Association of lifestyle and other risk factors with breast cancer according to menopausal status: a case-control study in the Region of Western Pomerania (Poland).

ABSTRACT

PURPOSES: The purpose of this study was to examine the association between family history, reproductive, anthropometric, lifestyle factors and risk of breast cancer according to menopausal status, using data from a case-control study conducted in the Region of Western Pomerania (Poland). METHODS: A total, 858 women with histological confirmed breast cancer and 1085 controls, free of any cancer diagnosis, aged 28-78 years, were included in the study. The study was based on a self-administered questionnaire. Logistic regression was used to compute odds ratios and 95% confidence intervals and a broad range of potential confounders was included in analysis. RESULTS: Protective effect of a late age at menarche, a longer period of breast-feeding, increased levels of recreational physical activity, total vegetables or fruits intake, and intake of vitamins on the risk of breast cancer was observed among both pre- and post-menopausal women. Familial history of breast cancer, active or passive smoking, experience of a crude psychological stress were positively associated with breast cancer regardless menopausal status. Current body weight, current body mass index, increased alcohol intake elevated breast cancer risk in postmenopausal women, while these factors did not alter risk among premenopausal women. Increased consumption of red meat or animal fats elevated the risk in premenopausal women. More educated premenopausal women had lower breast cancer than those graduated from elementary school. Low family income increased the risk in premenopausal women. CONCLUSION: There is evidence for a dose-response relationship between several lifestyle factors and breast cancer risk. The results also suggest that some different mechanisms may operate in breast cancer etiology in pre-and post-menopausal women. A multifactorial process of breast cancer development, the complex interaction between physical activity, diet, energy intake and body weight, inconsistent and inconclusive data on breast cancer risk factors coming even from well-designed epidemiological studies are the case for continual update knowledge on primary prevention and identification of changes in behavior that will reduce the risk.