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New blood test shows promise for screening of CRC, precancerous lesions
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Surface enhanced Raman spectroscopy analysis of blood plasma was shown to detect colorectal cancer and adenomatous polyps with high accuracy, according to research data.
“This is a screening technology you can use on anybody,” Haishan Zeng, PhD, from the BC Cancer Agency in Canada, said in a press release. The test “may yield a cheaper and less invasive initial screening test for colon cancer that could complement colonoscopy, though further clinical trials will need to demonstrate the safety and effectiveness of the blood test before it is routinely used,” according to the release.
Zeng and colleagues analyzed blood samples from 21 patients with CRC, 23 with adenomatous polyps and 25 healthy controls who were recruited at Vancouver General Hospital during scheduled colonoscopy. According to the press release, they mixed the plasma samples with silver nanoparticles and analyzed them using surface-enhanced Raman spectroscopy (SERS), which “uses a laser to excite the sample and measure shifts in the vibrational energy of its molecules. [This] can provide insight into the sample’s molecular structure.”
They found that SERS was able to discriminate samples of patients with polyps and CRC from healthy controls with 86.4% sensitivity and 80% specificity. Furthermore, it was able to discriminate samples of patients with polyps from those with CRC with 71.4% sensitivity and 95.6% specificity, and discriminate samples of patients with polyps from healthy controls with 91.3% sensitivity and 80% specificity. The area under the ROC curve for polyps and CRC vs. healthy controls was 0.938; for polyps vs. CRC it was 0.869; and for polyps vs. healthy controls it was 0.945.
“The result demonstrated that the plasma SERS spectra hold great promise for polyps and CRC detection with high sensitivity and specificity,” the researchers wrote.
According to the press release, the researchers did not determine the exact biomolecular sources for the differences between blood samples. “We are planning new research to identify these responsible molecules,” Zeng said.
“A blood test for colon cancer will never replace colonoscopy: once polyps are identified, a colonoscopy is still the best way to figure out where they're located so that they can be removed,” the release said. “However, a blood test could be used as a first line of defense to identify patients with warning signs of cancer; these high-risk patients could then be referred for a colonoscopy to learn more.” – by Adam Leitenberger
Disclosure: The researchers report they received financial support from the Canadian Institutes of Health Research.
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