Bakgrund: Endometrios är en östrogenberoende sjukdom där endrometriala lesioner växer utanför livmodern och ofta ger smärta. Dagens behandling i Sverige består av bl.a. kombinerade hormonella preventivmedel, gestagener och gonadotropinfrisättandehormon (GnRH) -agonister, men den botar inte endometrios och ger inte alltid fullgod smärtkontroll. Aromatasinhibitorer (AI) har identifierats som potentiell behandling mot endometrios. De hämmar aromatas som katalyserar omvandlingen till östrogener. Anastrozol (An) och letrozol (Le) är AI. Syfte: Att undersöka om premenopausala kvinnor med smärta pga. endometrios kan få smärtlindring av läkemedelsbehandling med aromatasinhibitorer kombinerat med gestagener, kombinerade hormonella preventivmedel eller GnRH-agonister. Metod: Litteraturstudie där artiklar uppsökta i PubMed användes som underlag. Fem studier valdes ut. Resultat: An i kombination med GnRH-agonist som postoperativ behandling sågs ge mindre smärta, färre återfall och längre tid till återfall efter behandlingens slut än behandling med bara GnRH-agonist. Le i kombination med GnRH-agonist sågs ge samma grad av smärtlindring som Le i kombination med gestagen. Le i kombination med GnRH-agonist minskade bentätheten (BMD) och gav besvärliga biverkningar. Le i kombination med GnRH-agonist gav fler biverkningar än Le i kombination med gestagen. Le kombinerat med gestagen gav mer smärtlindring än enbart gestagen, men smärtan återkom efter behandlingsslut. Kombinationen gav fler biverkningar än enbart gestagen, men påverkade inte BMD. An i kombination med etinylestradiol plus levonorgestrel gav smärtlindring, dock sågs Le i kombination med etinylestradiol plus levonorgestrel som postoperativ behandling inte ge mer smärtlindring än enbart etinylestradiol plus levonorgestrel. An i kombination med etinylestradiol plus levonorgestrel gav en del biverkningar, men inte BMD-påverkan. Slutsats: AI kombinerat med GnRH-agonist verkar ge smärtlindring och verkar kunna förlänga återfallsintervallet vid postoperativ administrering vid endometrios. Det kan dock ge besvärliga biverkningar inkl. BMD-förlust. AI i kombination med etinylestradiol plus levonorgestrel verkar ge smärtlindring vid endometrios, dock ej mer än etinylestradiol plus levonorgestrel som monoterapi. AI kombinerat med noretisteron verkar minska smärta vid endometrios under behandlingen men kan ge besvärliga biverkningar. Fler omfattande, randomiserade och blindade studier med långtidsbehandling krävs för att kunna dra definitiva slutsatser om effekten av AI i kombination med gestagener, med kombinerade hormonella preventivmedel eller med GnRH-agonister mot endometriossmärta.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A deficiÃncia de estrÃgeno tem mostrado aumentar a remodelaÃÃo Ãssea, podendo afetar algumas doenÃas Ãsseas como a periodontite. A biossÃntese desse hormÃnio à catalisada pela enzima aromatase e sua inibiÃÃo à importante para terapia do cÃncer de mama. Os pacientes que usam inibidores da aromatase como o Anastrozol (ANA) mostram maior nÃmero de fraturas e menor densidade Ãssea. Considerando, entÃo, o papel do estrÃgeno na resposta inflamatÃria e no metabolismo Ãsseo, alÃm dos efeitos adversos do ANA e da periodontite ser caracterizada por um processo inflamatÃrio que resulta em perda Ãssea alveolar, o objetivo desse estudo foi de investigar se o ANA afeta a periodontite em ratas ovariectomizadas. Para isto, o ANA (0,02, 0,1 e 0,5 mg/kg-v.o.) foi avaliado em um modelo de periodontite induzida por ligadura em ratos durante 11 dias. A periodontite foi analisada atravÃs de macroscopia, de histologia e da atividade de mieloperoxidase (MPO). As dosagens sÃricas de estrÃgeno, o leucograma, a variaÃÃo de massa corpÃrea e as funÃÃes hepÃtica, renal e esplÃnica tambÃm foram consideradas. A ovariectomia reduziu os nÃveis sÃricos de estrÃgeno apÃs 14 dias, mas nÃo exacerbou a periodontite ou aumentou a atividade de mieloperoxidase (MPO) quando comparada aos animais falso ovariectomizados (F-OVX). Embora o ANA nÃo tenha aumentado a perda Ãssea alveolar (POA), a administraÃÃo deste fÃrmaco por 11 dias aumentou a atividade de MPO. A ovariectomia combinada ou nÃo ao ANA nÃo promoveu nenhuma mudanÃa nas funÃÃes hepÃtica, renal ou esplÃnica, mas causou uma leucocitose promovida por cÃlulas mononucleares no 11 dia. Os animais ovariectomizados que receberam salina (SAL) tambÃm mostraram maior ganho de massa corpÃrea e a curva de peso do ANA foi similar à curva do SAL. Em conclusÃo, embora a reduÃÃo de estrÃgeno por 25 dias e a administraÃÃo de ANA por 11 dias nÃo tenha aumentado a POA, o ANA aumentou a atividade de MPO. / Estrogen deficiency was shown to increase bone remodeling, may affect some bone diseases as periodontitis. Biosynthesis of this hormone is catalyzed by aromatase enzyme and her inhibition is important for breast cancer therapy. The patients who use aromatase inhibitors as Anastrozole (ANA) show greater number of fractures and lower bone density. Since estrogen role in the inflammatory response and the bone metabolism, besides those adverse effects of ANA and periodontitis is characterized by an inflammatory process that results in alveolar bone loss, the aim of this study was to investigate whether ANA affects the periodontitis in ovariectomized rats. For this, ANA (0.02, 0.1 and 0.5 mg/kg-v.o.) was evaluated in ligature-induced periodontits for 11 days in ovariectomized rats. Periodontitis was analyzed through macroscopy, histology and by myeloperoxidase (MPO) activity. Serum dosage of estrogen, leukogram, corporal mass variation and liver, renal and spleen functions were also analyzed. The ovariectomy reduced the serum levels of estrogen after 14 days, but did not worsen the periodontitis nor increased MPO activty when compared to sham ovariectomized (S-OVX) animals. Although, ANA did not increase alveolar bone loss (ABL), administration of this drug for 11 days increased the MPO activity. The ovariectomy combined or not with ANA no promoved any changes in liver, renal or spleen functions, but caused leukocytosis promoved by mononuclear cells at 11th day. Ovaricetomized animals that received saline (SAL) also showed more gain of corporal mass and ANA weight curve were similar to SAL curve. In conclusion, although the estrogen reduction for 25 days and the administration of anastrozole for 11 days did not increase the ABL, the ANA increased the MPO activity.

Made available in DSpace on 2015-07-22T20:50:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-25. Added 1 bitstream(s) on 2015-08-11T03:25:59Z : No. of bitstreams: 1 Publico-11912.pdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Introdução: A endocrinoterapia é uma das principais responsáveis pela redução de mortalidade do câncer de mama. Biomarcadores preditivos de resposta celular precoce vêm sendo estudados com intuito de prever precocemente a hormonioresistência. Freqüentes deleções e mutações têm sido descritas no gene p16 em diversos tipos de tumores, mas pouco se sabe sobre seu papel no câncer de mama e seu comportamento após endocrinoterapia neoadjuvante com tamoxifeno e anastrozol. Objetivos: Estudar a expressão do p16 e dos receptores de estrogênio e progesterona (RE e RP) em pacientes na pós - menopausa com carcinoma de mama RE e/ ou RP (+) após curto período (26 dias) de tratamento com tamoxifeno, anastrozol e placebo. Métodos: Estudo prospectivo randomizado duplo-cego realizado com 58 pacientes dos Hospitais Pérola Byington e São Paulo da UNIFESP (São Paulo - Brasil) com carcinoma ductal infiltrativo de mama, nos estádios II e III, que no período pré-operatório foram subdivididas em três grupos: P (placebo, N=25), T (tamoxifeno 20mg/dia, N=15) e A (anastrozol 1mg/dia, N=18). A biópsia foi realizada no momento do diagnóstico e após a cirurgia definitiva (26º dia) e os tumores foram isolados por micro-arranjos teciduais. O estudo imunoistoquímico foi realizado com anticorpos para p16 (Dako- OA315), RE (Neomarkers-M7047), RP (Dako- M3569). Realizou-se o estudo semiquantitativo utilizando-se os critérios de Allred e o estudo estatístico pelo teste paramétrico de Anova. Resultados: A positividade do p16 variou de 22 para 17%, respectivamente pré e pós tratamento com anastrozol; de 8 para 4% no grupo placebo e não houve variação, com 7% de positividade, no grupo que recebeu tamoxifeno. A comparação entre grupos e tempos não apresentou relação significativa para o p16 (p=0,17). Não foi encontrada correlação entre a positividade do p16 e o status hormonal (RE e RP). Conclusão: Não houve diferença estatística significante entre os três grupos estudados. Futuros estudos com métodos moleculares poderão esclarecer dúvidas suscitadas a respeito do tempo de exposição à droga necessária para interferir nos biomarcadores e proteínas. / Background: Frequent deletions or mutations of the INK4 gene, which encodes the cyclin-dependent kinase 4 inhibitor p16INK4a, have been documented in various human cancers, but little is known about the role of this tumor suppressor gene in primary breast cancer and there is a lack in the literature about its expression behavior in neoadjuvant endocrinetherapy with tamoxifen or anastrozole. Objective: Analysis of p16INK4a expression in patients with invasive ductal carcinomas (IDC) prior to tamoxifen and anastrozole neoadjuvant treatment and possible correlation between predictive and prognostical factors – estrogen receptor (ER), progesterone receptor (PgR). Methods: We examined p16INK4a mRNA expression and its relationship with short period (26 days) neoadjuvant endocrine therapy with tamoxifen and anastrozole in 58 primary breast cancers with palpable ER-positive IDC. They were double-blind randomized in three neoadjuvant treatment groups for 21 days: Anastrozole 1mg/day (n= 17), Placebo (n=25) and Tamoxifen 20mg/day (n=15). Biomarkers status (ER, PgR and p16) were obtained by comparing single immunohistochemical evaluation of pre and post-surgery samples using Allred’s method. Statistical analyses were performed using the SPSS software for Windows. Results: Variation in p16 was 22% to 17% in anastrozole group, 8% to 4% in placebo group and there was no variation in tamoxifen group, standing in 7%. There was no significant statistical diference in p16INK4a expression among the three groups (p=0.17). Variation in p16 was 12% to 9% (p<0.05) when considering the three groups together. There was a significant decrease of p16 expression in pre and post surgery results. There was no significant statistical correlation between p16 expression and hormonal status (RE and RP). Conclusions: There was no significant statistical diference in p16INK4a expression among the three groups. There was a significant statistical decrease in p16INK4a expression when compared pre and post surgery values. These findings could indicate that expression of p16 and variation in pre and post surgery samples are associated with hormone responsiveness and mechanisms of resistance. There were no significant statistical correlation between p16 expression and hormonal status (RE and RP). Further studies are necessary to understand their functional interrelationships and whether high p16INK4a expression may be associated with a lack of hormone responsiveness in breast cancer. / TEDE / BV UNIFESP: Teses e dissertações

Background: In the ‘Arimidex’, Tamoxifen Alone or in Combination (ATAC) trial, the aromatase inhibitor (AI) anastrozole had a ignificantly better efficacy and safety profile than tamoxifen as initial adjuvant therapy for hormone receptor-positive (HR+) early breast cancer (EBC) in postmenopausal patients. To compare the combined long-term clinical and economic benefits, we carried out a cost-effectiveness analysis (CEA) of anastrozole versus tamoxifen based on the data of the 100- month analysis of the ATAC trial from the perspective of the German public health insurance. Patients and Methods: A Markov model with a 25-year time horizon was developed using the 100-month analysis of the ATAC trial as well as data obtained from published literature and expert opinion. Results: Adjuvant treatment of EBC with anastrozole achieved an additional 0.32 quality-adjusted life-years (QALYs) gained per patient compared with tamoxifen, at an additional cost of D 6819 per patient. Thus, the incremental cost effectiveness of anastrozole versus tamoxifen at 25 years was D 21,069 ($ 30,717) per QALY gained. Conclusions: This is the first CEA of an AI that is based on extended follow-up data, taking into account the carryover effect of anastrozole, which maintains the efficacy benefits beyond therapy completion after 5 years. Adjuvant treatment with anastrozole for postmenopausal women with HR+ EBC is a cost-effective alternative to tamoxifen. / Hintergrund: Bei der adjuvanten Therapie von postmenopausalen Patientinnen mit Hormonrezeptor-positivem (HR+) Mammakarzinom belegen die ATAC-100-Monatsdaten (ATAC-Studie: ‘Arimidex’, Tamoxifen Alone or in Combination) einen signifikanten Vorteil von Anastrozol gegenüber Tamoxifen in Bezug auf Rezidivrisiko und Verträglichkeit. Es wurde eine Kosten-Nutzwert-Analyse von Anastrozol im Vergleich zu Tamoxifen aus der Sicht des deutschen Gesundheitssystems durchgeführt. Material und Methoden: Als Berechnungsbasis wurde ein Markov- Modell zur Abschätzung der Kosteneffektivität entwickelt. Der Modellierungszeitraum umfasste 25 Jahre. Die Daten wurden anhand der ATAC-100-Monatsdaten, vorliegender Literatur und durch ein interdisziplinäres Expertenteam ermittelt. Ergebnisse: Eine adjuvante Therapie mit Anastrozol erzielte 0,32 quality-adjusted life-years (QALYs) pro Patientin mehr, verglichen mit einer adjuvanten Tamoxifentherapie. Die zusätzlichen Kosten der Therapie mit Anastrozol lagen bei 6819 D pro Patientin. Im Vergleich mit Tamoxifen erzielte Anastrozol einen ICER (Incremental Cost-Effectiveness Ratio) von 21 069 D (30 717 $)/QALY über den gesamten Modellierungszeitraum. Schlussfolgerung: Diese Kosten- Nutzwert-Analyse eines Aromatasehemmers basiert erstmals auf einer Datenanalyse, die auch das Follow-Up und den sogenannten Carryover- Effekt nach einer abgeschlossenen 5-Jahres-Therapie beinhaltet. Anastrozol ist auch nach dieser Analyse aus der Sicht des deutschen Gesundheitssystems eine kosteneffektive Therapieoption für postmenopausale Patientinnen mit einem HR+ frühen Mammakarzinom. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: In the ‘Arimidex’, Tamoxifen Alone or in Combination (ATAC) trial, the aromatase inhibitor (AI) anastrozole had a ignificantly better efficacy and safety profile than tamoxifen as initial adjuvant therapy for hormone receptor-positive (HR+) early breast cancer (EBC) in postmenopausal patients. To compare the combined long-term clinical and economic benefits, we carried out a cost-effectiveness analysis (CEA) of anastrozole versus tamoxifen based on the data of the 100- month analysis of the ATAC trial from the perspective of the German public health insurance. Patients and Methods: A Markov model with a 25-year time horizon was developed using the 100-month analysis of the ATAC trial as well as data obtained from published literature and expert opinion. Results: Adjuvant treatment of EBC with anastrozole achieved an additional 0.32 quality-adjusted life-years (QALYs) gained per patient compared with tamoxifen, at an additional cost of D 6819 per patient. Thus, the incremental cost effectiveness of anastrozole versus tamoxifen at 25 years was D 21,069 ($ 30,717) per QALY gained. Conclusions: This is the first CEA of an AI that is based on extended follow-up data, taking into account the carryover effect of anastrozole, which maintains the efficacy benefits beyond therapy completion after 5 years. Adjuvant treatment with anastrozole for postmenopausal women with HR+ EBC is a cost-effective alternative to tamoxifen. / Hintergrund: Bei der adjuvanten Therapie von postmenopausalen Patientinnen mit Hormonrezeptor-positivem (HR+) Mammakarzinom belegen die ATAC-100-Monatsdaten (ATAC-Studie: ‘Arimidex’, Tamoxifen Alone or in Combination) einen signifikanten Vorteil von Anastrozol gegenüber Tamoxifen in Bezug auf Rezidivrisiko und Verträglichkeit. Es wurde eine Kosten-Nutzwert-Analyse von Anastrozol im Vergleich zu Tamoxifen aus der Sicht des deutschen Gesundheitssystems durchgeführt. Material und Methoden: Als Berechnungsbasis wurde ein Markov- Modell zur Abschätzung der Kosteneffektivität entwickelt. Der Modellierungszeitraum umfasste 25 Jahre. Die Daten wurden anhand der ATAC-100-Monatsdaten, vorliegender Literatur und durch ein interdisziplinäres Expertenteam ermittelt. Ergebnisse: Eine adjuvante Therapie mit Anastrozol erzielte 0,32 quality-adjusted life-years (QALYs) pro Patientin mehr, verglichen mit einer adjuvanten Tamoxifentherapie. Die zusätzlichen Kosten der Therapie mit Anastrozol lagen bei 6819 D pro Patientin. Im Vergleich mit Tamoxifen erzielte Anastrozol einen ICER (Incremental Cost-Effectiveness Ratio) von 21 069 D (30 717 $)/QALY über den gesamten Modellierungszeitraum. Schlussfolgerung: Diese Kosten- Nutzwert-Analyse eines Aromatasehemmers basiert erstmals auf einer Datenanalyse, die auch das Follow-Up und den sogenannten Carryover- Effekt nach einer abgeschlossenen 5-Jahres-Therapie beinhaltet. Anastrozol ist auch nach dieser Analyse aus der Sicht des deutschen Gesundheitssystems eine kosteneffektive Therapieoption für postmenopausale Patientinnen mit einem HR+ frühen Mammakarzinom. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

O câncer de mama é a principal causa de mortalidade por câncer entre as mulheres. Alguns biomarcadores e características clínicas são utilizados para avaliar o prognóstico e prever a resposta a uma série de abordagens terapêuticas. A Homocisteína é conhecida como um fator de risco para doença vascular aterosclerótica, mas sua participação na biologia do câncer ainda é incerta. Cisteína é o aminoácido sulfurado derivado da Homocisteína no ciclo da Metionina. Este ciclo metabólico origina as bases nitrogenadas e também determina o nível de metilação da molécula de DNA. É atualmente reconhecido que a hipometilação global do genoma é um evento chave na transformação maligna das células. O objetivo deste estudo foi avaliar os níveis séricos de homocisteína e cisteína como biomarcadores de sobrevida e de progressão da doença em câncer de mama. Também foi avaliado o efeito de um curso de curta duração (um mês) de tratamento hormonal sobre os níveis de Homocisteína, Cisteína e metilação do DNA. Amostras de sangue foram obtidos por ocasião da biópsia inicial (pré-tratamento) em todas as pacientes e, de tumor e de tecido normal adjacente, ao diagnóstico eem um mês após, para as pacientes que receberam o regime hormonal neo-adjuvante (pré-operatório). Todas as pacientes eram mulheres na pós-menopausa, com tumores de mama ressecáveis, acompanhadas em dois hospitais públicos, que consentiram em participar de outros dois protocolos de pesquisa prévios. Homocisteína e Cisteína foram analisadas por HPLC e a metilação global do DNA do tecido foi determinada por meio da técnica de MSRE (Methylation-Sensitive Restriction Enzyme). Foi observada uma diferença significativa entre os níveis pré e póstratamento de Homocisteína e Cisteína em tumores avançados, sugerindo um papel prognóstico em pacientes com características clínicas reservadas. As variações nos níveis de Homocisteína se mostraram significativamente correlacionadas com a sobrevida livre de doença. O modelo de risco proporcional de Cox demonstrou que os níveis de homocisteína e o status dos linfonodos representaram fatores prognósticos independentes em termos de sobrevida livre de doença. Embora mais estudos sejam necessários para confirmar estes resultados, nossa pesquisa sugere que a Homocisteína pode ser usada como um biomarcador de prognóstico para câncer de mama / Breast cancer is the leading cause of cancer mortality among women. Some biomarkers and clinical features are used to evaluate prognosis and to predict response to a range of therapeutic approaches. Homocysteine is well known as a risk factor in atherosclerotic vascular diseases, but its participation in cancer biology is still unclear. Cysteine is a sulfur amino acid derived from Homocysteine in the Methionine cycle. This metabolic cycle originates the nitrogenous bases and determines the methylation level of the DNA molecule as well. It is currently recognized that the global hipomethylation of the genome is a key event in the malign transformation of cells. The aim of this study was to evaluate serum Homocysteine and Cysteine as biomarkers of survival and disease progression in breast tumor, as well as the methylation status of tumor and normal tissues. The effect of a short course (one month) of hormonal treatment on Homocysteine, Cysteine and DNA methylation levels was also evaluated. Blood samples were collected during the initial biopsy (pretreatment) in all patients and, tumor samples and normal adjacent tissue, at diagnosis and one month after, for the patients that received neo-adjuvant hormonal regimen (pre-treatment). All patients were post-menopausal women, with resectable breast tumors, followed at two public hospitals, and that had consented to participate in two previous research protocols related to their disease. Serum Homocysteine and Cysteine were analyzed by HPLC and tissue global DNA methylation was determined by the MSRE (Methylation- Sensitive Restriction Enzyme) technique. A significant difference was observed between pre- and post-treatment levels of Homocysteine and Cysteine in advanced tumors, suggesting a prognostic role in patients with poor clinical characteristics. Variations in Homocysteine levels were significantly correlated with disease free survival. Cox proportional risk model demonstrated that nodal status and Homocysteine levels were independent prognostic factors for Disease Free Survival. Although more studies are needed to confirm these results, our research suggests that Homocysteine might be used as a prognostic biomarker for breast cancer

O câncer de mama é a principal causa de mortalidade por câncer entre as mulheres. Alguns biomarcadores e características clínicas são utilizados para avaliar o prognóstico e prever a resposta a uma série de abordagens terapêuticas. A Homocisteína é conhecida como um fator de risco para doença vascular aterosclerótica, mas sua participação na biologia do câncer ainda é incerta. Cisteína é o aminoácido sulfurado derivado da Homocisteína no ciclo da Metionina. Este ciclo metabólico origina as bases nitrogenadas e também determina o nível de metilação da molécula de DNA. É atualmente reconhecido que a hipometilação global do genoma é um evento chave na transformação maligna das células. O objetivo deste estudo foi avaliar os níveis séricos de homocisteína e cisteína como biomarcadores de sobrevida e de progressão da doença em câncer de mama. Também foi avaliado o efeito de um curso de curta duração (um mês) de tratamento hormonal sobre os níveis de Homocisteína, Cisteína e metilação do DNA. Amostras de sangue foram obtidos por ocasião da biópsia inicial (pré-tratamento) em todas as pacientes e, de tumor e de tecido normal adjacente, ao diagnóstico eem um mês após, para as pacientes que receberam o regime hormonal neo-adjuvante (pré-operatório). Todas as pacientes eram mulheres na pós-menopausa, com tumores de mama ressecáveis, acompanhadas em dois hospitais públicos, que consentiram em participar de outros dois protocolos de pesquisa prévios. Homocisteína e Cisteína foram analisadas por HPLC e a metilação global do DNA do tecido foi determinada por meio da técnica de MSRE (Methylation-Sensitive Restriction Enzyme). Foi observada uma diferença significativa entre os níveis pré e póstratamento de Homocisteína e Cisteína em tumores avançados, sugerindo um papel prognóstico em pacientes com características clínicas reservadas. As variações nos níveis de Homocisteína se mostraram significativamente correlacionadas com a sobrevida livre de doença. O modelo de risco proporcional de Cox demonstrou que os níveis de homocisteína e o status dos linfonodos representaram fatores prognósticos independentes em termos de sobrevida livre de doença. Embora mais estudos sejam necessários para confirmar estes resultados, nossa pesquisa sugere que a Homocisteína pode ser usada como um biomarcador de prognóstico para câncer de mama / Breast cancer is the leading cause of cancer mortality among women. Some biomarkers and clinical features are used to evaluate prognosis and to predict response to a range of therapeutic approaches. Homocysteine is well known as a risk factor in atherosclerotic vascular diseases, but its participation in cancer biology is still unclear. Cysteine is a sulfur amino acid derived from Homocysteine in the Methionine cycle. This metabolic cycle originates the nitrogenous bases and determines the methylation level of the DNA molecule as well. It is currently recognized that the global hipomethylation of the genome is a key event in the malign transformation of cells. The aim of this study was to evaluate serum Homocysteine and Cysteine as biomarkers of survival and disease progression in breast tumor, as well as the methylation status of tumor and normal tissues. The effect of a short course (one month) of hormonal treatment on Homocysteine, Cysteine and DNA methylation levels was also evaluated. Blood samples were collected during the initial biopsy (pretreatment) in all patients and, tumor samples and normal adjacent tissue, at diagnosis and one month after, for the patients that received neo-adjuvant hormonal regimen (pre-treatment). All patients were post-menopausal women, with resectable breast tumors, followed at two public hospitals, and that had consented to participate in two previous research protocols related to their disease. Serum Homocysteine and Cysteine were analyzed by HPLC and tissue global DNA methylation was determined by the MSRE (Methylation- Sensitive Restriction Enzyme) technique. A significant difference was observed between pre- and post-treatment levels of Homocysteine and Cysteine in advanced tumors, suggesting a prognostic role in patients with poor clinical characteristics. Variations in Homocysteine levels were significantly correlated with disease free survival. Cox proportional risk model demonstrated that nodal status and Homocysteine levels were independent prognostic factors for Disease Free Survival. Although more studies are needed to confirm these results, our research suggests that Homocysteine might be used as a prognostic biomarker for breast cancer