Gynaecologic oncologist Dr. Janice Kwon explains the tests and processes that may lead a woman to choose an oophorectomy (i.e. removal of ovaries).
Q: How strongly does my family’s history of ovarian cancer predict my own risk for the disease?
A: Family history is very important. Women who have a first-degree relative (mother or sister) with ovarian cancer, specifically a high-grade serous cancer, have at least a 10% risk of carrying a gene mutation that increases their risk of breast and ovarian cancer. If there is a family history of breast cancer at a young age (less than 45), or more than two family members with breast and/or ovarian cancer at any age, or the diagnosis of a triple negative breast cancer, this also increases the risk for a mutation.
Q: What are tumour suppressor genes BRCA1 and BRCA2?
A: We all have tumour suppressor genes BRCA1 and BRCA2. When they are functioning normally, they help to repair damage that occurs to our DNA. When a woman inherits a mutation in one of these genes, that gene doesn’t produce the protein that helps to repair DNA damage, and that can ultimately lead to breast and/or ovarian cancer.
Q: Should I be tested for both BRCA1 and BRCA2? When and how might I do that?
A: If you have a significant family history of cancer, your doctor should refer you to the BC Hereditary Cancer Program for consideration of genetic counselling and testing. If you have had a personal history of ovarian cancer, and it is a high-grade serous cancer, you are automatically eligible for BRCA1/BRCA2 testing. That diagnosis is associated with a 20% probability of a mutation in one of those two genes.
Q: What type of diagnosis or test result would suggest the need to remove my ovaries?
A: If you had genetic testing that confirmed a mutation in either BRCA1 or BRCA2 genes, you would be advised to have your ovaries and fallopian tubes removed soon after you are finished having children.
Q: What physiological changes might I experience after an oophorectomy?
A: Oophorectomy in young women will put them immediately into menopause. This is because of a deficiency in estrogen. In the absence of hormone replacement therapy, there are short-term effects, such as hot flashes, night sweats, and vaginal dryness, but there are also potential long-term effects such as an increase in coronary heart disease and osteoporosis.
Q: How reduced is my risk for ovarian cancer with an oophorectomy?
A: Oophorectomy reduces the risk of ovarian cancer by about 90%, but it is also important to recognize that it also reduces the risk of breast cancer by about 50%. The reduction in breast cancer risk is attributed to a decrease in estrogen.
Q: Does removal of my fallopian tubes reduce my risk of ovarian cancer?
A: Our knowledge about the origin of ovarian cancer has evolved over the last decade. We used to think that all ovarian cancers start in the ovaries, but we have learned that the majority of these cancers probably arise in the fallopian tubes instead, and then spread early to the adjacent ovaries.
The BC OVCARE group launched a province-wide educational campaign in 2010, encouraging women and their health care providers to consider opportunistic salpingectomy (removal of the fallopian tubes) at the time of hysterectomy for benign conditions, or instead of tubal ligation, in order to reduce ovarian cancer risk. No one has yet proven that salpingectomy will reduce ovarian cancer risk, but based on our new knowledge of this cancer, we believe that this will help to prevent a proportion of these cancers. We have demonstrated that salpingectomy is safe in the short term, and based on statistical modeling, it should be cost-effective as an ovarian cancer risk-reducing strategy.