Study Published in World Journal of Gastroenterology Shows Potential for microRNAs to Predict Gastric Cancer Recurrence

PHILADELPHIA and REHOVOT, Israel, Nov. 4, 2011 /PRNewswire/ -- Rosetta Genomics, Ltd. (NASDAQ: ROSG), a leading developer and provider of microRNA-based molecular diagnostics, announces that results from a joint study by researchers at the Institutes of Oncology, Davidoff Center, Rabin Medical Center, Beilinson Hospital and Golda-Hasharon Hospital in Petach-Tikva, Israel show that in post-resection gastric cancer patients microRNAs may serve to predict the risk of recurrence.

The study, entitled "microRNAs as a potential prognostic factor in gastric cancer," was published online September 21, 2011, and is set to appear in the print edition of the World Journal of Gastroenterology.   The abstract of the study can be viewed online at: http://www.ncbi.nlm.nih.gov/pubmed/22046085.

This retrospective study compared microRNA profiles in surgically resected primary gastric cancer tumors between patients with and without recurrence in order to evaluate their prognostic impact.  

Key Findings

• Three microRNAs were found to be differentially expressed in tumors from patients with good prognosis versus patients with bad prognosis, namely miR-451 (p<0.0002), miR-199a-3p (p<0.0027) and miR-195 (p<0.0046).
• High expression of each of these three microRNAs was associated with poorer prognosis for both recurrence and survival.
• Using miR-451, the positive predictive value for non-recurrence was 100% (13/13).
• The expression of differential microRNAs was verified by qRT-PCR, showing high correlation to microarrays and similar separation into prognosis groups.

Commenting on the clinical utility for such a potential microRNA prognostic, Baruch Brenner, M.D., Institute of Oncology, Davidoff Center, Rabin Medical Center, Beilinson Hospital and the lead author of the study, said, "The results of this study showed that three microRNAs may indeed serve as biomarkers for the risk of recurrence of gastric cancer after resection, and add to the accumulating data on the prognostic role of microRNAs in gastric cancer."

"Another strong point of this study is that it provides meaningful predictive values, which may have important implications for patient care. Informed decision-making using a test with a high positive predictive value can spare patients unnecessary and sometimes toxic post-surgery treatment.  We were able to identify a group of samples with low signals of miR-451 for which the positive predictive value for non-recurrence was 100%.  Thus, our finding, if validated, suggests that those with low miR-451 expression do not require adjuvant therapy because their risk of recurrence is low," concluded Dr. Brenner.  

"With nearly one million new cases of gastric cancer worldwide each year and a high incidence of recurrence, an accurate prognostic biomarker signature would be of significant value as clinicians currently rely on the staging of disease as the primary predictor.  This study underscores the need for better selection of patients for various treatment strategies as patients with a good prognosis may be spared potentially toxic adjuvant chemotherapy and radiation, and those with a poor prognosis may receive such treatment or even be offered investigational treatment programs," noted Kenneth A. Berlin, President and Chief Executive Officer of Rosetta Genomics. "This study further supports the role of microRNAs as important biomarkers and further validates the strength of Rosetta's microRNA discovery and development platform."  

About Gastric Cancer

Gastric cancer is a highly aggressive and lethal malignancy. It accounts for 8.6% of all new cancer cases worldwide and is the second leading cause of cancer deaths. Of the estimated 930,000 people newly diagnosed with gastric cancer each year, some 700,000 will die of the disease.(1) Although surgery is the standard treatment of localized gastric cancer, the results are often disappointing, with recurrence rates as high as 70% after successful complete resection. Attempts to improve outcomes with adjuvant therapy have yielded only modest success.

About miRview® Products

miRview® are a series of microRNA-based diagnostic products offered by Rosetta Genomics. miRview® mets and miRview® mets2 accurately identify the primary tumor type in metastatic cancer and CUP. miRview® squamous accurately identifies the squamous subtype of non-small cell lung cancer, which carries an increased risk of severe or fatal internal bleeding and poor response to treatment for certain therapies.  miRview® meso diagnoses mesothelioma, a cancer connected to asbestos exposure.  miRview® lung accurately identifies the four main subtypes of lung cancer using small amounts of tumor cells. miRview® tests are designed to provide objective diagnostic data; it is the treating physician's responsibility to diagnose and administer the appropriate treatment. In the U.S. alone, Rosetta Genomics estimates that approximately 200,000 patients a year may benefit from the miRview® mets and miRview® mets2 test, 60,000 from miRview® squamous, 60,000 from miRview® meso and more than 1 million patients worldwide from miRview lung. The Company's tests are offered directly by Rosetta Genomics in the U.S., and through distributors around the globe. For more information, please visit www.mirviewdx.com. Parties interested in ordering the test can contact Rosetta Genomics at (215) 382-9000 ext. 309.

About microRNAs

microRNAs (miRNAs) are recently discovered, small RNAs that act as master regulators of protein synthesis, and have been shown to be highly effective biomarkers.  The unique advantage of microRNAs as biomarkers lies in their high tissue specificity, and their exceptional stability in the most routine preservation methods for biopsies, including Formalin Fixed Paraffin Embedded (FFPE) block tissue and fine needle aspirate (FNA) cell blocks. It has been suggested that their small size (19 to 21 nucleotides) enables them to remain intact in FFPE blocks, as opposed to messenger RNA (mRNA), which tends to degrade rapidly. In addition, early preclinical data has shown that by controlling the levels of specific microRNAs, cancer cell growth may be reduced.  To learn more about microRNAs, please visit www.rosettagenomics.com .   

About Rosetta Genomics

Rosetta Genomics develops and commercializes a full range of microRNA-based molecular diagnostics.  Founded in 2000, the company's integrative research platform combining bioinformatics and state-of-the-art laboratory processes has led to the discovery of hundreds of biologically validated novel human microRNAs. Building on its strong patent position and proprietary platform technologies, Rosetta Genomics is working on the application of these technologies in the development and commercialization of a full range of microRNA-based diagnostic tools. The Company's miRview product line is commercially available through its Philadelphia-based CAP-accredited, CLIA-certified lab.  

Forward-Looking Statements

Various statements in this release concerning Rosetta's future expectations, plans and prospects, including without limitation, statements relating to the potential of microRNAs in the diagnosis and treatment of disease, constitute forward-looking statements for the purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including risks related to: Rosetta's approach to discover microRNA technology and to work on the application of this technology in the development of novel diagnostics and therapeutic tools, which may never lead to commercially accepted products or services; Rosetta's ability to obtain, maintain and protect its intellectual property; Rosetta's ability to enforce its patents against infringers and to defend its patent portfolio against challenges from third parties; Rosetta's need and ability to obtain additional funding to support its business activities; Rosetta's dependence on third parties for development, manufacture, marketing, sales, and distribution of products; Rosetta's ability to successfully develop its products and services; Rosetta's ability to obtain regulatory clearances or approvals that may be required for its products and services; the ability to obtain coverage and adequate payment from health insurers for the products and services comprising Rosetta's technology; competition from others using technology similar to Rosetta's and others developing products for similar uses; Rosetta's dependence on collaborators; and Rosetta's short operating history; as well as those risks more fully discussed in the "Risk Factors" section of Rosetta's Annual Report on Form 20-F for the year ended December 31, 2010 as filed with the Securities and Exchange Commission. In addition, any forward-looking statements represent Rosetta's views only as of the date of this release and should not be relied upon as representing its views as of any subsequent date. Rosetta does not assume any obligation to update any forward-looking statements unless required by law. 

(1) Parkin DM, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002.  C.A. Cancer   J Clin 2005; 55(2): 74-108 doi:10.3322/canjclin.55.2.74  PMID:  15761078

SOURCE Rosetta Genomics