Women who undergo IVF treatment have an increased risk of developing borderline, non-fatal ovarian tumours according to a clinical study from the Netherlands. In the research, IVF-treated women were almost twice as likely to be diagnosed with this kind of cancer in later life compared with subfertile women whose ovaries are not exposed to the stimulation required as part of the fertility treatment.
However, the researchers, as well as much of the UK national press, are keen to point out that the overall risk of getting any kind of ovarian cancer after IVF treatment remains very low, at just 0.71 percent, compared with 0.45 percent in women among the general population.
As study co-author, Professor Curt Burger said: 'The main message is that women who have had IVF shouldn't be alarmed. The incidence of ovarian cancer [in the study] was extremely low'.
The research took place over a 15-year period, and involved over 19,000 women who had undergone IVF and over 6,000 women who were subfertile but did not receive IVF treatment. At the end of the study follow-up, IVF-treated women were 1.9 times more likely to have developed borderline, non-fatal ovarian tumours compared with women in the general Dutch population.
Professor Flora van Leeuwen from the Netherlands Cancer Institute in Amsterdam, who led the study, said: 'Borderline ovarian tumours are tumours with a low malignancy potential, which means that they are not fatal, but would require extensive surgery and cause substantial morbidity'.
She added: 'If we find out that women who receive several IVF cycles or large doses of ovarian stimulating drugs are at a greater risk of ovarian cancer, then these women would need to be informed about these risks when continuing IVF treatment, and possibly advised to discontinue treatment after three to six cycles'.
Ovarian cancer is the fifth most common cancer diagnosed among women in the UK, with more than 6,500 cases per year. Around 4,500 women die of the disease each year as it is often diagnosed at a very late stage.
Dr Claire Knight, a senior health information officer at Cancer Research UK told the BBC that the relatively small number of cancer cases in the study made firm conclusions hard to reach. She emphasised that the results certainly do not show that IVF causes ovarian cancer.
'Women can reduce their risk of ovarian cancer by being a non-smoker and keeping a healthy weight, and women who have taken the Pill or been pregnant are also at lower risk', she added.