Can you tell me how is breast cancer hormone dependent?

Through receptors.: Breast cancer cells have receptors on the surface. You can think of these like light switches. Most breast cancers have receptors for estrogen or progesterone, the female hormones. These hormones can bind to the receptor turning it on, and telling the cancer cell to grow. Often the treatment for breast cancer involves blocking these hormone or the receptors they bind to. I hope that helps!