limited to platinum-based chemotherapy. Furthermore, in the case of HER2 expression, the HER2-directed monoclonal antibody trastuzumab is an approved targeted drug for first line treatment. According to the pivotal randomized-controlled phase III registration study, trastuzumab is improving overall survival from 11.1 to 13.8 months. Unfortunately not all patients respond and almost all initial responders eventually develop resistance and experience tumor progression. The prospective multicenter VARIANZ study aimed to identify resistance biomarkers for HER2-targeted treatment in advanced gastric and esophagogastric junction cancer. More than 500 patients receiving medical treatment for stage IV GC were recruited in 35 German sites and followed for up to 48 months. HER2 status was assessed centrally by immunohistochemistry (IHC) and chromogenic-in-situ-hybridization (ISH). Within the study a HER2 test deviation rate (22.3%) between central and local test was associated with negative impact on patient survival. Patients who received trastuzumab with centrally confirmed HER2+ status (central HER2+/local HER2+) lived significantly longer compared to patients who received trastuzumab for local HER2+ but central HER2 stage IV GC (20.5 months vs. 10.9 months, 95% CI [8.2, 14.4], p<0.001) [1]. In the present analysis, we investigated methodological and biological variables that may promote deviating HER2 test results. Methods We analyzed HER2 testing procedures and participation in quality assurance programs of 105 participating local pathology laboratories. Furthermore, tumor localization, histological subtypes and tested tumor material (for local and central test) were compared between patients with centrally confirmed (central HER2+/local HER2+, n=68) and unconfirmed HER2 status (central HER2-/local HER2+, n=68). Results Central confirmation of the local HER2 IHC scores were seen for the majority of locally HER2- IHC 0/1 (172/178; 96.6%), but less frequently for locally IHC3+ (57/124; 46.0%) cases. Neither use of specific IHC methods nor participation in round robin tests varied between cohorts with confirmed (central HER2+/local HER2+, n=68) or deviating (central HER2-/local HER2+, n=68) HER2 test results. We found seven IHC antibodies (HercepTest, 4B5, SP3, CB11, UMAB36, A0485, EP3) in routine use in Germany, with HercepTest and 4B5 being the most commonly used. 46 (43.8%) local pathology laboratories participated in quality assurance programs for HER2 testing in GC. The distribution of the tested tumor material (primary tumor biopsy, surgical specimen, or biopsy from metastasis), related to both local and central HER2 testing, was comparable between the cohorts studied. Regarding tumor characteristics, deviating test results were more frequently found in GC vs. EGJC (69.1% vs. 39.7%; p=0.001). Within the Laurén histological classification deviating status (central HER2-/local HER2+) was more often found in diffuse type GC (23.5% vs. 5.9% for confirmed HER2+, p=0.004). Conclusion and Interpretation VARIANZ study has shown that GC patients with deviating HER2 test results had poor trastuzumab benefit [1], so we dedicated this work to the important question of the underlying causes of HER2 test deviations in GC. Our analysis demonstrates that neither the antibody platform used for IHC nor participation in round robin tests of local pathology institutes correlated with the deviation rate for HER2 test results. In contrast, we found that tumor characteristics such as primary tumor location and histological phenotype had an impact on test deviations: more HER2 test deviations were seen in distal GC compared to EGJC as well as in the diffuse versus intestinal subtype according to Laurén’s classification. One main limitation of our study is the so far barely used IHC HER2-antibody CB11 for central testing. However, in our study its highly specific properties [2–4] enabled it to identify patients who benefited from trastuzumab. In contrast to breast cancer HER2 is very heterogeneously expressed in GC [5, 6]. Due to this different expression, the HER2 testing scheme was adapted for GC [7]. Nevertheless, the success of HER2-targeted therapy in GC lags significantly behind breast cancer therapy [5]. HER2 heterogeneity is a known issue in GC, even in early stages [8]. Although much has been published [6, 9–11] , there is no generally agreed definition for HER2 heterogeneity or diagnostic procedure to identify HER2 heterogeneity. There are different approaches, for example using the relative number of HER2+ stained tumor cells [10, 12] or the deviation in HER2 status in a set of primary biopsies [13]. HER2 heterogeneity has already been associated with limited trastuzumab benefit and decreased overall survival in trastuzumab treated patients [1, 13, 14]. We conclude that the central confirmation of the HER2 status is a correlate of lower HER2 heterogeneity and may serve as an indicator for better treatment efficacy of trastuzumab. Further we assume that for distal GC location and for the diffuse subtype where HER2 positivity in general is less common [2, 15–18] weak HER2 expression and intratumoral heterogeneity account for more deviating test results. In our view, HER2 diagnostic scheme for GC should be adapted. Adaption of HER2 thresholds to identify patients benefiting from trastuzumab treatment has been already postulated [1, 17]. Our data suggests that only patients with low HER2 heterogeneity may benefit from trastuzumab treatment. For the selection of patients with low HER2 heterogeneity, the above tumor characteristics, such as tumor localization and histological subtype, should be reported. EGJC and the intestinal subtype are positive indicators of the presence of low HER2 heterogeneity. The use of highly specific IHC antibodies should be preferred. Furthermore, a positive result in IHC should always be confirmed by the examination of a paired specimen and the percentage of positive stained tumor cells should be reported. This might improve survival outcomes with targeted treatment, prevent overtreatment and associated side effects and costs and may enable successful studies of other promising HER2 targeting drugs.

Les cancers colorectaux et les cancers du sein sont deux des affections malignes les plus fréquentes dans les pays industrialisés. Lorsqu’elles sont diagnostiquées à un stade précoce, ces tumeurs sont traitées efficacement par la chirurgie associée ou non à la radiothérapie. Pour des tumeurs localisées ayant certains facteurs de pronostic péjoratifs, pour les tumeurs localement avancées, ou pour les tumeurs métastasiques, une chimiothérapie est instaurée. Cependant, la chimiothérapie à elle seule ne permet pas de guérir les patients aux stades avancés de ces 2 types de cancers. C’est pourquoi d’autres alternatives comme l’immunothérapie ou des traitement plus ciblés sont en cours d’étude ou viennent récemment d’être validés.Notre travail a porté sur deux modèles d’immunothérapie dans deux formes de cancers . 1/Dans un modèle expérimental chez le rat, un traitement par un analogue de lipide A permet de guérir tous les animaux porteurs de carcinomatose péritonéale macroscopique d’origine colique. 2/ Chez la femme porteuse de carcinome mammaire localement avancé et surexprimant l’oncoprotéine HER2, un traitement préopératoire comportant du trastuzumab permet d’obtenir la disparition complète des tumeurs et des métastases axillaires chez la moitié des patientes. A partir de prélèvements tissulaires issus de ces 2 modèles, nous avons pu montrer que des analyses histologiques et surtout immunohistochimiques pouvaient permettre d’appréhender les mécanismes de régression tumorale.Dans les régressions des carcinomatoses chez le rat, le rôle du monoxyde d’azote, de l’apoptose des cellules tumorales et de l’infiltration des tumeurs par les cellules dendritiques puis des macrophages a été proposé. Dans la régression des tumeurs du sein, le rôle des cellules NK, via un mécanisme d’ADCC a été suggéré. Ces travaux ont permis de montrer que, malgré ses limites, et en particuliers l’impossibilité de démonstration mécanistique, l’immunohistochimie peut permettre de proposer des hypothèses intéressantes, qui doivent être secondairement confirmées par des expérimentations complémentaires. / In the developed countries, colorectal and breast cancers are two of the most common malignancies. When the diagnosis is made at the beginning of the disease, surgery, associated or not with radiotherapy may cure the patients. For tumors that present some pejorative prognostic factors,for locally advanced tumors or for metastasic disease, chemotherapy has to be prescribed. However, in these 2 types of cancer, chemotherapy is not able to cure patients suffering from metastasic stage and alternative treatments as immunotherapy or targeted therapies are studied or are still validated.Our work was based on 2 different models of immunotherapy in 2 types of cancer. In an experimental model of carcinomatoses of colorectal cancer in rats, Lipid A injections are able to cure all the rats, even at a macroscopic stage and in half of the women affected by locally advance HER2-overexpressing breast cancer, trastuzumab based preoperative treatment are able to obtain the total disappearance of the tumor. When we look on tumor samples obtained in these two models, we can show that histology and even more immunohistochemistry are able to propose some mechanisms of regression of the tumors. In the rat model, we can show the role of nitric oxide, apotosis, dendritic cells and macrophages and in the breast cancer regression, we show the role of NK cells and ADCC. Theses works show that immunohistochemistry, even if insufficient, may propose some interesting hypotheses that have to be confirm by other experimentations.

Introdução: O câncer de mama é o segundo tipo de câncer mais frequente no mundo, com cerca de 1,67 milhões de casos novos e 521 mil mortes a cada ano. O câncer de mama pode ser classificado em diferentes grupos, sendo o subtipo HER2 positivo um dos mais agressivos e relacionado a um mal prognóstico. No entanto novas terapias, tendo como alvo o receptor HER2, vem sendo desenvolvidas com a finalidade de melhorar as condições das pacientes. Dentre elas encontra-se o trastuzumabe, um anticorpo monoclonal recombinante humanizado do tipo IgG1, o qual se liga com alta afinidade ao domínio extracelular do receptor HER2. O uso do trastuzumabe está associado a um aumento da taxa de sobrevida de mulheres com câncer de mama HER2 positivo. O trastuzumabe é geralmente bem tolerado, porém pode apresentar alguns eventos adversos dentre eles, a cardiotoxicidade, a qual pode levar à interrupção do tratamento, fazendo com que as pacientes se privem dos benefícios desta terapia medicamentosa. Além desse efeito, outros podem afetar a satisfação da paciente tais como as reações imunes relacionadas à infusão do trastuzumabe, eventos gastrointestinais, fadiga, dentre outros. Com a finalidade de aprimorar os cuidados à saúde, faz-se necessário avaliar os eventos adversos ao tratamento, bem como a qualidade de vida (QV) das mulheres com câncer de mama HER2 positivo que fazem uso do trastuzumabe visando contribuir para o aumento do seu bem-estar e garantir melhores resultados terapêuticos. Objetivo: Avaliar o perfil farmacoepidemiológico das mulheres com câncer de mama HER2 positivo que utilizaram o trastuzumabe atendidas pelo Sistema Único de Saúde, junto ao Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo. Casuística e métodos: O presente trabalho é um estudo observacional, descritivo e quantitativo, o qual foi realizado em duas partes. Parte A: restrospectiva, na qual se avaliou os eventos adversos ao trastuzumabe em monoterapia e/ou combinado com a quimioterapia descritos nos prontuários e por meio de exames laboratoriais e dos resultados do ecocardiograma. Foram utilizados modelos de regressão logística para estimar odds ratios e seus respectivos intervalos de confiança de 95%, com a finalidade de verificar a associação dos eventos adversos mais frequentes e uma série de variáveis sociodemográficas e clínicas das mulheres. Parte B: prospectiva, na qual, além da avaliação dos eventos adversos, foi também avaliada a QV das pacientes por meio do questionário específico para câncer QLQ-C30 e seu módulo de câncer de mama BR-23 da European Organization for Research and Treatment of Cancer (EORTC) em quatro momentos: antes do início da quimioterapia, após o término da quimioterapia, durante o uso do trastuzumabe e após o término do uso trastuzumabe. Análise de variância (ANOVA) para medidas repetidas foi utilizada para as comparações entre os escores médios obtidos das escalas e itens individuais dos questionários. Resultados Parte A: Foram analisados os prontuários de 79 pacientes que iniciaram o trastuzumabe entre 2007 e 2011. A incidência de reações imunes relacionadas a infusão do trastuzumabe aconteceu em 16 (20,3%) pacientes. A cardiotoxicidade ocorreu em 26 (32,9%) pacientes, sendo que treze (16,4%) destas interromperam permanentemente o tratamento, três (3,8%) interromperam temporariamente e 10 xi (12,6%) terminaram o tratamento sem interrupção. Com relação aos outros eventos adversos, os mais frequentes apresentados com o uso da quimioterapia combinada com o trastuzumabe foram dor (20,4%), náusea e vômito (15,9%), febre (9,7%), e neutropenia (7,1%), sendo apresentados por 55,7% das mulheres. Com relação ao uso do trastuzumabe em monoterapia, os mais frequentes foram: dor (19,6%), fadiga (10,8%), náusea e vômito (9,8%), e cefaleia (8,8%) apresentados por 49,4% das mulheres. Com exceção da cardiotoxicidade, nenhum outro evento adverso levou à descontinuação do tratamento. Não foram encontradas associações entre os eventos adversos mais frequentes e as variáveis sociodemográficas e clínicas das pacientes pelos modelos de regressão logística. Resultados Parte B: Dez pacientes foram incluídas no estudo, no período de outubro de 2011 a julho de 2012. Durante o uso do trastuzumabe e após o seu término foi observada uma melhora significativa da QV das pacientes nos parâmetros fadiga e efeitos colaterais sistêmicos, em comparação com o momento em que estavam utilizando os quimioterápicos. Entretanto estudos mais extensos com uma maior população são necessários para que possa ser avaliada a existência de associação entre os dados clínicos e sociodemográficos das pacientes como os resultados de QV. Conclusão: Embora o trastuzumabe seja um medicamento relativamente seguro para o tratamento do câncer de mama HER2 positivo, este pode causas alguns eventos adversos. Na população estudada, o único evento que levou à interrupção do tratamento foi a cardiotoxicidade, entretanto outros estudos mostraram que outros eventos adversos também foram capazes de ocasionar a descontinuação do tratamento. Para tanto são necessários que sejam tomados alguns cuidados para a prevenção e manejo desses eventos adversos, como um acompanhamento mais regular da função cardíaca e monitoramento constante das pacientes durante a infusão do trastuzumabe. Além disso, o trastuzumabe mostrou ter efeito positivo sobre a QV das pacientes. A avaliação da QV é importante, pois fornece informações clínica úteis em relação ao real impacto do tratamento proposto sobre a saúde e bem-estar das pacientes e pode também orientar na busca de estratégicas para minimizar os eventos adversos ao tratamento. / Introduction: Breast cancer is the second most common cancer in the world, with about 1.67 million new cases and 521,000 deaths each year. Breast cancer can be classified into different groups, being the HER2 positive subtype one of the most aggressive and related to a poor prognosis. However, new therapies that target the HER2 receptor have been developed in order to improve the conditions of patients. Among them is trastuzumab, a recombinant humanized monoclonal antibody of the IgG1 type, which binds with high affinity to the extracellular domain of the HER2 receptor. The use of trastuzumab is associated with an increase in the survival rate of women with HER2 positive breast cancer. Trastuzumab is generally well tolerated, but may have some adverse events, among them the cardiotoxicity, which can lead to treatment discontinuation, depriving patients of the benefits of this therapy. In addition to this effect, others may affect patient satisfaction such as immune reactions related to the infusion of trastuzumab, gastrointestinal events, fatigue, among others. In order to improve health care, it is necessary to assess treatment adverse events and quality of life (QoL) of women with HER2-positive breast cancer that uses trastuzumab to contribute to the increase in their welfare and ensure better treatment results. Objective: To evaluate the pharmacoepidemiological profile of women with HER2-positive breast cancer that used trastuzumab attended by Brazilian public health system, in the General Hospital of Ribeirão Preto Medical School, University of São Paulo. Patients and methods: This is an observational, descriptive and quantitative study, which was conducted in two parts. Part A: retrospective, in which it was evaluated the adverse events to trastuzumab alone and / or combined with chemotherapy described in the medical records and by laboratory tests and echocardiogram results. We used logistic regression models to estimate odds ratios and their 95% confidence intervals to verify the association of the most frequent adverse events and a number of sociodemographic and clinical variables. Part B: prospective, in which besides the evaluation of adverse events it was also evaluated the QoL of patients through the specific questionnaire QLQ-C30 cancer and its breast cancer module BR-23 from the European Organization for Research and Treatment of Cancer (EORTC) in four moments: before the start of chemotherapy, after the end of chemotherapy, during the use of trastuzumab and after the trastuzumab use. Results Part A: The medical records of 79 patients who started the trastuzumab between 2007 and 2011 were analysed. The incidence of immune reactions related to the infusion of trastuzumab occurred in 16 (20.3%) patients. Cardiotoxicity occurred in 26 (32.9%) patients, and 13 (16.4%) of these permanently discontinued the treatment, three (3.8%) discontinued temporarily and 10 (12.6%) completed treatment without interruption. In relation to the other adverse events, the most common events described with the use of trastuzumab combined with chemotherapy were pain (20.4%), nausea and vomiting (15.9%), fever (9.7%), and neutropenia (7.1%), being presented by 55.7% of women. Regarding the use of trastuzumab in monotherapy, the most common were pain (19.6%), fatigue (10.8%), nausea and vomiting (9.8%) and headache (8.8%) presented by 49.4% of women. Except for cardiotoxicity, no other adverse events led to treatment discontinuation. xiii No associations were found between the most frequent adverse events and the sociodemographic and clinical variables of the patients by logistic regression models. Results Part B: Ten patients were included in the study from October 2011 to July 2012. During the use of trastuzumab and after its completion, a significant improvement in QoL of patients on the parameters fatigue and systemic side effects were observed in comparison with the moment they were using chemotherapy. Nevertheless, larger studies with a larger population are needed in order to evaluate if there is an association between clinical and social demographic data of the patients with the results of QoL. Conclusion: Although trastuzumab is a relatively safe medication for the treatment of HER2 positive breast cancer, it may cause some adverse events. In this population, the only event that led to treatment interruption was cardiotoxicity, although other studies have shown that other adverse events were also able to cause treatment discontinuation. Therefore, some precaution needs to be taken for the prevention and management of those adverse events, such as a more regular monitoring of cardiac function and constant monitoring of patients during trastuzumab infusion. Furthermore, trastuzumab has shown to have a positive effect on patients QoL. The assessment of QoL is important as it provides useful clinical information regarding the real impact of the proposed treatment on the health and welfare of patients and can also guide the search for strategies to minimize treatment adverse events.

Introdução: O câncer de mama é o segundo tipo de câncer mais frequente no mundo, com cerca de 1,67 milhões de casos novos e 521 mil mortes a cada ano. O câncer de mama pode ser classificado em diferentes grupos, sendo o subtipo HER2 positivo um dos mais agressivos e relacionado a um mal prognóstico. No entanto novas terapias, tendo como alvo o receptor HER2, vem sendo desenvolvidas com a finalidade de melhorar as condições das pacientes. Dentre elas encontra-se o trastuzumabe, um anticorpo monoclonal recombinante humanizado do tipo IgG1, o qual se liga com alta afinidade ao domínio extracelular do receptor HER2. O uso do trastuzumabe está associado a um aumento da taxa de sobrevida de mulheres com câncer de mama HER2 positivo. O trastuzumabe é geralmente bem tolerado, porém pode apresentar alguns eventos adversos dentre eles, a cardiotoxicidade, a qual pode levar à interrupção do tratamento, fazendo com que as pacientes se privem dos benefícios desta terapia medicamentosa. Além desse efeito, outros podem afetar a satisfação da paciente tais como as reações imunes relacionadas à infusão do trastuzumabe, eventos gastrointestinais, fadiga, dentre outros. Com a finalidade de aprimorar os cuidados à saúde, faz-se necessário avaliar os eventos adversos ao tratamento, bem como a qualidade de vida (QV) das mulheres com câncer de mama HER2 positivo que fazem uso do trastuzumabe visando contribuir para o aumento do seu bem-estar e garantir melhores resultados terapêuticos. Objetivo: Avaliar o perfil farmacoepidemiológico das mulheres com câncer de mama HER2 positivo que utilizaram o trastuzumabe atendidas pelo Sistema Único de Saúde, junto ao Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo. Casuística e métodos: O presente trabalho é um estudo observacional, descritivo e quantitativo, o qual foi realizado em duas partes. Parte A: restrospectiva, na qual se avaliou os eventos adversos ao trastuzumabe em monoterapia e/ou combinado com a quimioterapia descritos nos prontuários e por meio de exames laboratoriais e dos resultados do ecocardiograma. Foram utilizados modelos de regressão logística para estimar odds ratios e seus respectivos intervalos de confiança de 95%, com a finalidade de verificar a associação dos eventos adversos mais frequentes e uma série de variáveis sociodemográficas e clínicas das mulheres. Parte B: prospectiva, na qual, além da avaliação dos eventos adversos, foi também avaliada a QV das pacientes por meio do questionário específico para câncer QLQ-C30 e seu módulo de câncer de mama BR-23 da European Organization for Research and Treatment of Cancer (EORTC) em quatro momentos: antes do início da quimioterapia, após o término da quimioterapia, durante o uso do trastuzumabe e após o término do uso trastuzumabe. Análise de variância (ANOVA) para medidas repetidas foi utilizada para as comparações entre os escores médios obtidos das escalas e itens individuais dos questionários. Resultados Parte A: Foram analisados os prontuários de 79 pacientes que iniciaram o trastuzumabe entre 2007 e 2011. A incidência de reações imunes relacionadas a infusão do trastuzumabe aconteceu em 16 (20,3%) pacientes. A cardiotoxicidade ocorreu em 26 (32,9%) pacientes, sendo que treze (16,4%) destas interromperam permanentemente o tratamento, três (3,8%) interromperam temporariamente e 10 xi (12,6%) terminaram o tratamento sem interrupção. Com relação aos outros eventos adversos, os mais frequentes apresentados com o uso da quimioterapia combinada com o trastuzumabe foram dor (20,4%), náusea e vômito (15,9%), febre (9,7%), e neutropenia (7,1%), sendo apresentados por 55,7% das mulheres. Com relação ao uso do trastuzumabe em monoterapia, os mais frequentes foram: dor (19,6%), fadiga (10,8%), náusea e vômito (9,8%), e cefaleia (8,8%) apresentados por 49,4% das mulheres. Com exceção da cardiotoxicidade, nenhum outro evento adverso levou à descontinuação do tratamento. Não foram encontradas associações entre os eventos adversos mais frequentes e as variáveis sociodemográficas e clínicas das pacientes pelos modelos de regressão logística. Resultados Parte B: Dez pacientes foram incluídas no estudo, no período de outubro de 2011 a julho de 2012. Durante o uso do trastuzumabe e após o seu término foi observada uma melhora significativa da QV das pacientes nos parâmetros fadiga e efeitos colaterais sistêmicos, em comparação com o momento em que estavam utilizando os quimioterápicos. Entretanto estudos mais extensos com uma maior população são necessários para que possa ser avaliada a existência de associação entre os dados clínicos e sociodemográficos das pacientes como os resultados de QV. Conclusão: Embora o trastuzumabe seja um medicamento relativamente seguro para o tratamento do câncer de mama HER2 positivo, este pode causas alguns eventos adversos. Na população estudada, o único evento que levou à interrupção do tratamento foi a cardiotoxicidade, entretanto outros estudos mostraram que outros eventos adversos também foram capazes de ocasionar a descontinuação do tratamento. Para tanto são necessários que sejam tomados alguns cuidados para a prevenção e manejo desses eventos adversos, como um acompanhamento mais regular da função cardíaca e monitoramento constante das pacientes durante a infusão do trastuzumabe. Além disso, o trastuzumabe mostrou ter efeito positivo sobre a QV das pacientes. A avaliação da QV é importante, pois fornece informações clínica úteis em relação ao real impacto do tratamento proposto sobre a saúde e bem-estar das pacientes e pode também orientar na busca de estratégicas para minimizar os eventos adversos ao tratamento. / Introduction: Breast cancer is the second most common cancer in the world, with about 1.67 million new cases and 521,000 deaths each year. Breast cancer can be classified into different groups, being the HER2 positive subtype one of the most aggressive and related to a poor prognosis. However, new therapies that target the HER2 receptor have been developed in order to improve the conditions of patients. Among them is trastuzumab, a recombinant humanized monoclonal antibody of the IgG1 type, which binds with high affinity to the extracellular domain of the HER2 receptor. The use of trastuzumab is associated with an increase in the survival rate of women with HER2 positive breast cancer. Trastuzumab is generally well tolerated, but may have some adverse events, among them the cardiotoxicity, which can lead to treatment discontinuation, depriving patients of the benefits of this therapy. In addition to this effect, others may affect patient satisfaction such as immune reactions related to the infusion of trastuzumab, gastrointestinal events, fatigue, among others. In order to improve health care, it is necessary to assess treatment adverse events and quality of life (QoL) of women with HER2-positive breast cancer that uses trastuzumab to contribute to the increase in their welfare and ensure better treatment results. Objective: To evaluate the pharmacoepidemiological profile of women with HER2-positive breast cancer that used trastuzumab attended by Brazilian public health system, in the General Hospital of Ribeirão Preto Medical School, University of São Paulo. Patients and methods: This is an observational, descriptive and quantitative study, which was conducted in two parts. Part A: retrospective, in which it was evaluated the adverse events to trastuzumab alone and / or combined with chemotherapy described in the medical records and by laboratory tests and echocardiogram results. We used logistic regression models to estimate odds ratios and their 95% confidence intervals to verify the association of the most frequent adverse events and a number of sociodemographic and clinical variables. Part B: prospective, in which besides the evaluation of adverse events it was also evaluated the QoL of patients through the specific questionnaire QLQ-C30 cancer and its breast cancer module BR-23 from the European Organization for Research and Treatment of Cancer (EORTC) in four moments: before the start of chemotherapy, after the end of chemotherapy, during the use of trastuzumab and after the trastuzumab use. Results Part A: The medical records of 79 patients who started the trastuzumab between 2007 and 2011 were analysed. The incidence of immune reactions related to the infusion of trastuzumab occurred in 16 (20.3%) patients. Cardiotoxicity occurred in 26 (32.9%) patients, and 13 (16.4%) of these permanently discontinued the treatment, three (3.8%) discontinued temporarily and 10 (12.6%) completed treatment without interruption. In relation to the other adverse events, the most common events described with the use of trastuzumab combined with chemotherapy were pain (20.4%), nausea and vomiting (15.9%), fever (9.7%), and neutropenia (7.1%), being presented by 55.7% of women. Regarding the use of trastuzumab in monotherapy, the most common were pain (19.6%), fatigue (10.8%), nausea and vomiting (9.8%) and headache (8.8%) presented by 49.4% of women. Except for cardiotoxicity, no other adverse events led to treatment discontinuation. xiii No associations were found between the most frequent adverse events and the sociodemographic and clinical variables of the patients by logistic regression models. Results Part B: Ten patients were included in the study from October 2011 to July 2012. During the use of trastuzumab and after its completion, a significant improvement in QoL of patients on the parameters fatigue and systemic side effects were observed in comparison with the moment they were using chemotherapy. Nevertheless, larger studies with a larger population are needed in order to evaluate if there is an association between clinical and social demographic data of the patients with the results of QoL. Conclusion: Although trastuzumab is a relatively safe medication for the treatment of HER2 positive breast cancer, it may cause some adverse events. In this population, the only event that led to treatment interruption was cardiotoxicity, although other studies have shown that other adverse events were also able to cause treatment discontinuation. Therefore, some precaution needs to be taken for the prevention and management of those adverse events, such as a more regular monitoring of cardiac function and constant monitoring of patients during trastuzumab infusion. Furthermore, trastuzumab has shown to have a positive effect on patients QoL. The assessment of QoL is important as it provides useful clinical information regarding the real impact of the proposed treatment on the health and welfare of patients and can also guide the search for strategies to minimize treatment adverse events.

Bröstcancer räknas idag till den vanligaste cancerformen bland kvinnor. År 2018 avled drygt 1400 personer till följd av sjukdomen, nästan alla som avled var diagnostiserade med metastaserad bröstcancer. Överlevnaden för bröstcancer är starkt kopplad till tumörstadiet vid diagnos, en tidig upptäckt är därför förenad med en bättre prognos. Human epidermal growth factor receptor 2 (HER2) är en tyrosinkinas receptor som kan hetero- eller homodimerisera med andra receptorer i samma familj, vilket är starten för en intracellulär signaleringskaskad genom olika signaleringsvägar som sedan leder till olika cellsvar såsom anti-apoptos, differentiering, proliferation och överlevnad. Denna receptor är överuttryckt i 20-30% av all bröstcancer, såkallad HER2-positiv bröstcancer. HER2-positiv bröstcancer är en aggressiv och snabbväxande bröstcancerform, förknippad med utveckling av metastaser. Vid metastaserad HER2-positiv bröstcancer ges så kallade målinriktade läkemedel, såsom antikroppar riktade mot HER2. En av dessa antikroppar är den monoklonala IgG antikroppen trastuzumab emtansin (T-DM1), vilken är konjugerad till en cytotoxisk molekyldel (DM1). Syftet med detta examensarbete var att undersöka om läkemedlet T-DM1 är effektiv som behandling i avseende på överlevnaden hos patienter med metastaserad eller avancerad HER2-positiv bröstcancer, samt att undersöka vilken relation HER2-associerade tumörbiomarkörer har för effektiviteten av läkemedlet. För att besvara frågeställningens syfte valdes fyra kliniska studier ut från den medicinska referensdatabasen PubMed. Dessa studier undersökte effektivitetsparametrarna; progression free survival (PFS), overall survival (OS) eller objective response rate (ORR) som antingen primär eller sekundär endpoint. Studiernas resultat tyder på att T-DM1 är effektiv som behandling mot HER2-positiv metastaserad bröstcancer där patienter tidigare har fått behandling i den metastaserade bröstcancerfasen då den PFS var längre för patienterna vars behandling bestod av T-DM1 jämfört mot de patienter som fick kontrollbehandling. Det är svårt att dra någon generell slutsats om hurvida T-DM1 effektivitet är kopplad till olika biomarkörer i HER2-signaleringsvägen eftersom endast tre studier har undersökts i detta syfte, dock tyder det på att ett uttryck av HER2 mRNA över median är förenat med längre PFS med T-DM1 behandling. Vidare sågs inget samband för varken PTEN-status eller PIK3CA-status i avseende på överlevnaden eftersom T-DM1 verkade vara effektiv oavsett uttryck. Dock behöver mer forskning utföras för att undersöka relationen mellan överlevnaden och PIK3CA-status, då muterad PIK3CA verkar vara förenat med en sämre prognos. Överlevnaden för patienter med HER2-positiv metastaserad cancer är låg, och sjukdomen anses inte som botbar i dagsläget. Ytterligare forskning i området behövs, samt utveckling av nya och effektivare behandlingsalternativ för att förlänga både PFS och den totala överlevnaden. / Breast cancer is considered as the most common form of cancer among women. In 2018, more than 1400 people died as a result of the disease and almost all who died were diagnosed with metastatic breast cancer. Survival is strongly linked to the stage of the tumor at the diagnosis, an earlier finding is therefore associated with better prognosis. Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase receptor, which can hetero- and homodimerize with other receptors in the same family, leading to an intracellular signalling cascade through various signalling pathways. The cascade lead to cellular responses such as anti-apoptosis, differentiation, proliferation and survival. HER2 is overexpressed in 20-30 % of all breast cancers, so-called HER2-positive breast cancer. HER2-positive breast cancer is an aggressive and fast-growing form, associated with the development of metastases. In metastatic HER2-positive breast cancer, target drugs, such as antibodies directed against HER2, are given. One of these is the monoclonal antibody trastuzumab emtansine (T-DM1), which is conjugated to a cytotoxic molecule (DM1). The purpose of this literature study was to investigate whether the drug T-DM1 is effective as a treatment to prolong the survival in patients with metastatic breast cancer, the purpose was also to investigate the relationship of HER2-related tumor biomarkers on the efficacy of the drug. To answer the purpose of the literature study, four clinical trials were selected from the medical reference database PubMed. All of the selected trials investigated one or more of the efficiency parameters; progression free survival (PFS), overall survival (OS) or objective response rate (ORR), as either primary or secondary endpoints. According to the investigated trials, the result indicate that T-DM1 is effective as a treatment for HER2-positive metastatic breast cancer, where patients previously been treated in the metastatic or advanced setting. T-DM1 showed prolonged PFS compared to control treatment. It is difficult to draw any general conclusion whether T-DM1 efficiency is linked to various biomarkers in the HER2 signaling pathway, as only three studies have been investigated for this purpose. However, it indicates that an HER2-mRNA &gt; median is associated with a longer PFS with T-DM1 treatment. Furthermore, no relationship was seen for either PTEN- or PIK3CA-status with respect to survival, since T-DM1 appeared to be effective regardless of expression. However, more research needs to be done to investigate the relationship between survival and PIK3CA-status, as mutated PIK3CA appears to be associated with poorer prognosis. The survival rate for patients with metastatic or advanced HER2-positive breast cancer is low, and the disease is not considered as curable at present. Further research is needed, as well as the development of new and more effective treatment to extend both PFS and OS for these patients.

Thèse ou mémoire avec insertion d'articles / Le cancer du sein est le cancer le plus fréquent au niveau mondial chez la femme, représentant 12% des nouveaux cas de cancers en 2020. C'est une maladie complexe et hétérogène classée en fonction de l'expression de trois marqueurs moléculaires : le récepteur aux estrogènes (ER), le récepteur à la progestérone (PR) et le récepteur épidermique humain 2 (HER2) qui donnent lieu à quatre sous-types moléculaires qui sont les sous-types luminal A (ER+ et/ou PR+, HER2-), luminal B (ER+ et/ou PR+, HER2+), HER2 (ER-/PR-,HER2+) et triple-négatif (ER-, PR- et HER2-). Chaque sous-type moléculaire possède des caractéristiques spécifiques qui le définissent. En effet, la prévalence, le taux de survie, l'agressivité ou encore les types de traitements administrés sont différents. Les traitements du cancer du sein se basent sur l'histologie de la tumeur, le sous-type moléculaire ainsi que sur l'âge et le statut ménopausique de la patiente. Il existe deux principaux types de stratégies thérapeutiques : la thérapie généralisée (ou thérapie non ciblée) et la thérapie personnalisée. D'une part, la thérapie généralisée, comme la chimiothérapie, la radiothérapie et la chirurgie qui sont utilisées de manière routinière dans le traitement du cancer du sein, s'appuie sur la capacité des cellules à devenir malignes. D'autre part, la thérapie personnalisée consiste à cibler spécifiquement un biomarqueur impliqué dans le cancer du sein comme le sont ER et HER2. Ainsi, la thérapie endocrinienne (hormonothérapie) cible directement ER ou la synthèse des estrogènes, tandis que les thérapies anti-HER2 ciblent le domaine extracellulaire du récepteur ou bloquent son activité tyrosine kinase. Toutefois, malgré des progrès importants dans le développement de nouvelles stratégies thérapeutiques, le traitement du cancer du sein reste un défi de taille. En effet, certaines patientes ne peuvent pas recevoir de traitements ciblés comme les patientes avec une tumeur triple-négative puisqu'elles n'expriment ou ne surexpriment aucun des trois marqueurs moléculaires. De plus, que ce soit la thérapie généralisée ou la thérapie personnalisée, tous ces traitements entraînent des effets secondaires qui peuvent être délétères pour les patientes. Finalement, chez certaines patientes la thérapie prescrite peut se révéler inefficace à cause des cellules tumorales qui sont ou sont devenues résistantes au traitement. Ce projet de doctorat se découpe en deux parties distinctes qui font face aux deux problématiques mentionnées : trouver des thérapies plus personnalisées mais aussi des thérapies généralisées (aussi appelées thérapies non-ciblées) qui soient plus efficaces et avec le moins d'effets secondaires possible. La première partie porte sur l'étude des effets du trastuzumab (thérapie anti-HER2 conventionnellement administrée pour les patientes avec une tumeur HER2+) en fonction de la phosphorylation du récepteur dans les tumeurs HER2-. La deuxième partie quant à elle se consacre à l'étude de la nouvelle molécule de synthèse RM-581 sur les différents sous-types moléculaires du cancer du sein. La première étude a permis d'identifier un sous-groupe de patientes qui ne surexpriment pas HER2 mais qui présentent la forme phosphorylée du récepteur - spécifiquement sur la tyrosine 877- (HER2-/pHER2$^\textup{Y877}$+), sur une cohorte de 497 patientes représentatives de la distribution des sous-types moléculaires grâce à des tests d'immunohistochimie. Cette étude a aussi permis de montrer que pHER2$^\textup{Y877}$ était un marqueur de sensibilité au trastuzumab en faisant des tests de prolifération sur différentes lignées cellulaires du cancer du sein représentant les différentes combinaisons de statut HER2 et pHER2$^\textup{Y877}$. Ces résultats ouvrent la voie vers une nouvelle stratégie de traitement pour les patientes qui ne peuvent pas recevoir de trastuzumab car ne surexpriment pas HER2, comme les patientes avec une tumeur triple-négative, mais qui surexpriment pHER2$^\textup{Y877}$. La deuxième étude a permis de confirmer que l'aminostéroïde RM-581 est efficace contre tous les sous-types moléculaires du cancer du sein, notamment les sous-types luminal A et triple-négatif, dans des lignées cellulaires du cancer du sein cultivées aussi bien en 2D qu'en 3D en réalisant des tests de prolifération permettant de calculer la concentration médiane inhibitrice. Nous avons également confirmé que RM-581 entraîne l'activation du stress du réticulum endoplasmique (RE) menant à l'apoptose cellulaire puisque celui-ci entraîne l'augmentation de l'expression de marqueurs de l'apoptose due au stress du RE. Cette étude a donc permis de mettre en avant RM-581 comme une nouvelle molécule anticancéreuse pour le cancer du sein et particulièrement le sous-type triple-négatif, ce qui pourrait offrir un nouveau traitement pour ces patientes. Ce projet a permis d'identifier deux nouvelles stratégies thérapeutiques (l'une très personnalisée et l'autre plus généralisée/non-ciblée) contre le cancer du sein et plus spécifiquement contre le sous-type triple-négatif qui est le sous-type moléculaire le plus agressif et avec le plus mauvais pronostic. / Breast cancer is the most diagnosed cancer among women worldwide, representing 12% of all new cancer cases in women in 2020. This is a complex and heterogenous disease classified according to the expression of three molecular markers: estrogen receptor (ER), progesterone receptor (PR) and human epidermal receptor 2 (HER2) leading to four molecular subtypes which are luminal A (ER+ and/or PR+, HER2-), luminal B (ER+ and/or PR+, HER2+), HER2 (ER-/PR-, HER2+) and triple-negative -TNBC- (ER-, PR- and HER2-). Each molecular subtype has specific characteristics such as prevalence, survival, grade, and the type of treatments. Breast cancer treatments are based on the tumor histology, molecular subtypes and patient's age and menopausal status. There are two major types of therapeutic strategies: generalized therapy and personalized therapy. Firstly, generalized therapy, like chemotherapy, radiotherapy, and surgery which are commonly used for breast cancer treatment, is based on the capacity of cells to become malignant. On the other hand, personalized therapy specifically targets a biomarker involved in breast cancer such as ER or HER2. Endocrine therapy can directly target ER or estrogen biosynthesis whereas anti-HER2 therapies can target the extracellular domain of the receptor or its tyrosine kinase domain. However, despite significant progress in the development of new therapeutic strategies, breast cancer treatment remains a major challenge. For example, some patients cannot receive targeted therapies, like TNBC patients as they do not express or overexpress any of the three biomarkers. Furthermore, all breast cancer treatments (targeted and generalized or non-targeted therapies) cause side effects that can be deleterious for patients. Lastly, the prescribed therapy can be ineffective for some patients because of tumoral cells that are or became resistant to the treatment. This project is composed of two distinct parts that face the two issues mentioned: to find more personalized therapies and to find generalized therapies (also called non-targeted therapies) that are more effective and less deleterious. The first part focuses on the study of trastuzumab (anti-HER2 treatment) effects depending on HER2 phosphorylation in HER2-negative breast cancer cell lines. The second part focuses on the study of RM-581, a new synthesis molecule, on the different breast cancer molecular subtypes. The first study identified a subgroup of patients who do not overexpress HER2 but express the phosphorylated form of HER2 at tyrosine 877 specifically (HER2-/pHER2$^\textup{Y877}$+), on a cohort of 487 patients that is representative of breast cancer molecular subtypes distribution. This study showed that pHER2$^\textup{Y877}$ was a marker of trastuzumab sensitivity. In fact, we performed proliferation assay on breast cancer cell lines according to their combination of HER2 and pHER2$^\textup{Y877}$ status. These results paved the way for a new therapeutic strategy for breast cancer patients who overexpress pHER2$^\textup{Y877}$ but could not receive trastuzumab (because they do not overexpress HER2), like TNBC patients. The second study confirmed that the aminosteroid RM-581 is effective against all breast cancer molecular subtypes, especially luminal A and TNBC subtypes, in breast cancer cell lines cultured in 2D and 3D. We also confirmed that RM-581 induces endoplasmic reticulum stress leading to cellular apoptosis. These results proved that RM-581 could be a new anticancer molecule for breast cancer treatment, in particular for TNBC patients. This project emphasized two new therapeutic strategies (one more personalized, and the other more generalized) for breast cancer and more specifically TNBC which is the most aggressive and with the worst survival breast cancer molecular subtype.

Chez la souris, la thérapie anti-HER2 est dépendante de la présence de cellules T CD8+IFN-γ+ et des réponses IFN de type I. Ces IFN sont induits par les TLRs suite à la reconnaissance de signaux de danger, appelés PAMPs et DAMPs. Les TLR-3 et TLR-9 sont tous deux de bons inducteurs d’IFN de type I et sont également capable d’agir en synergie afin d’augmenter les niveaux d’IFN-γ, de TNF-α et d’IL-12. Notre hypothèse fut que la stimulation de ces deux TLRs mènerait à l’amélioration de l’activité anti-tumorale du trastuzumab via le recrutement et l’activation des cellules immunitaires. Nos buts furent de confirmer le potentiel thérapeutique de la combinaison de l’anticorps anti-HER2, de l’agoniste de TLR-3, le poly(I:C), et de l’agoniste de TLR-9, le CpG ODN. Des études in vivo et in vitro nous ont permis de découvrir une synergie entre ces agents qui résulte en une cytotoxicité ciblée plus efficace. De plus, cette thérapie s’avéra efficace chez des modèles CD8-dépendants et CD8-indépendents. Les souris purent rejeter leur tumeur et demeurer sains plusieurs semaines après l’arrêt des injections. Ces souris étaient également protégées lors d’un challenge, soulignant ainsi la présence d’une immunité mémoire. Nous avons aussi découvert que l’administration combine de trastuzumab des deux agonistes de TLRs mène à des réponses systémiques. Des études de déplétion confirmèrent que les cellules T CD8+ sont cruciales pour la protection à long terme des animaux, mais que les pDC sont moins impliquées que ce que l’on pourrait croire. Leur absence n’a que modestement affecté les effets de notre thérapie. À l’opposé, les cellules NK sont d’importants médiateurs des effets thérapeutiques. Des expériences d’ADCC ont révélé que le CpG ODN et poly(I:C) ont tous deux la capacité d’améliorer les fonctions des cellules NK, mais que la stimulation simultanée des TLR-3 et TLR-9 permet de maximiser les effets bénéfiques du trastuzumab. De la même manière, l’addition de CpG ODN et de poly(I:C) aux anticorps anti-HER2 a permis d’augmenter les réponses pro-inflammatoires, plus spécifiquement l’IFN-γ, le TNF-α, l’IP-10 et l’IL-12. / In murine models, anti-HER2 therapy has been shown to be dependent on IFN-γ-producing CD8+ T cells and type I IFN responses. These IFN are induced by TLRs following the recognition of danger signals, called PAMPs or DAMPs. Both TLR-3 and TLR-9 are well known inducers of type I IFN and were also shown to act synergistically to enhance the levels of IFN-γ, TNF-α, and IL-12. Our hypothesis thus was that the stimulation of those two TLRs would lead to an enhancement of the activity of trastuzumab against tumor cells by the recruitment and activation of immune cells. Our goals were to assess the potential therapeutic effects of a combination of anti-HER2 mAbs, TLR-3 agonist poly(I:C) and TLR-9 agonist CpG ODN. In vivo and in vitro studies enabled us to discover a synergy between all agents resulting in a more efficient targeted cytotoxicity. Moreover, this therapy was fully effective in a CD8-dependant cell line as well as a CD8-independent one. Mice were able to completely reject their tumor and remain tumor-free weeks after the injections. Those mice were also protected against a rechallenge, thus underlining the presence of an immune memory. We also discovered that the combined administration of trastuzumab and the TLR agonists leads to systemic responses. Depleting studies confirmed that T CD8+ cells are crucial for the animal to remain tumor-free on the long term, but that pDC are far less involved than what we could have thought. Their absence only modestly affected the outcome of our therapy. On the counterpart, NK cells were important mediators of the therapeutic effect. ADCC assays revealed that both CpG ODN and poly(I:C) are able to enhance the functions of NK cells, but that simultaneous stimulation of the TLR-3 and TLR-9 allows to maximize the beneficial effects of trastuzumab. The same way, the addition of both CpG ODN and poly(I:C) to the anti-HER2 mAbs further enhanced pro-inflammatory responses, more specifically IFN-γ, TNF-α, IP-10 and IL-12.

Abstract Cancer treatments have remarkably improved over the past years since targeted therapies and immunotherapy have been introduced to the field of oncology. The benefit of these new therapies is often limited, however, by de novo or acquired therapy resistances, which should be noticed when making clinical decisions. In this current work, we studied the prognostic and predictive values of several immunological markers in metastatic HER2-positive breast cancer treated with trastuzumab, because trastuzumab is still given to patients according to the HER2 status only, without certainty of tumor response. We also determined the role of HER2 and HER3 for cancer stem cells (CSC) in ALK translocated non-small cell lung cancer (NSCLC) cell lines since the CSCs are causing therapy resistance and cancer recurrence. The results demonstrated that a high number of cytotoxic T cells, together with a high number of M1-like macrophages in the center of the tumor (CT), are promising and independent prognostic factors in HER2-positive breast cancer. These markers together also can predict the progression of the disease and the length of trastuzumab discontinuation in tumor response. Expression of HER2 and HER3 increased the stem-like properties of ALK translocated NSCLC cells, which were decreased when the expressions were downregulated. HER2-HER3-dependent CSCs also mediated the ALK therapy resistance. In conclusion, this study suggests that patients with a favorable immunological tumor profile (high number of cytotoxic T cells and M1-like macrophages in the CT) could be treated in a less-intensive manner, that trastuzumab discontinuation could be feasible for these patients, and that targeting of HER2 and HER3 receptors can lead to more effective killing of cancer stem-like cells and should be further studied. / Tiivistelmä Syöpähoidot ovat kehittyneet huomattavasti, kun kohdennetut hoidot ja immunologiset hoidot ovat tulleet perinteisten hoitojen rinnalle. Usein näiden hoitojen hyötyä kuitenkin rajoittaa jo olemassa oleva lääkeresistenssi tai sen kehittyminen, mikä tulisi ottaa huomioon hoitoja suunniteltaessa. Tässä työssä tutkittiin immunologisia merkkiaineita, joilla voitaisiin ennustaa trastutsumabi-hoidon vastetta sekä potilaiden ennustetta levinneessä HER2-positiivisessa rintasyövässä. Tällä hetkellä trastutsumabi-hoitopäätös tehdään pelkän HER2-geenimonistuman mukaan ilman varmuutta siitä, hyötyykö potilas oikeasti hoidosta. Lisäksi tutkimme HER2- ja HER3-reseptorien merkitystä syövän kantasoluille ALK-translokoituneessa ei-pienisoluisessa keuhkosyövässä (NSCLC), sillä syövän kantasolut ovat yksi merkittävimmistä tekijöistä lääkeresistenssin kehittymisessä ja syövän uusiutumisessa. Työssä havaittiin, että kasvaimen keskellä oleva suuri määrä sytotoksisia T-soluja sekä M1-tyypin makrofageja on yhteydessä potilaiden parempaan ennusteeseen ja että kyseiset merkkiaineet ovat toisistaan riippumattomia. Merkkiaineet pystyivät ennustamaan myös taudin etenemistä sekä trastutsumabi-hoitokeskeytyksen pituutta. HER2- ja HER3-proteiinien tuotto lisäsi ALK-translokoituneiden NSCLC-solujen kantasolumaisia ominaisuuksia, jotka puolestaan vähenivät, kun proteiinien tuotto estettiin. Lisäksi HER2-HER3 -riippuvaiset syövän kantasolut säätelivät lääkeresistenssiä kyseisessä taudissa. Työn tulokset viittaavat siihen, että potilaita, joilla on suotuisa kasvaimen immunoprofiili (suuri määrä sytotoksisia T-soluja ja M1-tyypin makrofageja kasvaimen keskellä) pystyttäisiin hoitamaan keveimmillä hoidoilla ja HER2-hoitokeskeytys voisi olla mahdollinen näillä potilailla. Lisäksi työ korostaa HER2- ja HER3-reseptorien kohdentamista syövän kantasolumaisten solujen tehokkaamman tuhoamisen saavuttamiseksi. / Huomautus/Notice Painetussa virheelliset ISBN -tunnukset: ISBN (print) 978-952-42-2343-8 pitäisi olla 978-952-62-2343-8. ISBN (PDF) 978-952-42-2344-5 pitäisi olla 978-952-62-2344-5. Printed version has incorrect ISBNs: ISBN (print) 978-952-42-2343-8 it should be 978-952-62-2343-8. ISBN (PDF) 978-952-42-2344-5 it should be 978-952-62-2344-5.

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The overexpression of the human epidermal growth factor receptor-2 (HER-2) in 20-25% of human breast cancers was investigated as a target for development of a gold nanoparticle (AuNP) based radiosensitizer for improving the efficacy of neoadjuvant X-radiation therapy of the disease. HER-2 targeted AuNPs were developed by covalently conjugating trastuzumab, a Health Canada approved monoclonal antibody for the treatment of HER-2-overexpressing breast cancer, to 30 nm AuNPs. Trastuzumab conjugated AuNPs were efficiently internalized by HER-2-overexpressing breast cancer cells (as assessed by darkfield microscopy and transmission electron microscopy) and increased DNA damage from X-radiation in these cells by more than 5-fold. To optimize delivery of AuNPs to HER-2-overexpressing tumors, high resolution microSPECT/CT imaging was used to track the in vivo fate of 111In-labelled non-targeted and HER-2 targeted AuNPs following intravenous (i.v.) or intratumoral (i.t.) injection. For i.v. injection, the effects of GdCl3 (for deactivation of macrophages) and non-specific (anti-CD20) antibody rituximab (for blocking of Fc mediated liver and spleen uptake) were studied. It was found that HER-2 targeting via attachment of trastuzumab paradoxically decreased tumor uptake as a result of faster elimination of the targeted AuNPs from the blood while improving internalization in HER-2-positive tumor cells as compared to non-targeted AuNPs. This phenomenon could be attributed to Fc-mediated recognition and subsequent sequestration of trastuzumab conjugated AuNP by the reticuloendothelial system (RES). Blocking of the RES did not increase tumor uptake of either HER-2 targeted or non-targeted AuNPs. Following i.t. injection, our results suggest that Au-NTs redistribute over time and traffick to the liver via the ipsilateral axillary lymph node leading to comparable exposure as seen with i.v. administration. In contrast, targeted AuNPs are bound and internalized by HER-2-overexpressing tumor cells following i.t. injection, with a lower proportion of AuNPs redistributing to normal tissues. In vivo, the combination of HER-2 targeted AuNPs injected i.t. and X-radiation (11 Gy) yielded a 46% decrease in tumor size over a 4 month period in contrast to an 11.5% increase in tumor size for X-radiation treatment alone. Toxicology studies (evaluated through complete blood cell counts, by serum transaminase and creatinine measurements and by monitoring the body weight) demonstrated no apparent normal organ toxicity from the combination of HER-2 targeted AuNPs and X-radiation. These results are promising for the clinical translation of HER-2-targeted AuNPs for radiosensitization of tumors to X-radiation.