Sunday, September 16, 2012

New Genetic Test Which Identifies DNA Changes in Tumors



The Cancer Genetics Laboratory at Baylor College of Medicine now offers the Cancer Exome Sequencing test, which uses next-generation sequencing to identify acquired changes in the DNA of a patient’s tumor.

“Cancer exome sequencing is poised to change the current paradigm of genetic testing for cancer patients,” said Dr. Federico Monzon, director of molecular pathology at the Cancer Genetics Laboratory at BCM. “Rather than testing a single gene or panel of genes, cancer exome sequencing will provide comprehensive profile of acquired mutations in tumor tissue.”
DNA change due to cancerous tumors






The term exome refers to the portion of the human genome that contains the DNA sequence that directs protein synthesis. These functionally important regions of DNA are referred to as exons. The 22,000 known genes are comprised of approximately 180,000 exons and represent about 3 percent of the genome.

Most errors in DNA sequence that lead to altered protein function in tumors are located in theexons; therefore, exome sequencing is an efficient method for tumor DNA sequence analysis to uncover genetic causes for tumor behavior.

Some of these acquired mutations can be used to predict tumor aggressiveness or determine the likelihood of response/resistance to targeted agents or other forms of cancer therapy.

“We are entering a new era in individualized cancer diagnosis and treatment in which molecular profiling of the cancer as well as the patient will determine the optimal therapeutic approach for a given patient,” said Dr. C. Kent Osborne, director of the Lester and Sue Smith Breast Center and the NCI-designated Dan L. Duncan Cancer Center at BCM.