Outcomes of Elderly Patients With Node-Positive Colon Cancer: A Multicenter Population-Based Cohort Study

In this large population-based cohort study, we examined the prognostic significance of various clinical, pathological, and contextual variables for their correlation with survival in elderly patients with stage III colon cancer.

Patients aged ≥ 70 years with stage III colon cancer, diagnosed in Saskatchewan during 2012-2018, were evaluated. A Cox proportional multivariate survival analysis was performed to determine factors correlated with overall survival (OS) and disease-free survival.

Overall, 404 eligible patients with a median age of 79 years and a male-to-female ratio of 1:1 were identified. Among them, 48% were aged ≥ 80 years, 66% had ≥ 1 major comorbid illness, 46% had high-risk disease, and 50% had a node-positive to node-harvested (NPNH) ratio of > 0.1. Forty-three percent of patients received adjuvant chemotherapy. The 5-year disease-free survival with chemotherapy was 49% versus 30% without chemotherapy (P < .001). The 5-year OS with adjuvant chemotherapy was 64% versus 49% without chemotherapy (P < .001). On multivariate analysis a past history of cancer, hazard ratio (HR) 1.47 (95% CI, 1.12-1.94); presence of an ostomy, HR 1.53 (1.16-2.03); NPNH ratio > 0.1, HR 1.51 (1.15-1.98); grade III tumor, HR 1.54 (1.16-2.04); WHO performance status > 1, HR 1.42 (1.06-1.90); no adjuvant chemotherapy, HR 1.82 (1.32-2.50); high-risk stage III disease, HR 1.60 (1.22-2.11), and baseline carcinoembryonic antigen > 5, HR 1.98 (1.50-2.61) were independently correlated with OS.

This study highlights the prognostic importance of several factors in elderly patients with stage III colon cancer, particularly the benefit of adjuvant chemotherapy on survival. Key predictors of poorer OS include a past history of cancer, presence pf an ostomy, and a higher NPNH ratio. These findings emphasize the need for personalized treatment approaches to improve outcomes in this vulnerable population.