THURSDAY, Nov. 19, 2020 (HealthDay News) -- Fertility treatments such as in vitro fertilization don't appear to increase a woman's risk of ovarian cancer, a new study finds.
Previous studies suggested that women who used this assisted reproductive technologies (ART) such as IVF to get pregnant may be at risk for ovarian cancer and non-malignant borderline tumors, due to increased levels of sex hormones needed to stimulate egg production, as well as multiple punctures disrupting ovarian tissue.
ART involves removing eggs from a woman's ovaries surgically, fertilizing them in a lab and then placing them in the womb.
In this study, researchers analyzed data from the Netherlands to compare more than 30,600 women who received ovarian stimulation for ART between 1983 and 2001 and nearly 10,000 infertile women who didn't receive such treatment.
After a median follow-up of 24 years, the women had 158 invasive cancers and 100 borderline ovarian tumors. (Median means half were followed longer, half for less time.)
Significantly, women who had ART did not have a higher cancer risk than infertile women who did not have ART -- even after more than 20 years had passed.
Compared with women in the general population, women who used ART did have a higher ovarian cancer risk.
Researchers said this was mainly because a higher proportion of women who received ART never had children. Childlessness has been shown to be a strong risk factor for ovarian cancer, according to authors of the study published Nov. 17 in JNCI: Journal of the National Cancer Institute.
They also found that the risk of ovarian cancer decreased among women with a larger number of successful ART cycles that resulted in childbirth.
Compared with women in the general population and infertile women who didn't have ART, women who had ART had almost double the odds for borderline ovarian tumors, according to the study.
But the risk didn't rise after more treatment cycles or longer follow-up, suggesting that it might owe to underlying patient characteristics rather than ART itself, according to the researchers.
Borderline tumors are rare in the general population and generally easy to treat, they noted.
"Reassuringly, women who received ovarian stimulation for assisted reproductive technology do not have an increased risk of malignant ovarian cancer, not even in the long run," said lead author Flora van Leeuwen, an epidemiologist at the Netherlands Cancer Institute in Amsterdam.
"However, it is important to realize that even with the long follow-up in our study, the median age of the women at end of follow-up was only 56 years," she said in a journal news release.
Noting that the incidence of ovarian cancer in the population increases at older ages, van Leeuwen said it is important to follow women who have had ART even longer.
For more on ovarian cancer, see the American Cancer Society.
SOURCE: JNCI: Journal of the National Cancer Institute, news release, Nov. 17, 2020