Doctors may soon be able to detect and monitor a patient's cancer with a simple blood test, reducing or eliminating the need for more invasive procedures, according to a new study.
Researchers from Purdue University in the US identified a series of proteins in blood plasma that, when elevated, signify that the patient has cancer.
The study was done with samples from breast cancer patients, but it is possible the method could work for any type of cancer and other types of diseases, researchers said.
The work relies on analysis of microvesicles and exosomes in blood plasma.
"There are so many types of cancer, even multiple forms for different types of cancer, that finding biomarkers has been discouraging," said W Andy Tao of Purdue University Centre for Cancer Research.
"This is definitely a breakthrough, showing the feasibility of using phosphoproteins in blood for detecting and monitoring diseases," Tao added.
Researchers found nearly 2,400 phosphoproteins in a blood sample and identified 144 that were significantly elevated in cancer patients.
They then compared one-milliliter blood samples from about 30 breast cancer patients with six healthy controls.
The researchers used centrifuges to separate plasma from red blood cells, and high-speed and ultra-high-speed centrifuges to further separate microvesicles and exosomes.
Those particles, which are released from cells and enter the bloodstream, may play a role in intercellular communication and are thought to be involved in metastasis, spreading cancer from one place to another in the body.
"The samples we used were 5 years old, and we were still able to identify phosphoproteins, suggesting this is a viable method for identifying disease biomarkers," Tao said.
The study was published in the journal Proceedings of the National Academy of Sciences.