Future directions of diagnostic and therapeutic strategies specific to subtypes of small cell lung cancer

Small cell lung cancer exhibits rapid proliferation and significant metastatic potential. There are significant epidemiologic and biological associations with tobacco carcinogens. While most small cell lung cancers display neuroendocrine characteristics, a significant subset of tumors does not possess these features. Genomic profiling of small cell lung cancer demonstrates genetic instability, nearly universal inactivation of the tumor suppressor genes TP53 and RB1, and a significant mutation burden. Due to early metastasis, a limited number of patients are suitable for curative lung resection, necessitating adjuvant platinum-etoposide chemotherapy for these individuals. Consequently, most patients are presently receiving chemoradiation, with or without the addition of immunotherapy. For patients with disease localized to the chest, standard treatment comprises thoracic radiotherapy alongside concurrent platinum-etoposide chemotherapy. Patients diagnosed with metastatic disease receive treatment that combines platinum-etoposide chemotherapy with immunotherapy utilizing an anti-programmed death-ligand 1 monoclonal antibody. Small cell lung cancer initially exhibits a strong response to platinum-based chemotherapy; however, these responses are temporary due to the emergence of drug resistance. Recent years have seen an accelerated accumulation of biological insights into the disease, resulting in a redefinition of the classification scheme for small cell lung cancer. The emerging understanding of molecular subtypes in small cell lung cancer may delineate distinct therapeutic vulnerabilities. The integration of these recent findings with existing knowledge of small cell lung cancer biology and clinical management could result in significant improvements in patient care for this condition. The authors provide an overview of multimodal clinical approaches in small cell lung cancer, emphasizing recent advancements in research that may expedite clinical development.