Background: Anaplastic lymphoma kinase (ALK) rearrangements have been reported as an important oncogenic driver in 5– 7% non-small cell lung cancer (NSCLC) patients. Reports about the intergenic region (IGR) as an ALK fusion partner are rare. In this study, we report a novel IGR (chr2: 30,316,870)-ALK fusion in an advanced lung adenocarcinoma patient that responded effectively to crizotinib combined with pemetrexed.
Case Presentation: A 68-year-old Chinese female was diagnosed with stage IV right lung adenocarcinoma (cT3N3M1c). The targeted next-generation sequencing (NGS) of 14 cancer-related genes identified an IGR (chr2: 30,316,870)-ALK fusion. Her lung lesions have been successfully converted from a partial response to a complete response after administrating crizotinib for 1 year combined with 6 cycles of chemotherapy with pemetrexed. So far, her progression-free-survival has reached 21 months.
Conclusion: In this case, we firstly report a novel IGR (chr2: 30,316,870)-ALK fusion by using targeted NGS, and highlight the efficacy of crizotinib combined with pemetrexed to reduce unbearable gastrointestinal adverse reactions. It provides valuable clinical guidance for the treatment of similar cases in the future.

Keywords: NSCLC, IGR-ALK, NGS, crizotinib, pemetrexed