Abstract
OBJECTIVES: Chemoimmunotherapy is the first-line treatment for extensive-stage small cell lung cancer (ES-SCLC). This study aims to evaluate the survival outcomes and safety of chemoimmunotherapy in young patients with ES-SCLC. PATIENTS AND METHODS: Patients with pathologically or cytologically confirmed ES-SCLC from three centers and divided into two age groups: young (aged ≤ 45 years) and control (aged > 45 to ≤ 75 years) between January 2015 and December 2023. We assessed progression-free survival (PFS), overall survival (OS), and safety between the two age groups. RESULTS: Of the whole 347 patients, 59 were in the young group, while 288 were in the control group. The young group exhibited poorer PFS (median, 4.67 vs. 5.40 months, p < 0.001) and OS (median, 13.7 vs. 14.4 months, p = 0.028) compared with the control group, particularly in the context of chemoimmunotherapy [PFS (median, 4.50 vs. 5.57 months; p = 0.002), OS (median, 13.20 vs. 15.33 months; p = 0.012), respectively]. Additionally, in the young group, chemoimmunotherapy showed similar PFS (median, 4.50 vs. 5.75 months; p = 0.501) and OS (median, 13.20 vs. 13.70 months; p = 0.508) compared to chemotherapy. Moreover, the young group had a higher incidence of immune-related adverse events (irAEs) (30.51% vs. 11.46%, p < 0.001) and hematologic toxicity, including thrombocytopenia (25.42% vs. 14.24%, p = 0.033). CONCLUSIONS: The young group had poorer survival outcomes and chemoimmunotherapy may not provide a survival benefit in young patients, as evidenced by similar PFS and OS compared to chemotherapy. Additionally, the young group also experienced a higher incidence of immune-related adverse events (irAEs) and hematologic toxicity.