Robert W. Rebar, MD reviewing van den Belt-Dusebout AW et al. JAMA 2016 Jul 19.

After 21 years of follow-up, ovarian stimulation for IVF did not raise subsequent risk for breast cancer.

The high levels of circulating estrogens and progesterone during ovarian stimulation for in vitro fertilization (IVF) have prompted speculation that IVF might raise risk for breast cancer. To examine this issue, investigators in the Netherlands determined the incidence of breast cancer in 19,158 women who started IVF treatment between 1983 and 1995 (IVF group) and 5950 women who started other fertility treatments between 1980 and 1995 (non-IVF group); all were followed for a median of 21 years (mean baseline age, 33).

Thirty-eight percent of women in the IVF group and 28% in the non-IVF group remained nulliparous. Among all women who received any fertility treatment, 839 cases of invasive breast cancer and 109 cases of carcinoma in situ occurred, with 64% of breast cancers being diagnosed before age 51. Breast cancer incidence in the IVF group was not significantly different from that in the general Dutch population (standardized incidence ratio [SIR], 1.01) or from that in the non-IVF group (hazard ratio, 1.01). Cumulative incidence of breast cancer at age 55 was 3.0% in the IVF group and 2.9% in the non-IVF group (P=0.85). The SIR for breast cancer did not increase with time since treatment (≥20 years) in either group.

CITATION(S):

van den Belt-Dusebout AW et al. Ovarian stimulation for in vitro fertilization and long-term risk of breast cancer. JAMA 2016 Jul 19; 316:300.

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