Endometrial cancer after endometrial ablation vs medical management of abnormal uterine bleeding.

STUDY OBJECTIVE: To investigate whether endometrial ablation is associated with increased risk or delayed diagnosis of endometrial cancer compared with medical management of abnormal uterine bleeding. DESIGN: Multi-centered retrospective cohort study (Canadian Task Force classification II-2). SETTING: The study was performed using data from The Health Improvement Network, a representative population-based cohort of patients in 495 outpatient general practitioner practices in the United Kingdom. PATIENTS: Women aged >25 years with abnormal uterine bleeding diagnosed between June 1994 and September 2010. INTERVENTIONS: Endometrial ablation, medical management, or both. MEASUREMENTS AND MAIN RESULTS: A total of 234 721 women met study inclusion and exclusion criteria, 4776 of whom underwent endometrial ablation and the remaining 229 945 received medical management. Cox models compared endometrial cancer rates between ablation and medical management groups using hazard ratios. To investigate a possible diagnostic delay, the median time from bleeding diagnosis to endometrial cancer diagnosis in women in whom endometrial cancer developed was compared using the Mann-Whitney U test. All statistical tests were 2-tailed, with α = .05. During a median observation period of 4.07 years (interquartile range [IQR], 1.88-7.17), endometrial cancer developed in 3 women in the ablation group and 601 women in the medical management group (ablation hazard ratio, 0.45; 95% confidence interval, 0.15-1.40; p = .17). Median time to diagnosis was 237 in the ablation group, and 299 days in the medical management group (ablation IQR, 155-1350; medical management IQR, 144-1133.5; p = .99). Adjusted and sensitivity analyses did not change the results. CONCLUSIONS: No difference was observed in endometrial cancer rates, and there was no delay in diagnosis when comparing endometrial ablation vs medical management. Further studies are needed to investigate the effect of previous ablation exposure on histology or cancer stage at manifestation of endometrial cancer.