Integration of ımmunotherapy in limited-stage small cell lung cancer: a review of the literature

Limited-stage small cell lung cancer (LS-SCLC) is characterized by rapid proliferation and a high propensity for early relapse, resulting in poor prognosis. For decades, the standard of care has remained concurrent chemoradiotherapy followed by prophylactic cranial irradiation. The advent of immune checkpoint inhibitors has recently stimulated investigation into novel therapeutic strategies for this patient population. This review summarizes the biological rationale, feasibility, and current clinical evidence regarding the use of immunotherapy in LS-SCLC. In early-phase studies, the use of immunotherapy as a neoadjuvant approach has predominantly been evaluated through Phase II or retrospective trials with limited sample sizes; nonetheless, the achieved response rates have been found clinically promising. Studies concerning immunotherapy administered concurrently with chemoradiotherapy present heterogeneous outcomes, necessitating further advanced-phase clinical trials to definitively establish the efficacy and safety of this approach. In contrast, consolidation immunotherapy has yielded data with the highest level of evidence in LS-SCLC, primarily driven by the ADRIATIC trial. The results of the ADRIATIC study support the adoption of consolidation durvalumab following concurrent chemoradiotherapy as a new standard of care in the management of LS-SCLC. However, reliable biomarkers capable of predicting the clinical benefit of neoadjuvant, concurrent, and consolidation immunotherapies, as well as the specific patient subgroups that would derive the greatest benefit, have yet to be clearly defined. Consequently, prospective large-scale trials remain critical to addressing existing uncertainties regarding the optimal timing of immunotherapy and patient selection.