Photodynamic therapy may salvage chemotherapy failure in gastric cancer: A case report and a literature review.

Given the highly heterogeneous characteristics of advanced gastric cancer (GC), most patients must receive neoadjuvant therapy or conversion therapy consisting of chemotherapy to decrease tumor grade and improve the likelihood of complete resection. Drug resistance, however, always leads to an aborted conversion therapy and inevitable death. When meet drug resistance, alternative drug regimens will be applied with immunotherapy or targeted therapy, whose clinical efficacy remains limited when new drug resistance or severer liver and kidney toxicity emerge. Photodynamic therapy (PDT), a novel treatment, has demonstrated remarkable therapeutic efficacy in different stages of GC. However, no report has been reported so far on the clinical application of photodynamic therapy in conversion therapy after drug resistance. Here we report a case of middle-aged patient with advanced GC, who experienced failure of conversion therapy consisted of multi-line chemotherapy along with immunotherapy. Ultimate success was achieved through a comprehensive conversion therapy of PDT, chemotherapy, immunotherapy, and targeted therapy. Subsequently, the patient underwent robotic-assisted radical gastrectomy while the surgical specimen showed no tumor cell exists. The patient underwent 3 cycles of systemic adjuvant therapy following surgical intervention. Presently, the patient remains 17 months in a satisfactory state of health.