A recent article in the journal Human Reproduction has attracted a fair bit of attention because it suggests a possible link between in vitro fertilization (IVF) and later increased risk of ovarian cancer.
Certain factors increase a woman’s risk of getting ovarian cancer, including a family history of reproductive cancers, personal history of cancer, certain gene mutations, increasing age, hormone replacement therapy, and infertility itself. Right now, it’s still very hard to determine how much fertility treatments – such as the ovarian stimulation used in IVF – may contribute to increased risk.
For the current study, researchers in the Netherlands identified about nineteen thousand women with fertility problems who received in vitro fertilization, and about six thousand women who had fertility problems before IVF was in common use and so did not receive it. The researchers used questionnaires and medical and cancer records to follow the women for fourteen to sixteen years, from the time of their first IVF treatment or first infertility diagnosis.
The authors found a two-fold risk of ovarian cancer in women who had IVF. Most of this increased risk, however, was for “borderline ovarian tumors,” a noninvasive type that may require surgery but typically has a good prognosis. There was no significant difference in rates of invasive ovarian cancer between the two groups. The authors also note that even larger studies are needed to confirm or refute their findings and to examine any possible relationship between the dose of ovarian stimulation treatments and increased ovarian cancer risk.
They also make this important point:
Knowledge about the magnitude of the risks associated with ovarian stimulation is important for women considering starting or continuing IVF treatment, as well as their treating physicians.
A 2006 review of existing literature on the topic also observed “a stronger association…between fertility drug use and borderline tumors of the ovary,” but called the finding “not consistent among the available studies to date.”