How does having a close relative with triple negative breast cancer - versus a different type of breast cancer - affect a person’s risk for breast cancer?

It is a clue that the cancer could be inherited, placing a relative with that gene mutation at higher risk. In the general population, there is a 5 to 10 percent chance that breast cancer is hereditary. Among women with triple negative breast cancer, the chance of hereditary breast cancer can be closer to 30 percent.