Physical Activity Is Associated with Malignant and Benign Breast Diseases in Low-Income Brazilian Women

Abstract

We compared the relationships among percentage of body fat (%BF) and physical activity with breast cancer (BC) and benign breast diseases (BBD) in low-income Brazilian women. A case-control study including 106 incident BC cases, 178 incident BBD cases, and 181 control women recruited from a public hospital-based screening center was conducted. Logistic regression models showed that sedentary women have a higher odds of developing BC in the age adjusted model [odds ratio (OR) = 2.39, 95% confidence interval (CI) 1.43–3.99]. After adjusting for hormonal-related risk factors and family history of breast cancer (OR = 2.94, 95%CI 1.50–5.79) and also for the %BF (OR = 2.71, 95%CI 1.36–5.37) the odds remained high. Independent of the adjustments made, %BF did not affect the odds for developing BC. When the same models were tested for women with BBD, we found a significant association with sedentary lifestyle in all models tested, with an OR = 3.03 (95%CI 1.69–5.42) in the fully adjusted model. In the same way, in the fully adjusted model %BF was significantly associated to risk for BBD (OR = 0.54, 95%CI 0.30–0.98). Similar to results found in other populations, our data suggest that physical activity is an important, independent protective factor for the risk of developing BC and BBD in low-income women from an admixed population.

ACKNOWLEDGMENTS

We thank the women who participated in this study and the physicians, surgeons, and nurses of the Hospital Maternidade Odete Valadares for the selection and clinical assessment of the patients and for assisting with the data collection. We also thank Dr. Carlos Eduardo Paiva, of the Fundação Pio XII, Hospital de Câncer de Barretos for reviewing the histological diagnosis; Lílian Almeida for conducting the questionnaires; and Denise Xavier Amora for help in the database elaboration. This study was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - 484998/2007-2), Fundação de Amparo à Pesquisa de Minas Gerais (FAPEMIG, EDT-2040-03), Universidade Federal de Ouro Preto, and Programa de Ensino Tutorial (PET/SESu/MEC, scholarship to Wander R. Furtado), Brazil. The funding sources had no involvement in the study.