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No / Neoadjuvant chemoradiotherapy (neo-CRT) prior to surgery is the standard of care for oesophageal adenocarcinoma (OAC) patients. Unfortunately, most patients fail to respond to treatment. MiR-187 was previously shown to be downregulated in neo-CRT non-responders, whist in vitro miR-187 overexpression enhanced radiosensitivity and upregulated PTEN. This study evaluates the role of miR-187 and downstream PI3K signalling in radiation response in OAC. The effect of miR-187 overexpression on downstream PI3K signalling was evaluated in OAC cell lines by qPCR and Western blotting. PTEN expression was analysed in OAC pre-treatment biopsies of neo-CRT responders and non-responders. Pharmacological inhibition of PI3K using GDC-0941 was evaluated in combination with radiotherapy in two-dimensional and three-dimensional OAC models in vitro and as a single agent in vivo. Radiation response in vitro was assessed via clonogenic assay. PTEN expression was significantly decreased in neo-CRT non-responders. MiR-187 overexpression significantly upregulated PTEN expression and inhibited downstream PI3K signalling in vitro. GDC-0941 significantly reduced viability and enhanced radiation response in vitro and led to tumour growth inhibition as a single agent in vivo. Targeting of PI3K signalling is a promising therapeutic strategy for OAC patients who have repressed miR-187 expression and do not respond to conventional neo-CRT. This is the first study evaluating the effect of PI3K inhibition on radiosensitivity in OAC, with a particular focus on patients that do not respond to neo-CRT. We have shown for the first time that targeting of PI3K signalling is a promising alternative therapeutic strategy for OAC patients who do not respond to conventional neo-CRT.

Le cancer colo-rectal est un problème de santé publique majeur dans les pays développés. Le cancer du rectum est défini comme une marge distale de la tumeur à moins de 15 cm de la marge anale. Sa prise en charge optimale impose une discussion entre une chirurgie mutilante emportant les sphincters ou une chirurgie conservatrice laissant en place l'appareil sphinctérien et évitant l'incontinence et la colostomie. L’Imagerie par résonance magnétique (IRM) est l’examen de référence pour le diagnostic de la tumeur initiale. Dans projet, nous avons utilisé des outils IRM modernes comme la volumétrie et l’imagerie de diffusion dans l’évaluation thérapeutique des cancers du rectum après chimioradiothérapie.Nous avons ainsi montré que la variation de volume tumoral au cours du traitement du cancer du rectum était associée à une survie sans récidive à 5 ans : les patients dont le volume tumoral diminuait d'au moins 70% au cours du traitement néoadjuvant avaient une survie à 5 ans sans récidive et un grade de régression histologique significativement plus élevée que chez les patients dont le volume diminuait de moins de 70%. En utilisant la même technique de volumétrie tumorale tridimensionnelle au cours d'un essai thérapeutique, nous avons également montré pour la première fois que la variation précoce de volume tumoral du rectum au cours du traitement néoadjuvant par chimiothérapie seule pouvait prédire le succès du traitement ultérieur par radio-chimiothérapie puis chirurgie. L'étude de la variation précoce de volume tumoral est actuellement utilisée dans un essai randomisé prospectif multicentrique dans lequel la variation de volume tumoral du rectum après radio-chimiothérapie néoadjuvante chez des patients avec tumeur avancée (T3c, T4) est le déterminant de la poursuite d'un traitement radio-chimiothérapique néoadjuvant ou le traitement chirurgical radical (essai GRECCAR4, ClinicalTrials.gov NCT01333709). Nous nous sommes ensuite intéressés à l’imagerie de diffusion et en particulier l’IVIM marqueur prédictif de réponse thérapeutique. Dans cette étude, la diffusion pure permettait d’obtenir des résultats prometteurs pour l’évaluation de la réponse au traitement néoadjuvant. Finalement, nous présenterons les perspectives de recherche concernant un type particulier de réponse, les réponses colloïdes. / Colo-Rectal Cancer is the third most commonly diagnosed cancer in males and the second in females. Around 30% of all colorectal cancers are diagnosed in the rectum. Despite the major improvements that have been made management of rectal cancer still remains a challenge. Chemoradiotherapy (CRT) followed by surgery has been widely adopted for the management of locally advanced rectal cancers because this approach increases the probability of anal sphincter preservation, decreases the local recurrence rate and decreased the risk of colostomy. As we enter the era of personalized medicine with therapies stratified according to the risk of local or distant recurrence, imaging has become an essential tool in the preoperative decision making, to avoid both under- and overtreatment. Magnetic Resonance (MR) imaging is now an essential tool to enable the oncology team to make appropriate treatment decisions. First, we demonstrated that tumor shrinkage after preoperative chemotherapy–radiation therapy was associated with good response. Second, we demonstrated that early tumor volume decrease after induction chemotherapy before chemoradiotherapy was as well associated with good patient prognosis. Third, we demonstrated the added value of DW MR imaging for predicting tumor response using IVIM, a more sophisticated diffusion analytic approaches, which allows quantitative parameters that reflect tissue microcapillary perfusion and tissue diffusivity to be derived. In this study we demonstrated that true diffusion was associated with regression grade on pathology. Finally, we will present our perspectives especially in tumor response evaluation in patient with colloidal response.

BACKGROUND:Neoadjuvant chemotherapy followed by cytoreduction surgery has been used where an accurate cytologic or pathologic diagnosis is usually required before the initiation of neoadjuvant chemotherapy. However, it is difficult to make definitive diagnosis of presence of cancer cells, particularly gynecologic versus non-gynecologic origin, from those ascites specimens due to the absence of specific biomarkers of gynecologic cancers. In the present study, we evaluated if, in addition to the routine morphologic diagnosis, the biomarker PAX8 could be useful in recognition of ovarian epithelial cancer cells prior to the neoadjuvant chemotherapy.METHODS:Two hundred and two cytology specimens including 120 pretreatment ovarian cancer samples, 60 benign controls, and 22 malignant non-gynecologic cases were studied. All cytology slides were morphologically reviewed in a blinded fashion without knowing corresponding pathology diagnosis, if present. A total of 168 cytology specimens with a cell block were stained with PAX8 and Calretinin. These included patients with potential for ovarian cancer neoadjuvant chemotherapy (n=96), metastatic cancers (n=22), and benign controls (n=50).RESULTS:Among the 96 ascitic samples prior to neoadjuvant chemotherapy, 76 (79%) showing morphologic features consistent with cancers of ovarian primary were all PAX+/Calretinin-. The remaining 20 (21%) cases were positive for adenocarcinoma, but morphologically unable to be further classified. Among the 22 metastatic cancers into the pelvis, one case with PAX8+/Calretinin- represented a renal cell carcinoma and the remaining 21 PAX8-/Calretinin- metastatic cancers were either breast metastasis (n=4) and the metastasis from gastrointestinal tract (n=17). Among the 50 benign control pelvic washing cases, 5 PAX8+/Calretinin-cases represented endosalpingiosis (n=4) and endometriosis (n=1), 25 PAX8-/Calretinin+cases showed reactive mesothelial cells, and the remaining 20 specimens with PAX8-/Calretinin- phenotype typically contained inflammatory or blood cells without noticeable diagnostic epithelia.CONCLUSIONS:PAX8 identifies all Mullerian derived benign or malignant epithelia. When combining with Calretinin, PAX8 is a sensitive marker to diagnose the carcinomas of ovarian origin, which will be ideal to be used for those patients with a possible advanced ovarian cancer prior to receiving neoadjuvant chemotherapy.

Background: Patients with locally advanced esophageal cancer who are treated with trimodality therapy have a high recurrence rate. Preclinical evidence suggests that inhibition of cyclooxygenase 2 (COX2) increases the effectiveness of chemoradiation, and observational studies in humans suggest that COX-2 inhibition may reduce esophageal cancer risk. This trial tested the safety and efficacy of combining a COX2 inhibitor, celecoxib, with neoadjuvant irinotecan/cisplatin chemoradiation. Methods: This single arm phase 2 trial combined irinotecan, cisplatin, and celecoxib with concurrent radiation therapy. Patients with stage IIA-IVA esophageal cancer received weekly cisplatin 30 mg/m(2) plus irinotecan 65 mg/m(2) on weeks 1, 2, 4, and 5 concurrently with 5040 cGy of radiation therapy. Celecoxib 400 mg was taken orally twice daily during chemoradiation, up to 1 week before surgery, and for 6 months following surgery. Results: Forty patients were enrolled with stage IIa (30 %), stage IIb (20 %), stage III (22.5 %), and stage IVA (27.5 %) esophageal or gastroesophageal junction cancer (AJCC, 5th Edition). During chemoradiation, grade 3-4 treatment-related toxicity included dysphagia (20 %), anorexia (17.5 %), dehydration (17.5 %), nausea (15 %), neutropenia (12.5 %), diarrhea (10 %), fatigue (7.5 %), and febrile neutropenia (7.5 %). The pathological complete response rate was 32.5 %. The median progression free survival was 15.7 months and the median overall survival was 34.7 months. 15 % (n = 6) of patients treated on this study developed brain metastases. Conclusions: The addition of celecoxib to neoadjuvant cisplatin-irinotecan chemoradiation was tolerable; however, overall survival appeared comparable to prior studies using neoadjuvant cisplatin-irinotecan chemoradiation alone. Further studies adding celecoxib to neoadjuvant chemoradiation in esophageal cancer are not warranted.

Objectives: A decrease in Ki67 during neoadjuvant therapy predicts response to tamoxifen. Previous trials have shown a decreased Ki67 in breast tumors with as little as two or more weeks of preoperative tamoxifen. Shortening the preoperative treatment time in window of opportunity clinical trials makes these trials more attractive to women. POWERPIINC examined the effect of 7 days of preoperative tamoxifen on breast tumor proliferation and patient symptoms. Methods: Women with untreated stage I/II, ER-positive, invasive breast cancer with no contraindications to tamoxifen were enrolled. Women received 20 mg of tamoxifen for 7 days up to the day of surgery. Proliferation was assessed by Ki67 immunohistochemistry before and after 7 days of tamoxifen. Symptoms and QOL were assessed by the FACT-ES and MENQOL. Adherence was measured by pill counts. Results: 52 women were enrolled, and 44 were evaluable for Ki67. The median age was 58.5 years, and the median tumor diameter was 1.2 cm. Most women (73%) were post-menopausal. Most tumors were PR positive (88%) and HER2-negative (92%). The Ki67 decreased by a geometric mean of 40% (95% CI 29%-63%), and 73% (95% CI 57%-85%) of women had tumors with decreased proliferation (p = 0.0001 by paired t-test). Adherence to taking tamoxifen during the preoperative period was 100%. Women reported minimal bother from psychosocial or physical symptoms at baseline or on the day of surgery. Conclusion: Seven days of tamoxifen showed a similar relative decrease in Ki67 as that reported for longer courses, was acceptable to women, and could be considered for window of opportunity studies.

O câncer de mama é o segundo tipo de câncer mais freqüente no mundo e o mais comum entre as mulheres. A quimioterapia neoadjuvante tem sido introduzida para diminuir o tamanho do tumor, permitindo a conservação da mama e ganhando controle sobre possíveis metástases. Polimorfismos em genes envolvidos no reparo do DNA, controle do ciclo celular, apoptose e enzimas do metabolismo e eliminação de drogas, poderiam determinar a susceptibilidade individual ao câncer e a resposta ao tratamento. A proteína p53 é um fator de transcrição envolvido, entre outras funções, no processo de apoptose. Por outro lado, a glicoproteína P é uma proteína de transmembrana responsável pelo efluxo de drogas nas células. Polimorfismos do gene TP53, Arg72Pro e Pro47Ser, tem sido observado alterando o potencial de indução de apoptose; quanto ao polimorfismo C3435T do gene MDR-1, tem demonstrado sua influência sobre a atividade ou expressão da glicoproteína P. O presente trabalho teve por objetivo investigar se os polimorfismos os genes TP53 e MDR-1 na susceptibilidade de câncer de mama e na resposta a quimioterapia neoadjuvante. Para isso, 116 pacientes com câncer de mama e 120 indivíduos controles foram genotipados pela da técnica de PCRRFLP. Analisando os genes TP53 e MDR-1, as freqüências alélicas e genotípicas encontradas foram similares em pacientes e controles para os polimorfismos Arg72Pro e C3435T; no entanto, para o polimorfismo Pro47Ser só foram observados indivíduos apresentando o genótipo selvagem. Os genótipos homozigotos polimórficos para os genes TP53 e MDR-1 foram mais freqüentes nos controles não brancos e com idade maior que 50 anos, respectivamente, sugerindo uma associação dos respectivos genótipos com etnia e idade. Não foi encontrada associação com as demais variáveis em relação ao risco de câncer de mama. Também não foram observadas associações entre as características pré-tratamento das pacientes em relação à distribuição dos genótipos. Quanto à resposta à quimioterapia, não houve associação significativa quando as respostas clínicas e patológicas foram avaliadas. Porém, na distribuição do número de linfonodos, encontraram-se freqüências aumentadas nos genótipo Pro/Pro do gene TP53 para 1-3 linfonodos metastáticos e no genótipo TT do gene MDR-1 para 4 linfonodos axilares metastáticos. Com base nesses dados, não foi possível estabelecer associações entre os polimorfismos e a susceptibilidade ao desenvolvimento de câncer de mama, como também não foi possível determinar sua relação com a resposta à quimioterapia neoadjuvante na nossa amostra. No entanto, mais estudos devem ser feitos para determinar a contribuição destes polimorfismos no câncer de mama e seu tratamento, e assim estabelecer estratégias de quimioterapia mais eficazes. / Breast cancer is the second most common cancer in the world and the most common among women. Neoadjuvant chemotherapy has been introduced to downstage tumors, facilitating breast conservation and gaining control of probably metastasis. Polymorphisms in genes involving DNA repair, cell cycle control, apoptosis and drugs metabolizing enzymes could determine the individual susceptibility to cancer and response to treatment. The p53 protein is a transcription factor and among other functions, is involved in apoptosis. Moreover, the P-glycoprotein is a transmembrane protein responsible for drug efflux from the cells. Polymorphisms of the gene TP53, Arg72Pro and Pro47Ser, have been observed an altered apoptosis-inducing potential; whereas, the polymorphism of the gene MDR-1, C3435T, has demonstrated influence on the Pglycoprotein activity or expression levels. In this study, our purpose was to investigate whether TP53 and MDR-1 polymorphism would be involved with breast cancer risk and the response to neoadjuvant chemotherapy. We analyzed 116 patients with breast cancer and 120 health controls by PCR-RFLP technique. The genotypic and allelic frequencies for Arg72Pro and C3435T polymorphisms in patients and controls were similar. For the Pro47Ser polymorphism, only individuals with the wild-type genotype were observed. The polymorphic homozygous genotypes of the TP53 and MDR-1 genes were more frequent in controls for the non whitegroup and for the >50 years group, respectively, suggesting an association with genotypes and their ethnicity and age. There was no association with the other variables analyzed for breast cancer risk. The distribution of pretreatment patient characteristics was not significantly different among the polymorphic variants. Furthermore, no association was observed when the clinical and pathological responses were evaluated. However, patients with the Pro/Pro variant (TP53 gene) and patients with the TT (MDR-1 gene) were more likely to have 1-3 and 4 metastatic axillary lymph nodes, respectively. Based on these data, it was not possible to determine associations between polymorphisms and susceptibility to breast cancer neither to the response to neoadjuvant chemotherapy in our sample. However, further studies should be done to determine the contribution of these polymorphisms in the breast cancer risk and its treatment, and thus, establish strategies for more effective therapies.

Neoadjuvant chemotherapy has become standard practice in patients with high-risk early breast cancer as it improves rates of breast conservation surgery and enables prediction of recurrence and survival by using response to treatment as a surrogate. Previous studies have focused on generating molecular datasets to develop prediction models of response, though little is known on how tumours and their microenvironments are modulated by neoadjuvant chemotherapy. The thesis aims at molecularly characterising tumour changes during neoadjuvant chemotherapy in a cohort of 168 patients. Serial tumour samples at diagnosis, and, when available, midway through chemotherapy and on completion of treatment were profiled by shallow whole genome sequencing, deep exome sequencing and transcriptome sequencing, resulting in the generation of an unprecedented genomics dataset with tumours in situ while patients received chemotherapy. Molecular predictors of response to chemotherapy were inferred from the diagnostic biopsy. Several novel observations were made, including previously undescribed associations between copy number alterations, mutational genotypes, neoantigen load, HLA genotypes and intra-tumoural heterogeneity with chemosensitivity. Possible mechanisms of chemoresistance included LOH at the MHC Class I locus, decreased expression of MHC Class I and II genes and drug influx molecules, as well as increased expression of drug efflux pumps. A complex relationship between proliferation, tumour microenvironment composition (TME) and response to treatment was explored by deconvoluting bulk RNAseq data and performing digital pathology orthogonal validation. Clonal and microenvironment dynamic changes induced by/associated with chemotherapy were then modelled. Two types of genomic responses were identified, one in which the clonal composition was stable throughout treatment and another where clonal emergence and/or extinction was evident. Validation by multi-region deep sequencing confirmed the dynamics of the clonal landscape. Clonal emergence was shown to be associated with higher proliferation and decreased immune infiltrate, with an increase in genomic instability and homologous recombination deficiency during treatment. The immune TME composition and activity mirrored response to treatment, with cytolytic activity and innate and adaptive immune infiltrates linearly correlating with the degree of residual disease remaining after chemotherapy. Finally, the circulating tumour DNA (ctDNA) genomic landscape was explored by using shallow whole genome sequencing and targeted sequencing of plasma DNA. Tumour mutations detected on exome sequencing were also detected in ctDNA in plasma, supporting the use of liquid biopsies as a biomarker for monitoring response to therapy and detection of minimal residual disease.

Introduction: The incidence of gastro-oesophageal cancers has increased considerably over the last decade. As the disease is associated with a poor prognosis, there is a need to identify markers of treatment response which could be used in the future to improve the management of gastro-oesophageal tumours. Aims: 1) To compare the ability of published histological grading criteria (Becker, Mandard and Ninomiya) to assess response to neo-adjuvant chemotherapy (NCT) in gastro-oesophageal cancers. 2) To evaluate the expression of thymidylate synthase (TS) in pre-treatment diagnostic biopsy samples as a predictive marker of response to NCT. 3) To investigate whether measurements of hypoxia obtained using pimonidazole are prognostic for treatment outcome in patients with gastro oesophageal adenocarcinoma (ACC). 4) To study the prognostic significance and clinicopathological associations of epithelial mesenchymal transition (EMT) related proteins S100A4, Vimentin and Snail1 in gastro-oesophageal junction (GOJ) tumours. 5) To evaluate the ability of dynamic contrast enhanced (DCE) MRI to assess chemoradiotherapy (CRT) induced changes in oesophageal cancer. Methods: 1) Formalin fixed paraffin embedded (FFPE) tumour blocks and haematoxylin and eosin stained slides of samples from resected tumours (n=66) were obtained from patients who received NCT for gastric and GOJ tumours. The slides were scored independently by two observers and kappa scores calculated. 2) Pre-treatment diagnostic tissue biopsy samples were obtained from 45 patients with gastric and GOJ cancer who received NCT. TS expression was assessed using immunohistochemistry (IHC) and scored by two observers. The clinical and pathological data were analysed. 3) 57 patients were prospectively administered intravenous pimonidazole and the tumour specimens were collected both at staging laparoscopy and resection. IHC was performed to assess pimonidazole expression and determine its association with clinico-pathological factors. 4) Tissue microarrays were prepared from resection specimens from GOJ ACC. IHC was performed to investigate EMT related protein expression. 5) DCE-MRI was performed on five patients diagnosed with oesophageal cancer treated with CRT. Multiple pharmacokinetic parameters were evaluated. Findings: 1) Becker's histological grading criteria was the most reproducible and prognostic of outcome. The incidence of complete histological response (5%) was low in patients receiving NCT. 2) No prognostic benefit of TS expression was identified. 3) Results from only 34 patients were available for analysis. 77% pimonidazole positivity was observed. Preoperative anaemia was associated with significant tumour pimonidazole expression (p=0.04). Pimonidazole was not prognostic for outcome. 4) The overall positive expression was S100A4 (85%), Vimentin (14%) and Snail1 (89%). The increased expression of S100A4 at the tumour body (p=0.02) and luminal surface (p=0.01) was associated with a poor outcome. 5) Significant changes were measured in DCE-MRI pharmacokinetic parameters after CRT. Conclusion: 1) Becker's histological response grading criteria should be further studied in routine clinical practice for response assessment to NCT. 2) TS should be explored further as a marker of NCT response in gastro-oesophageal cancer. 3) Hypoxia is a characteristic feature of upper gastrointestinal ACC and is associated with anaemia. 4) S100A4 is the most useful marker of EMT in GOJ adenocarcinoma. 5) DCE-MRI tracer kinetic parameters should be explored in a larger study to assess their ability to monitor the efficacy of and predict response to neo-adjuvant treatment.