Is There an Increased Long-Term Risk for Ovarian Cancer After Assisted Reproductive Technology?
Fertility treatment is not associated with an increased long-term risk of ovarian cancer, according to the results of a large-scale multicenter study presented by Spaan et al at the 35th Annual Meeting of the European Society of Human Reproduction and Embryology (Abstract O-183). The findings, presented by Mandy Spaan, MSc, a PhD student at the Netherlands Cancer Institute, showed that women who had been treated with assisted reproductive technology (ART) were more likely to develop invasive tumors than those in the general population, but that risk was no greater than that found in subfertile women who did not have ART.
Commenting on the findings, Ms. Spaan said, “The increase in risk is not statistically significant and is likely to be due to nulliparity, not ART.” She added that parity itself also seems to be “a protective factor” for women treated with ART in borderline cases where abnormal cells form in ovarian tissue.
Methods
This Netherlands Cancer Institute study was based on data from the Dutch OMEGA cohort, which included medical questionnaires. Researchers identified 30,625 women from 12 Dutch in vitro fertilization centers (median age = 33 years at start of treatment) with at least one ART cycle completed between 1983 and 2001. The control non-ART group (n = 9,988) had experienced fertility problems, but had not received treatment between 1980 and 2001.
The investigators adjusted for confounding factors such as endometriosis, age at start of treatment, body mass index, and contraceptive use. The follow-up began when women were in their 20s (median, non-ART = age 25; ART = age 22) and ended in their mid-50s (non-ART = age 57; ART = age 56). Causes of subfertility in both groups included unexplained, male factor, and tubal.
Findings
A total of 158 invasive ovarian cancer cases (n = 118 in the ART group; n = 40 in the non-ART group) and 100 borderline cases (n = 83 in the ART group; n = 17 in the non-ART group) were diagnosed among the women. Incidence in the ART group was marginally higher than in the non-ART group, both for invasive disease (standardized incidence ratio [SIR] = 1.43 in the ART group vs 1.15 in the non-ART group) and for borderline disease, and compared with that in the general population, with risk greatest at 15 to 19 years posttreatment. For borderline tumors, there was also a higher risk than in the general population for both ART and non-ART groups (SIR = 2.20 in the ART group vs 1.84 in the non-ART group).
The study suggests, said Dr. Spaan, that giving birth may be a protective factor against ovarian cancer. It showed that the risk of invasive ovarian cancer was greater for nulliparous women in both ART and non-ART groups than for those who had given birth. This was also the case for borderline tumors.
Disclosure: For full disclosures of the study authors, visit eshre.eu/ESHRE2019.
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