Association of enrollment in Medicare Advantage plans versus fee-for-service in patients with a late-stage diagnosis of gynecologic cancer.

Abstract

11140 Background: In the United States, uterine cancer is the most common gynecologic (GYN) cancer; and ovarian cancer causes more deaths each year than any other GYN cancer. There are currently no recommended population-wide screening tests for ovarian or uterine cancer, which are heavily concentrated in older women. Medicare is the primary health insurer for 97% of Americans aged 65 years and older. This study is the first to examine the association between Medicare enrollment plan – Medicare Advantage (MA) versus fee-for-service (FFS) – and stage at diagnosis among older women newly diagnosed with ovarian or uterine cancer. Methods: Using the linked Surveillance, Epidemiology, and End Results (SEER) registries and Medicare enrollment data, we identified 101,193 women aged 65 years and older with newly diagnosed ovarian or uterine cancer between 2007-2019. We categorized patients into two groups: 1) those continuously enrolled in Medicare MA for six months prior to their diagnosis, through the diagnosis month, and the month following diagnosis; 2) those continuously enrolled in Medicare FFS within the same eight-month window. Late-stage was defined as “Distant” stage (with “Local” and “Regional” stages representing an earlier-stage diagnosis) using the SEER Summary Stage variable. The association between Medicare enrollment plan and stage was examined through multivariable logistic regression modeling that adjusted for sociodemographic characteristics. The influence of each predictor on the difference in the probability of late stage was summarized as an adjusted marginal effect (ME). Results: Among uterine cancer patients, 37% had MA insurance. Compared with Medicare FFS enrollees, the adjusted percentage of late-stage diagnosis was 0.6 percentage points (ppt) lower for MA enrollees (95% CI = -1.1-(-0.1); P<0.05). Notably, patients were more likely to have a late-stage uterine diagnosis if they were: non-Hispanic Black or Hispanic (vs. non-Hispanic White); age 75 and older (vs. between 65 -74); and residing in a lower SES neighborhood. Among ovarian cancer patients, 34% had MA insurance. We found no significant difference between Medicare MA and FFS enrollees in ovarian cancer stage at diagnosis. Of note, Non-Hispanic Black patients were significantly more likely to be diagnosed with late-stage disease compared to Non-Hispanic White, and likewise for patients aged 75 and older (vs. between 65-74). Conclusions: Among Medicare beneficiaries (age 65+) diagnosed with uterine cancer, those enrolled in an MA plan were significantly less likely to be diagnosed at a later stage. In similar analyses for ovarian cancer, there was no such MA - FFS difference in the probability of late-stage. As enrollment in Medicare Advantage plans continues to grow, it becomes increasingly important to identify whether there are significant outcome differences between MA and FFS plans.