What is breast cancer?

Breast cancer begins in breast tissue. Most of the tumors that develop in breast tissue are benign. Some breast tumors are cancerous, but have not yet spread to other parts of the body. This type of breast cancer is called "in situ," and it can almost always be cured with treatment. The most serious type of breast cancer is invasive, meaning that the cancerous tumors have spread to other parts of the body.Breast cancer is the second most common cancer among women (behind skin cancer). The good news is that the rate of death from breast cancer has declined over the last few years. This is probably because more tumors have been found early, when treatment can help the most. Mammograms and breast exams (both self-exams and exams by a doctor) can help find breast cancers early.