The problem with this model, according to Dr. Jessup, is that, while more than 150 hospitals in the U.S. currently perform the qRT-PCR assay for BCR-ABL, and it has proven quite sensitive for molecular monitoring of CML. “None of these hospital laboratories can directly compare their results to any other.” He proposes that daily use of a calibrator/control for the assay could “harmonize results between labs, but a control is not readily available now.”
Dr. Jessup said that, “each lab becomes a silo of efficiency,” and “reproducibility within labs is excellent”; however, studies have shown considerable differences in the copy number of BCR-ABL between laboratories in samples taken at the time of diagnosis and after treatment. “The CLIA process reinforces precision,” but not as much accuracy, added Dr. Jessup.
He described global harmonization efforts under way to standardize the multitude of home-brew qRT-PCR assays, including an International Standardization Project in Australia and efforts to develop reference standards for use across Europe. In the U.S., the NCI will facilitate development of standards and reagents for the BCR-ABL assay.
Rosetta Genomics is applying its miRNA discovery process to the identification of diagnostic biomarkers for cancer, quantifying miRNA levels in a range of tissues and body fluids and creating disease-linked miRNA signatures.
Late last year the company introduced its first three miRNA-based cancer diagnostic tests. miRview™ squamous can differentiate between samples of squamous versus non-squamous non-small cell lung cancer (NSCLC) to stratify patients for treatment.
The company’s miRview mets product can identify the tissue-of-origin for 25 metastatic tumor types with a specificity of 97%. Knowledge of the tissue of origin of metastatic disease can guide therapeutic decision-making. For differentiating malignant mesothelioma or metastatic cancer affecting lung and pleural tissue from adenocarcinoma the company developed miRview meso.
In 2010, Rosetta plans to commercialize miRscreen™ Colon, a serum-based miRNA biomarker test that can differentiate patients with and without colorectal cancer. The test, with 91% sensitivity and 72% specificity, can be used to screen for colon cancer in blood samples to identify high-risk patients who should undergo colonoscopy.