Johns Hopkins Kimmel Cancer Center scientists have completed the first draft of the genetic code for breast and colon cancers. Their report, published online in the journal Science Express, identifies close to 200 mutated genes, now linked to these cancers, most of which were not previously recognized as associated with tumor initiation, growth, spread or control.

"Just as sequencing the human genome laid the groundwork for subsequent research in genetics, these data lay the foundation for decades of research on colon and breast cancers," says Victor Velculescu, M.D., Ph.D., assistant professor of oncology at the Johns Hopkins Kimmel Cancer Center.

Although gene discoveries by independent scientists scattered around the world have provided clues, Velculescu says relatively few genes have been shown to be altered in cancers. The Hopkins gene hunters say the number of genes that were altered in breast and colorectal cancer genomes surprised them. "We expected to find a handful of genes, not 200," says Tobias Sjöblom, a lead author and postdoctoral fellow at Hopkins' Kimmel Cancer Center.

Despite the potential rewards envisioned by cancer biologists, efforts to map cancer genes have drawn criticism from others who say that funding dollars should be spent on projects yielding more immediate benefits for detection and treatment.