Successful treatment of an elderly patient with lung squamous cell carcinoma by tislelizumab and chemotherapy: a case report with novel imaging findings.

The advent of immunotherapy has transformed the therapeutic landscape for inoperable, locally advanced Non-Small cell lung cancer (NSCLC), particularly for lung squamous cell carcinoma (LUSC) with a predominance of negative driver genes. Based on the results of clinical trials such as KEYNOTE-042 and KEYNOTE-407, PD-1/PD-L1 inhibitors are now recognized as the standard of care for first-line or second-line treatment in many countries. Among the 17 immune checkpoint inhibitors sanctioned in China, tislelizumab, a domestically developed PD-1 inhibitor, enjoys broad application. Here, we present a case of a patient with LUSC who attained complete remission by cyst formation with the combination of tislelizumab and chemotherapy. Despite the absence of expression data for this patient, imaging studies revealed a reduction in the primary lesion size and the emergence of an uncommon cystic alteration post-treatment with sequential immunochemotherapy and tislelizumab monotherapy. As per the most recent follow-up, the lesion has vanished entirely. This outcome holds significant implications for the treatment of driver gene-negative LUSC by tislelizumab.