In the realm of small cell lung cancer (SCLC), treatment standards have seen little evolution, with limited options and poor outcomes, especially in extended disease (ED) cases. The advent of immune checkpoint inhibitors (ICIs) has marked a significant advance, albeit with modest benefits compared to other cancers. Variations in the tumor microenvironment may affect immunotherapy efficacy. Molecular studies have unveiled four distinct SCLC subtypes, each with unique therapeutic targets. Despite this, targeted therapies remain elusive. Understanding SCLC’s molecular landscape is crucial for advancing treatment. In a recent review, the rationale behind immunotherapy in SCLC is reviewed, highlighting key trials and emerging therapeutic avenues. SCLC’s immunogenic nature, coupled with its high tumor mutational burden, suggests potential for immunotherapy despite challenges like limited immune cell infiltration and PD-L1 expression. Integrating new molecular classifications into treatment approaches may pave the way for more effective therapies. Despite progress, gaps persist in understanding SCLC.
