Coexistence of a novel CCNY-ALK and ATIC-ALK double-fusion in one patient with ALK-positive NSCLC and response to crizotinib: a case report.

Anaplastic lymphoma kinase (ALK) rearrangement, one of the common oncogene rearrangements in the mutational history of lung adenocarcinoma, occurs in approximately 5% of non-small cell lung cancer (NSCLC) patients who could be effectively treated with ALK tyrosine kinase inhibitors (TKIs). The earlier phase III PROFILE 1014 study has shown that crizotinib, a first-generation ALK-TKI, significantly improved progression-free survival (PFS) compared with platinum-based chemotherapy in patients with previously untreated advanced ALK-positive NSCLC. Thus, clinicians must screen potential candidates for this driver alteration to guide ALK inhibitor therapy with a molecular testing platform capable of capturing all ALK fusions. Echinoderm microtubule-associated proteins, including the gene, are the most common ALK rearrangement partner. With the widespread use of the next-generation sequencing (NGS) techniques, which could approach enable the simultaneous screening of multiple genetic alterations, increasingly ALK rearrangement partners have been documented. However, the concurrent two ALK rearrangements within the same patient have rarely previously been reported. Here, we describe a novel CCNY-ALK (C1:A20) and ATIC-ALK (A7:A20), coexisting in the same case with poorly differentiated NSCLC and providing evidence of its sensitivity to ALK inhibitors. The newly identified rearrangement partners can be added to the list of ALK rearrangements that occurred in ALK-positive NSCLC, as it could lead to prolonged disease control. Also, while different ALK rearrangement variants might bring differing clinical outcomes, we discuss the impact of the co-mutations of these two ALK rearrangements on the sensitivity to ALK inhibitors. However, the impact of co-mutations on the pathogenesis of NSCLC should be further studied to supply more theoretical insight that co-mutations present for personalized anti-cancer therapy.