The "Light Knife" for Gastric Cancer: Photodynamic Therapy

Photodynamic therapy (PDT) has been used clinically to treat cancer for more than 40 years. Some solid tumors, including esophageal cancer, lung cancer, head and neck cancer, cholangiocarcinoma, and bladder cancer, have been approved for and managed with PDT in many countries globally. Notably, PDT for gastric cancer (GC) has been reported less and is not currently included in the clinical diagnosis and treatment guidelines. However, PDT is a potential new therapeutic modality used for the management of GC, and its outcomes and realization are more and more encouraging. PDT has a pernicious effect on tumors at the irradiation site and can play a role in rapid tumor shrinkage when GC is combined with cardiac and pyloric obstruction. Furthermore, because of its ability to activate the immune system, it still has a specific effect on systemic metastatic lesions, and the adverse reactions are mild. In this Review, we provide an overview of the current application progress of PDT for GC; systematically elaborate on its principle, mechanism, and the application of a new photosensitizer in GC; and focus on the efficacy of PDT in GC and the prospect of combined use with other therapeutic methods to provide a theoretical basis for clinical application.