Do fatty breasts increase or decrease breast cancer risk?

Abstract

Few studies have investigated the association of non-dense area or fatty breasts in conjunction with breast density and breast cancer risk. Two articles in a recent issue of Breast Cancer Research investigate the role of absolute non-dense breast area measured on mammograms and find conflicting results: one article finds that non-dense breast area has a modest positive association with breast cancer risk, whereas the other finds that non-dense breast area has a strong protective effect to reduce breast cancer risk. Understanding the interplay of body mass index, menopause status, and measurement of non-dense breast area would help to clarify the contribution of non-dense breast area to breast cancer risk.

Figure 1

Models of breast cancer risk odds ratios for breast dense area and non-dense (fat) area. A model from Pettersson and colleagues [1] is shown on the left, and a model from Lokate and colleagues [2] is shown on the right. Models are adjusted for age, age of menopause, family history of breast cancer, parity, body mass index, and alcohol use. Additional adjustments for the model from Pettersson and colleagues [1] are age of menarche and alcohol use. Additional adjustments for the model from Lokate and colleagues [2] are height, number of children, and hormone therapy use.