Treatment-Related Adverse Events in Extended Stage Small Cell Lung Cancer Patients Receiving First-Line Chemoimmunotherapy Versus Chemotherapy Alone: A Systematic Review and Meta-Analysis

Introduction: Nowadays the prognosis of extended stage (ES) small cell lung cancer (SCLC) patients is poor. However, a high response rate to first-line chemotherapy (CT) and the addition of immune checkpoint inhibitors (ICIs) have notably ameliorated the outcome of these patients. The aim of our study is to compare treatment-related adverse events (TRAEs) between ES- SCLC patients receiving first-line ICIs adding CT and those receiving only CT. Methods: All phase III clinical trials published between 15 June 2008, and 30 June 2024, likenessing ICIs adding systemic CT and only CT in treatment-na & iuml;ve ES-SCLC patients were retrieved. Results: Twenty-six types of adverse events were included, grouped into ten categories, for a total of 43,391 observations (observations in immune group n = 22,643 and in placebo group n = 20,748) and 9831 events. Our analysis suggested a statistically significant increase in hematological events in patients receiving ICIs plus CT compared with CT alone. Conversely, blood pressure alterations such as hypertension were more frequent in patients treated with CT alone. Conclusions: Despite our analysis confirming the manageable safety profile of chemoimmunotherapy, this remains an issue to be further investigated.