Featured Research

from universities, journals, and other organizations

New method for early detection of colon cancer

Date:
September 4, 2013
Source:
American Association for Cancer Research (AACR)
Summary:
A new, highly sensitive method to detect genetic variations that initiate colon cancer could be readily used for noninvasive colon cancer screening, according to a new study.

A new, highly sensitive method to detect genetic variations that initiate colon cancer could be readily used for noninvasive colon cancer screening, according to a study published in Cancer Prevention Research, a journal of the American Association for Cancer Research.

"Tumor cells are released into stool from the surface of precancers and early-stage colon cancers, but detecting a cancer-initiating genetic mutation among a large quantity of normal DNA from a patient's stool is like looking for a needle in a haystack," said Bettina Scholtka, Ph.D., assistant professor in the Department of Nutritional Toxicology at the University of Potsdam in Nuthetal, Germany. "By combining for the first time locked nucleic acid-based, wild-type blocking polymerase chain reaction and high-resolution melting, we were able to achieve the desired sensitivity. The extremely high sensitivity of this technique allows us to find very low amounts of different types of the cancer-initiating mutations in patients' stool samples.

"Colon precancer cells carrying these genetic variations are routinely shed in stool samples, but these cells can be detected in blood only after the cancer has advanced, so stool is better than blood if we are to catch these cancers at a very early stage," she added.

About 60 percent and 40 percent of patients with colorectal cancer have genetic variations in the genes APC and KRAS, respectively. Because these variations are also present in precancers, methods for spotting them can help detect colon cancers early. The new method described in this study can detect a single cancer-specific gene variation among 10,000 times the amount of normal DNA, and is up to 5,000-fold more sensitive than other noninvasive screening methods.

A multicenter study is needed to validate the sensitivity and specificity of this new method in comparison with standard screening methods like colonoscopy, according to Scholtka.

Scholtka and colleagues used 80 human colon tissue samples representing cancers and precancers to detect genetic variations using a combination of two techniques: The first technique -- locked nucleic acid (LNA)-based, wild-type blocking (WTB) polymerase chain reaction -- suppressed normal DNA present in large quantities in the sample; and the second technique -- high-resolution melting (HRM) -- enhanced the detection of genetic variations.

The researchers were able to detect APC variations in 41 of the 80 samples. They were also able to detect previously unknown variations in APC. In contrast, the routinely used technique called direct sequencing could detect variations only in 28 samples.

They then analyzed 22 stool samples from patients whose colon tissues had APC variations, and nine stool samples from patients whose colon tissues did not have APC variations, as controls. They were able to detect APC variations in 21 out of 22 samples.

The researchers also detected variations in the KRAS gene using 20 human colon tissue samples to demonstrate that the WTB-HRM method can be used to detect variations in genes other than APC.

"By using our technique for examining a selection of genes that become mutated during the process of colon cancer formation, it is possible to detect the very first stage of colon cancer and even precancers in a stool sample," said Scholtka. "It will be possible to prevent cancer in many cases by removing the precancerous lesions after early detection."


Story Source:

The above story is based on materials provided by American Association for Cancer Research (AACR). Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Gerecke, C. Mascher, U. Gottschalk, B. Kleuser, B. Scholtka. Ultrasensitive Detection of Unknown Colon Cancer-Initiating Mutations Using the Example of the Adenomatous Polyposis Coli Gene. Cancer Prevention Research, 2013; 6 (9): 898 DOI: 10.1158/1940-6207.CAPR-13-0145

Cite This Page:

American Association for Cancer Research (AACR). "New method for early detection of colon cancer." ScienceDaily. ScienceDaily, 4 September 2013. <www.sciencedaily.com/releases/2013/09/130904092459.htm>.
American Association for Cancer Research (AACR). (2013, September 4). New method for early detection of colon cancer. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2013/09/130904092459.htm
American Association for Cancer Research (AACR). "New method for early detection of colon cancer." ScienceDaily. www.sciencedaily.com/releases/2013/09/130904092459.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins