While the technical success of a test is always an important consideration, it is extremely important in the case of uveal melanoma because the majority (more than 80%) of primary eye tumors are treated by radiation therapy. Due to the potential negative effect of radiation on gene expression profiling, genetic testing, and cytology, the tumor tissue sample must be taken PRIOR to radiation therapy. Furthermore, due to the potential for biopsy complications, the majority of ocular oncologists do not take a repeat or backup biopsy sample. As a result, if the subsequent test is not technically successful, then the physician and patient will lose the opportunity to act upon the results.

The DecisionDx-UM test has undergone extensive analytic validation. Multiple studies have shown that the test has excellent inter-assay, intra-assay, and inter-instrument reliability, with an overall technical success rate of 96% in reporting results. Assay performance on routinely submitted clinical specimens is part of Castle Biosciences’ ongoing Quality Control/Quality Assurance (QC/QA) program.  As of October 2019, a total of 10,138 clinical samples have been submitted for the DecisionDx-UM test. Of these samples, 90% were FNAB tissue and the remaining 10% were FFPE tissue.  

Published studies have also documented the superior technical success rate of gene expression profiling when compared to that of cytologic and genetic tests. Notably, Plasseraud, et al reported a technical success rate of 96.3% from 5,516 samples tested with DecisionDx-UM between 2010 and 2017. As shown in the table below, the failure rate for DecisionDx-UM test averaged between 3%-4% in published studies, while chromosome 3 testing and cytology have shown failure rates ranging from 13% to 50%.