Blood Based Gene Expression Assay Diagnoses Lung Cancer

The applicability of whole blood–based gene expression profiling for the detection of non-small-cell lung cancer (NSCLC) has been evaluated.

The blood test has been developed for smokers, and uses molecular biological methods and biochips to quantify the ribonucleic acid (RNA) that has been isolated from gene stabilized blood samples.

Scientists at the University of Bonn (Germany) collaborating with others, generated expression profiles from PAXgene-stabilized blood samples from three independent groups consisting of NSCLC cases and controls, using a whole-genome gene expression analysis system. After RNA isolation, complementary RNA was biotin-labeled, hybridized, and scanned.

Several genes were consistently differentially expressed in whole blood of NSCLC patients and controls. These expression profiles were used to build a diagnostic classifier for NSCLC, which was validated in an independent validation set of NSCLC patients (stages I–IV) and hospital-based controls. The analysis identified 484 NSCLC-specific features, 199 cancer modules including 26% of all NSCLC-associated modules were identified to show a significant enrichment. This indicates that genes used to build a classifier for NSCLC cases in this study represent, in part, a subset of biologically cooperating genes that are also differentially expressed in primary lung cancer. To stabilize the RNA, the blood was drawn into PAXgene vials (QIAGEN; Copenhagen Denmark) and was hybridized using the Sentrix whole genome bead chips (Illumina Inc.; San Diego, CA, USA).

Joachim L. Schultze, MD, a professor at the University of Bonn, said, "It was important to us that a subsequent test not only be able to differentiate lung cancer patients from healthy subjects, but also from persons with chronic lung diseases." The scientists are presently planning an analogous but much larger study with ten times as many patients, in order to confirm the results. If the present results prove to be true in such a study, there would no longer be anything standing in the way of developing the blood test to the point of being ready to be put on the market. The study was published on May 15, 2011 in the journal Clinical Cancer Research.

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University of Bonn
QIAGEN
Illumina Inc.