IVF treatment is not associated with an increase in breast, cervical or endometrial cancer, according to analysis of thousands of patient medical records. Ovarian cancer risk was also examined but too few people with ovarian cancer were included in the study for a conclusive result to be shown.
Scientists at the National Cancer Institute in Maryland, USA, analysed the medical records of over 67,000 Israeli women who had IVF procedures between 1994 and 2011. They compared these with the records of nearly 20,000 women who had not undergone IVF treatments, looking specifically at occurrences of the four types of cancer.
IVF patients did not have increased rates of breast, cervical or endometrial cancer. A very small, non-significant trend of increasing risk of ovarian cancer was seen with increasing numbers of IVF treatment cycles. Ovarian cancer remained rare in all patient groups studied, with only 45 cases arising in all the women in the study.
Speaking to Reuters, Dr Bengt Källén, director of the Tornblad Institute at Lund University, Sweden, who was not involved in the study, was among commentators observing that even if an association between IVF and ovarian cancer was established, correlation did not mean causation.
'Infertile women have a primary problem with their ovaries and IVF has nothing to do with it', Dr Källén said. 'It's a rather difficult thing to disentangle if there is an effect from the hormones or from the IVF procedure'.
'What is surprising all of us who are working in this area is how almost every study gets a different answer', Dr Louise Brinton, who led the study, told Reuters. She described her own study's results as 'fairly reassuring' and recommended that monitoring of IVF patients should continue.
The study was published in the journal Fertility and Sterility.