In a step that could lead to new ways of detecting and treating cancer, Johns Hopkins researchers reported yesterday that they had deciphered the genetic code of breast and colon tumors.
The discovery, described in the online version of the journal Science, is the first time anyone has spelled out the complete genetic makeup - or genome - of a human cancer. In doing so, the scientists identified close to 200 genes whose mutations play a role in the formation and spread of the disease.
Dr. Bert Vogelstein, one of three Hopkins University researchers who spearheaded the effort, said the discovery gives cancer researchers precise targets for new drugs and screening tests. Some in the field said the study might have opened a new era in cancer research, showing scientists the methods to crack the genomes of other malignancies as well.
"It's like viewing the enemy's game plan," said Vogelstein, a professor of oncology, adding that the team will next turn its attention to mapping brain and pancreatic cancers.
"There are numerous ways the information can be exploited. The first is viewing the enemy, seeing what its weak points are and formulating an attack plan."
Also leading the effort were Dr. Kenneth W. Kinzler and Dr. Victor E. Velculescu. Together, the three head a lab that is widely regarded as one of the most fertile in cancer research.
The report comes less than a year after the National Institutes of Health announced a three-year, $100 million project to begin mapping cancer's genetic underpinnings. The agency plans to announce two "milestones" in the effort next week.
Though it dovetails with the federal program, the Hopkins project was conducted independently and largely with private money. Still, federal officials lauded the Hopkins program, saying it demonstrates the feasibility of the larger effort.
"We anticipate that as [the federal program] scales up, we may be able to identify the majority of genetic changes that cause the most important and common forms of the major cancers," Dr. Francis Collins, director of the National Human Genome Research Institute, said in a written statement.
"In fact, the large number of mutations reported in this paper offers a glimpse of what is yet to come and provides exciting new directions for drug discovery in breast and colon cancer."
In both a historical and practical sense, the Hopkins study was an outgrowth of federal and private programs that, by 2003, mapped the composition of the approximately 20,000 genes that make up each human cell.
