Risk and Protective Factors for Breast Cancer in Midwest of Brazil

Abstract

Patterns of physical activity, body composition, and breastfeeding are closely related to health and are influenced by environmental, economic, and social factors. With the increase of sedentary lifestyle and overweight, many chronic diseases have also increased, including cancer. Breast cancer is the most common cancer in women worldwide, and the knowledge of its risk and protective factors is important to the adoption of primary prevention strategies. We aimed to investigate some risk and protective factors for breast cancer among women from Midwest Brazil. It is a case-control study of outpatient basis, carried out with 93 breast cancer cases and 186 controls. Socioeconomic, gynecological, anthropometric, and lifestyle variables were collected, and odds ratios (ORs) values were estimated (significance level, 5%; confidence interval (CI), 95%). Per capita income equal to or lower than 1/2 Brazilian minimum wage (OR = 1.88; CI = 1.06–3.29), residence in rural area (OR = 4.93; CI = 1.65–14.73), and presence of family history of breast cancer (OR = 5.38; CI = 1.46–19.93) are risk factors for breast cancer. In turn, physical activity (past 6 months) (OR = 0.23; CI = 0.10–0.55) and leisure physical activity at 20 years old (OR = 0.13; CI = 0.03–0.54) are protective factors for the disease in women who live in Midwest of Brazil.

Risk factors of breast cancer and knowledge about the disease: an integrative revision of Latin American studies

“…Decreased educational level may explain increased risk of non-participation on screening programs and BSE in three out of four studies (Chart 2) 22,29,50 . This argument cannot explain the results of Inamuru et al, who compared in a case-control study several reproductive risk factors among women from rural regions and urbanized centres of Mid-western Brazil (Chart 2) 37 : Additionally, the authors of this study also identified lower income and decreased educational level as risk factors for women living in rural areas (Chart 2) 37 . In contrast, two studies from Mexico and Chile that identified higher educational level as risk factor were based on data obtained from hospitals of urban centres (Chart 2) 34,40 .…”

“…Risk factors were subdivided into four main categories: Lifestyle-related, reproductive, socio economic and environmental risk factors, respectively, a category of history of BC (Chart 2). Several authors have analysed risk factors of all four categories 30,34,37,38,[40][41][42] . Two studies performed in Uruguay for example, included a broad range of different risk factors 41,42 .…”

“…In studies on the risk of BC, four authors identified decreased educational level as risk factor (Chart 2) 22,29,37,50 . In contrast, three authors identified increased educational level as risk factor (Chart 2) 34,36,40 .…”

“…Changing lifestyle and reproductive patterns in Latin American countries may additionally increase the risk of BC 5,6 . In literature, delayed childbearing, low parity and short breastfeeding periods represent well-established reproductive risk factors for BC [7][8][9] .…”

“…Additionally, early age at menarche and late age at menopause are reproductive factors that increase the risk of the disease 7 . Obesity and overweight are also risk factors for BC 6,10 . Other well-established lifestyle-related risk factors are physical inactivity and sedentarism, alcohol consumption, smoking and intake of several hormones like estrogens 11 .…”