Study of In Vitro Fertilization Finds No Cancer Risk
Daling says that more historical information would help to interpret the data as well. "Patients often receive fertility drugs long before they are referred for IVF and that's critical for interpreting the results. Previous pregnancies and oral contraceptive use is important as well. Of course, most women [who] develop breast, ovarian, and uterine cancers [develop it] later in life, so ongoing follow-up may yield more definitive results."
In fact, the Australians are currently planning just that. "We've made a case for following these women well into the future and there seems to be support for such a project," says Venn. Of the research conducted at the University of Washington, Venn sees little application for IVF protocols in Australia. "The reality is that women in this country don't often undergo as many cycles; three or so is the norm here and most women aren't treated with fertility drugs outside of IVF. It's also important to remember that not every cycle even requires fertility drugs; often there are frozen embryos from previous cycles held in reserve."
Venn says one finding does require further explanation. "We noted that women whose infertility was not linked to a specific cause had an increased incidence of ovarian and uterine cancer whether or not they received infertility drugs. In some of these women, infertility may actually have been a ... symptom of an underlying cancer. It's definitely an area for further study."