Anaplastic lymphoma kinase (ALK) partners identified by next-generation sequencing in Chinese patients with solid tumors.

Abstract

3555 Background: Anaplastic lymphoma kinase (ALK) rearrangement is a validated therapeutic driver gene in non-small cell lung cancer (NSCLC). More than 30 different fusion partner genes of ALK in NSCLC have been reportedand most of these ALK fusions respond well to ALK inhibitors crizotinib. With the development of next-generation sequencing (NGS), more novel partners for ALK rearrangement have been identified. Here, we aimed to report the landscape of ALK rearrangement in Chinese patients with solid tumors. Methods: Tissue or blood samples were subjected to NGS in a College of American Pathologists-certified and Clinical Laboratory Improvement Amendments-accredited lab for ALK arrangement. Results: In total, we profiled more than 40,000 patients, among which 72 cases with 52 ALK fusion partner, harboring 17 reported partners and 35 novel partners. The average ALK rearrangement patients' age was 53 years (range, 17-76 years). Among all the ALK fusion cases (n = 72), lung cancer were the largest proportion with 77.8% (n = 56), colorectal cancer accounted for, 5.5% (n = 4), liver cancer accounted for 4.2% (n = 3), biliary cancer, melanoma, carcinosarcoma and inflammatory myofibroblastic tumor accounted for 2.8% (n = 2) respectively, and only one case (n = 1) was malignant peritoneal mesothelioma. The most common ALK fusion partners were KIF5B (n = 6), DCTN1 (n = 5) and STRN (n = 5). In 38 cases, 35 novel ALK fusion partners were discovered. The novel CLIP4-ALK, EHBP1-ALK, PLB1-ALK occurred twice in 6 patients, which were two lung cancer patients with CLIP4-ALK fusion, two lung cancer patients with PLB1-ALK fusion, one hepatic cellular cancer patients with EHBP1-ALK, and one melanoma patients with EHBP1-ALK. There were two special lung cancer cases with two ALK fusions. One case detected the novel LRIG1-ALK fusion and novel PLB1-ALK fusion, the other case detected novel GLI3-ALK fusion and reported HIP1-ALK fusion. Conclusions: Novel ALK fusions are detected in patients with not only NSCLC but also other solid tumors. NGS fusion assay is an optional method for screening novel fusions.