The Benefit and Tolerability of Adjuvant Chemotherapy in Elderly Stage III Colon Cancer Patients: A 3 Year Retrospective Audit

Objectives: The benefit of adding oxaliplatin to adjuvant fluoropyrimidine chemotherapy in patients >70 years is controversial. This retrospective audit investigated usage, benefit and tolerability of adjuvant chemotherapy for colon cancer in older adults. Materials and methods: Patients aged >60 years with stage III colon cancer referred for adjuvant chemotherapy between 2010–2012 were identified from a tertiary hospital oncology database. Data were collected on demographics, chemotherapy received, completion rates, toxicities, relapse and survival. Comparison was made between the older group (age >70 years) and the younger group (age 60-70 years). Results: 95 eligible patients were identified; 50 in the older group (median age 76), 45 in the younger group (median age 66), 56% male, 82% NZ European and 5% Maori. Older patients were less likely to receive adjuvant chemotherapy (76% and 91% in the older and younger group respectively, p=0.0017), especially oxaliplatincontaining regimens (14% and 47% of older and younger groups, respectively). Similar proportions in each group completed >80% of planned chemotherapy doses with no significant difference in early discontinuation due to toxicities. Survival was poorer in the older group (HR=2.90, 95% CI 1.40-5.47), including those who received chemotherapy (HR=3.22, 95% CI 1.42-6.88) but there was no significant difference in relapse-free survival between older and younger patients. Conclusion: Adjuvant chemotherapy was commonly offered to older adults with stage III colon cancer, although oxaliplatin was largely restricted to younger patients. While relapse-free survival was similar between age groups and chemotherapy types, older patients had poorer survival despite adjuvant chemotherapy.