BACKGROUND: 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).
METHODS: A retrospective cohort study was conducted using the Surveillance Epidemiology, and End Results (SEER)–Medicare linked database. Patients (greater than or equal to 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.
RESULTS: 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.
CONCLUSION: 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.
