A comparison of mortality and costs associated with FOLFOX versus FOLFIRI in stage IV colorectal cancer

Abstract

Objective:

To examine cost and mortality among stage IV colorectal cancer (CRC) patients treated with 5-fluorouracil (5FU)/leucovorin/oxaliplatin (FOLFOX) or 5FU/leucovorin/irinotecan (FOLFIRI).

Methods:

Adult CRC patients newly treated with FOLFOX or FOLFIRI were identified from a large database using medical and pharmacy claims for services delivered January 1, 2002 through December 31, 2005. Cancer stage for a subset of patients was abstracted from medical records. Outcomes were annualized costs calculated for 4 years of observation, and deaths as recorded by the National Death Index. Cost was analyzed using generalized linear modeling; mortality was modeled using Cox proportional hazards analysis.

Results:

Unadjusted annualized median and mean costs were $134,401 and $152,213, respectively, for the FOLFOX cohort (n = 41) and $103,150 and $107,994 for the FOLFIRI cohort (n = 86). Death occurred among five (12%) FOLFOX and 42 (53%) FOLFIRI patients. Adjusted analysis revealed no significant difference in cost between cohorts, even after adjusting for reduced irinotecan costs due to generic availability. Incremental costs associated with one additional life saved per year were only $1,236 higher for patients treated with FOLFOX compared with FOLFIRI. Cox analysis revealed a significant survival advantage for FOLFOX over FOLFIRI (HR = 5.2; 95% CI: 1.7–15.8).

Conclusions:

A significant survival benefit was seen for CRC patients receiving FOLFOX versus FOLFIRI; multivariate analysis revealed no significant cost differences. However, the small sample size may have resulted in lack of adequate power to detect a difference between cohorts. There may be factors influencing mortality that were not included in the multivariate modeling.

Key words::

• Colorectal neoplasms
• Chemotherapy
• Drug costs
• FOLFOX regimen
• IFL protocol
• Mortality

Transparency

Declaration of funding

Support for this study was provided by Sanofi-Aventis Pharmaceuticals.

Declaration of financial/other relationships

At the time this study was conducted, M.A.N, S.S., M.K., and C.H. were employed by i3 Innovus, and B.S. was employed by Sanofi-Aventis US. C.H. and M.K. are currently employed by Innovus. All authors were involved in the study design, analysis, and manuscript preparation.

Acknowledgments

The authors would like to acknowledge Herb Heien for his assistance with statistical analysis and Victoria Porter for her assistance with preparation of this manuscript.