MicroRNAs may predict risk of recurrence in post-resection gastric cancer patients

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."