How a simple blood test may hold the key to detecting cancer

Researchers at Purdue University have developed a process to study blood that could open the door to detecting cancer in patients with a simple blood test.

While the complex procedure is years away from routine use, it could one day prove effective at early detection of cancer and early relapses, said W. Andy Tao, a professor of biochemistry at Purdue who led the work.

For now, Tao’s work has looked only at a small number of patients with breast cancer, but it could have implications for other cancers as well, said Timothy Ratliff, Robert Wallace Miller Director of the Purdue University Center for Cancer Research.

“The exciting part is it’s a blood test that really offers the potential to detect many different diseases,” Ratliff said.

The work appeared earlier this week in an online early edition of the Proceedings of the National Academy of Sciences.

Scientists have long known that substances known as phosphoproteins play a role in forming cancer cells. The presence of these so-called biomarkers could signal cancer. But phosphoproteins remain elusive in the blood because the liver releases an enzyme that allows the bad actors to disguise themselves as innocent bystanders.

These phosphoproteins could be found in tissue samples, but that would require an invasive and expensive procedure, Tao said.

“This biomarker has long been difficult to test,” Tao said. “My purpose is to come up with a much easier method.”

Using an ultra-high-speed centrifuge, Tao and his colleagues separated plasma from blood. That plasma contained sacs, or vesicles, that had encased phosphoproteins in their unaltered state.

The scientists compared blood samples from 30 breast cancer patients and six healthy women. Out of nearly 2,400 phosphoproteins detected, 144 existed in significantly higher numbers in the samples from the patients who had cancer.

Now, Tao wants to conduct a larger study to analyze and evaluate the many phosphoproteins that appear to be implicated in cancer. He has a side company, Tymora Analytical in the Purdue Research Park, that’s working on simplifying the technology so doctors could one day analyze blood samples without using a centrifuge.

Down the road, the technique could be used in concert with other screening methods, Tao said. For instance, if a mammogram detects something unusual but it’s not clear what that is, this test could prove useful in helping the doctor and patient decide whether to proceed with a biopsy.

After cancer treatment, regular blood tests that look for these phosphoproteins could help track whether cancer has returned, somewhat akin to the way prostate specific antigen, or PSA, testing is used to monitor a potential prostate cancer recurrence.

The method could also prove useful in the detection of a range of cancers as well as inflammatory diseases like arthritis, Ratliff said.

“Each cancer will probably have a different pattern, but all of those will have to be determined,” he said.

Call IndyStar reporter Shari Rudavsky at (317) 444-6354. Follow her on Twitter and Facebook.

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