Multicancer Detection (MCD) Testing in Gastrointestinal Cancers: An Evolving Tool for Early Diagnosis

The current review aims to summarize the benefits and limitations of the novel multicancer detection tests (MCD) for diagnosing gastrointestinal (GI) malignancies.

Traditional cancer screening methods can reduce deaths in malignancies involving the GI tract. For GI cancers, screening options vary by type and often involve invasive techniques with limited sensitivity. MCDs offer a promising, non-invasive (simple blood draw) alternative by analyzing biomarkers such as cell-free DNA and RNA using advanced techniques and machine learning to detect cancers across multiple organ sites. Large studies like the PATHFINDER trial and THUNDER study have demonstrated the feasibility and accuracy of MCD assays in identifying cancer signals, with high sensitivity and specificity in some GI organs that lack routine screening tests (e.g., liver, pancreas, and stomach). Despite these advancements, MCD testing faces challenges, including high costs, lack of FDA approval, false positives, and limited data on clinical utility in reducing cancer-specific mortality. MCD should not be a substitute for age-appropriate cancer screenings but may complement existing methods, particularly for cancers with no current screening tools, such as cholangiocarcinoma and pancreatic cancer. Clinicians need to discuss the limitations of MCDs, including the potential for overdiagnosis, patient anxiety, and financial burden due to insurance coverage gaps.

MCD is a promising, non-invasive test that can augment traditional cancer screening. As the role of MCD in cancer detection evolves, further research is essential to establish how it will be integrated into clinical practice, ensuring informed, shared decision-making with patients.