I was recently asked to comment on a study that sought to address the risk of ovarian cancer in women who undergo in vitro fertilization (IVF). I thought the request came at a very interesting time, seeing as I had just been asked to comment on fertility preservation in newly diagnosed breast cancer patients.
In a population-based study by a team in the Netherlands, led by Prof. van Leeuwen, the risk of ovarian malignancies (both borderline tumors and invasive cancers) was calculated for women who underwent IVF and was compared to women with infertility but who did not undergo IVF and to a population based sample of “normal” women.
The major finding was that with a median follow-up of nearly 15 years, the use of IVF was associated with a significantly increased risk of ovarian malignancies. However, a closer look of the data showed the following as well: (1) the risk was associated with an increased incidence of borderline cancers (nearly two-fold higher compared to women without a history of infertility) but not of invasive ovarian cancer; (2) the risk did not increase with the number of IVF cycles performed; and (3) nulliparity carried a HIGHER risk of borderline malignancies (almost 3-fold) but women who had children did not face this statistically increased risk (the risk was 7.35 with a 95% confidence interval between 0.75 and 10.85).
Interpretation of these statistics when considered together is difficult. One would assume that if IVF carried a risk of malignancy that the more frequent the number of IVF cycles performed, the higher the risk would be, but this was not the case. In addition, the finding that nulliparity was tied to risk but having children was not makes me suspect other causes are at play here; perhaps the etiology of infertility was the more biologically important reason that was underlying risk? The authors were not able to determine this even in their large study.
However much these statistics say, though, it is also important to pay attention to the number of cases seen. In that 15-year period, the incidence of ovarian malignancies was less than 1% in both women with a history of infertility, whether they underwent IVF (0.5%) or did not (0.2%).
So, what is the take home message? Life is not without its risks. Undergoing IVF does not guarantee parenthood, but even in light of this data, the risk appears minimal, and the benefits (and challenges) of parenthood I propose far outweigh them.