Preventing cancer by surgically removing the ovaries.
What is an oophorectomy?
In this procedure a surgeon removes both ovaries – the almond shaped organs on either side of the uterus. The ovaries produce hormones that control the reproductive cycle. Removing the ovaries reduces the amount of oestrogen and progesterone circulating in the body. This can halt, or slow down the growth of breast and ovarian cancers that need hormones to grow. Usually this procedure is combined with removing the fallopian tubes as well (salpingo-oophorectomy).
What is a prophylactic oophorectomy?
This is the same procedure mentioned above and it is an option reserved for women with a high risk of breast and ovarian cancer due to an inherited mutation in the BRCA1 or BRCA2 gene. High risk women who are 35 years or older and have completed their families are the best candidates for this type of surgery.
Prophylactic oophorectomy may also be recommended in exceptional circumstances with the presence of a strong family history of breast and ovarian cancer but where there is no genetic alteration.
Although this type of surgery is usually done to decrease ovarian cancer risk, it can also reduce the risk of breast cancer.
How much can oophorectomy reduce the risk of cancer?
In the presence of the BRCA mutation after this surgery the risk of developing an ovarian cancer would be reduced by 80 to 90 percent. It is important to note that the reduction in ovarian cancer risk is not 100 percent, as there is still a low subsequent risk of developing a type of cancer called primary peritoneal cancer. In the case of breast cancer, in premenopausal women, the expected risk reduction would be up to 50 percent.
Individual risk of breast and ovarian cancer will vary from person to person and is dependent on many factors such as family history, lifestyle choices and other strategies being used to decrease cancer risk. For some women, an oophorectomy may offer an acceptable choice. For other women, the risks of surgery and the potential side effects may not be worth the reduction in cancer risk.
What are the risks of oophorectomy?
It is a relatively safe procedure when performed by an experienced surgeon. Immediate or short-term complications include infection, intestinal obstruction and injury to other internal organs. The combined incidences of these problems are very low. More of a concern, however, would be the long term effect of losing the ovaries and the hormones that they produce. In women yet to undergo menopause, an oophorectomy results in early menopause.
The problems associated with early menopause are:
Osteoporosis: Bone thinning and increase in developing fractures.
Discomforts: These include hot flushes, sleep disturbances, concentration problems, vaginal dryness and sexual dysfunction. None of these are life-threatening, but they can significantly impact on, or reduce quality of life.
Heart disease: Cholesterol levels may go up and also the risk of heart disease.
Memory loss or dementia: Risks are higher in the absence of ovarian hormones.
Can hormone replacement therapy (HRT) be used after oophorectomy?
The use of low-dose hormone therapy after oophorectomy is highly controversial.
Propyhlactic oophorectomy significantly reduces the risk of breast and ovarian cancer, but at what cost? Studies have shown that women undergoing the procedure under the age of 45 years and who do not use HRT have a higher rate of premature death, cancer, heart disease and neurological disease. This has prompted experts in the field to recommend that, younger women who have surgically induced menopause (after an oophorectomy), consider taking low dose HRT for a short time, stopping by the age of 45 or 50. The problem that arises is that some types of HRT itself, can increase the risk of breast cancer – the very illness that was being avoided in the first place!
For this reason cancer-reducing options need to be individualised and tailor-made according to each person’s unique requirements. Always consult a doctor who specialises in this field. Factors that affect decision making would include: the type of HRT (oestrogen-only is associated with lower breast cancer risk); whether or not the uterus was removed at oophorectomy; and the length of time necessary to be on HRT.
Are there alternatives to oophorectomy for preventing ovarian cancer?
Oophorectomy will not be appropriate for every women trying to prevent breast or ovarian cancer. Other risk reducing measures include:
Increased screening: This would include ultrasound examinations of the ovaries and a blood test called CA125. This can be performed every six months. These tests are non-invasive and the idea is that if a cancer is present, it can be detected early. However, researchers have yet to demonstrate that this screening method saves lives.
Oral contraceptive pills: In the average-risk woman, taking birth control pills reduces the risk of ovarian cancer. There is also some research to suggest that the same may be true in high-risk women carrying BRCA mutations. The concern in this group of women is that oral contraceptives may increase the risk of breast cancer. However, the benefits of reducing ovarian cancer need to be measured against the risk of developing breast cancer. It is generally recommended that oral contraceptive pills be used no longer than five years.