Colitis-Associated CRC: Nature Reviews Gastroent & Hepatol | April 2026

Introduction

Colitis-associated colorectal cancer (caCRC) represents a distinct subtype of colorectal cancer that develops in patients with long-standing Inflammatory Bowel Disease, particularly Ulcerative Colitis and Crohn’s Disease. With the rising global burden of IBD, the population at risk for caCRC is steadily increasing. Unlike sporadic colorectal cancer, caCRC arises in a background of chronic inflammation, leading to unique molecular, cellular, and microenvironmental changes that influence tumor initiation and progression.

Problem Statement

Despite improved control of inflammation in IBD, caCRC remains a major clinical challenge because its pathogenesis is complex, heterogeneous, and fundamentally different from sporadic colorectal cancer, making early detection, risk stratification, and targeted therapy difficult.

Summary

This review highlights that caCRC is driven primarily by chronic inflammation-induced epithelial damage and regeneration. Persistent barrier disruption accelerates epithelial aging and promotes early genetic alterations—particularly early loss of p53, unlike the adenoma–carcinoma sequence seen in sporadic colorectal cancer. Inflammatory pathways such as IL-17 and NF-κB play a central role in early tumorigenesis. The tumor microenvironment is equally critical, involving dynamic interactions between epithelial cells, immune cells, cancer-associated fibroblasts, and the gut microbiome. Dysbiosis further amplifies inflammatory signaling and tumor promotion. caCRC is also characterized by rapid progression and a tendency toward mesenchymal tumor phenotypes, contributing to aggressive behavior. Importantly, the review emphasizes that future management will likely shift toward personalized strategies targeting inflammation, microbiome modulation, immune pathways, and stromal interactions to prevent and treat caCRC more effectively.