National Landscape of Neoadjuvant Therapy in Potentially Resectable Colon Cancer

Surgery followed by pathology-guided adjuvant therapy is standard treatment for colon cancer. Data from the FOxTROT clinical trial showed potential benefit of a 6-wk neoadjuvant chemotherapy (NACT) in T3/T4 patients. The present study evaluated real-world outcomes of neoadjuvant therapy in a national cohort of patients with resectable colon cancer.

169,120 patients with clinical stage I, II, or III colon cancer from the National Cancer Database registry were included. Patients were categorized as having received neoadjuvant therapy followed by surgery (NACT), surgery then adjuvant chemotherapy (AC), or surgery alone. Factors associated with treatment sequencing and outcomes were assessed.

Of identified patients, 1.4% received NACT including 0.5% of stage I, 1.8% of stage II, and 3.0% of stage III. For stage I, 5-y overall survival (OS) was 74.7% after AC, 62.2% after NACT, and 76.4% after SA. For stage II, 5-y OS was 73.2% after AC, 66.8% after NACT, and 64.3% after SA. For stage III, 5-y OS was 67.3% after AC, 67.7% after NACT, and 42.4% after SA. Cox proportional-hazards model suggested NACT had worse outcomes versus AC in clinical stages I (hazard ratio [HR] = 1.59, 95% confidence interval [CI] 1.39-1.85, P < 0.01) and II (HR = 1.37, 95% CI 1.23-1.52, P < 0.01). In stage III, there was no difference in OS between NACT and AC (HR = 1.1, 95% CI 0.99-1.22, P = 0.05).

In a real-world national cohort of patients with resectable colon cancer, NACT had no OS benefit over AC. Future studies should examine which subset of patients might benefit from neoadjuvant approaches.