Trends in chemotherapy and biologic treatment of U.S. metastatic colorectal cancer patients

Abstract

6553 Background: Several long-standing chemotherapy regimens are available to treat metastatic colorectal cancer (mCRC) including: oxaliplatin plus 5-fluorouracil (5-FU) and leucovorin (FOLFOX); and Irinotecan plus 5-FU and leucovorin (FOLFIRI). More recently, new biologic therapies were approved for use in mCRC. This cohort study examines trends in first-line chemotherapy treatments for newly diagnosed mCRC patients after the introduction of capecitabine (CAP) in 2001 and the biologic therapies in 2004. Methods: Using a large, US-based administrative medical claims database of a national commercially insured population, patients with newly diagnosed mCRC were identified from 2001 to 2005. At least 6-months of patient history prior to mCRC diagnosis were required to confirm patients were newly diagnosed. Patients were followed from initial mCRC diagnosis to death, disenrollment, or 12/31/2006. Results: Total of 3,781 newly diagnosed mCRC patients were identified between 2001–2005. On average over the 5 years, 58% of patients (with annual variation ± 4% points) received chemotherapy/biologic treatment in the year following their mCRC diagnosis; mean days to initiation of chemotherapy treatment decreased from 135 to 62 between 2001–2005. In 2001, FOLFIRI (40%), 5-FU (30%), and CAP (20%) were the most prevalent first-line treatments. In 2005, first-line treatment regimens were more diverse: FOLFOX plus bevacizumab (35%), FOLFOX alone (15%), 5-FU (15%), and CAP (15%) were the most prevalent, while 33% of patients used other treatment combinations. Among mCRC patients diagnosed in 2005, 63% were treated with at least one biologic therapy in the first year after diagnosis (57% received bevacizumab; 26% received cetuximab). Conclusions: While rates of chemotherapy use remained relatively constant between 2001–2005, patients initiated chemotherapy treatment sooner after their initial diagnosis and the standard course of therapy shifted from being FOLFIRI-based to FOLFOX-based. A rapid uptake in biologic therapies occurred. The majority of newly diagnosed mCRC patients were users of biologic therapy within one year following their introduction. [Table: see text]