If ovarian or breast cancer runs in your family, you may be at increased risk of developing one or both of these cancers yourself. Ovarian cancer is cancer that starts in a woman’s ovary. Breast cancer is cancer that starts in the breast (chest) of either a man or a woman.
In some cases, ovarian and breast cancer can be connected by a genetic mutation that is inherited by blood relatives in a family. This type of cancer is known as hereditary breast and ovarian cancer or HBOC.
BRCA1 and BRCA2 are specific genes located in human DNA. Everyone has both of these genes. When they are normal, the BRCA genes produce important proteins that keep tumors from growing, and help repair DNA that is damaged.
When the BRCA genes are damaged or mutate, the protein the helps fix DNA is not made, or does not work correctly. This means DNA that is damaged may not get repaired, and may eventually lead to cancer.
BRCA1 and BRCA2 genes can mutate or change in different ways. Researchers know that certain, specific changes in these genes cause an increased risk for women to develop breast or ovarian cancer.
Added together, BRCA genetic mutations account for between 20 and 25 percent of all hereditary breast cancers, and as much as 10 percent of all types of breast cancer, stated the National Cancer Institute.
BRCA1 and BRCA2 mutations are also known to cause about 15 percent of all cases of ovarian cancer. Breast and ovarian cancer that develops because of these mutations is likely to start at a younger age than these types of cancers that are not caused by inherited mutations.
People who have multiple cases of either breast or ovarian cancer on the same side of the family are at higher risk than if the cancer is caused by an inherited genetic mutation. Other factors that suggest a possible inherited risk for breast or ovarian cancer include:
• A woman in the family was diagnosed with cancer before age 45.
• A woman in the family was diagnosed with one of these cancers before age 50 and there are other types of cancer in the same family line.