Days of using painful bone biopsies to diagnose and treat certain cancers may be numbered as researchers have found that a simple blood test that uses a plastic chip about the size of a credit card can do the job.

The diagnosis and treatment of multiple myeloma, a cancer affecting plasma cells, traditionally forces patients to suffer through a painful bone biopsy. During that procedure, doctors insert a bone-biopsy needle through an incision to get a bone marrow sample -- or make a larger incision and remove a section of bone via surgery. Bone biopsies are used to guide treatment of certain other cancers, such as many types of leukemia.

The new study, published in the journal Integrative Biology, showed that a low-cost chip-based blood test can deliver the same diagnostic information as a bone biopsy -- but using a simple blood draw instead. This test will be able to help clinicians determine the stage of the disease, what type of drug will best treat the disease and monitor for signs of recurrence if the disease goes into remission, the researchers said.

"For the last 10 years, we've been developing a blood-based test for a variety of cancer diseases -- one of them is multiple myeloma," said Steven Soper, Professor at University of Kansas in the US. "We'll be able to eliminate the need for bone-marrow biopsies and allow the clinician to determine the best way to treat the disease using a blood draw," Soper added. Soper said that previous plastic chips to test for multiple myeloma had shortcomings, such as picking up regular blood cells instead of multiple myeloma cells in the blood.

By contrast, the new chip vastly improves testing performance and accuracy over previous chips for multiple myeloma, according to the researchers. High levels of circulating multiple myeloma cells are linked with more aggressive disease and worse outcomes, so a sensitive test is vital for assessing the state of the disease in a patient and devising the most effective therapy. "What's really nice is we can produce these chips for a couple of dollars per chip, which makes it really appropriate for testing in a clinical setting," Soper said. The new test for multiple myeloma developed by the team will be brought to market by BioFluidica, a San Diego-based company. "Patients will soon be benefiting from this technology," Soper said.