Advances in microfluidic chip technologies for the study and management of gastrointestinal cancers.

Gastrointestinal cancers (GICs) remain a major global health burden due to late-stage diagnosis, limited therapeutic efficacy, and poor prognosis. Conventional diagnostic and treatment strategies are often invasive, costly, and lack real-time monitoring capabilities, highlighting the need for the innovative and patient-centered approaches. This review critically examines the recent advances in microfluidic chip technologies for the diagnosis, modeling, and treatment of GICs, including gastric, colorectal, liver, pancreatic, and esophageal cancers. Microfluidic platforms enable the precise manipulation of microscale fluids, offering advantages such as reduced reagent consumption, high sensitivity, and integration of multiplexed assays into portable systems. Notably, recent studies demonstrate diagnostic performance with area under the curve (AUC) values exceeding 0.90 and sensitivities approaching 90%, while detection limits for key biomarkers such as ctDNA and proteins have reached attomolar (10⁻¹⁸ M) and picogram-per-milliliter levels. Applications discussed include circulating tumor cell (CTC) isolation, exosome and ctDNA detection, tumor-on-chip models, and microfluidic drug delivery systems. In addition, advances in materials, fabrication techniques, and fluid dynamics are evaluated for their role in optimizing device performance. Emerging integrations with machine learning further enhance diagnostic accuracy and predictive capability. Despite these promising developments, challenges related to standardization, scalability, and clinical validation remain. Overall, microfluidic technologies represent a transformative platform for enabling rapid, minimally invasive, and highly sensitive approaches to cancer diagnosis and personalized therapy in gastrointestinal oncology.