SP 3.12 Patterns and Predictors of Early Recurrence and Recurrence Free Survival in Colorectal Cancer

Abstract

Colorectal cancer (CRC) recurrence following curative surgery remains a major barrier to long-term patient outcomes. While individual risk factors have been extensively studied, their combined impact on recurrence patterns remains poorly defined. This study aimed to bridge this gap by exploring predictors through an integrated analysis of clinical, pathological, and molecular factors to better inform recurrence-free survival (RFS).

A retrospective cohort of 1,100 patients undergoing curative-intent CRC surgery (2018–2023) was analysed. Recurrence data were stratified by tumour site, focusing on first 3 years post-surgery. Clinical variables, TNM staging, systemic therapy, and molecular markers (MLH1, KRAS, NRAS, BRAF, MSI) were evaluated using Kaplan-Meier and Cox regression. This multivariate modelling was designed to reflect real-world clinical complexity.

Recurrence occurred in 17% of the cohort. Though most studies use 5-year survival, our data show that 3-year survival is dramatically worse after early recurrence. Integrated molecular analysis provided novel insights: KRAS mutations independently predicted worse RFS (HR 2.37), specifically associating with aggressive lung metastases, while BRAF mutations trended toward peritoneal disease. Conversely, MSI-high status correlated with significantly improved outcomes (p<0.05). Stratified analysis further highlighted distinct recurrence behaviours between colon and rectal cancers.

This study establishes a clinically relevant framework for predicting CRC recurrence by integrating routinely collected data. These findings support personalised, risk-adapted follow-up strategies that enhance patient safety, facilitating more informed patient discussions and laying the groundwork for future precision tools, such as circulating tumour DNA monitoring.