The prognostic impact of immune checkpoint inhibitors for the treatment of pulmonary sarcomatoid carcinoma: A multicenter retrospective study

Pulmonary sarcomatoid carcinoma (PSC) is an aggressive and poorly differentiated type of non-small cell lung carcinoma. Because of the rarity of PSC, the efficacy and toxicity of immunotherapy remain unclear. Hence, the aim of this study was to evaluate the efficacy and safety of immune checkpoint inhibitors (ICIs) for the treatment of advanced PSC. The study cohort was limited to 33 patients with pathologically confirmed PSC treated with ICIs in four hospitals in China from March 2018 to March 2022. Expression of programmed death ligand 1 (PD-L1) was detected by immunohistochemical analysis. Categorical variables were compared with the Fisher exact test and survival analysis was conducted with the Kaplan-Meier method. Of the 33 PSC patients, 8 (24.2%) received monotherapy with ICIs and 25 (75.8%) received combination therapy with ICIs. The objective response rate (ORR) and disease control rate (DCR) were 36.4% and 78.8%, respectively. The median durations of progression-free survival (PFS) and overall survival (OS) were 6.07 and 21.33 months, respectively. PD-L1 status in 16 available samples was assessed, which included 30.3% PD-L1-positive patients. The ORRs for PD-L1-positive vs. -negative patients were 50.0% and 90.0%, the DCR was 33.3% and 83.3%, and the median PFS was 17.50 and 6.07 months, respectively (p=0.812). The median OS was not reached in PD-L1-positive and -negative patients (p=0.655). The incidence of immune-related adverse (irAEs) was 48.5% and mainly included grade 1 or 2 (39.4%), while the incidence of grade 3 or 4 was 9.1%. Pneumonia (9.1%) and skin rash (9.1%) were the most frequent irAEs. Immunotherapy with ICIs was a promising regimen to improve the prognosis of patients with advanced PSC.