Positron emission tomography for initial staging of esophageal cancer among medicare beneficiaries

Background: The role of positron emission tomography (PET) in the initial staging of esophageal cancer is to detect occult metastases, but its ability to do so has not been evaluated at the population-level. In 2001, Medicare approved reimbursement of PET for esophageal cancer staging. We hypothesized rapid adoption of PET after 2001 and a coincident increase in the prevalence of stage IV disease. Methods: A retrospective cohort study [1997-2009] was conducted of 12,870 Medicare beneficiaries with esophageal cancer using the Surveillance, Epidemiology, and End-Results (SEER)-Medicare database. Results: PET use increased from <3% before 2001 to 44% in 2009 (post-PET era) (P trend <0.001). Over the same period, the prevalence of stage IV disease also increased (20% in 1997 and 28% in 2009, P trend <0.001). After adjusting for changing patient characteristics over time, the rate of increase in stage IV disease in the post-PET era [relative risk (RR) = 1.06; 95% confidence interval (CI), 1.00-1.13] was no different than the rate of increase in the pre-PET era (RR = 1.02; 95% CI, 1.02-1.04). Over the entire study period, the prevalence of unrecorded stage decreased by more than half (43% to 18%, adjusted P trend <0.001) with coincident increases in stage 0-III (37% to 53%, adjusted P trend <0.001) as well as stage IV disease. Conclusions: The increasing frequency of PET use and stage IV disease over time is more likely explained by improved documentation rather than PET's ability to detect occult metastases. The absence of compelling population-level impact compliments previous studies, revealing an opportunity to increase value through selective use of PET.