MicroRNAs accurately identify four histological types of renal tumors: Study

Rosetta Genomics, Ltd. (NASDAQ:ROSG), a leading developer and provider of microRNA-based molecular diagnostics, announces that a peer-reviewed article entitled "Accurate Molecular Classification of Renal Tumors Using MicroRNA Expression" has been published in the online version of The Journal of Molecular Diagnostics. The study demonstrates the ability of microRNAs to accurately identify four histological types of renal tumors, namely clear cell, papillary, and chromophobe renal cell carcinoma, as well as oncocytoma, a benign tumor. The study is available online at: http://jmd.amjpathol.org/cgi/content/abstract/jmoldx.2010.090187v1

“Treatment options for RCC have increased significantly over the past decade, with targeted therapies playing an important role in this transformation. As with other types of cancers, the medical community is realizing the importance of accurate cancer subclassification for treatment choice and response for RCC”

The current classification of renal cell carcinoma includes four main types: conventional (clear cell), papillary, chromophobe, and collecting duct carcinoma, as well as unclassified renal cell carcinoma. Oncocytoma, papillary adenoma, mesonephric adenoma and angiomyolipoma are the main benign tumors in the kidney.

The publication describes a study of microRNA expression profiles in more than 120 renal tumor samples. Six microRNA biomarkers that are specifically expressed in the four most common histological types of renal tumors were identified, and were used to design an algorithm to classify these tumors. This classifier had 93% accuracy in diagnosing an independent test set of renal tumors.

The different histological subtypes of Renal Cell Carcinoma (RCC) vary in their clinical course and their prognosis. Patients with Clear-Cell RCC have a poorer prognosis, and differences may also exist between the prognosis of patients with papillary and chromophobe RCC (Non-Clear Cell).

Initial studies show differences in responses of RCC subtypes to targeted therapies, and future therapies may be individualized for each type. The accurate identification of these subtypes may play an important role in patient management and in the selection of patients for clinical trials of RCC drugs in development.

"Treatment options for RCC have increased significantly over the past decade, with targeted therapies playing an important role in this transformation. As with other types of cancers, the medical community is realizing the importance of accurate cancer subclassification for treatment choice and response for RCC," noted Kenneth A. Berlin, President and CEO of Rosetta Genomics. "Efforts are being made to understand which patients may benefit from particular therapies and to design targeted therapies to specific cancer subtypes. As demonstrated in this recent publication, microRNAs are powerful biomarkers that can accurately differentiate subtypes of RCC and have the potential to be used to for helping to target therapies to the appropriate RCC subtype."