Narrative review of neoadjuvant therapy in patients with locally advanced colon cancer

Abstract

Colorectal cancer is a leading cause of cancer-related morbidity and mortality worldwide, with more than 1.9 million new cases reported in 2020, and is associated with major survival challenges, particularly in patients with locally advanced colon cancer (LACC). LACC often involves T4 invasion or extensive nodal involvement and requires a multidisciplinary approach for management. Radical surgery followed by adjuvant chemotherapy remains the primary treatment strategy for LACC. However, achieving complete tumor resection (R0) is challenging because locally advanced colon tumors typically infiltrate adjacent organs or nodes. Advancements in LACC treatment have involved neoadjuvant chemotherapy (NACT), neoadjuvant chemoradiotherapy (NACRT), and neoadjuvant immunotherapy (NAIT). Studies such as FOxTROT and PRODIGE 22 have demonstrated that NACT, particularly with FOLFOX or CAPOX, can lead to major tumor downstaging, improved survival rates, and increased R0 resection rates. Predictive biomarkers, such as mismatch repair (MMR) status and T stage, are crucial in identifying candidates who may benefit from NACT. NACRT has demonstrated promise in enhancing tumor regression, particularly in patients with rectal cancer, underscoring its potential for use with LACC. NAIT, particularly for deficient MMR tumors, has emerged as a novel approach, with studies such as NICHE-2 and NICHE-3 reporting excellent pathologic responses and pathologic complete responses. Integrating these therapies can enhance the surgical and survival outcomes of patients with LACC, highlighting the importance of personalized treatment strategies based on tumor characteristics and response to neoadjuvant interventions. This review discusses the evolving landscape of LACC management, focusing on optimizing treatment approaches for improved patient outcomes.

Keywords: locally advanced colon cancer; mismatch repair; neoadjuvant chemoradiotherapy; neoadjuvant chemotherapy; neoadjuvant immunotherapy.