Removal of the breasts and ovaries offers the best hope for women who have a high-risk cancer gene, according to a new report published in the journal Lancet.
Offering advice to women who have a fault in BRCA1 has been difficult because there was no clear evidence on the effectiveness of preventive surgery.
The new report, by a team of researchers from Cancer Research UK, brings together results from a series of international studies and shows that current cancer prevention techniques, such as screening or drug treatments, do not offer the same chance of survival as surgery for this group of women.
Lead researcher, Dr. Paul Harkin of Queen's University Belfast says: "Surgery to remove a woman's breasts and ovaries may seem like a drastic step, but we have to remember that the women involved in these studies are at a very high risk of breast and ovarian cancer.
"However, it's important to emphasize that the choice lies with the women themselves. Some women decide to undergo surgery because it gives them peace of mind, others prefer to watch and wait. Either way it can be a traumatic experience and it's vital that women receive the best possible counseling to help them make their choices."
For women with a faulty BRCA1 who opt for a program of screening, the lifetime risk of breast cancer is as high as 85 percent for. The new report reveals that the removal of both breasts reduces the risk by at least 90 percent.
The risk of dying from the disease is between 10 and 20 per cent over 20 years for women with a faulty gene on a screening program.
Surgery to remove both ovaries is thought to reduce the risk of ovarian cancer 24-fold and can also reduce the risk of breast cancer by half.
One study showed that women who had surgery to remove both breasts and ovaries gained an estimated 12 extra years of life compared to screening alone.
Lead author Dr. Richard Kennedy, also from Queens, says: "One reason for the failure of screening in this group of women is that tumors are often fast growing and can develop between screening appointments. And for this reason experts have feared that cancer patients who have a fault in BRCA1 would fare worse than other patients.
"Encouragingly, this report shows that women who have breast cancer and a fault in BRCA1 are just as likely to survive the disease as other patients, and some of the research shows that ovarian cancer patients with a faulty BRCA1 are more likely to survive than other ovarian cancer patients."
The researchers believe that between one in 500 and one in 1,000 women worldwide carry a faulty BRCA1 gene, but it is more common in some populations, for example Jewish women of Eastern European origin. Whilst a screening method to test for the gene is available, the researchers estimate that it fails to pick up 30 to 40 per cent of BRCA1 mutations.
The report also addresses the emotional and sexual issues of opting for preventive surgery but results were mixed. Some studies have shown that surgery can lead to depression and have an impact on sexuality while others show no adverse effects on either.
SOURCES:
The Lancet, September 28, 2002
Cancer Research UK (http://www.cancerresearchuk.org)