To this date, we cannot totally prevent cancer from forming; however, for certain cancers we can reduce the risk of it developing. Approximately one half of cancer cases can be prevented by modifying risk factors or by early detection of precancerous lesions. For breast and ovarian cancers, approximately 10% will develop due to hereditary predisposition. We have preventive procedures that can help to reduce the risk of hereditary cancer.
Prevention of cancer can take place in 3 different ways: primary prevention addresses the cause of the cancer, secondary prevention identifies the development of cancer before you have signs or symptoms, and tertiary prevention reduces the progression or complications of the cancer once it has already developed.
Risk reduction procedures, often called "preventive oncology" or "prophylactic surgery," are procedures aimed at removing the location where cancer is most likely to form. This is an especially important option in the case of ovarian cancer. Those with a hereditary predisposition can have up to a 40-60% lifetime risk for developing ovarian cancer. Detection of early stageovarian cancer is difficult. Unfortunately, 75% of ovarian cancers will have spread outside of the ovaries at the time of diagnosis. Current guidelines do not recommend screening for ovarian cancer for the general population, but for those with mutations in genes that increase their risk, screening -- such as tests for a blood marker (CA 125) and transvaginal ultrasound to look at the ovaries -- are available. Another option is surgery to remove the ovaries and Fallopian tubes, called bilateral salpingo-oophorectomy (BSO). This surgery provides a 90-95% risk reduction of developing ovarian cancer, as well as a 50% risk reduction of breast cancer in premenopausal women. The Fallopian tubes will be removed as well, due to an increased risk of Fallopian tube cancer in this population.
A prophylactic/preventive BSO is an option for a woman who is at a higher risk for ovarian cancer. The recommendation for women who have a BRCA1 or BRCA2 mutation is to undergo BSO between ages 35-40 years or after childbearing is complete. In this population, it is not required to remove the uterus (hysterectomy) unless a woman is having issues such as excessive bleeding, large or multiple fibroids, pain, or evidence suggestive of uterine (endometrial) cancer or an increased risk for uterine cancer. One should be advised that even after a BSO there is still a small risk for primary peritoneal (abdominal wall) cancer. This means that careful follow-up and screening is still important.
Preventive gynecologic surgery, such as removal of the ovaries, has been shown to improve overall and cancer-related survival in women with hereditary breast and ovarian cancer risks. Similarly, this risk reduction or preventive oncology has also dramatically reduced the risk of developing ovarian cancer in those who have Lynch syndrome.
If you are premenopausal before you have your surgery, you will experience early menopause following removal of the ovaries. The use of hormone replacement therapy (HRT) can be controversial. Some healthcare providers and researchers strongly believe there is an increased risk of developing breast cancer with greater than 5 years of continuous use of HRT. This would apply to those women who decided to remove their ovaries, but keep their breasts. For those women who had prophylactic double mastectomy (removal of both breasts) and prophylactic BSO, the use of HRT is believed to be relatively safe with a small risk of peritoneal cancer. Long-term follow up data is lacking, so careful counseling regarding the risks and benefits of HRT is recommended.