What is the main cause of breast cancer?

Good Question: But unfortunately there is no one good answer , 99% of breast cancers are in woman only 1% in men , first fundamental woman are exposed repeated assaults by estrogen/progesterone hormonal cycles , men are not. Beside genetic so many factors contribute to the genesis of breast , we all should hope some day we will find exact cure breast cancer , now only alternative is awareness , early detect.

It's complicated :(: The main risk factor is being a woman. 1/8 will get breast cancer during her lifetime. Smoking will increase your risk (of breast and other cancers) so please consider quitting. Not exercising, drinking alcohol, perhaps a high-fat diet also may contribute. Genetics are a factor as well. If you have many affected family members you need to discuss it with your md. Bleeding needs to be addressed.