IVF (in-vitro fertilization) treatments increase the risk of having ovarian tumors, a new 15-year study published in the journal Human Reproduction says.
Ovarian cancer rates were twice as high among women given fertility drugs to produce eggs, BBC News reports. Many of the tumors the women developed, however, were borderline ovarian tumors.
Borderline ovarian tumors are not fatal and may never become malignant, but they typically require surgery, CBS News reports.
Lead researcher Flora van Leeuwen of the Netherlands Cancer Institute in Amsterdam said the findings were significant because the study was the first to include a comparison group of sub-fertile women not undergoing IVF. That is important because having difficulty conceiving or never having been pregnant are in themselves known risk factors for ovarian tumors.
The study followed more than 25,000 women attending IVF clinics in the Netherlands in the 1980s and 1990s, BBC News reports. Sixty-one women in the IVF group of 19,000 developed ovarian tumors, 31 of which were considered borderline ovarian cancer and 30 of which were invasive cancer, CBS News reports.
"Although this study shows that ovarian stimulation may increase the risk of much less aggressive borderline ovarian tumors, it underlines the fact that ovarian stimulation for IVF is not a major risk factor for invasive ovarian cancer,” Prof. Hani Gabra, of the Ovarian Cancer Action Research Centre at Imperial College London, told BBC News.
"The main message is that women who have had IVF shouldn't be alarmed,” study co-author Professor Curt Burger, told BBC News. "The incidence of ovarian cancer was extremely low."