These subgroup meta-analysis results indicated that PD-1/PD-L1 inhibitors could reduce the risk of disease progression for NSCLC (HR = 0.58, 95%CI = 0.39–0.76) with moderate heterogeneity (I2 = 51.0%, P = 0.057) using a random effects model, and the pooled HR for PFS in SCLC was 0.79 (95%CI = 0.65–0.93) with low heterogeneity (I2 = 0.0%, P = 0.353). The gene discussed is PDCD1; the disease is small cell lung carcinoma.