A test that costs less than $1 (Rs.60) and yields results in minutes is more sensitive and exact than the current standard test for early-stage prostate cancer, US-based researchers say.
The simple test, developed by University of Central Florida scientist Qun "Treen" Huo, holds promise of early detection of one of the deadliest cancers among men.
It would also reduce the number of unnecessary and invasive biopsies stemming from the less precise prostate-specific antigen (PSA) test that is now being used.
"It is a simple test. It is much better than the test we have right now, which is the PSA and it is cost-effective," said co-author Inoel Rivera, urologic oncologist at Florida Hospital Cancer Institute.
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.
Gold nanoparticles are known for their extraordinary efficiency at absorbing and scattering light.
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.
Huo and her team developed a technique known as nanoparticle-enabled dynamic light scattering assay (NanoDLSay) to measure the size of the particles by analyzing the light they throw off.
That size reveals whether a patient has prostate cancer and how advanced it may be.
Although it uses gold, the test is cheap. A small bottle of nanoparticles suspended in water costs about $250 (Rs.15,000) and contains enough for about 2,500 tests.
"Because it is low-cost, we are hoping most people can have this test in their doctor’s office. If we can catch this cancer in its early stages, the impact is going to be big," the authors noted.After lung cancer, prostate cancer is the second-leading killer cancer among men.
The results of the pilot studies were published in journal ACS Applied Materials and Interfaces.