Heterogeneity between subgroups of first-line chemoimmunotherapy for extensive-stage small cell lung cancer patients: a meta-analysis and systematic review - Kang, Wenwen; Cheng, Jing; Pan, Luyun; Zhan, Ping; Liu, Hongbing; Lv, Tangfeng; Han, Hedong; Song, Yong (Frontiers in Oncology, 2024)