A Long-Term Survival Case Report of a Patient with Pulmonary Sarcomatoid Carcinoma Accompanied by Brain Metastasis: Implications for Immunotherapy.

Introduction: Pulmonary sarcomatoid carcinoma (PSC) is a rare and highly malignant pathological subtype of non-small cell lung cancer. Most patients are diagnosed at an advanced stage. Chemotherapy is a treatment option to be considered. However, PSC is not sensitive to chemotherapy. The high expression of PD-L1 in PSC and the abundant infiltration of immune cells suggest that immunotherapy may be effective for PSC. Case Presentation: Here, we present a case of PSC. The patient was diagnosed with advanced lung cancer with metastases to the brain, liver, left adrenal gland, and bone. After 4 cycles of chemotherapy combined with camrelizumab, the patient received monotherapy with immunotherapy. After the progression of brain metastases, brain radiotherapy was added. It has been 43 months since the patient was diagnosed with lung cancer. The patient's condition remains stable and there are no obvious side effects. Conclusion: For patients with PSC, genetic testing is necessary. The efficacy of immunotherapy in patients with PSC is worthy of expectation.