Cost-utility analysis of chemotherapy regimens in elderly patients with stage III colon cancer

Chemotherapy prolongs survival for stage III colon cancer patients but community-level evidence on the effectiveness and cost effectiveness of treatment for elderly patients is limited. Comparisons were between patients receiving no chemotherapy, 5-fluorouracil (5-FU), and FOLFOX (5-FU + oxaliplatin).

A retrospective cohort study was conducted using the Surveillance Epidemiology, and End Results (SEER)-Medicare linked database. Patients (≥65 years) with American Joint Committee on Cancer stage III colon cancer at diagnosis in 2004-2009 were identified. The 3-way propensity score matched sample included 3,534 patients. Effectiveness was measured in life-years and quality-adjusted life-years (QALYs). Medicare costs (2010 US dollars) were estimated from diagnosis until death or end of study.

FOLFOX patients experienced 6.06 median life-years and 4.73 QALYs. Patients on 5-FU had 5.75 median life-years and 4.50 median QALYs, compared to 3.42 and 2.51, respectively, for the no chemotherapy patients. Average total healthcare costs ranged from US$85,422 for no chemotherapy to US$168,628 for FOLFOX. Incremental cost-effectiveness ratios (ICER) for 5-FU versus no chemotherapy were US$17,131 per life-year gained and US$20,058 per QALY gained. ICERs for FOLFOX versus 5-FU were US$139,646 per life-year gained and US$188,218 per QALY gained. Results appear to be sensitive to age, suggesting that FOLFOX performs better for patients 65-69 and 80+ years old while 5-FU appears most effective and cost effective for the age groups 70-74 and 75-79 years.

FOLFOX appears more effective and cost effective than other strategies for colon cancer treatment of older patients. Results were sensitive to age, with ICERs exhibiting a U-shaped pattern.