A recent observational study published in the journal Cancer highlights the expanding role of circulating tumor DNA (ctDNA) testing for minimal residual disease (MRD) in patients with metastatic gastroesophageal cancer. In an interview with Targeted Oncology, Dr. Rutika Mehta explained that although ctDNA is commonly used in early-stage cancers, it may also provide valuable insights for advanced disease, where standard surveillance often falls short.
Traditional monitoring with CT scans and blood markers like CEA can miss early recurrences, especially in diffuse-type gastric cancers that spread to the peritoneum. By the time recurrence is visible on imaging, patients frequently present with widespread disease rather than a more treatable oligometastatic state. The study analyzed ctDNA levels during treatment to assess their prognostic value. Patients whose ctDNA cleared from positive to negative had significantly better outcomes, while those with a deep decline of over 90% experienced improved progression-free survival. Conversely, rising ctDNA levels often provided an early warning of disease progression before it became detectable on scans, offering a potential lead-time advantage for clinical decision-making.
These findings suggest that ctDNA/MRD testing could become an important tool for personalized monitoring in gastroesophageal cancer. By detecting disease activity earlier than conventional imaging, clinicians may be able to intervene sooner, adjust treatment strategies, and better tailor therapies to individual patients. As this technology evolves, ctDNA testing has the potential to improve long-term outcomes and provide a more precise approach to managing this challenging cancer type.