months); 3-and 5-year survival rates were 57.3% and 54.2%, respectively. For the whole cohort, 57.4% (35/ 61), 37.7% (23/61) and 21.3% (13/61) patients expressed PD-L1 1%, 5% and 10%, respectively; and 3-year survival rate was 60.0%, 72.3% and 74.0%, respectively. When the positivity threshold of PD-L1 expression was defined as PD-L1 expression 5%, the MST in patients with PD-L1 (+) tumors was significantly longer than that with PD-L1 (-) tumors (NR vs. 34 months, p ¼ 0.0321). No significantly survival differences were observed when PD-L1 positivity threshold was defined as 1% or 10%. For patients with stage I SCLC, the MST in patients with PD-L1 expression 5%, was significantly longer than that in patients with PD-L1 expression < 5% (NR vs. 56 moths, p ¼ 0.03). Regardless of the positivity threshold of PD-L1 expression with 1%, 5% or 10%, for patients with stage II or III SCLC, no significant survival differences were observed. Multivariate analysis indicated postoperative chemotherapy (hazard ratio [HR] ¼ 0.322, p ¼ 0.023), PCI (HR ¼ 0.105, p ¼ 0.029) and PD-L1 expression (HR ¼ 0.253, p ¼ 0.008) were independent prognostic factors for OS. Conclusion: PD-L1 highly expressed in patients with resectable SCLC. The level of PD-L1 expression could predict the survival of patients in this setting.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.