Minimal residual disease in colorectal cancer. Tumor-informed versus tumor-agnostic approaches: unraveling the optimal strategy.

Background: Circulating tumor DNA (ctDNA) analysis has emerged as a minimally invasive tool for detecting minimal residual disease (MRD) in colorectal cancer (CRC) patients. This enables dynamic risk stratification, earlier recurrence detection, and optimized post-surgical treatment. Two primary methodologies have been developed for ctDNA-based MRD detection: tumor-informed strategies, which identify tumor-specific mutations through initial tissue sequencing to guide ctDNA monitoring, and tumor-agnostic approaches, which utilize predefined panels to detect common cancer-associated genomic or epigenomic alterations directly from plasma without prior tissue analysis. The debate over which is superior in terms of sensitivity, specificity, cost-effectiveness, and clinical feasibility remains unresolved.

Design: This review summarizes studies published up to November 2024, exploring the utility and performance of tumor-informed and tumor-agnostic approaches for ctDNA analysis in CRC. We evaluate the strengths and limitations of each methodology, focusing on sensitivity, specificity, and clinical outcomes.

Results: Both strategies demonstrate clinical utility in postoperative risk stratification and guiding adjuvant chemotherapy decisions in CRC patients. Tumor-informed approaches generally exhibit superior sensitivity and specificity for recurrence prediction, attributed to their personalized tumor profile designs. However, these methods are limited by the need for prior tissue sequencing and higher associated costs. In contrast, tumor-agnostic approaches offer broader applicability due to their reliance on plasma-only analysis, although with relatively lower sensitivity. Technological advancements, including fragmentomics and multi-omic integrations, are expanding the capabilities of ctDNA-based MRD detection, enhancing the performance of both approaches.

Conclusions: While tumor-informed strategies currently offer higher precision in MRD detection, tumor-agnostic approaches are gaining traction due to their convenience and improving performance metrics. The integration of novel technologies in ongoing clinical trials may redefine the optimal approach for MRD detection in CRC, paving the way for more personalized and adaptive patient management strategies.