# First‐Line Treatment of Advanced Thoracic SMARCA4‐Deficient Undifferentiated Tumor: A Case Report and Review of the Literature

## TL;DR

A case report explores treatment of a rare aggressive lung tumor with immunotherapy and antiangiogenic drugs, achieving 18 months survival.

## Contribution

Reports a novel treatment approach combining PD-1 inhibitors and antiangiogenic therapy for SMARCA4-deficient undifferentiated tumor.

## Key findings

- Combination therapy achieved 18 months overall survival in a patient with SMARCA4-UT.
- Grade 3 immune myocarditis occurred as a significant adverse effect during treatment.
- PD-1 inhibitors with antiangiogenic drugs may improve prognosis for this aggressive tumor.

## Abstract

Thoracic SMARCA4‐deficient undifferentiated tumor (SMARCA4‐UT) of the chest is a highly aggressive smoking‐related thoracic malignancy with a median overall survival (OS) of only 4–7 months.

In this article, we report a case of a 74‐year‐old male patient who was admitted to the hospital with recurrent cough with sputum and CT suggestive of a right pleural occupying lesion. Admission to the hospital and perfect CT showed right pleural thickening with multiple metastases in the mediastinum and liver, and the diagnosis of SMARCA4‐UT (SMARCA4 expression deletion) was confirmed by pathologic biopsy and immunohistochemistry. The genetic test map suggested high PD‐L1 expression (TPS 80%) and the patient was treated with sindilizumab (200 mg q3w) combined with bevacizumab (500 mg q3w). Grade 3 immune myocarditis occurred during treatment, and bevacizumab maintenance therapy was continued after discontinuing immunosuppression. During follow‐up, the patient achieved a final OS of 18 months.

This case suggests that PD‐1 inhibitors combined with antiangiogenic therapy may improve the prognosis of SMARCA4‐UT, but the adverse effects observed during the treatment course demanded equally critical attention.