Case report of neoadjuvant treatment with sugemalimab combined with platinum-based doublet chemotherapy in stage IIIB lung squamous cell carcinoma and research in potential biomarkers

Here we present a case of stage IIIB (cT3N2M0) lung squamous cell carcinoma, who was potentially resectable, and underwent a complete resection after three cycles of neoadjuvant therapy induced by sugemalimab combined with platinum-based doublet chemotherapy. The assessment of resected lung sample and lymph nodes has shown a pathological complete response in this case, although the radiographical response was stable. Potential biomarkers that may correlate with the efficacy were also explored in this case. A positive expression of PD-L1 level at baseline, and the clearance of tumor mutation burden via ctDNA after neoadjuvant regimens, as well as the varieties of tumor microenvironment shown as macrophage marker and PSMB-8, PSMB-9, PSMB-10, the immunoproteasome (IP) subunits, using the assay of multiple immunofluorescence and immunohistochemistry respectively, have all indicated the favorable and long-lasting effect of the combination strategy in the neoadjuvant setting.