Abscopal effect induced by modulated radiation therapy and pembrolizumab in a patient with pancreatic metastatic lung squamous cell carcinoma.

The main recurrence pattern for lung cancer patients after radical surgery is distant metastasis. The probability of pancreatic metastasis in patients diagnosed with lung squamous cell carcinoma is 0.02%, with a poor prognosis. Chemotherapy is the preferred treatment for recurrence. Single lesions or oligometastasis can be surgically resected, and local lesions with compression symptoms can be treated with radiotherapy. The FDA and NMPA have approved first-line indications for immunotherapy for lung squamous cell carcinoma. Here, we report the case of a 57-year-old male patient with lung squamous cell carcinoma who developed pancreatic metastasis after radical resection. The disease progressed after first-line chemotherapy, and the patient was treated with immunotherapy combined with radiotherapy. We subsequently observed the abscopal effect of intensity modulated radiation therapy (IMRT) and pembrolizumab with disappearance of lung metastasis after radiotherapy for pancreatic metastasis. The patient's tumor symptoms were relieved with prolonged survival.