Chinese researchers develop new method for prostate cancer screening

Chinese researchers said Tuesday they have developed a simple, cheap and non-invasive method to screen for prostate cancer, a common type of cancer in men worldwide.

The new method, described in the U.S. journal Applied Physics Letters, combined an existing spectroscopy technique called surface-enhanced Raman scattering (SERS) with a new, sophisticated analysis technique called support vector machine (SVM).

When applied to blood samples collected from 68 healthy volunteers and 93 people who were clinically confirmed to have prostate cancer, the technique could identify the cases of cancer with an accuracy of 98.1 percent, said Shaoxin Li of China's Guangdong Medical College, who led the study, in a statement.

"The results demonstrate that label-free serum SERS analysis combined with SVM diagnostic algorithm has great potential for non- invasive prostate cancer screening," said Li. "Compared to traditional screening methods, this method has the advantages of being non-invasive, highly sensitive and very simple for prostate cancer screening."

According to the World Health Organization, prostate cancer is one of the most common types of cancer in men worldwide and a leading cause of cancer-related death. Every year, there are about 899,000 new cases and 260,000 mortalities, comprising six percent of all cancer deaths globally. About one in every six men will develop prostate cancer over their lifetimes.

While a simple blood test for elevated levels of a protein marker known as prostate specific antigen (PSA) has been used for years to screen for early cases of prostate cancer, the test is far from perfect because the elevated PSA levels can be caused by many things unrelated to cancer.

The U.S. Preventative Services Task Force recommends against PSA-based screening for prostate cancer because it contributes to over-diagnosis, uncomfortable tissue biopsies and other unnecessary treatment, which can be costly and carry significant side effects.

Many scientists have thought about applying SERS to cancer detection because the surface-sensitive type of spectroscopy has been around for years and is sensitive enough to identify subtle signals of DNA, proteins or fatty molecules that would mark a case of cancer, but the challenge is that these changes are, if anything, too subtle, Li said.

For example, the signal differences between the serum samples taken from the 68 healthy volunteers and the 93 people with prostate cancer were too tiny to detect. So to accurately distinguish between these samples, Li's group employed a powerful spectral data processing algorithm called SVM, which effectively showed the difference.

Li said their next research step is to refine the new method and explore whether this method can distinguish cancer staging.