What causes breast cancer? Regardless of the medical technology we possess, scientists have not been able to distinguish a single cause for breast cancer. However, breast cancer is now discussed in terms of risk factors as opposed to a single cause. Having a risk factor for breast cancer increases the likelihood of developing this disease, as opposed to breast cancer being attributed to a single cause. Therefore, if you are concerned about breast cancer, think in terms of the risk factors involved, rather than a specific cause. It's not possible to identify and remove the causes of breast cancer, but it's certainly possible to control some of these risk factors.