Response characteristics of tislelizumab plus chemotherapy as first-line treatment for advanced squamous non-Small cell lung cancer

Objective: To investigate the response characteristics of first-line tislelizumab combined with chemotherapy in patients with advanced squamous non-small cell lung cancer (sq-NSCLC). Methods: This retrospective study enrolled 40 patients with advanced sq-NSCLC treated at Yancheng Third People’s Hospital between January 2021 and December 2024. Tumor response characteristics were analyzed, and the association between depth of response (DepOR) and progression-free survival (PFS) was further evaluated. Results: As of June 30, 2025, objective responses were observed in 29 patients (72.5%). Among responders, 82.8% achieved their first response within the first two efficacy evaluations (within 12 weeks), while 17.2% achieved their first response at the third or subsequent evaluations (18–33 weeks). The median PFS for patients with DepOR of 30%–49%, 50%–69%, and 70%–100% was 7.4 months, 14.8 months, and 20.2 months, respectively. Compared with patients with DepOR of 30%–49%, those achieving deeper responses (50%–69% and 70%–100%) demonstrated significantly prolonged PFS (P < 0.05). Conclusion: Most patients with advanced sq-NSCLC who responded to first-line tislelizumab plus chemotherapy achieved tumor response within the first two efficacy evaluations. Deeper tumor responses were associated with longer PFS, suggesting that premature discontinuation of immunotherapy should be avoided in the absence of disease progression or unacceptable toxicity.