Do Fertility Treatments and Technologies Increase Ovarian Cancer Risk?

Fertility treatment, according to the results of a large multicenter study presented by Spaan and colleagues at the 35th Annual Meeting of the European Society of Human Reproduction and Embryology, is not associated with an increase in ovarian cancer risk in the long term!

The findings, presented by Mandy Spaan, a doctoral student at the Netherlands Cancer Institute, showed that women treated with assisted reproductive technology (ART) were more likely to develop cancer than women in the general population. However, their risk was no greater than that found in infertile women who had not undergone ART. What does this mean?

Note: Assisted reproductive technology is a general term for medical procedures used primarily to address infertility. It includes procedures such as in vitro fertilization (IVF). It may involve intracytoplasmic sperm injection, cryopreservation of gametes or embryos, and/or the use of fertility drugs.

Commenting on the study’s findings, Mandy Spaan said, “The increase in risk is not statistically significant and may be due to the use of assisted reproductive technology and nulliparity (never having had children)” (for example, not having children and not breastfeeding are known risk factors for breast cancer). Spaan also added that having children appeared to be a “protective factor” for women treated with ART. In other words, the main issue appears to be the risk associated with not having children rather than the risk introduced by ART.

Study Details

This Netherlands Cancer Institute study is based on data from the Dutch OMEGA cohort, which includes medical questionnaires. Researchers identified 30.625 women from 12 Dutch in vitro fertilization centers who had completed at least one assisted reproductive technology (ART) cycle between 1983 and 2001 (median age at the start of treatment = 33 years). The non-ART control group included 9.988 women who had experienced fertility problems but had not undergone ART treatment between 1980 and 2001.

The researchers also accounted for confounding factors such as endometriosis, age at the start of treatment, body mass index , and use of oral contraceptives. Follow-up continued from the women’s 20s into their 50s.

Results

• Among 30 thousand women, a total of 158 ovarian cancer cases developed: 118 in the ART group and 40 in the non-ART group.
• 100 borderline tumors were diagnosed: 83 in the ART group and 17 in the non-ART group).
• The incidence (number of new cases over a given period) in the ART group was higher than in the general population for both cancer and borderline tumors. For ovarian cancer, the standardized incidence ratio [SIR] was 1.43 in the ART group and 1.15 in the non-ART group. For borderline tumors, SIR was 2.20 in the ART group compared with 1.84 in the non-ART group.
• Cancer risk was found to be highest between 15 and 19 years after treatment.

In Conclusion, the Study suggests that giving birth may protect against ovarian cancer. In both the ART and non-ART groups, women who were nulliparous (had never given birth) had a higher ovarian cancer risk than those who had given birth. This was also true for borderline tumors.