Clapper, Patti, Schweizer and Mason

Drawing on recent research into better methods of diagnosing mesothelioma from several cancer centers around the world, a molecular diagnostics company has released a test for mesothelioma that uses microRNAs as indicators.  The company, Rosetta Genomics, is touting this new test as an accurate method for screening patients suspected of having undiagnosed malignant pleural mesothelioma. Furthermore, the test has shown to improve accuracy in differentiating mesothelioma from adenocarcinoma in the lung or pleura.

MicroRNAs are little snippets of genetic code that allow communication between cells.  They attach to corresponding points on messenger RNA (mRNA) and essentially tell the cell which genes to express and which to suppress. 

This new test, marketed as miRview meso, uses tissue samples and can provide results in as few as ten days. 

Similar tests microRNA tests have been suggested in correlation with blood samples but this test requires a biopsy.  And therein lay the difficulty. 

Currently, biopsy is the only way to accurately confirm or deny a mesothelioma diagnosis.  The hurdle that Rosetta Genomics will have to overcome is proving that their test is at least as accurate as current biopsy techniques. 

One area in which the Rosetta Genomics test could be better than current testing is in the ease with which it could differentiate mesothelioma from other forms of cancer.  Rosetta Genomics’ Head of Clinical Laboratory research and Medical Director Tina Edmonston pointed out that “differentiating MPM from primary and metastatic carcinoma in the lung and pleura can be challenging for pathologists, even with the use of immunohistochemistry.”  She went on to say that “the choice of markers [used in the test], as well as interpretation of the results in equivocal cases can be subjective.”  It is her hope that the new microRNA test from her company could help eliminate the irregularities in testing and decrease the numbers of false positives and missed diagnoses. 

The test, according to the company’s web page, showed 95% sensitivity and 96% specificity making it much more reliable than other proposed microRNA tests.  These results are achieved by using proprietary technology including specific techniques for extracting samples from biopsied tissue and “quantitative Real-Time Polymerase Chain Reaction (qRT-PCR)” to assess the number of mesothelioma-associated microRNAs within the sample.

While the promise this new mesothelioma test shows is exciting, it probably won’t replace traditional testing methods for quite some time.  And though it does represent the “next step” in mesothelioma testing, it does not necessarily allow for earlier diagnosis.  Patients still must notice symptoms, be examined by health professionals, who in turn must recognize potential mesothelioma tumors, and undergo a biopsy. 

Researchers working on blood tests for mesothelioma using related microRNAs as biomarkers are hopeful that this approach will produce much faster results as these techniques can be used without a biopsy sample.