Not Two Cancers, But One

Colon and rectal cancers one in the same

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) For years, it's been thought that colon cancer differed from rectal cancer. After all, they are two different diseases, occurring in two different organs. Right? Recent research has shown that the two diseases may not be different at all.

Scientists found that the same genetic alterations occur in both colon and rectal tissues, regardless of where they originate.

As a result, researchers now believe the two diseases can be classified as one - colorectal cancer.

"Colorectal cancer screening should start at age 50."

These are the findings of a large-scale study conducted by The Cancer Genome Atlas (TCGA). In analyzing a number of different genomes, colon and rectal cancers could not be distinguished from one another.

"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 National Institutes of Health (NIH) Director Francis S. Collins, MD, PhD. "The data and knowledge gained here have the potential to change the way we diagnose and treat certain cancers."

Researchers found that the same 24 genes were altered or mutated in a majority of the 224 colorectal cancer specimens examined.

During the study, the scientists identified three additional genes that may drive the development of colorectal cancer.

Additionally, two genes were seen to be possible targets for potential drug therapies. These are the ERBB2 and IGF2 genes which are either mutated or overexpressed (too many) in colorectal cancers.

"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, MD, National Cancer Institute director.

The study, funded by the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI) was published July 19 in the journal Nature.

The authors declared no competing financial interests existed. 

Reviewed by: 
Review Date: 
July 30, 2012
Last Updated:
September 16, 2013