Most studies found that breast cancer is less common in countries where the typical diet is low in total fat, low in polyunsaturated fat, and low in saturated fat. On the other hand, many studies of women in the United States have not found breast cancer risk to be related to dietary fat intake. Researchers are still not sure how to explain this apparent disagreement. An injury to the breast causes cancer. Injury or trauma to the breast does not cause cancer.
Fat necrosis can occur when breast tissue becomes injured or bruised.
When the body tries to heal the bruise, it can develop scar tissue. This scar tissue or fat necrosis can be mistaken as cancer on a mammogram. However, symptoms of injury should resolve within a month. Another reason for this myth is that, especially among women who do not do monthly breast self-exam, an injury may draw their attention to a breast lump that had actually been present for some time. A recent analysis using data from most of the large, well-designed, published studies found that women now using oral contraceptives have a slightly greater risk of breast cancer than those women not using them.