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Many Copy Number Variations Universal Among Diverse Tumors
An international team of researchers has created a genome-scale map of 26 different cancers, revealing more than 100 genomic sites where DNA from tumors is either missing or abnormally duplicated compared to normal tissues. The study, the largest of its kind, finds that most of these genetic abnormalities are not unique to one form of cancer, but are shared across multiple cancers. "Our findings show that many genome alterations are universal across different cancers. Although this has been known for some types of changes, the degree to which so many alterations are shared was pretty surprising to us," said senior author Dr. Matthew Meyerson, a professor of pathology at the Dana-Farber Cancer Institute and senior associate member of the Broad Institute of Harvard and MIT. "It suggests that, in the future, a driving force behind cancer treatment will be common genomic alterations, rather than tumors' tissue of origin." In 2004, a scientific team led by researchers at the Dana-Farber Cancer Institute and the Broad Institute launched a project to systematically map genetic changes across different cancers. They focused on a particular type of DNA change in which segments of a tumor's genome are present in abnormal numbers of copies. Instead of the usual two copies, tumors often carry several copies of one piece of DNA (an "amplification") or may lack it altogether (a "deletion"). These genetic abnormalities are known as somatic copy-number alterations or SCNAs. As the foundation for their analysis, the scientists collected over 2,500 cancer specimens representing more than two dozen cancer types, including lung, prostate, breast, ovarian, colon, esophageal, liver, brain, and blood cancers.