Treatment Patterns, Costs, and Survival among Medicare-Enrolled Elderly Patients Diagnosed with Advanced Stage Gastric Cancer: Analysis of a Linked Population-Based Cancer Registry and Administrative Claims Database

PURPOSE: To assess real-world treatment patterns, health care utilization, costs, and survival among Medicare enrollees with locally advanced/unresectable or metastatic gastric cancer receiving standard first-line chemotherapy. MATERIALS AND METHODS: This was a retrospective analysis of the Surveillance, Epidemiology, and End Results-Medicare linked database (2000~2009). The inclusion criteria were as follows: (1) first diagnosed with locally advanced/unresectable or metastatic gastric cancer between July 1, 2000 and December 31, 2007 (first diagnosis defined the index date); (2) ≥65 years of age at index; (3) continuously enrolled in Medicare Part A and B from 6 months before index through the end of follow-up, defined by death or the database end date (December 31, 2009), whichever occurred first; and (4) received first-line treatment with fluoropyrimidine and/or a platinum chemo-therapy agent. RESULTS: In total, 2,583 patients met the inclusion criteria. The mean age at index was 74.8±6.0 years. Over 90% of patients died during follow-up, with a median survival of 361 days for the overall post-index period and 167 days for the period after the completion of first-line chemotherapy. The mean total gastric cancer-related cost per patient over the entire post-index follow-up period was United States dollar (USD) 70,808±56,620. Following the completion of first-line chemotherapy, patients receiving further cancer-directed treatment had USD 25,216 additional disease-related costs versus patients receiving supportive care only (P<0.001). CONCLUSIONS: The economic burden of advanced gastric cancer is substantial. Extrapolating based on published incidence estimates and staging distributions, the estimated total disease-related lifetime cost to Medicare for the roughly 22,200 patients expected to be diagnosed with this disease in 2014 approaches USD 300 millions.