Blood-based colon cancer screen shows promise in UW-Madison study

April 08, 2019

MADISON - If caught early, nearly all cases of colon cancer are curable. Though this should make screening tests straightforward, colon cancer screening suffers from a paradoxical combination of low compliance rates and overdiagnosis. In a study published April 8, 2019 in the Proceedings of the National Academy of Sciences, a group of University of Wisconsin-Madison scientists has identified four blood-based fingerprints - human protein markers - associated with the pre-cancerous forms of colon cancer that are most likely to develop into disease.

The scientists expect their findings will ultimately lead to a blood test for the cancer, adding a method to help increase screening rates while reducing overtreatment.

"This study is the first peek at the possibility that there will be blood markers for a minimally-invasive procedure that can reduce over-diagnosis. They do exist," says senior author Bill Dove, professor of oncology and genetics with the McArdle Laboratory for Research and Carbone Cancer Center at UW-Madison.

The gold standard for colon cancer screening is optical colonoscopy, where patients must complete a day-long prep to empty their bowels before undergoing an invasive procedure - factors that contribute to low screening compliance.

When a doctor finds growths in the colon during the procedure, in most cases, they will remove those polyps and have them analyzed as either cancerous or benign (which are further divided into high or low-risk of becoming cancerous).

Another screening option, computed tomographic colonography, requires a similar bowel prep but provides a non-invasive image of the colon. This method requires a follow-up optical colonoscopy and polyp removal if it reveals an area of concern. In many low-risk cases, physicians will recommend a monitoring approach instead.

In studies of patients undergoing computed tomographic colonoscopy, researchers have found that the majority of small polyps detected during screening will never become cancerous and treating them is unnecessary.

To cut down on over-treatment, the researchers in this study looked for proteins that are elevated in the blood of only those patients who have growing polyps or cancerous polyps but not elevated in patients with non-growing polyps or no polyps at all.

They examined blood samples from 90 optical colonoscopy patients - split into groups of no, low- or high-risk pre-cancerous polyps - and 31 computed tomographic colonography patients who were monitored without polyp removal.

Next, the scientists selected 19 proteins they previously found to be elevated in rodent models of colon cancer and performed a technique known as mass spectrometry to measure protein concentrations in the patients' blood.

Because they already knew the results of each patients' colonoscopy, the researchers could correlate patient blood marker findings with their outcomes, allowing them to identify which markers, if any, are specifically associated with growing or cancerous polyps.

Lead study author Melanie Ivancic found four elevated proteins that are associated with early colon cancer in the patients studied.

"There's good evidence they're being conserved in early disease in humans," Dove says. "We didn't expect we could find blood markers for such small, early, pre-malignant polyps in humans, but we did."

The group at UW-Madison is just one of many studying ways to improve early detection of colon cancer. Dove notes that others, including Exact Sciences Corporation, also in Madison, have already developed effective, non-invasive screening tests. He views a potential blood-based test as a complement to these others.

"We believe success may come from combining multiple strategies that are statistically independent from each other- called 'orthogonality,'" Dove says. "Our study reports markers that, though modest in power, may contribute to orthogonal quantitative marker panels to detect the growing pre-malignant adenoma in the colon."
-end-
The project was supported by grants from the National Institutes of Health, the National Cancer Institute and the Wisconsin Alumni Research Foundation. Author Perry Pickhardt is co-founder of VirtuoCTC, consultant for Bracco and Check-Cap, and shareholder of SHINE, Elucent, and Cellectar. Authors Melanie Ivancic, Perry Pickhardt, Mark Reichelderfer, Michael Sussman and Bill Dove are inventors on patent application PCTUS2015065049 submitted by The Wisconsin Alumni Research Foundation that covers the quantitative proteomic analysis, animal model, and patient resource design described in this report.

Sarah Perdue, saperdue@wisc.edu, 608-262-6062

Download a photo of Prof. Bill Dove: https://uwmadison.box.com/s/lmmhvzj4e2y0h9k3hps7taktyz0oy746

University of Wisconsin-Madison

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.