Retrospective analysis of neoadjuvant therapy in T3 and T4 colon adenocarcinoma

Neoadjuvant chemotherapy (NAC) is increasingly being considered over standard upfront surgery followed by adjuvant chemotherapy for locally advanced colon cancer. Studies have been underpowered to look at the effect of NAC on overall survival (OS) in individual clinical T stages. A nationwide retrospective analysis using the National Cancer Database from 2010 to 2020 evaluated NAC for T3 and T4 (N0-2, M0) colon adenocarcinoma. Use of NAC increased from 1,73% in 2010 to 12.13% in 2020. In analysis combining clinical T3 and T4 patients. NAC was associated with worse OS (HR 1.16; 95% CI 1.07-1.26). The figure shows separate analysis of T3 patients (panel A) and T4 patients (panel B). There was no OS benefit for T3 patients undergoing NAC over upfront surgery (HR 1.13; 95% CI 0.99-1.28) but there was a significant OS benefit with NAC versus upfront surgery among T4 patients (0.85; 0.77-0.95). The authors conclude that this analysis highlights the importance of evaluating the survival benefit of NAC seperately for T3 and T4 colon adenocarcinoma in future studies.