Abstract 2638: Clinical characteristics and PD-L1 expression of pulmonary sarcomatoid carcinoma

Abstract

Abstract Introduction: Pulmonary sarcomatoid carcinoma (PSC) is a poorly differentiated non-small cell lung cancer (NSCLC) containing a component of spindle cell or giant cell. Because the prevalence of PSC is very rare, there is insufficient data about clinical feature, therapeutic strategy and prognosis. Method: We reviewed the medical records of 26 patients diagnosed with PSC from January 2009 to June 2015, and analyzed the clincopathological characteristics, treatment modality and their outcome, and risk factors of overall survival (OS). Programmed death ligand 1 (PD-L1) expression was tested in 13 patients by using archival tissues (PD-L1 IHC 22C3 pharmDx assay). Results: The median age of PSC patients was 69.5 years. 23 patients were male. 25 patients were current or former heavy smokers. Pleomorphic carcinoma was the most common subtype, and epidermal growth receptor mutation (EGFR) was positive in 2 of 11 patients who were tested. Among 13 patients tested for programmed death ligand 1 (PD-L1), eight showed PD-L1 high expression (tumor proportion score, TPS ≥ 50%). Four patients showed low expression (1% ≤ TPS ≤ 49%), and one patient showed no expression (TPS < 1%). The median OS of all patients was 286 days. Age and the time from symptom onset to diagnosis were significantly associated with OS. PD-L1 expression showed the trend of positive prognostic value on OS in univariate analysis but was insignificant in multivariate analysis. 12 patients were treated with chemotherapy: 9 with platinum-based doublet therapy, 2 with tyrosine kinase inhibitor and 1 with docetaxel. 7 patients showed partial response or stable disease. The median OS and progression free survival of patients receiving chemotherapy were 260 days and 85 days, respectively. Conclusions: It has poor prognosis compared with ordinary NSCLC. However, PSC patients showed comparatively fair response to chemotherapy and generally showed higher PD-L1 expression. Active treatment with cytotoxic chemotherapy, EGFR TKIs or immune checkpoint inhibitors are necessary to achieve a better results of PSC management. Citation Format: Sung Yong Lee, Jae Kyeom Shim, Jee Youn Oh, Kyung Hoon Min, Gyu Young Hur, Jae Jeong Shim, Kyung Ho Kang, Bong Kyung Shin, Young Seok Lee. Clinical characteristics and PD-L1 expression of pulmonary sarcomatoid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2638. doi:10.1158/1538-7445.AM2017-2638