Multicenter Retrospective Analysis of Pulmonary Sarcomatoid Carcinoma Clinically Diagnosed Using Small Biopsy Specimens.

Abstract

Background/aim: Pulmonary sarcomatoid carcinoma is a rare disease known for its aggressiveness, with numerous studies evaluating the efficacy of various therapeutic approaches. However, pulmonary sarcomatoid carcinoma is histologically defined according to WHO classification based on surgical specimens, whereas in clinical practice, most cases of advanced lung cancer are diagnosed based on small biopsy specimens. This retrospective study aimed to present the clinical course of patients diagnosed with pulmonary sarcomatoid carcinoma based on small biopsy specimens.

Patients and methods: Data of patients who were diagnosed with pulmonary sarcomatoid carcinoma based on small biopsy specimens and treated with platinum-doublet chemotherapy and/or an immune checkpoint inhibitor-containing regimen between 2005 and 2022 were analyzed.

Results: Data from 12 patients were analyzed, including five patients treated with platinum-doublet chemotherapy and 11 patients treated with an immune checkpoint inhibitor-containing regimen. The median progression-free survival among the five patients treated with platinum-doublet chemotherapy was 1.5 months [95% confidence interval (CI)=0.7-4.1]. Of these, four patients subsequently received immune checkpoint inhibitor-containing therapy. The median overall survival from the initiation of platinum-doublet chemotherapy in these five patients was 14.7 months (95%CI=1.2-16.2). In contrast, 11 patients treated with immune checkpoint inhibitor therapy showed a median progression-free survival and overall survival of 8.9 months [95%CI=0.3-not estimated (NE)] and 10.8 months (95%CI=1.0-NE), respectively.

Conclusion: Pulmonary sarcomatoid carcinoma diagnosed based on small biopsy specimens is refractory to platinum-doublet chemotherapy, and immune checkpoint inhibitor therapy may improve the prognosis.