Abstract
BACKGROUND: Immune checkpoint inhibitors (ICIs) have become the standard first-line treatment for non-oncogene-addicted advanced squamous non-small cell lung cancer (NSCLC). Here we report the first case of a squamous NSCLC patient without a complete response (CR) from ICI-based first-line therapy and remained progression-free after with more than 2 years of continued camrelizumab. CASE DESCRIPTION: A 62-year-old man was found to have multiple pulmonary nodules and a 4.2 cm × 3.1 cm soft-tissue mass adjacent to the pulmonary artery on routine imaging in May 2021. He had a 37-year history of smoking and no significant comorbidities. Contrast-enhanced computed tomography (CT) revealed a 4.4 cm × 2.8 cm mass near the left-upper hilar region and multiple small bilateral pulmonary nodules. Brain magnetic resonance imaging, abdominal CT, and bone scan showed no distant metastasis. CT-guided biopsy confirmed poorly differentiated squamous cell carcinoma. Immunohistochemistry was positive for P40 and CK5/6, with a Ki-67 index of 50%. The patient was diagnosed with cT2bN0Mx squamous NSCLC, and began first-line treatment in June 2021 with camrelizumab (200 mg), paclitaxel (300 mg), and carboplatin (400 mg), administered every 21 days. After two cycles, a partial response (PR) was achieved. He completed six cycles of combination therapy by December 2021. During treatment, he developed reactive capillary hemangiomas related to camrelizumab, which was resolved after temporary discontinuation and thalidomide. Due to the coronavirus disease 2019 pandemic, camrelizumab maintenance therapy was administered every 1-2 months from October 2021 to April 2024. Imaging in November 2024 showed a stable soft-tissue shadow and small nodules without clear progression. As of July 2025, the patient remained progression-free, with a duration of response of 49 months since his initial PR. CONCLUSIONS: For squamous NSCLC patients without a CR to induction therapy, continuing ICI maintenance therapy beyond 2 years-rather than discontinuing treatment-may potentially extend overall survival.