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.