Researchers have found no association between IVF treatment and increased risk of breast cancer in a study that was deemed highly important because of the implications it could have on the future of the treatment.
Researchers in the Netherlands have shown in their paper findings of a study between 1980 and 1995 and 25 years of follow-up that the treatment doesn’t increase the risk of breast cancer. The study involved 19,158 women who started IVF treatment between 1983 and 1995 and 5,950 women starting other fertility treatments between 1980 and 1995. As per the information provided by researchers, the median age of study participants was 54 years for the IVF group and 55 years for the non-IVF group.
To find out the incidences of invasive and in situ breast cancers in women who underwent IVF treatments researchers resorted to data available from the Netherlands Cancer Registry from 1989 to 2013. Among 25,108 women, 839 cases of invasive breast cancer and 109 cases of in situ breast cancer occurred after a median follow-up of 21 years.
Researchers found that breast cancer risk in women who underwent IVF treatment was not significantly different from that in the general population and from the risk in the non-IVF group. The cumulative incidences of breast cancer at age 55 were 3 percent for the IVF group and 2.9 percent for the non-IVF group.
The risk did not differ by type of fertility drugs or subfertility diagnosis and was not increased at 20 or more years after IVF treatment. Women with 7 or more IVF cycles had a significantly decreased risk compared with women treated with 1 to 2 IVF cycles. Poor response to the first IVF cycle was also associated with decreased breast cancer risk.
“These findings are consistent with the absence of a significant increase in the long-term risk of breast cancer among women treated with these IVF regimens,” the authors write in their study.