Sysmex Inostics, Mundelein, Ill, a subsidiary of Sysmex Corp, has announced new data from a real-world prospective evaluation of the company’s OncoBeam RAS CRC test during routine clinical use in hospital laboratories across Spain.1

The OncoBeam RAS CRC assay was granted the CE mark in 2016 as part of a global collaboration with Merck KGaA. It is a comprehensive blood-based test that evaluates 34 mutations in KRAS and NRAS (RAS) genes, as recommended by clinical practice guidelines, to determine RAS mutation status in metastatic colorectal cancer (mCRC) patients prior to the initiation of targeted therapy. OncoBeam RAS CRC is the only liquid biopsy assay with CE mark status for plasma RAS mutation analysis, and it has been installed at a number of certified centers of excellence over the past year.

In order to support clinical adoption of the test, Sysmex Inostics conducted a rigorous real-world evaluation of the performance of OncoBeam RAS CRC in routine use by a consortium of 10 preeminent Spanish hospital centers. The prospective performance evaluation compared the RAS mutation results of OncoBeam RAS CRC liquid biopsy testing to tissue testing in a sampling of patients from each hospital. The study evaluated test results from more than 230 patients. The overall concordance of results from plasma and tissue RAS mutation testing was 90.5%, with positive percent agreement of 86.9% and negative percent agreement of 95.1%.

To gather more insight into discordant cases, tissue was reanalyzed with Beaming and revealed two false-negative local tumor tissue RAS results. In patients presenting with isolated peritoneal or lung metastases, plasma false-negative results were observed more frequently. This confirmed previously reported findings indicating that isolated lung metastases and peritoneal lesions are typically less likely to deposit tumor DNA into peripheral circulation. The overall prevalence of RAS mutations in plasma (51.3%) and tissue (56.5%) matched the expected prevalence of RAS mutations in mCRC patients.

In this first prospective real-world RAS mutation performance comparison study across a network of hospital laboratories certified to perform OncoBeam testing in routine clinical practice, a high overall agreement was observed between results obtained from plasma and tissue samples. Overall, the findings indicate that plasma OncoBeam RAS testing is a viable solution for rapid delivery of RAS mutation status to determine mCRC patient eligibility for anti-EGFR therapy.

“Since the OncoBeam platform was installed a little over a year ago, we have been rigorously evaluating its performance to ensure its appropriateness for routine clinical practice,” says lead author of the study Jesus Garcia-Foncillas, MD, director of the cancer institute at the University Hospital Fundacion Jimenez Diaz, of the Autonomous University of Madrid. “Based on our experience and these recent results, we are enthusiastically supportive of OncoBeam blood-based testing, and grateful to have this valuable test available for mCRC patients. OncoBeam has demonstrated accurate and reliable performance in real-world practice and is a significant benefit to patient care, providing RAS mutation status results within days, which helps to accelerate treatment decisions for patients with advanced disease.”

Requiring only a single blood draw, the highly sensitive OncoBeam RAS CRC test is a simplified method for determining the RAS mutation status of tumors. The test has the potential to provide mutation status results within days to help guide quicker treatment decisions. Moreover, the blood-based test is an alternative to tissue biopsies or other surgical procedures, and can be performed when no tumor tissue is available or a rapid test result is crucial for therapy success. The OncoBeam RAS CRC test is currently available across Asia Pacific, China, and Europe, to determine RAS mutation status for newly diagnosed mCRC patients with a simple blood draw in routine clinical practice.

For more information, visit Sysmex Inostics.


  1. Garcia-Foncillas J, Tabernero J, Aranda-Aguilar E, Benavides M, et al. First prospective multicenter real-world RAS mutation comparison between OncoBeam-based liquid biopsy and tissue analysis [abstract of presentation at the European Society for Medical Oncology annual meeting (Madrid, Spain: 8–12 September 2017)]. Ann Oncol. 2017; 28(suppl 5):129P; doi: 10.1093/annonc/mdx363.045.