(Press-News.org) PHILADELPHIA — 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."
###
Follow the AACR on Twitter: @AACR
Follow the AACR on Facebook: http://www.facebook.com/aacr.org
About the American Association for Cancer Research
Founded in 1907, the American Association for Cancer Research (AACR) is the world's oldest and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR membership includes more than 34,000 laboratory, translational, and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in more than 90 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis, and treatment of cancer by annually convening more than 20 conferences and educational workshops, the largest of which is the AACR Annual Meeting with more than 18,000 attendees. In addition, the AACR publishes eight peer-reviewed scientific journals and a magazine for cancer survivors, patients, and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the scientific partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration, and scientific oversight of team science and individual grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit http://www.AACR.org.
To interview Bettina Scholtka, contact the press office of the University of Potsdam at 49-0-331-977-0 or presse@uni-potsdam.de. For other inquiries, contact Jeremy Moore at jeremy.moore@aacr.org or 215-446-7109.
New method for early detection of colon cancer
2013-09-04
ELSE PRESS RELEASES FROM THIS DATE:
NUS study highlights effectiveness of community-based cardiac rehabilitation
2013-09-03
With a growing incidence of cardiovascular disease in Asia, lifestyle modification such as weight loss and routine exercise plays an important role in early primary cardiovascular disease prevention. While it is widely known that patients with cardiovascular conditions will benefit from participating in a structured cardiac rehabilitation programme, particularly in a convenient and affordable community-based setting, there is no published data that showed the effectiveness of such a programme in the Asian population to date.
With the idea of health promotion in mind, ...
Evidence of production of luxury textiles and extraction of copper from unknown part of Cypriote Bronze Age city
2013-09-03
A Swedish archaeological expedition from the University of Gothenburg has excavated a previously unknown part of the Bronze Age city Hala Sultan Tekke (around 1600-1100 BC). The finds include a facility for extraction of copper and production of bronze objects, evidence of production of luxurious textiles, as well as ceramics and other objects imported from all over the Mediterranean but also from central Europe.
'One of our conclusions is that the Bronze Age culture in Hala Sultan Tekke played a central role in the Eastern Mediterranean. Cyprus served as an important ...
Exploitation of Indian workers on 457 visas
2013-09-03
Recent research, by Dr Selvaraj Velayutham published in a forthcoming issue of The Economic and Labour Relations Review, published by SAGE, details the exploitation of Indian immigrant workers in Australia on 457 visas.
Whilst the exploitation was often by fellow-countrymen, it is the 457 visa system that makes this exploitation possible. Unless temporary immigrants accept the poor conditions offered, they face deportation. In effect they have been tricked into coming to Australia by false promises, and have often had to borrow heavily to pay dishonest recruitment agents. ...
Canine remote control
2013-09-03
That old "best friend" can get a bit tiresome, all that rolling over, shaking paws, long walks and eating every crumb of food off the floor. But, what if there were a way to command your dog with a remote control, or even via your smart phone...or even without hands?
Jeff Miller and David Bevly of the Department of Mechanical Engineering, at Auburn University, Auburn, Alabama, have devised just such a system and describe details in a forthcoming issue of the International Journal of Modelling, Identification and Control. The device based on a control suite with a microprocessor, ...
Study finds language and tool-making skills evolved at the same time
2013-09-03
Research by the University of Liverpool has found that the same brain activity is used for language production and making complex tools, supporting the theory that they evolved at the same time.
Researchers from the University tested the brain activity of 10 expert stone tool makers (flint knappers) as they undertook a stone tool-making task and a standard language test. They measured the brain blood flow activity of the participants as they performed both tasks using functional Transcranial Doppler Ultrasound (fTCD), commonly used in clinical settings to test patients' ...
Mouse groups reveal complex relationships
2013-09-03
A common belief is that our modern, stimulation-filled environment encourages individualistic behavior (or anti-social behavior, depending on one's point of view), while simpler surroundings give rise to a more developed community life. New research at the Weizmann Institute shows that this assumption – at least for mice – is based in reality: Mice that have been raised in a stimulus-rich environment have less complexity in their social interactions than those growing up in more Spartan conditions. The findings were based on two innovative developments: The first is an ...
Oldest land-living animal from Godwana found
2013-09-03
A postdoctoral fellow from Wits University has discovered the oldest known land-living animal from Gondwana in a remote part of the Eastern Cape. Dr Robert Gess, from the Evolutionary Studies Institute at Wits, discovered the 350 million year old fossilised scorpion from rocks of the Devonian Witteberg Group near Grahamstown. This unique specimen, which is a new species, has been called Gondwanascorpio emzantsiensis.
His discovery has been published in the peer reviewed journal African Invertebrate on Wednesday, 28 August 2013.
Explaining his discovery, Gess said that ...
Research could lead to a new test to predict women at risk of pregnancy complications
2013-09-03
Researchers from The University of Manchester and Central Manchester University Hospitals NHS Trust have identified proteins in the blood that could be used to predict whether a woman in her first pregnancy is at increased risk of developing pre-eclampsia.
Pre-eclampsia is a complication of pregnancy where the mother develops high blood pressure and protein is present in the urine. In some cases, this can develop into a serious condition for both mother and baby and the only cure is delivery of the baby, often prematurely.
Women who have had pre-eclampsia previously ...
Added benefit of lisdexamfetamine is not proven
2013-09-03
Lisdexamfetamine dimesylate (trade name: Elvanse) has been approved in Germany since March 2013 as part of a comprehensive treatment programme for attention deficit/hyperactivity disorder (ADHD) in children aged 6 years and over when response to previous treatment with the drug methylphenidate was inadequate. No added benefit of the drug versus the appropriate comparator therapy could be established in the assessment of the drug manufacturer's dossier according to the Act on the Reform of the Market for Medicinal Products (AMNOG). The manufacturer did not present any relevant ...
Level playing field for Clostridium difficile diagnosis
2013-09-03
The largest study of its kind has shown the most effective test for the diagnosis of Clostridium difficile (C-Diff), a bacterial infection which causes 15,000-20,000 deaths a year in hospitals in the United States.
C-Diff affects the digestive system, and is most common in hospital patients treated with antibiotics for other infections.
The multi-centre study, carried out by UK researchers at the University of Leeds, in partnership with colleagues from the University of Oxford, University College London and St George's, University of London, tested more than 12,000 ...