AGO Recommendations for the Diagnosis and Treatment of Patients with Early Breast Cancer: Update 2015

Individual risk factors can be classified into non-modifiable, modifiable, and socially defined factors. Currently, there is good evidence that changes in some modifiable risk factors could substantially decrease the individual breast cancer risk. High total fat intake influences the body mass index (BMI) and may increase the breast cancer risk. Consequently, a healthy and lowin-fat diet should be preferred. Neither intake of fruits and vegetables nor the addition of micronutrients, trace elements, or vitamins may reduce the breast cancer risk [3, 4]. However, prevention of diabetes mellitus type II, physical activity, and maintaining normal weight could reduce the breast cancer incidence and mortality [5]. Alcohol use may be more strongly associated with the risk of hormone-sensitive breast cancers compared to hormone-insensitive subtypes, suggesting distinct etiologic pathways [6]. In contrast, smoking is associated with overall breast cancer risk. Especially smoking at a young age (long before the first pregnancy) increases the risk by up to 60%. Never smoking reduces the lifetime risk by 15–24% [7, 8].