Understanding the Genetics of Colon Cancer

Reported December 30, 2009
Understanding the Genetics of Colon Cancer
(Ivanhoe Newswire) -- As researchers and clinicians search for causes and cures for colorectal cancer, 160,000 cases are diagnosed and 57,000 patients die of the disease each year. It is the second leading cause of death from cancer among adults, after lung cancer.

In a recent study, Dr. Sanford Markowitz, professor at Case Western Reserve University School of Medicine and oncologist at Case Medical Center, and co-author, Dr. Monica Bertagnolli, from the Brigham and Women's Hospital, Harvard Medical School, were quoted as saying, "Today's challenges are to understand the molecular basis of individual susceptibility to colorectal cancer and to determine factors that initiate the development of the tumor, drive its progression, and determine its responsiveness or resistance to antitumor agents."

Studies that aid in understanding colorectal cancer on a molecular level have provided genetic testing for high-risk familial forms of the disease, predictive markers for selecting patients for certain classes of drug therapies and molecular diagnostics for the noninvasive detection of early cancers.

For example, patients with inherited mutations in tumor-suppressor genes, such as APC, MLH1, and MSH2, have a very high risk of colorectal cancer and require early and frequent surveillance for colon cancer and often prophylactic surgery.

Patients whose colon cancers have mutations in either RAS or BRAF genes are known not to benefit from treatment with the anti-colon cancer agent Cetuximab.

The development of molecular diagnostics for the early detection of colorectal cancer is emerging as an important tool in clinical practice. One example is the development of stool DNA tests for early detection of colorectal cancer or advanced adenomas. Stool DNA testing for colorectal cancer has now been added to the cancer-screening guidelines of the American Cancer Society.
SOURCE: New England Journal of Medicine, December 17, 2009
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