Limited-stage small-cell lung cancer: complete response after salvage chemoradiation and continued serplulimab

What happened, in summary

This 49-year-old Asian man, with a smoking and drinking history of more than 20 years, presented in March 2023 with chest tightness, shortness of breath, and dry cough. Chest CT showed a 3.1 x 2.4 cm nodule in the posterior right lower lobe and enlarged right hilar and mediastinal lymph nodes. EBUS-TBNA confirmed small-cell lung cancer in nodal disease, and PD-L1 expression was CPS 1. PET-CT confirmed the lung primary and nodal metastases without distant metastasis, and brain MRI was unremarkable. He was staged T2aN2M0 and classified as limited-stage small-cell lung cancer. He enrolled in a phase II trial of concurrent chemoradiation followed by serplulimab. Initial treatment included 2 cycles of etoposide/cisplatin induction, then concurrent chemoradiation with 2 more cycles of etoposide/cisplatin and thoracic radiotherapy to 45 Gy in 15 fractions. He also received hippocampal-avoidance prophylactic cranial irradiation, 25 Gy in 10 fractions. Imaging showed partial response, and serplulimab consolidation began. After 4 cycles, right supraclavicular nodal recurrence appeared. The team treated it aggressively with definitive nodal chemoradiation using carboplatin/etoposide, then resumed serplulimab and added 4 cycles of irinotecan during resumed immunotherapy. After 17 cycles of immunotherapy, the primary lesion had completely resolved and the supraclavicular node had shrunk to 0.4 cm. As of May 13, 2025, brain MRI and CT of neck, chest, and abdomen showed complete response with no radiologic recurrence or metastasis. Treatment toxicity was limited, with one episode of grade III ALT elevation that resolved with symptomatic care. No other significant toxicities were described during the reported treatment course.