Heterogeneity in advanced pulmonary sarcomatoid carcinoma and its efficacy to immune checkpoint inhibitors

Background: Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with non-small cell lung cancer but rarely been explored in pulmonary sarcomatoid carcinoma (PSC). This multicenter study aimed to evaluate the effectiveness of ICIs for PSC and its underlying mechanism. Methods: Advanced PSC who received ICIs between August 2018 and May 2022 from 11 centers in China were included. Clinical characteristics and treatment information were collected. Whole-exome sequencing (WES) and whole transcriptome sequencing were conducted on pre-treatment samples to explore the mechanism. Results: 113 patients with PSC were enrolled, the median PFS for patients receiving ICIs therapy was 8.77 months (95 % confidence interval, 4.21 to 13.32). Combining ICIs with anti-angiogenic agents significantly increased PFS (p = 0.04). Liver metastasis and combination therapy with anti-angiogenic agents were independent risk factors for PFS (Hazard Ratio [HR] = 3.652, p = 0.019 and HR = 0.435, p = 0.017, respectively). WES showed that PSC presented with a TMB of 6.3 mutations per million base pairs. High expression of TNFα signaling and glycolysis related gene showed a better prognosis. Conclusions: ICIs showed promising benefits for advanced PSC, and the addition of anti-angiogenic therapy might be a more effective treatment strategy for this disease.