Abstract
PURPOSE: To assess how first course of treatment affects cancer-specific survival in women diagnosed with endometrial cancer younger than 50 years old. METHODS: Public-use data from the Surveillance, Epidemiology, and End Results program were used. The study included 82,721 women diagnosed with primary, invasive endometrial cancer between 2000 and 2011. We assessed type of treatment using Cox's proportional hazards models to determine survival disparity by age and stage. RESULTS: Cancer-specific survival significantly improved for those aged ≥50 years with late stage, but did not improve for those <50. First course of treatment significantly affected cancer-specific survival for endometrial cancer patients. Regardless of age, survival was greatly improved for late-stage patients who received a combination of surgery and radiation [hazard ratio (HR) 0.62 [95 % confidence interval (CI) 0.47-0.78] and 0.64 (95 % CI 0.59-0.68)] compared to those who received total hysterectomy with removal of ovaries and tubes. However, the proportion of patients who received combination therapy decreased over time. The magnitude of decrease was larger in patients <50 than in those aged ≥50. Overall, about 24-57 % of the difference in cancer-specific survival over time in patients aged <50 was explained by their initial treatment. CONCLUSIONS: Improvement in cancer-specific survival was only seen in older women with late-stage diagnosis. Despite improvements in diagnoses and treatments, the difference in age-specific survival indicates that more should be done to understand why these rates are not improving for those younger than 50 years old.