On average, women have about a 2% chance of developing ovarian cancer in their lifetime. Women with a close relative affected with ovarian cancer may have a slightly increased risk of around 4-5%.
Women who have a faulty BRCA1 the ovarian cancer risk to age 80 years is 44% and 17% for BRCA2 carriers.
The risk of developing ovarian cancer starts to increase in the late 30s for BRCA1 carriers and from 45 for BRCA2 carriers.
• What is risk reducing ovarian surgery?
• How is BSO performed?
• When should I consider risk reducing ovarian surgery?
• Should I have a hysterectomy?
What is ovarian risk reducing surgery?
A risk-reducing bilateral salpingo-oophorectomy (Bilateral [both sides], salpingo- [fallopian tube], oophor- [ovaries], ectomy [excision of]) is the surgical removal of a woman’s ovaries and fallopian tubes before an ovarian cancer has occurred.
This surgery is the most effective way of reducing the risk of developing ovarian cancer to around 5%. It is important to remove the fallopian tubes as well as the ovaries as it is now thought that “ovarian cancer” commonly starts in the fallopian tubes. Further research is required to establish whether it would be possible to reduce the risk of ovarian cancer by only removing the fallopian tubes.
If a woman with a BRCA2 alteration has a risk reducing BSO performed before they reach the menopause there may be a slight reduction in the risk of developing breast cancer before they reach 50. It is no longer suggested that removal of the ovaries has any major impact on the risk of breast cancer for women with BRCA1 mutations.
When should I consider risk reducing ovarian surgery?
Women may choose to have risk-reducing BSO once they have decided they do not wish to have any more children. They also need to consider their individual risk of ovarian cancer against the risks of the surgery and the impact of a premature menopause
The risk of ovarian cancer in women who carry a BRCA1 or BRCA2 gene fault does not begin to rise markedly until after the age of 37 for BRCA1 carriers and after 45 for BRCA2 carriers.
Once the ovaries are removed, a woman is no longer fertile and is unable to have children naturally and risk- reducing BSO is only considered once women are 100% sure they do not want to have any more children.
For women carrying the BRCA1 mutation surgery to remove the ovaries is considered after 35 years of age but for women carrying BRCA2 surgery may be delayed until women are in their early to mid 40’s.
It is not recommended to have the ovaries removed before age 35 due to the adverse effects of a very premature menopause however if a woman is considering sterilization prior to this she should discuss the option of removing the fallopian tubes completely.
While risk-reducing BSO minimises the risk of ovarian cancer it cannot reduce the risk to 0%. On very rare occasions it is not possible to remove all ovarian tissues due to scar tissue (adhesions). Another very rare situation is that women may develop ovarian cancer in the cells of the lining of the abdominal wall (peritoneum) even when they have had their ovaries removed.
Women choosing to have risk-reducing BSO before their natural menopause may experience the symptoms of a surgical menopause, which is described below. Some may have no significant symptoms at all but other women may find menopausal symptoms quite distressing.
How is risk-reducing BSO performed?
There are two main surgical ways of removing the ovaries; keyhole (laparoscopy) or open surgery (laparotomy). Both are carried out under general anaesthetic. Whichever approach is used, after the operation both ovaries and tubes will be sent to a laboratory to check if ovarian cancer is already present.
Most risk-reducing oophorectomies are done laparoscopically and a small 1cm cut (incision) will be made in the belly button (umbilicus) through which a camera will be inserted. Carbon dioxide gas is used to inflate the abdomen so that the surgeon will be able to see the pelvic organs. A further two or three small incisions will then be made in the lower abdominal wall to create space for the safe insertion of instruments with which the surgeon will remove the ovaries and tubes. Some women feel some discomfort after surgery, mainly shoulder pain or bloating related to the use of the carbon dioxide gas. As with all operations, it is normal to feel tired for a day or two after the surgery.
Keyhole surgery may be performed as a day case or may involve one overnight stay in hospital. The average return to normal activity is two to three weeks but this does between different women depending on their usual work, family and exercise commitments.
Sometimes it is not possible to performed the surgery without an open operation. Women who are more likely to need an open incision include those who are overweight, those in poor general health, who have had previous operations on their abdomen, who have had a hysterectomy, women with endometriosis or pelvic inflammatory disease.
The average hospital stay after open surgery is longer, with up to five nights before discharge. The average return to normal activity is about four to six weeks for open surgery.
Should I have a hysterectomy at the same time?
The risk of endometrial cancer (cancer of the lining of the womb) is not thought to be increased in women with BRCA1 or BRCA 2 mutations however one recent study has suggested that the small number of women with a BRCA1 mutation who developed endometrial cancer were more likely to have more aggressive tumours.
The womb is not usually removed as part of the risk-reducing BSO operation, although some women with a history of gynaecological problems may consider having a hysterectomy (removal of the womb) during the surgery.
Women who have had a hysterectomy will require oestrogen only HRT and this may be a better option for some women. For example, if a woman has decided that she is not having risk reducing breast surgery and has not had breast cancer, oestrogen only HRT is not associated with an increased risk of breast cancer.
A hysterectomy is a bigger operation, with greater risk of complications and may lengthen the hospital stay and time spent getting better.