Survival analisis in breast cancer's women in Santa Catarina, Brazil.

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Abstract Abstract #6093 BACKGROUND: Overall survival after breast cancer diagnosis is influenced by the characteristics study's group, the study's place and biological factors.
 OBJECTIVES: Define overall survival in five-years and the associated factors with the prognosis of breast cancer's women in Santa Catarina, Brazil.
 MATERIALS AND METHODS: this is a historic cohort study, with data from diagnoses from January 2000 to December 2002 from Registro Hospitalar de Cancer of the Centro de Pesquisas Oncológicas,SC and the Hospital de Caridade, both in south Brazil, and complemented with data from the Mortality Information System until December 2007. The time of survival was calculated as the range of the date of diagnosis (biopsy or surgery) until the date of death or end of monitoring (5 years). The survival curves were estimated by the Kaplan-Meier method, using the log-rank test for comparison of the curves stratified. The effect of co-variable model was estimated by the semi-parametric risk proportionate, Model Cox, with the Schoenfelder analysis of residuals to assess whether the co-variables of the final model respect the principle of proportionality over time. The analysis was made using R 2.5.0.
 RESULTS: 1002 women were included, and 262 deaths occurred, this 235 by breast cancer. The overall survival after 5 years was 76.2% (CI 95% 73,6-78,9%). Variables were associated with survival by the Kaplan-Meier curves: age, race/color, education, clinical stage, treatments received. This includes these variables in the model of Cox, remaining in the final model, as independent factors: age until 30 years (HR: 3,09, CI 95% 1,25-7,67); illiterate (HR 3,70, CI 95% 1,44-9,55); staging III (HR 5,27, CI 95% 2,56-10,82) and staging IV (HR 14,07, CI 95% 6,81-29,06); treatment with chemotherapy alone (HR 1,95, CI 95% 1,12-2,40), surgery, chemotherapy and radiotherapy (HR 2,38, CI 95% 1,36-4,16), compared to surgery and hormontherapy (HR 1.00). The Cox model variables respect the principle of proportionality over time (p=0,25).
 CONCLUSIONS: The overall survival in breast cancer, proved to be better than in other Brazilian states. The instruction presents itself as a strong influence on survival, where illiterate women have worse prognosis. The combinations of treatment are also factors independent and influenced by biological factors. The diagnosis in advanced stages is one of the most important factors for worse survival, and modifiable through campaigns of early detection and mammography screening. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6093.