Studies support diagnostic utility of molecular classification in difficult-to-diagnose metastatic cancer

bioTheranostics, Inc., developer of innovative oncology diagnostic tests and solution provider for metastatic cancer, today announced findings from two studies showing high diagnostic accuracy for CancerTYPE ID^® in determining the primary tumor site in high-grade, metastatic tumors. Results were reported at the 2012 annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago.

“The results strongly support the diagnostic utility of molecular classification in difficult-to-diagnose metastatic cancer.”

CancerTYPE ID is the leading molecular classifier that has been shown to discriminate among tumor types that pose diagnostic dilemmas in metastatic cancer.

In a prospectively defined, blinded study in collaboration with the City of Hope National Medical Center (Abstract #e21019), high-grade, primarily metastatic cases were selected by lead investigators Lawrence Weiss, M.D., and Peiguo Chu, M.D. In the study, performance of immunohistochemistry (IHC) for primary site diagnosis was directly compared with CancerTYPE ID in a series of 122 difficult-to-diagnose cases. Results, which were scored within a clinically relevant categorization system designated by Dr. Weiss, were compared with reference diagnoses established by clinical correlation.

In this difficult-to-diagnose, high-grade metastatic cancer cohort, CancerTYPE ID demonstrated a 10 percent absolute accuracy improvement versus IHC.

bioTheranostics Chief Scientific Officer Mark Erlander, Ph.D., noted that this is the first study to directly compare the diagnostic accuracy of molecular classification versus IHC. "These results demonstrate superior accuracy with the CancerTYPE ID molecular classifier compared with IHC, which has been the cornerstone technique in pathologic evaluation of metastatic cancer for tumor classification," Erlander said. "The results strongly support the diagnostic utility of molecular classification in difficult-to-diagnose metastatic cancer."

A second blinded, multi-institutional study (Abstract #10588) with three centers of excellence (UCLA, Mayo Clinic, and Massachusetts General Hospital), evaluated the accuracy of CancerTYPE ID in determining primary tumor type by looking at 790 archival tumor specimens. In the largest validation study of a molecular classifier to date, a comprehensive and diverse range of tumor samples was processed and adjudicated between the three hospitals, including metastatic, mainly poorly differentiated and undifferentiated primary cases, and limited-tissue specimens.

Results comparing tumor type predicted by the classifier with the adjudicated reference diagnosis showed that the top prediction for main tumor type was accurate 87 percent of the time, and the tumor subtype was accurate 82 percent of the time. Test accuracy was 94 percent when "cannot be excluded" (rule-in) tumor types were included with the top prediction.

The study also showed that there was no statistical difference in CancerTYPE ID's ability to classify primary versus metastatic tumors. Similarly, no statistical difference in performance was observed in cases where specimen quantity was limited, as is common with core and fine needle biopsies.

Richard Ding, CEO of bioTheranostics, said these studies further validate the diagnostic accuracy of the CancerTYPE ID assay for classifying a diverse set of tumors and support its clinical utility in a wide array of clinically relevant situations, including metastatic tumors, high-grade tumors, and limited-tissue specimens.

"Diagnostic certainty for tumor classification is essential for selection of site-specific chemotherapy, appropriate biomarker testing, and effectiveness of molecular targeted treatments," Ding said. "CancerTYPE ID has shown its value compared with standard-of-care IHC in identifying metastatic cancers—by far the most difficult-to-diagnose tumors. And the largest validation study ever for a molecular classifier showed the power of CancerTYPE ID in identifying tumors without any loss of performance between primary and metastatic tumors, and even when there is a small amount of specimen, which is increasingly common. These results support the use of CancerTYPE ID as a standardized diagnostic aid when primary tumor site is uncertain."

CancerTYPE ID is being exhibited at bioTheranostics' booth, No. 16097.