Endometriosis Increases Ovarian Cancer Risk, Study Reveals

A study shows women with endometriosis are at a higher risk of having recurrent reproductive system surgeries and developing ovarian cancer than women without the disease.

Endometriosis is a fairly common disease among women, affecting about one in ten. It causes severe pain when the tissue that lines the uterus, the endometrium, grows outside a woman's uterus. Endometriosis most commonly involves the ovaries, fallopian tubes and the tissue lining the pelvis.

When endometriosis affects the ovaries, cysts may form called endometriomas. The surrounding tissue becomes irritated and develops scar tissue and adhesions, fibrous tissue causing organs and pelvic tissues to stick to each other. Symptoms of endometriosis can include: painful periods, pain with intercourse, pain with bowel movements or urination, excessive bleeding, infertility, fatigue and bloating.

Studies have shown that ovarian cancer occurs at higher than expected rates in women with endometriosis. A rare form of cancer, called endometriosis-associated adenocarcinoma, has been linked to the disease.

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The new study, Impact of endometriosis on risk of further gynecological surgery and cancer: A national cohort study, was published in September 2017 in BJOG: An International Journal of Public Health.

No researchers have conducted long-term studies with large groups to evaluate the risk of endometriosis patients having additional surgeries. This study out of Scotland followed almost 300,000 women from 1981 to 2010. They also found that women with endometriosis are at a higher risk of increased surgeries and developing ovarian cancer than women who have had laparoscopic sterilization.

Up to 50% of women with endometriosis complain of pain five years after having surgery or other treatments for their condition. And because surgery is the main treatment for endometriosis, women often have more than one to help alleviate their pain. A hysterectomy is the most common surgical option when other treatments fail and fertility is not a concern of the patient.

Ovarian cancer is another concern for patients with endometriosis. Limited research was done in the past; studies that assessed the link between the two have relied on self-reported diagnosis of endometriosis.

Because of this past limited research, the University of Aberdeen and Edinburgh set out to see if endometriosis could affect the risk of reproductive system surgeries and the development of ovarian cancer.

Researchers looked at 17,834 newly diagnosed women with endometriosis, 83,303 with no evidence of endometriosis, 162,996 women who went through laparoscopic sterilization, and 17,834 age-matched controls.

They looked at the risk of further gynecologic surgery, the number and types of surgery, the length of time between surgeries and the woman’s risk of cancer. Researchers discovered women with endometriosis were at a 69% higher risk of additional surgery than those without endometriosis.

Also, the women with endometriosis who did not have laparoscopic sterilization performed had triple the risk of additional surgeries. And five and a half times the risk of the controls. The research also showed that women with endometriosis had a 77% higher risk of developing ovarian cancer than aged-matched controls and a 75% higher risk that women who had laparoscopic sterilization.

Read on to learn more about these discoveries.