Molecular and clinical analysis of Chinese patients with anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer

Anaplastic lymphoma kinase (ALK) fusions have been recognized as a therapeutic target in non-small cell lung cancer (NSCLC). However, molecular signatures and clinical characteristics of the Chinese population with ALK-rearranged NSCLC are not well elucidated. In the present study, we carried out targeted next-generation sequencing on tissue and plasma ctDNA samples in 1688 patients with NSCLC. Overall, ALK fusions were detected in 70 patients (4.1%), and the frequencies of ALK fusions detected in tissue and plasma samples were 5.1% and 3.3%, respectively. Additionally, the prevalence of breakpoint locations for EML4-ALK fusions in ctDNA was significantly correlated with that in tumor tissues (R-2 = .91, P = .045). According to age, the incidence rates of ALK fusions among young (age <45 years), middle-aged (between 45 and 70 years) and elderly (>70 years) patients were significantly different (P < .001). In 70 ALK-rearranged cases, coexistence of epidermal growth factor receptor (EGFR) alterations and ALK fusions was detected in 12 cases (17.1%) and EGFR mutations tended to coexist with non-EML4-ALK rearrangements. Notably, novel ALK fusion partners, including TRIM66, SWAP70, WNK3, ERC1, TCF12 and FBN1 were identified in the present study. Among EML4-ALK fusion variants, patients with variant V1 were younger than patients with variant V3 (P = .023), and TP53 mutations were more frequently concurrent with variant V3 compared with variant V1 (P = .009). In conclusion, these findings provide new insights into the molecular-clinical profiles of patients with ALK-rearranged NSCLC that may improve the treatment strategy of this population.