Cancer in IVF patients treated at age 40 and older: long term follow up

Abstract Research Question: Current knowledge of cancer risk among women who had In-Vitro Fertilization (IVF) is based mainly on the study of women treated in their 30s, frequently with short follow up periods. Therefore, information about the risk of cancer among infertile menopausal women is limited. We aimed to evaluate the risk of cancer among IVF patients treated at age 40 and older and followed up for an extended period. Design: Historical cohort study of all IVF patients treated at age 40 and older at two university-affiliated IVF units in Jerusalem, Israel, from 1994-2002. Data were cross-linked with the Israel National Cancer Registry update to 2016. The Standardized Incidence Ratios (SIR) and 95% confidence intervals were computed by comparing the observed number of cancer cases to the expected cancer rate in the general Israeli population adjusted for age and year of birth. In addition, Kaplan Meier analysis was performed in order to take into account the length of follow-up period. Results: 501 patients were included in the analysis, with mean follow up of 16.7±3.7 years (range 2-22 years). Mean age at first IVF cycle was 42.3 years (±2.1). Mean number of IVF cycles was 3.2 ±2.6 (range 1-15). Thirty-six of the 501 women (7.2%) developed invasive cancer, as compared to 47.2 expected cases, for SIR=0.76 (95% CI 0.53-1.06); 22 women were diagnosed with invasive breast cancer, compared to 19.84 expected, SIR=1.11 (95% CI 0.69-1.68). Conclusions: In this study, IVF treatment in older women was not found to be significantly associated with an excess risk of cancer at long term follow up. However, further studies are needed to confirm these findings.