%0 Case Reports
%T Case report: A rapid response to immunotherapy in a thoracic SMARCA4-deficient undifferentiated tumor with respiratory failure.
%A Shi L
%A Lin L
%A Ding Y
%A Zeng Y
%A Chen X
%J Front Oncol
%V 12
%N 0
%D 2022
%M 36452500
%F 5.738
%R 10.3389/fonc.2022.1020875
%X Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is an extremely rare and poor-prognosis malignancy, which has recently been noted as a subtype of lung tumors. We presented a case of SMARCA4-UT in a 50-year-old man with progressively worsening respiratory failure. The tumor was the first reported to involve pulmonary artery, and 90% of tumor cells expressed programmed cell death ligand 1 (PD-L1). High tumor mutational burden (TMB, 23.93/Mb) and mutations in SMARCA4 were detected. It is the first reported case to receive Tislelizumab monotherapy with considerable improvement in clinical condition and no adverse events. As a result of our case, we highlight the importance of recognizing SMARCA4-UT as an individual entity, as well as the efficacy of immune checkpoint inhibitor therapy, particularly in patients with high levels of TMB and PD-L1 expression.