Comparison of clinical outcomes in patients with advanced pulmonary sarcomatoid carcinoma treated with immunotherapy-based regimens or chemotherapy: A study based on the SEER database and multicentric real-world settings.

Background: Pulmonary sarcomatoid carcinoma (PSC) is a rare lung cancer characterized by early metastasis and invasion. It is predominantly diagnosed at a locally advanced or metastatic stage, hindering the possibility of surgical intervention. However, a standard treatment for advanced PSC remains unestablished. This study evaluated the effects of chemotherapy and immunotherapy-based strategies in patients with advanced PSC.

Methods: The Surveillance, Epidemiology, and End Results (SEER) database and data from three cancer centers were used in this retrospective study. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were conducted to identify the prognostic factors.

Results: In total, 202 patients with stage IV PSC were identified from the SEER database (median OS, 5 months). The median follow-up time of patients from the three centers was 18.8 months. First-line treatment with immunotherapy-based regimens and chemotherapy was administered to 12 and 27 patients, respectively. The median PFS was 2.1 and 7.3 months [hazard ratio (HR), 0.16; 95% confidence interval (CI), 0.06-0.40; P < 0.001], while the median OS was 3.6 and 21.4 months (HR, 0.21; 95% CI, 0.09-0.50; P < 0.001) in the chemotherapy and immune-based groups, respectively. The immunotherapy-based regimen was an independent prognostic factor for PFS (HR, 0.21; 95% CI, 0.08-0.55; P = 0.001) and OS (HR, 0.20; 95% CI, 0.08-0.49; P < 0.001).

Conclusions: Conventional chemotherapy offered limited benefits in patients with advanced PSC; however, those who received first-line immunotherapy-based regimens exhibited significantly improved responses.