Blood-Based Platelet RNA Tests Detects Cancer

By LabMedica International staff writers
Posted on 01 Dec 2015

Cancer is primarily diagnosed by clinical presentation, radiology, biochemical tests, and pathological analysis of tumor tissue, increasingly supported by molecular diagnostic tests.

A ribonucleic acid (RNA) test of blood platelets can be used to detect, classify and pinpoint the location of cancer by analyzing a sample equivalent to one tiny sample of blood. Using this new method for blood-based RNA tests of blood platelets, scientists have been able to identify cancer with 96% accuracy.

Image: Scanning electron micrograph of a clump of activated platelets (Photo courtesy of Brown University).

Image: Schematic overview of tumor-educated platelets (TEPs) as biosource for liquid biopsies (Photo courtesy of Cancer Cell).

An international team of scientists including those at Umea University (Sweden) studied blood samples from 283 individuals of which 228 people had some form of cancer and 55 showed no evidence of cancer. To minimize effects of long-term storage of platelets at room temperature and loss of platelet RNA quality and quantity, samples were processed within 48 hours after blood collection. By comparing the blood samples RNA profiles, team could identify the presence of cancer with an accuracy of 96% among patients. Among the 39 patients in the study in which an early detection of cancer had been made, 100% of the cases could be identified and classified.

Tumor tissues of patients were analyzed for the presence of genetic alterations by tissue DNA sequencing, including next-generation sequencing SnaPShot (Thermo Fisher; Waltham MA, USA) assessing 39 genes over 152 exons with an average sequencing coverage of greater than 500. Immunohistochemistry and fluorescent in situ hybridization (FISH) were also used. In follow-up tests using the same method, the investigators could identify the origin of tumors with a so far unsurpassed accuracy of 71% in patients with diagnosed cancer in the lung, breast, pancreas, brain, liver, colon and rectum. The samples could also be sorted in subdivisions depending on molecular differences in the cancer form, which can be of great use in the choice of treatment method.

Jonas A. Nilsson, PhD, a coauthor of the study said, “Being able to detect cancer at an early stage is vital. We have studied how a whole new blood-based method of biopsy can be used to detect cancer, which in the future renders an invasive cell tissue sample unnecessary in diagnosing lung cancer, for instance. In the study, nearly all forms of cancer were identified, which proves that blood-based biopsies have an immense potential to improve early detection of cancer.” The study was published on October 29, 2015, in the journal Cancer Cell.

Related Links:
Umea University
Thermo Fisher