Caught early, many cancers are better treatable. Hence, cancer screening is a critical approach for preventing cancer and cancer deaths. While there are many existing ways to screen for different types of cancer, there is still a great need for more safe, cheap and effective screening methods.
Now a team of researchers led by Shaoxin Li at Guangdong Medical College in China has demonstrated the potential of a new, non-invasive method to screen for prostate cancer. The researchers describe their laboratory success testing an existing spectroscopy technique called Surface-Enhanced Raman Scattering or SERS with a new, sophisticated analysis technique called Support Vector Machine or SVM.
The study, published in Applied Physics Letters, combined SERS and SVM and applied them to blood samples collected from 68 healthy volunteers and 93 people who were clinically confirmed to have prostate cancer. The scientists found that this technique could identify the cases of cancer with an accuracy of 98.1%.
… signal differences between the serum samples taken from healthy volunteers and cancer patients were too tiny to detect… but if [this] technique is safe and effective in clinical trials, it may become a new method to help early detection and diagnosis…
Clinical trials
“If the technique proves safe and effective in clinical trials, it may become a new method available to patients and their doctors, helping to improve the early detection and diagnosis of this type of cancer,”Li said.
“The results demonstrate that label-free serum SERS analysis combined with SVM diagnostic algorithm has great potential for non-invasive prostate cancer screening,” Li noted. “Compared to traditional screening methods, this method has the advantages of being non-invasive, highly sensitive and very simple for prostate cancer screening.”
A common cause
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 6% of all cancer deaths globally. About 1 in every 6 men will develop prostate cancer over their lifetimes.
PSA-based screening
While a simple blood test for elevated levels of a protein marker known as Prostate Specific Antigen or 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.
This contributes to over-diagnosis, uncomfortable tissue biopsies and other unnecessary treatment, which can be costly and carry significant side effects. Because of this, the U.S. Preventative Services Task Force now recommends against PSA-based screening for prostate cancer.
According to Li, 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 key molecules in very low abundance, like pesticide residues on a contaminated surface. This would seem to make it perfect for spotting subtle signals of DNA, proteins or fatty molecules that would mark a case of cancer — exactly why he and his team tackled the problem.
“The challenge,” Li said, “was that these changes were, if anything, too subtle. 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, support vector machine, which effectively showed the difference.”
“While the work is preliminary, it shows that serum SERS spectroscopy combined with SVM diagnostic algorithm has the potential to be a new method for non-invasive prostate cancer screening,” Li further explained. The next research step, Li and his team are interested in perusing is to refine the method and explore whether this method can distinguish cancer staging.
For more information
Li S, Zhang Y, Xu J, Li L, Zeng Q, Lin L, Guo Z, et al. Noninvasive prostate cancer screening based on serum surface-enhanced Raman spectroscopy and support vector machine Applied Physics Letters,AIP September 2, 2014.[Article]
Photo: A team led by researchers at Guangdong Medical College in China has demonstrated the potential of a new, non-invasive method to screen for prostate cancer, a common type of cancer in men worldwide. Photo courtesy: S.Li/Guangdong Medical College, China.
Copyright ? 2014 Sunvalley Communication. All rights reserved. Republication or redistribution of Sunvalley Communication content, including by framing or similar means, is expressly prohibited without the prior written consent of Sunvalley Communication. Sunvalley Communication shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Onco’Zine and Oncozine are registered trademarks and trademarks of Sunvalley Communication around the world.
