In Vitro Fertilization and Breast Cancer Incidence
Because many of the risk factors for breast cancer are hormone related, some people have been concerned that in vitro fertilization (IVF) might increase breast cancer risk. However, a long-term study published in July 2016 found that women who had IVF did not have a higher incidence of breast cancer compared to women who had other fertility treatments or to women in the general population.
The study, conducted in the Netherlands, looked at almost 20,000 women who had IVF and almost 6,000 who had other types of fertility treatments, following them for more than 20 years. They found a breast cancer rate per 100,000 women of 163.5 for IVF, 167.2 for non-IVF fertility treatments, and 163.3 among women with no fertility treatments, which is not a significant difference. The median age was 53.8 for the IVF group and 55.3 for the non-IVF group at the end of the study.
One earlier study found an increased risk of breast cancer among women over 40 who had more than four IVF treatments. Other studies have not found an association between IVF and breast cancer.
Issues to think about
If you are considering IVF treatments, what do these studies mean to you? The size and length of the Netherlands study makes it credible. However, the studies’ authors point out that the participants were treated before 1995. Since then IVF procedures have changed, so the results might be different for patients treated today.
One issue I would be concerned about is that the median age at the conclusion of the study was younger than the median age for breast cancer in the United States. A study that went longer might have drawn different conclusions.
Because breast cancer is a slow-growing disease that can takes years to develop, and because IVF procedures are constantly evolving, it would be nearly impossible to design a study that could promise women that IVF poses zero risk. Nevertheless, this study, combined with earlier ones, should reassure people that IVF probably would not be a significant breast cancer risk. Women who have other risk factors for breast cancer should discuss the issue frankly with their doctors to determine the pros and cons of IVF for them personally.
For most couples longing for a baby, the slight possibility of an increased chance of breast cancer more than 20 years later probably seems like a risk to take. Competent fertility doctors will be able to help couples understand how these studies might apply to them and help them decide the best course of action.
See More Helpful Articles:
Phyllis Johnson is an inflammatory breast cancer survivor who serves on the Board of Directors for the Inflammatory Breast Cancer Research Foundation, the oldest 501(3)(c) organization focused on research for IBC. She is a list monitor for an online support group at www.ibcsupport.org. She stays current on cancer information through attendance at conferences such as the National Breast Cancer Coalition’s Project LEAD® Institute. A retired teacher, she has been writing about cancer issues at HealthCentral since 2007.