Gene rearrangements frequently act as oncogenic driver mutations and determine the onset and progression of cancer. RNA-based next-generation sequencing (NGS) is being used with increasing frequency for solid tumors. The purpose of our study is to investigate the feasibility and utility of an RNA-based NGS fusion panel for solid tumors.
We conducted a retrospective, single-institution review of fusion panels requested between May 2022 and March 2023. Demographic, clinical, pathologic, and molecular findings of the patients were reviewed. The utility of the RNA-based NGS fusion panel for the pathologic diagnosis of solid tumors was assessed.
Our study included 345 cases, and a fusion event was identified in 24.3% (78/321) of cases. Among the 110 cases submitted for diagnostic purposes, a fusion event was detected in 42.7% (47/110) of cases. The results led to refinement or clarification of the initial diagnosis in 31.9% (15/47) of cases and agreement or support for the initial diagnosis in 59.6% (28/47) of cases. Furthermore, our study indicated that the overall cellularity (tumor and normal tissue) of the tested specimen influences the success of the testing process.
In summary, this study demonstrated the feasibility and utility of an RNA-based NGS fusion panel for a wide variety of solid tumors in the appropriate clinicopathologic context. These findings warrant further validation in larger studies involving multiple institutional patient cohorts.

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