Low Overall Survival in Women With De Novo Metastatic Breast Cancer: Does This Reflect Tumor Biology or a Lack of Access to Health Care?

Abstract

PURPOSE As a result of its epidemiologic and therapeutic aspects, metastatic breast cancer (MBC) is a highly relevant clinical condition. This study aimed to estimate overall survival (OS) in women with de novo MBC in a Brazilian population. PATIENTS AND METHODS Patients were identified in the Goiânia population-based cancer registry between 1995 and 2011. All women with metastatic disease at diagnosis were included in the study. OS was analyzed at 5 and 10 years of follow-up. We used the Kaplan-Meier estimator and Cox regression for statistical analysis. RESULTS Over the 16-year period covered by the study, 5,289 women were diagnosed with breast cancer in Goiânia. Of these, 277 women (5.2%) had MBC. OS rates at 5 and 10 years were 19.9% and 7.3%, respectively. The mean OS time of women treated in the public health system was 7.5 months shorter than in women who had private health care (19.7 v 27.2 months, respectively). In the univariable analysis, the following factors were statistically significant for OS: T3/4 staging, histologic grade 3, progesterone receptor status, tumor phenotype, breast surgery, CNS metastasis at initial presentation, and surgery for resection of metastasis. In multivariable analysis, initial CNS metastasis (hazard ratio, 3.09; 95% CI, 1.16 to 8.19) and breast surgery (hazard ratio, 0.45; 95% CI, 0.25 to 0.78) remained independent prognostic factors. CONCLUSION OS was lower than rates found in specialist centers in Brazil and in developed countries. Several intrinsic and extrinsic factors were significant in predicting OS. Despite the difference in the 5-year survival rate, the type of access to health care was not significant in the multivariable analysis of the entire period.