A study on Israeli women receiving fertility treatments found that IVF (in vitro fertilization) does not appear to raise the risk of breast and other female cancers, says a new report published in Fertility & Sterility.
Lead author Louise Brinton, from the National Cancer Institute, Rockville, Maryland, and team wrote that none of the gynecological cancers were significantly elevated after IVF treatment.
Doctors and scientists have wondered whether some procedures used in IVF treatments might increase a woman’s risk of developing cancers, such as the administration of ovulation-stimulating medications or puncturing of the ovaries to retrieve eggs.
In fact, some earlier studies had pointed towards a higher risk of breast cancer and borderline ovarian tumors among women who underwent IVF early in life. A 2011 Dutch study suggested that stimulating the ovaries to produce eggs for IVF may raise the risk of developing ovarian tumors, some of which could eventually become cancerous.
However, other studies had found very little evidence of such a link.
Experts say it has been hard to determine whether IVF raises cancer risk in females because there may be other factors in women who have difficulties conceiving.
Brinton and team gathered and examined data from the medical records of 67,608 female patients who had undergone IVF treatments between 1994 and 2011, as well as 19,795 patients who wanted but never received IVF treatment.
They compared those data with a national cancer registry. By the June 22nd, 2011, the following cancer diagnoses had been made (from both groups of women):
- Breast cancer – 522
- Endometrial cancer – 41
- Ovarian cancer – 45
- In-situ cervical cancer – 311
- Invasive cervical cancer – 32
The researchers found that:
- IVF made no difference to a woman’s breast cancer risk
- IVF treatment made no significant difference to women’s gynecological cancers
- Ovarian cancer risk rose very slightly among those with more rounds of IVF treatment. However, the authors said that this slight increase in risk might have been due purely to chance.
With only 45 ovarian cancer cases in the entire study, the authors said it was not possible to compellingly link IVF to ovarian cancer risk.
In an abstract in the same journal, the authors concluded:
“Our results regarding long-term effects were largely reassuring, but women receiving IVF should continue to be monitored given that the procedures involve potent ovulation stimulators and repeated ovarian punctures.”