Ovarian stimulation used in treatments against infertility does not increase the risk of cancer, according to a new study published June 30, 2014, contradicting other studies.
Stimulating the production of oocytes (eggs) is the first step before more advanced treatments, such as insemination or in vitro fertilization (IVF). It is suspected to increase the risk of ovarian cancer since 1993. However, three studies published this year had raised doubts within the scientific community.
Whittemore and colt, of the Collaborative Ovarian Cancer Croup (C.O.C.G), had thus found a 3-fold increase in the risk of invasive epithelial ovarian cancer in women who used a treatment for infertility compared to fertile women. Moreover, they were not reflected increased risk among infertile women who did not use treatment. To explain this mechanism, researchershave suggested a decrease in destructive phenomena and cyclic ovarian epithelial repair in ovulation.
Cancer and ovarian stimulation: no convincing link
No studies were truly coming confirm or refute this conclusion until today. Researchers studied more than 10,000 women who underwent ovarian stimulation between 1965 and 1988. Following them for almost thirty years, the researchers have not established a link between the stimulation and increased cancer risk. Only certain women taking Clomid (Clomiphene Citrate) for an extended period (more than 12 cycles) were exposed to a higher risk of breast cancer.
However, despite the statistical significance of this study, Humberto Scoccia, infertility specialist at the University of Illinois at Chicago acknowledged that monitoring should continue to the extent that most of the women studied are still young and that cancers can occur thereafter.
Are you at risk for Ovarian Cancer?
Ovarian cancer is ranked 7th in the most common cancers and 5th for mortality. In Canada and USA, 1 in 70 women will be affected by ovarian cancer during her lifetime (1 in 9 women for breast cancer).
Having a family history (first-degree relatives) of breast cancer or ovarian cancer is undoubtedly a risk factor to develop ovarian cancer. Other risk factors include absence or low number of pregnancies, having had a personal history of breast cancer, uterine or colon cancer, earlymenarche (the first menstrual cycle) late menopause, as well as having a known BRCA1 or BRCA2. Finally, smoking and obesity could also be factors.
- Trabert B, Lamb EJ, Scoccia B, Moghissi KS, Westhoff CL, Niwa S, Brinton LA: Ovulation-inducing drugs and ovarian cancer risk: results from an extended follow-up of a large US infertility cohort. Fertil Steril (In Press) 2013.
- Fathalla NEF. Incessant ovulation a factor in ovarian neoplasia’? Lancet. 1971: 2:163