Cancer in women after assisted reproductive technology.

OBJECTIVE: To evaluate the risk of cancer after assisted reproductive technology (ART) therapy.

DESIGN: Longitudinal cohort study.

SETTING: Not applicable.

PATIENT(S): New York, Texas, and Illinois residents between 2004 and 2009, treated with ART, comprising cycles of 113,226 women, including 53,859 women without prior ART treatment, who were linked to their respective state cancer registries and whose cycles were reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS).

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Diagnosis of cancer, as reported to the state cancer registry; standardized incidence ratios (SIR) and their 95% confidence intervals, comparing the observed to expected cancer cases based on age-specific cancer rates in the general population of each state.

RESULT(S): Among the cohort of women without prior ART therapy, hazard ratios (HR) and 95% confidence intervals (CI) were calculated for treatment parameters and reproductive history factors. The mean follow-up period was 4.87 years; among women without prior ART, 450 women developed 460 cancers. Women treated with ART had a statistically significantly lower risk for all cancers (for all women: SIR 0.78; CI, 0.73-0.83; women without prior ART: SIR 0.75; CI, 0.68-0.82), breast cancer, and all female genital cancers; a non-statistically-significant lower risk for endocrine and uterine cancer; and a non-statistically-significant higher risk for melanoma and ovarian cancer. Among women without prior ART, we found no statistically significant increased HR by parity, number of cycles, cumulative follicle-stimulating hormone dosage, or cycle outcome.

CONCLUSION(S): Women initiating ART treatment have no greater risk for developing cancer after nearly 5 years of follow-up compared with the general population and with other women treated with ART.