Objective:Crizotinib has demonstrated promising efficacy in patients with anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) in clinical trials.We conducted this retrospective multicenter study to assess the outcomes of crizotinib therapy in,to our knowledge,a large sample cohort of patients with ALK-positive advanced NSCLC.Methods:We reviewed the medical records of 484 unselected ALK-positive NSCLC patients treated with crizotinib at 5 cancer centers in China from January 2013 to November 2017.Clinical data were collected from the initiation of crizotinib therapy to Response Evaluation Criteria in Solid Tumors (RECIST)-defined progressive disease (PD).Results:A total of 428 eligible ALK-positive NSCLC patients were enrolled,273 (63.8％) of whom received crizotinib as first-line treatment.The median progression-free survival (PFS) and overall survival (OS) from the initiation of crizotinib treatment were 14.4 [95％ confidence interval (95％ CI),12.4-16.4] months and 53.4 (95％ CI,33.7-73.1) months,respectively.In subgroup analyses,patients who received crizotinib as first-line treatment showed a higher disease control rate (DCR) and a longer median OS compared with second-/later-line crizotinib treatment (94.8％ and OS not reached vs.89.0％ and 40.5 months,respectively).For 261 patients with RECIST-defined PD,multivariate Cox analysis revealed that in patients who received first-line crizotinib therapy,continued crizotinib beyond progressive disease (CBPD) and next-generation ALK inhibitors after crizotinib failure were associated with improved survival.Conclusions:This study has demonstrated the clinically meaningful benefit of crizotinib treatment in a large cohort of Chinese ALK-positive NSCLC patients.CBPD and next-generation ALK inhibitor treatment may provide improved survival after RECIST-defined progression on crizotinib.