NEW YORK (Reuters Health) – Postmenopausal women with ovarian cysts detected on ultrasound are not at increased risk of developing ovarian cancer or, for that matter, breast or endometrial cancer, UK researcher report in BJOG online July 15.
“A longer follow-up is required to definitively confirm these findings,” they caution.
In the introduction to their paper, Dr. Usha Menon, at the University College London EGA Institute for Women’s Health, and colleagues comment that the “time-honored” notion that ovarian cancer arises from malignant transformation of inclusion cysts of the ovary are being increasingly questioned.
Data for the current study come from the UK Collaborative Trial of Ovarian Cancer Screening in which over 200,000 postmenopausal women are being followed and about half of whom have periodic ultrasound screening. This identified 1234 women in the first year with inclusion cysts and 22,914 with normal ovaries, according to the report.
After a median follow-up of 6.13 years, four women with cysts and 32 with normal ovaries had developed ovarian cancer. This yielded a relative risk for ovarian cancer of 2.32 for women with cysts, but this was not statistically significant, the investigators found.
Similarly, the relative risks for invasive epithelial ovarian cancer, endometrial cancer and breast cancer were 1.92, 1.44, and 1.12, which again were not significant.
Furthermore, when compared to the UK age-adjusted expected rates of these cancers, the observed incidence was no different for women with inclusion cysts, Dr. Menon and colleagues report.
“Our data,” they conclude, “show that ultrasound-detected inclusion cysts in postmenopausal women do not seem to be associated with an increased incidence of primary invasive ovarian or hormone-dependent cancers, such as breast and endometrium.”
Assessing the malignant potential of ovarian inclusion cysts in postmenopausal women within the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a prospective cohort study