Inherited Breast and Ovarian Cancer

There is no doubt that susceptibility to breast and ovarian cancer is inherited in some families, but most cancer is genetic only at the level of the transformed cell, not in the germline cells of patients.

Abstract

IT IS now clear that susceptibility to breast and ovarian cancer is inherited in some families. Between 5% and 10% of breast cancer1,2and ovarian cancer3can be attributed to inheritance of a gene conferring high risk, followed by genetic changes specific to the target epithelial cells of the breast or ovary. For decades, there has been no doubt that cancer is genetic, in the sense that transformation of a normal cell to invasive and malignant growth is due to changes in the DNA. But most cancer is genetic only at the level of the transformed cell, not in the germline cells of patients. Consequently, most cancer is not inherited in families. Not all that is genetic is inherited. Meanwhile, it has been observed for centuries that breast cancer clusters in families.4Of course, given the very high incidence of breast cancer in our times, there are