Researchers in the Duke Institute for Genome Sciences & Policy have developed a model for predicting risk of recurrence in early stage colon cancer patients, and have used the model to also predict sensitivity to chemotherapy and targeted therapy regimens.
"These findings have important implications for individualizing therapy," said Katherine Garman, M.D., a gastroenterology fellow at Duke and lead investigator on the study. "By examining gene expression in early-stage colon cancer tumors, we have found certain patterns that seem to put some patients at higher risk for recurrence. By identifying these patients up front, we may be able to treat them in a targeted and proactive manner to prevent this recurrence and help them live longer and healthier lives."
The findings are due to appear in the online edition of the Proceedings of the National Academy of Sciences, between November 24 and November 26, 2008. The study was funded by the Emilene Brown Cancer Research Fund and the National Institutes of Health.
The researchers studied gene expression data from 52 samples of early stage colon cancer tumors, looking for patterns. Then they correlated the gene expression patterns with patient progress reports to track the recurrence of cancer. The predictive power of the correlations was subsequently tested in two independent data sets from 55 and 73 tumors, respectively.
"In our small dataset, we were able to predict which tumors were at risk for recurring, with 90 percent accuracy," Garman said.
In collaboration with colon cancer specialist David Hsu, M.D., the researchers then took their study one very significant step further, using the data garnered about gene expression and prognosis to examine response to several different types of therapy.
"Importantly, we found that the traditional chemotherapy given to patients with colon cancer varies considerably in its ability to treat tumors with a high likelihood of cancer recurrence," Garman said. "Using the gene-expression data to guide us, we then identified several other drugs and tested those drugs in our samples. The drugs chosen were novel targeted therapies and anti-inflammatory agents that go after certain cancer cell pathways and had been previously shown to alter colon cancer biology."