Endometrioma tied to ovarian cancer risk

Women with ovarian endometriomas and/or deep infiltrating endometriosis are at increased risk of ovarian cancer, as shown in a study.

For the study, researchers used data from the Utah Population database and identified 78,893 women with endometriosis (mean age at first diagnosis 36 years), which was classified as superficial endometriosis, ovarian endometriomas, deep infiltrating endometriosis, or ‘other’. These women were matched in a 1:5 ratio to women without endometriosis.

Women with vs without endometriosis tended to be nulliparous (31 percent vs 24 percent) and to have undergone a hysterectomy (39 percent vs 6 percent). The mean follow-up time was 12 years.

Ovarian cancer was diagnosed in 597 women. Women with vs without endometriosis had a more than fourfold higher risk of ovarian cancer (adjusted hazard ratio [aHR], 4.20, 95 percent confidence interval [CI], 3.59-4.91; adjusted risk difference [aRD], 9.90, 95 percent CI, 7.22–12.57), particularly type I ovarian cancer (aHR, 7.48, 95 percent CI, 5.80–9.65; aRD, 7.53, 95 percent CI, 5.46–9.61).

The highest risk increase was observed among women with deep infiltrating endometriosis and/or ovarian endometriomas. This was true for all ovarian cancers (aHR, 9.66, 95 percent CI, 7.77–12.00; aRD, 26.71, 95 percent CI, 20.01–33.41), type I ovarian cancer (aHR, 18.96, 95 percent CI, 13.78–26.08; aRD, 19.57, 95 percent CI, 13.80–25.35), and type II ovarian cancer (aHR, 3.72, 95 percent CI, 2.31–5.98; aRD, 2.42, 95 percent CI, −0.01 to 4.85).

The findings pinpoint a population that may benefit from counselling regarding ovarian cancer risk and prevention, as well as targeted screening and prevention studies, the researchers said.