Immunotherapy as a treatment for small cell lung cancer: a case report and brief review

Small cell lung cancer (SCLC), an aggressive disease characterized by rapid progression, early relapse and widespread metastasis, accounts for about 13–15% of lung cancer cases. Despite its initial sensitivity to chemotherapy and radiotherapy, SCLC commonly develops resistance to these treatments and, as such, has high recurrence rates. In recent years, immunotherapy has shown promising antitumor activity and the approach to tumor treatment has been changed, in particular, by programmed death receptor-1/ligand 1 (PD-1/L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) checkpoint inhibitors. SCLC has high immunogenicity, a high mutation burden, and other favorable immune factors, meaning immune checkpoint inhibitors (ICIs) could become a breakthrough in the treatment of SCLC. In our case report, we found that ICIs resulted in partial response (PR), and in our review, we focused on clinical trials of immunotherapy, especially in relation to ICIs in SCLC.