Does Fertility Treatment Increase Risk of Breast Cancer?
Posted: Thursday, August 16, 2018
No increased risk of invasive breast cancer or breast cancer overall was found in more than 250,000 British women who underwent infertility treatments between 1991 and 2010, according to the results of a population-based, data linkage cohort study published in BMJ. The women also had no increased risk of corpus uteri malignancies.
However, they had a slightly increased risk of in situ breast cancer, wrote the research team led by Alastair G. Sutcliffe, MD, PhD, of the University College London, UK. The risk elevation was associated with an increasing number of treatment cycles (P = .03). The absolute excess risk was 1.7 cases per 100,000 person-years. The study focused on 255,786 women who were recorded by the Human Fertilisation and Embryology Authority as having had assisted reproduction in the UK, representing 2,257,789 person-years (mean, 8.8 years/woman) of follow-up.
“We were surprised a little by the increased risk of ductal breast cancer, although we can explain it by increased health surveillance of these intensively medicalized couples rather than a true effect,” said Dr. Sutcliffe in an interview with Reuters Health.
Possible links to other malignancies were studied as well. The women experienced a higher-than-expected incidence of ovarian cancer, both invasive and borderline. “Increased risks of ovarian tumours were limited to women with endometriosis, low parity, or both,” noted Dr. Sutcliffe and colleagues in BMJ. And although the increased ovarian cancer risk might not be due to “assisted reproduction itself…both surveillance bias and the effect of treatment are also possibilities,” the team wrote, concluding that “ongoing monitoring of this population is essential.”
