Hyperprogression disease induced by Sintilimab combined with Oxaliplatin and S-1 after surgery: a case report and literature review.

[OBJECTIVE] To investigate the risk factors, underlying mechanisms, and preventive strategies associated with hyperprogressive disease (HPD) induced by immunotherapy.

[METHODS] We analyzed the clinical data of a patient who developed HPD following palliative gastrectomy and received a combination therapy of Sintilimab, S-1 (tegafur, gimeracil, and oteracil potassium), and Oxaliplatin (SOX). Additionally, a literature review on tumor immunotherapy was conducted to further explore the risk factors and mechanisms of HPD.

[RESULTS] In this case, the development of HPD was associated with a high postoperative tumor burden, elevated PD-1 expression, and aberrant activation of signaling pathways mediated by EGFR, MET, and FGFR1 amplifications. In addition, a TP53 p.F270V mutation led to inactivation of tumor suppressor function.

[CONCLUSION] Although immune checkpoint inhibitors (ICIs) have demonstrated significant efficacy in cancer treatment, HPD induced by ICIs can drastically shorten patients' OS, warranting cautious use in populations with high-risk factors. Effective prevention of HPD involves screening for risk factors, monitoring predictive biomarkers such as circulating-free DNA (cfDNA) via liquid biopsy, and identifying high-risk populations through gene mutation analysis.