In vitro fertilization and breast cancer: is there cause for concern
Fertility and Sterility, 06/01/2012
Stewart LM et al. – Commencing in vitro fertilization (IVF) treatment at a young age is associated with an increased rate of breast cancer.Methods
- Population–based cohort study using linked hospital and registry data.
- All women aged 20–44 years seeking hospital investigation and treatment for infertility in Western Australia during the period 1983–2002 (n = 21,025).
- There was no overall increase in the rate of breast cancer in women who had IVF (HR 1.10, 95% confidence interval [CI] 0.88–1.36), but there was an increased rate in women who commenced IVF at a young age.
- Women who commenced hospital infertility treatment at 24 years and required IVF had an unadjusted HR of breast cancer of 1.59 (95% CI 1.05–2.42) compared with women of the same age who had infertility treatment but no IVF.
- When adjusted for late age at first delivery, which is associated with an increased rate of breast cancer, and delivery of twins and higher–order multiples, which is associated with a decreased rate of breast cancer, the HR remained elevated at 1.56 (95% CI 1.01–2.40).
- Hazard ratios were not elevated in women who commenced treatment at age 40 and required IVF (adjusted HR 0.87, 95% CI 0.62–1.22).