Influence of Lifestyle Factors on Breast Cancer Risk: A Case-Control Study With a Representative Sample of the Brazilian Population

Abstract

Objective: To evaluate the influence of lifestyle factors on the chances of developing breast cancer in Brazilian women. Methodology: A case-control study was conducted with 542 women, 197 diagnosed with breast cancer and 345 healthy controls. All analyzes were adjusted for age and BMI. The International Physical Activity Questionnaire-Short form was used to estimate the level of physical activity. A standardized questionnaire was used in order to evaluate whether the volunteers were following dietary recommendations, smoking, and alcohol-related habits. We also collected anthropometric variables: weight (kg), height (m), and waist circumference (cm). A multivariate logistic regression model was performed to estimate the odds ratios (OR) and 95% confidence intervals (CI) of the relative risk of breast cancer with lifestyle factors. Results: The mean age of the patients was 52±11 years. Not following dietary recommendation (OR 1.78, 95%CI 1.12-2.89), smoking habit (OR 1.68, 95%CI 1.12-2.46), alcoholic habit (OR 2.16, 95%CI 1.48-3.16), and sedentary lifestyle (OR 1.89; 95%CI 1.129-2.76) were associated with a greater chance of developing breast cancer, regardless of age and BMI. Conclusions: The sedentary lifestyle, not following dietary recommendations, smoking, and consumption of alcoholic beverages increase the risk of developing breast cancer.