Navigation Links
Study shows colon and rectal tumors constitute a single type of cancer
Date:7/18/2012

The pattern of genomic alterations in colon and rectal tissues is the same regardless of anatomic location or origin within the colon or the rectum, leading researchers to conclude that these two cancer types can be grouped as one, according to The Cancer Genome Atlas (TCGA) project's large-scale study of colon and rectal cancer tissue specimens.

In multiple types of genomic analyses, colon and rectal cancer results were nearly indistinguishable. Initially, the TCGA Research Network studied colon tumors as distinct from rectal tumors.

"This finding of the true genetic nature of colon and rectal cancers is an important achievement in our quest to understand the foundations of this disease," said NIH Director Francis S. Collins, M.D., Ph.D. "The data and knowledge gained here have the potential to change the way we diagnose and treat certain cancers."

The study also found several of the recurrent genetic errors that contribute to colorectal cancer. The study, funded by the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI), both parts of the National Institutes of Health, was published online in the July 19, 2012, issue of the journal Nature.

There is a known negative association between aggressiveness of colorectal tumors and the phenomenon of hypermutation, in which the rate of genetic mutation is abnormally high because normal DNA repair mechanisms are disrupted. In this study, 16 percent of the specimens were found to be hypermutated. Three-fourths of these cases exhibited microsatellite instability (MSI), which often is an indicator for better prognosis. Microsatellites are repetitive sections of DNA in the genome. If mutations occur in the genes responsible for maintaining those regions of the genome, the microsatellites may become longer or shorter; this is called MSI.

NCI estimates that more than 143,000 people in the United States will be diagnosed with colorectal cancer and that 51,500 are likely to die from the disease in 2012. Colorectal cancer is the fourth most common cancer in men, after non-melanoma skin, prostate and lung cancer. It is also the fourth most common cancer in women, after non-melanoma skin, breast and lung cancer.

The researchers observed that in the 224 colorectal cancer specimens examined, 24 genes were mutated in a significant numbers of cases. In addition to genes found through prior research efforts (e.g., APC, ARID1A, FAM123B/WTX, TP53, SMAD4, PIK3CA and KRAS), the scientists identified other genes (ARID1A, SOX9 and FAM123B/WTX) as potential drivers of this cancer when mutated. It is only through a study of this scale that these three genes could be implicated in this disease.

"While it may take years to translate this foundational genetic data on colorectal cancers into new therapeutic strategies and surveillance methods, this genetic information unquestionably will be the springboard for determining what will be useful clinically against colorectal cancers,'' said Harold E. Varmus, M.D., NCI director.

The research network also identified the genes ERBB2 and IGF2 as mutated or overexpressed in colorectal cancer and as potential drug targets. These genes are involved in regulating cell proliferation and were observed to be frequently overexpressed in colorectal tumors. This finding points to a potential drug therapy strategy in which inhibition of the products of these genes would slow progression of the cancer.

A key part of this study was the analysis of signaling pathways. Signaling pathways control gene activity during cell development and regulate the interactions between cells as they form organs or tissues. Among other findings, the TCGA Research Network identified new mutations in a particular signaling cascade called the WNT pathway. According to the researchers, this finding will improve development of WNT signaling inhibitors, which show initial promise as a class of drugs that could benefit colorectal cancer patients.

In addition to examining the WNT pathway, the investigators also identified RTK/RAS and AKT-PI3K as pathways that are altered in a substantial set of colorectal tumors, which may show promise for targeting therapies for colorectal cancer. Because of these findings, drug developers may now be able to narrow their scope of investigation with an expectation of producing more focused therapeutic approaches, noted the researchers.

"It takes a critical group of researchers to conduct research at this scale and of this quality," said Eric. D. Green, M.D., Ph.D., NHGRI director. "This study is among the most comprehensive of its kind to date and vividly illustrates how TCGA data sets can shed new light on fundamental properties of human cancers."


'/>"/>

Contact: NCI Office of Media Relations
ncipressofficers@mail.nih.gov
301-496-6641
NIH/National Cancer Institute
Source:Eurekalert  

Related medicine news :

1. Spouses of severe-sepsis patients at high risk of depression, U-M study shows
2. A study shows that men and women have the same sexual fantasies
3. Sugary Drinks Not Replacing Milk as Kids Age: Study
4. Mammograms Have Limited or No Effect on Breast Cancer Deaths: Study
5. Milk Thistle of Little Help Against Hepatitis C: Study
6. ICAP study uses novel incentive to encourage HIV patient care and treatment
7. Study Ties Infant Birth Weight to Mothers Breast Cancer Risk
8. Moms Pot Use Doubles Risk of Preemie Birth: Study
9. Study shows how aging impairs immune response
10. Physical health problems substantially increase use of mental health services, study shows
11. Study: Children abused by parents face increased cancer risk
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study shows colon and rectal tumors constitute a single type of cancer
(Date:5/25/2016)... ... May 25, 2016 , ... New studies published ... injured workers across 15 states. The outcomes examined in these studies include recovery ... care, and satisfaction with medical care. , “The goal of the studies is ...
(Date:5/25/2016)... , ... May 25, 2016 , ... CloudLIMS, joins an ... and Life Sciences Tech Solution Providers list of 2016 by CIOReview. , In a ... and Life Sciences Tech Solution Providers 2016 has been concluded with. The positioning is ...
(Date:5/25/2016)... ... May 25, 2016 , ... The World Molecular Imaging ... Molecular Imaging.” The focus of ADDMI-IG will be geared towards how using molecular ... issues. Through ADDMI-IG WMIS will provide a platform for productive discussions about the ...
(Date:5/25/2016)... ... 2016 , ... DKT International, one of the largest private ... to release their 2015 global impact data. In 2015, DKT served over 30 ... and 3.8 million unsafe abortions across 21 countries worldwide. , “We are ...
(Date:5/25/2016)... ... May 25, 2016 , ... Afrimesure specializes in ... and pharmaceutical, to food and HVAC facilities. Their knowledgeable staff also takes care ... For medical applications, Afrimesure offers a variety of MadgeTech systems available for sterilization ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)... 2016 Niederländische Chirurgen haben ... es Ärzten erlaubt, ihre Expertise weltweit zu teilen ... Live Streaming mit einer Instant-Messaging-Funktion und der Möglichkeit, ... in Europa, Afrika, Asien und den ... Plattform registriert. Information und Weiterbildung   ...
(Date:5/24/2016)... , May 24, 2016 ... beide primären Endpunkte und ... Überlegenheit in ‚ausgezeichneter plus guter ... Colons    ,      (Logo: ... gab heute neue positive Daten von der MORA-Studie ...
(Date:5/24/2016)... 24, 2016  Diana Russell suffers from a form ... the inside out.  This disease has put her in ... children and grandchildren to leave her home.  Because of ... cannot haul the wheelchair.  So if there is a ... Diana is left to wait for the bus. ...
Breaking Medicine Technology: