There is no straight link between stress and breast cancer. However, long-term worry may indirectly raise the risk of breast cancer by lowering the immune system and encouraging bad habits like smoking, overeating, or drinking too much alcohol, all of which raise the risk of cancer. Long-term worry may also change hormone levels, such as by making the body make more cortisol, which may affect the growth of cancer.
Even though worry isn't thought to directly cause breast cancer, dealing with it in healthy ways, like through exercise, meditation, and social support, can improve your health and may even lower your risk of getting breast cancer. To improve your health and maybe even lower your risk of getting cancer, it's important to live a calm life and deal with stress in healthy ways. Regular tests and finding breast cancer early are still very important for lowering the risk of getting it.