Invasive Breast Cancer

Abstract

The incidence of breast cancer has been steadily increasing in the United States; 12% of American women will be diagnosed with the disease during their life. The most important risk factor for the development of breast cancer is female gender, with a female to male ratio of 100:1. Increasing age is an important risk factor in women, as well as the presence of breast cancer in a first-degree relative, early onset of menarche, nulliparity or first pregnancy after age 30, and menopause after age 55. While much as been recently made of the genetic basis for breast cancer, especially the BRCA-1 and 2 genes, it is important to remember that these genetic syndromes account for less than 10% of all breast cancers.