New blood test detects cancer with high accuracy

A new “liquid biopsy” blood test offers the potential to diagnose and monitor cancer much earlier and easier than current methods. The minimally-invasive test analyzes the RNA of blood platelets to detect cancer with 96% accuracy, and correctly identifies the type and location of cancer with 71% accuracy, according to the study published October 29, 2015 in the Journal Cancer Cell.

“Being able to detect cancer at an early stage is vital,” said study co-author Jonas Nilsson, PhD, researcher in the Oncology Department at Umeå University, in Umeå, Sweden. “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.”

The researchers collected blood samples and isolated the blood platelets from 55 healthy donors and 228 patients with localized and metastasized tumors. They used mRNA sequencing to compare patients’ “tumor-educated” platelets (TEPs) against known mRNA cancer profiles. The test identified the presence of cancer with 96% accuracy. Among 39 patients in which an early diagnosis of cancer had been made, the test identified and classified 100% of the cases.

The test is based on the discovery that cancer tumors “educate” blood platelets by altering the platelets’ RNA profile. Thus, analyzing the mRNA profiles of tumor-educated platelets provides diagnostic information about the tumor’s type and location.

In follow-up experiments using the same method, the test was able to pinpoint the location of primary tumors in the lung, breast, pancreas, brain, liver, colon, and rectum with 71% accuracy.

“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,” Dr. Nilsson said.

The test samples were also sorted by molecular differences in the type of cancer, which has the potential to be highly useful in choosing a method of treatment, the authors noted.

If further trials validate this “liquid biopsy”—which uses the equivalent of one drop of blood—this test promises to be an all-in-one platform for blood-based cancer diagnosis, treatment, and monitoring, the authors predicted.