Abstract
BACKGROUND: Combined small cell lung cancer (C-SCLC) is a special subtype of small cell lung cancer that is relatively rare, aggressive, and prone to early metastasis and has a poor prognosis. Currently, there are limited studies on C-SCLC, and there is no uniform standard treatment, especially for extensive C-SCLC, which still faces great challenges. In recent years, the development and progress of immunotherapy have provided more possibilities for the treatment of C-SCLC. We used immunotherapy combined with first-line chemotherapy to treat extensive-stage C-SCLC to explore its antitumor activity and safety. CASE SUMMARY: We report a case of C-SCLC that presented early with adrenal, rib, and mediastinal lymph node metastases. The patient received carboplatin and etoposide with concurrent initiation of envafolimab. After 6 cycles of chemotherapy, the lung lesion was significantly reduced, and the comprehensive efficacy evaluation showed a partial response. No serious drug-related adverse events occurred during the treatment, and the drug regimen was well tolerated. CONCLUSION: Envafolimab combined with carboplatin and etoposide in the treatment of extensive-stage C-SCLC has preliminary antitumor activity and good safety and tolerability.