Current News Releases
Nov. 5, 2007
Study may uncover genes responsible for breast, colon cancers
University of South Carolina scientists are among a group of researchers who may have discovered mutated genes that cause breast and colon cancers.
Dr. Phillip J. Buckhaults, an assistant professor at the University of South Carolina’s School of Medicine, and Dr. Randall Crowshaw, a surgery resident at the university’s medical school, worked with researchers from 11 medical and research centers around the nation on a study that examined the DNA sequence of more than 18,000 genes, the vast majority of the human genome.
They identified 280 candidate cancer genes, or CAN genes, that frequently become mutated in breast and colon cancers.
These are the genes that scientists believe cause most forms of these two diseases, said Buckhaults, a senior scientist with the S.C. Cancer Center, a research partnership between Palmetto Health and the University of South Carolina.
“Individual tumors on average have about 15 CAN genes mutated,” he said. “Tumors that look very similar under the microscope have very different sets of genes mutated, making tumors almost as genetically distinct as the people in whom they are found.”
This kind of discovery has huge implications, Buckhaults said, because scientists believe that knowing the exact composition of a cancer will allow them to treat it more appropriately from the first diagnosis.
“People who have cancer have very different clinical experiences,” he said. “Although two patients may have the same kind of cancer and be treated by the same physicians and medicines, their outcomes may be quite different. We wanted to know why some of those patients live while others die. We believe this discovery brings us closer to doing that.”
Clinicians typically treat cancer according to what has already happened in the body. This research may allow clinicians to treat cancer according to what it is capable of doing, he said.
“Researchers believe that the difference between a benign or malignant tumor is the mutation of the genes,” Buckhaults said. “If they can know exactly what genes those are, then they can provide better cancer treatment.”
As reported recently in the journal Science, benefits of the study would allow clinicians to do the following:
- design treatment specific to the patient based on the cancer’s genetic makeup;
- recognize the genetic makeup of cancer and its potential behavior in the future;
- design new chemotherapy treatment that targets mutant genes;
- prevent damages to normal cells through specifically designed chemotherapy.
The benefit that could occur most quickly is using gene mutation profiling to help make clinical decisions, something that could happen within five years, he said.
“Custom drugs will come later. Researchers are being recruited to the University of South Carolina who specialize in these types of projects,” he said.
Buckhaults praised the breast-cancer patients who provided samples of their tissue for the study by donating it to the South Carolina Cancer Center Tissue Bank.
“Breast-cancer patients in South Carolina were a critical part of the team,” he said. “They donated their tissue to the bank and made this discovery possible. Without their selfless act at a difficult time, we wouldn’t have been able to accomplish this. I consider them the real heroes.”
To move the project forward, Buckhaults said that collaboration among the S.C. Biorepository System, a newly formed statewide network of tissue banks, will be needed.
The multi-center study used 35 colon samples and 35 breast-cancer samples in advanced stages of disease. Future studies will require hundreds of samples for each cancer in every stage of disease, he said.
“This is clearly something no one cancer center can do alone,” Buckhaults said.
