Alcohol may keep estrogen levels higher for longer periods of time. Other breast problems in the past. They may be fluid-containing sacs called cysts or they may be solid lumps. Hormones stimulate the growth of other lumps or cysts, too. Woman who have had problems with non-cancer lumps, especially solid ones, are a little more likely to develop breast cancer.
Fat cells produce estrogen.
Women with extra fat have more estrogen in their blood and in fatty tissues like the breasts. Every year on estrogen is like an extra year before menopause. Although women cannot control how many years they menstruate or if they naturally produce more estrogen, some risk factors such as diet, drinking, weight, and estrogen pills are within their control. However, none of the risk factors which women control increases the chances of developing breast cancer like smoking does for lung cancer. Each woman must decide if small increases in risk are worth it to her.