Utility of Tumor Genomic Analysis for Diagnostically Challenging Cancer Cases

Abstract: Background - Poorly differentiated tumors are clinically challenging, since an unclear diagnosis hinders therapeutic planning and prognostication. Therefore, new diagnostic tools are necessary for effective management of these cases. Tumor genomic analysis and mutation interpretation guided by a growing wealth of published data has potential to meet this need by providing clinically actionable information.



Hypothesis/Objectives - Our objective was to determine the diagnostic, prognostic, and therapeutic utility of genomic analysis for cases with ambiguous diagnoses and therefore uncertain treatment plans and unclear prognoses.



Animals - Thirty-five clinical oncology cases submitted for tumor genomic analysis with SearchLight DNA™, a genomic tumor profiling panel, were selected for evaluation.



Methods - Cases with histories or pathology reports containing the words “poorly differentiated”, “anaplastic”, “probable”, “possible”, “suspect”, “suggestive”, “malignant”, “neoplasia/neoplasm” or “round cell tumor” without further description of tumor type, or any non-specific diagnostic descriptors such as “atypical” were evaluated as a case series. Tumor-only next-generation sequencing was performed for all cases to identify mutations with biomarker associations in 120 cancer genes. Mutations with diagnostic, prognostic, or predictive associations were annotated according to our proprietary biomarker database and reported. These genomic reports were reviewed to identify cases in which genomic data provided medically applicable direction.



Results - In over 80% of these cases, genomic data provided any combination of diagnostic clarity, prognostic guidance, and/or treatment options.



Conclusions and clinical importance - Genomic analysis is a useful tool for the clinical management of diagnostically challenging cancers that would otherwise be difficult to treat or prognosticate.