Comparing Genomic Profiles of ALK Fusion-Positive and ALK Fusion-Negative Nonsmall Cell Lung Cancer Patients.

Background  Anaplastic lymphoma kinase ( ALK ) fusion events account for 3 to 7% of genetic alterations in patients with nonsmall cell lung cancer (NSCLC). This study aimed to explore the landscape of ALK fusion-positive and ALK fusion-negative in a large cohort of NSCLC patients. Methods  The formalin-fixed paraffin-embedded specimens of NSCLC patients who underwent next-generation sequencing from 2020 to 2023 in Yinfeng Gene Technology Co., Ltd. Clinical laboratory were included in this study. Results  In the current study, a total of 180 (3.20%) patients tested positive for ALK fusions in 5,622 NSCLC samples. Within the ALK -positive cohort, a total of 228 ALK fusions were identified. Furthermore, five novel ALK fusion partners, including DAB1-ALK , KCMF1-ALK , KIF13A-ALK , LOC643770-ALK , and XDH-ALK were identified. In cases with ALK fusion-positive, TP53 alterations were the most prevalent (26.3%), followed by CDKN2A (8.4%), epidermal growth factor receptor ( EGFR , 5.6%), and ALK (5.6%). By contrast, EGFR alterations were most prevalent (51%) in patients with ALK fusion-negative NSCLC, followed by TP53 (42.7%), KRAS (11.6%), and CDKN2A (11.3%). A total of 10 cases where ALK fusion co-occurred with EGFR mutations were also identified. Notably, the ALK fusion positivity rate was higher in younger patients ( p  < 0.0001) and in female patients ( p  = 0.0429). Additionally, positive ALK test results were more prevalent in patients with high programmed death-ligand 1 expression, especially when applying a 50% cutoff. Conclusions  Collectively, these findings offer valuable genomic insights that could inform the personalized clinical care of patients with NSCLC harboring ALK fusions within the context of precision medicine.