Association between body mass index and breast cancer in patients from Salvador, Bahia

Abstract

Objective: Identify the association between body mass index (BMI) and breast cancer in a population of patients from two clinics in Salvador (BA). Methods: A case-control study in which 190 patients were recruited between 2012 and 2014, 68 diagnosed with ductal breast carcinoma and 122 controls. Sample calculation was performed with n=140 patients, through Winpepi program. Weight and height data were collected to calculate the body mass index of each patient. Based on the World Health Organization (WHO) criteria were classified as malnourished patients with BMI <18.5, those with normal BMI ≥18.5 and <25.0 kg/m², overweight ≥25 and <30 kg/m² and obese ≥30 kg/m². BMI proportions of each category were determined for cases and controls. Statistical analysis included performing chi-square test to evaluate the correlation between categorical variables. Results: Mean age was 56.7±13 years between cases and 53.1±11.9 years among controls. Mean BMI was 27.5±4.6 kg/m² among cases and 26.1±4.9 kg/m² among controls. The proportion of normal patients, overweight and obese was 33.8, 38.2 and 27.9% in the cases and 43.4, 43.4 and 13.1% among controls, respectively. There were significantly more obese among cases than among controls (OR=2.57, 95%CI 1.22–5.42; p=0.011), with women in premenopausal and post-menopausal. Conclusion: The results show a correlation between the presence of breast cancer and high BMI in this sample, consistent with the results of other studies.