One dollar test to detect prostate cancer early

A simple test that costs less than 60 rupees and yields results in minutes has been shown to be more sensitive and exact than the current standard test for early-stage prostate cancer, scientists say.
The test developed by University of Central Florida scientist Qun "Treen" Huo holds the promise of earlier detection of one of the deadliest cancers among men.
The test that cost less than a dollar would also reduce the number of unnecessary and invasive biopsies stemming from the less precise Prostate-Specific Antigen (PSA) test that is currently used.
"It's fantastic. It's a simple test. It's much better than the test we have right now, which is the PSA, and it's cost-effective," said Dr Inoel Rivera, a urologic oncologist at Florida Hospital Cancer Institute, which collaborated with Huo on the pilot studies.

When a cancerous tumour begins to develop, the body mobilises to produce antibodies. Huo's test detects that immune response using gold nanoparticles about 10,000 times smaller than a freckle.
When a few drops of blood serum from a finger prick are mixed with the gold nanoparticles, certain cancer biomarkers cling to the surface of the tiny particles, increasing their size and causing them to clump together.

Gold nanoparticles are known for their extraordinary efficiency at absorbing and scattering light.
Huo and her team developed a technique known as nanoparticle-enabled dynamic light scattering assay (NanoDLSay) to measure the size of the particles by analysing the light they throw off.

That size reveals whether a patient has prostate cancer and how advanced it may be.
And although it uses gold, the test is cheap. A small bottle of nanoparticles suspended in water costs about USD 250, and contains enough for about 2,500 tests.
"What's different and unique about our technique is it's a very simple process, and the material required for the test is less than USD 1," Huo said.
"And because it's low-cost, we're hoping most people can have this test in their doctor's office," said Huo.
After lung cancer, prostate cancer is the second-leading killer cancer among men, with more than 240,000 new diagnoses and 28,000 deaths every year, researchers said.

The most commonly used screening tool is the PSA, but it produces so many false-positive results - leading to painful biopsies and extreme treatments - that one of its discoverers recently called it "hardly more effective than a coin toss."
Pilot studies found Huo's technique is significantly more exact. The test determines with 90 to 95 per cent confidence that the result is not false-positive.
When it comes to false-negatives, there is 50 per cent confidence, significantly higher than the PSA's 20 per cent.
The findings were published in the journal ACS Applied Materials & Interfaces.