Rosetta Genomics test use miRNAs for cancer of unknown primary diagnostic

REHOVOT, Israel—Encouraged by the results of a recent study that used miRNAs to identify tumor origins in some metastatic cancers, a team led by Israel-based Rosetta Genomics is developing a technology that will facilitate a diagnostic test for patients with cancer of unknown primary (CUP).

According to the American Society of Clinical Oncology, nearly 70,000 patients in the United States are diagnosed with cancer each year, but there is still no reliable method for determining the origin of the metastases in those cases.

However, in a study published in the April 2008 edition of Nature Biotechnology, Rosetta Genomics said its scientists and their collaborators identified several dozen miRNA biomarkers in tumor and metastatic tissue that can effectively pinpoint where the cancer originated.

"Accurately identifying the origin of a metastasis in CUP patients can be critical for determining appropriate treatment, and currently presents a true unmet diagnostic need for patients and physicians," said Amir Avniel, president and CEO of Rosetta Genomics. "This research demonstrates the tremendous potential of microRNAs as effective biomarkers, and is a significant step towards the development of the first microRNA-based diagnostic tests."

Non-coding, regulatory miRNAs play roles both in development and in the genesis and progression of some cancers. Because they show high tissue specificity, miRNAs are a potential tool for tracking down metastatic cancer's origin.

The Rosetta Genomics team measured miRNA expression levels in 400 paraffin-embedded and fresh-frozen samples from 22 different tumor tissues and metastases. The scientists used miRNA microarray data of 253 samples to construct a transparent classifier based on 48 miRNAs. The paper demonstrated, based on a blinded test set, that the overall sensitivity of this classifier was approximately 85 percent, with two-thirds of the samples being classified with high confidence, reaching accuracy exceeding 90 percent and specificity of 99 percent.

The company said it expects a CLIA-certified laboratory to launch the first miRNA diagnostic tests applying its technology later this year.