Impact of Treatment Type on Overall Survival in Elderly Brazilian Women with Breast Cancer

Objective: To analyze the survival of elderly patients with breast cancer according to the type of treatment used. Methods: A cohort study of women aged 80 or over with breast cancer registered with the Brazilian National Cancer Institute (Instituto Nacional do $C{\hat{a}}ncer$ - INCA) between 2008 and 2009 was conducted. Prognosis was analyzed according to the cancer treatment performed: surgery, radiotherapy, or hormone therapy. Analysis of the overall 5-year survival rate was performed using the Kaplan - Meier method, and comparisons of curves were undertaken using the log-rank test. For multiple regression analysis, Cox regression was used, adjusting for age and clinical stage, considering values of p < 0.05 as significant. Data were all analyzed using the statistical package SPSS version 20. Results: 70 women with a mean age of $84.0{\pm}3.7years$ at diagnosis participated in the study. The median follow-up time was 37.1 months (range 0.5-75.5), and 31 deaths (44.3%) occurred during this time. The median survival time was 51.2 months (95% CI, 44.9-57.4), higher in those who underwent surgery (p = 0.012) and those who had hormone therapy (p=0.001). Treatment with surgery reduced the risk of death by 61.7% (HR 0.3; 95% CI, 0.1-0.6; p = 0.001) when adjusted for clinical stage and age at diagnosis. However, there was no significant benefit from radiotherapy (HR 1.2; 95% CI, 0.5-2.5; p = 0.694). Conclusion: Treatment with surgery and hormone therapy increased the survival of our Brazilian patients with breast cancer aged 80 or over.