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Removing Ovaries Might Increase the Risk of Colon Cancer

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Removing Ovaries Might Increase the Risk of Colon Cancer

Jun 09, 2016

Many women choose to have their ovaries removed during a hysterectomy. Though removing the ovaries adds little to overall risk of the surgery, it could contribute to colon cancer or other potential health problems. In this episode, Dr. Kirtly Parker Jones discusses the risks and benefits of removing the ovaries.

Episode Transcript

Dr. Jones: If you're having a hysterectomy for problems with your uterus, should you have your ovaries removed the same time? This is Dr. Kirtly Jones from obstetrics and gynecology at the University of Utah Healthcare, and this is The Scope.

Announcer: Covering all aspects of women's health this is the seven domains of women's health with Dr. Kirtley Jones on The Scope.

Dr. Jones: A recent study from Sweden published in the British Journal of Surgery found that women who have their ovaries removed were at higher risk of colon cancer. A more careful look at the numbers found that this was a study looking back through the Swedish Patient Registry, about 200,000 women who had their ovaries removed for one reason or another compared to thousands, hundreds of thousands of women who did not. They found that removing the ovaries increased the chance of developing colon cancer in the future by 30%.

Now, Scope listeners are smart about numbers and they should be asking themselves right now 30% of what? Although 30% increase is a scary figure, the real rate of colon cancer in women who did not have their ovaries removed, was 1.3/100. And in women who had their ovaries removed it was 1.6/100 and that was a 30% increase, but it's not so scary when you look at the real numbers.

Now this was a study looking back at health histories. And maybe women who had their ovaries removed had other health risks for colon cancer, but there is another strong set of scientific evidence that estrogen protects against colon cancer. In general, women get colon cancer later in life than men. In the women's health initiative, a prospective randomized placebo controlled trial - the gold standard of medical evidence - found that taking estrogen slightly decreased the risk of colon cancer compared to women who were taking placebo, about 30%.

Finally, in a lab, adding estrogens to colon cancer cells partly inhibits their growth. There's plausible evidence in the laboratory. There's a prospective randomized trial and there's some big data that says taking out your ovaries puts you at increased risk of colon cancer. However, women don't think of colon cancer as being a woman's problem, even though about 1 in 24 women, about 4% of women will get colon cancer in their lifetime compared to 1 in 21 men. So it isn't that uncommon.

Women think about ovarian cancer as being a woman's problem. The lifetime risk of ovarian cancer is 1 in 75, significantly less common than colon cancer in women. Of course taking the ovaries out just decreases the risk of colon cancer but taking up the ovaries mostly but not completely decreases the risk of ovarian cancer. The famous Nurses Health Study followed thousands of women for many years and looked at their health outcomes if there were other conditions that are more likely in women who have their ovaries removed. Coronary heart disease is more common in women who've had their ovaries removed and osteoporosis bone thinning is more common in women who have had their ovaries removed. Lung cancer, believe it or not, is more common in women who had their ovaries removed. Breast cancer is less common, of course, in women who've had their ovaries removed.

So your surgeon is in your tummy to perform a hysterectomy because you have too much bleeding, and you're under anesthesia and you're about 50 years old. Should you have your ovaries removed? Removing the ovaries adds very little to overall risk of the surgery and your ovaries look normal.

This is a conversation you should have had with your surgeon long before you were in the operating room. What are your risks of ovarian cancer? Do you have ovarian cancer in your immediate family? Do you carry a BRCA mutation that increases your risk of breast and ovarian cancer? Did your best friend die of ovarian cancer and it's your number one fear and you can't stop thinking about it? Then the answer is probably yes. Talk to your surgeon about removing your ovaries.

However, in one study, about 98% of women who had their ovaries removed at the time of the hysterectomy were not at increased risk of ovarian cancer. In the end, weighing the risks and benefits, it's a highly personal decision. Although a Mayo Clinic paper and the Nurses Health Study that looked at all causes of death found out that women who had their ovaries removed in the past for non-cancerous reasons died just a little younger than women who didn't.

This decision is one for you to make with your doctor, but you should come to your appointment prepared. You can just google, "Should I have my ovaries removed" and there lots of choices, but I would suggest the website at the University of Wisconsin as an excellent interactive tool. Google, "Should I have my ovaries removed University of Wisconsin" and it'll get you there. But it's also on our website.

Full disclosure, I am the OB/GYN editor for Healthwise, the non-profit patient education company who created this patient decision document. Get the facts, not just the fears and make the right decision for you, and thanks for joining us on The Scope.

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