{Reference Type}: Case Reports
{Title}: TIM-3 expression induces resistance to PD-1 inhibitor in G-CSF-producing lung spindle cell carcinoma: A case report.
{Author}: Hayashi F;Akagi K;Taniguchi H;Matsutake T;Kawahara H;Sekine I;Gyotoku H;Takemoto S;Soda H;Ashizawa K;Mukae H;
{Journal}: Thorac Cancer
{Volume}: 14
{Issue}: 36
{Year}: 2023 Dec 5
{Factor}: 3.223
{DOI}: 10.1111/1759-7714.15149
{Abstract}: Lung spindle cell carcinoma is an aggressive subtype of pleomorphic lung cancer resistant to cytotoxic chemotherapy. Programmed cell death-1 (PD-1) inhibitors have been reported to have clinical effects in patients with spindle cell carcinoma; however, the resistance mechanism to PD-1 inhibitors is yet to be fully elucidated. Herein, we report the case of an 88-year-old man with G-CSF-producing spindle cell carcinoma who acquired resistance to PD-1/PD-ligand 1 (L1) inhibitor in an early setting after a remarkable response. A histopathological review of the resistant specimen revealed a low count of CD8+ T cells and a predominant presence of M2 and TIM-3+ macrophages, indicating the presence of an immunosuppressive microenvironment. Our findings suggest a novel resistance mechanism to PD-1/PD-L1 inhibitors in G-CSF-producing spindle cell carcinoma.