How common is hereditary breast and ovarian cancer?
A. In 1999, more than 180,000 women will be diagnosed with breast cancer and about 27,000 women will be diagnosed with ovarian cancer in the US. Approximately 44,000 women will die due to breast cancer, while 13,500 will die due to ovarian cancer. An estimated five to ten percent of these breast and ovarian cancers are thought to be hereditary or due to an inherited predisposition. A woman with an inherited predisposition has an increased risk to develop both diseases. It is important to remember that most breast and ovarian cancers are not hereditary. Q. How is a predisposition to develop breast and ovarian cancer inherited? A. Each cell in our body has twenty-three pairs of chromosomes, for a total of forty-six. One chromosome from each pair comes from our mother and the other comes from our father. Each chromosome is composed of thousands of genes. Our genes carry the instructions for our growth and development and can determine such physical traits as hair, eye, and skin color. The
