Genomic Tests Guide Choice of Chemotherapy

A panel of genomic tests analyzes the unique molecular traits of a cancerous tumor and determines which chemotherapy will aggressively attack that patient's cancer.

The tests work by scanning thousands of genes from a patient's tumor to produce a genomic profile of the tumor's molecular makeup. The genetic molecule "messenger RNA” is extracted from a cancer patient's tumor cells. Molecules of the extracted messenger RNA labeled with fluorescent tags are placed on a tiny glass slide, called a gene chip, which binds to segments of DNA representing the tens of thousands of genes in the genome. When scanned with special light, the fluorescent RNA emits a luminescence that demonstrates how much RNA is present on the chip, and this reading indicates which genes are most active in the tumor.

Using the genomic test in the laboratory, scientists were able to choose the right chemotherapy for a patient's tumor type. They were then able to validate their predictions against patients' actual clinical outcomes. The test will enable doctors to select and initiate treatment with the best drug for a patient's tumor. Currently, various drugs are tried in succession until the right one is found.

Scientists at Duke University's Institute for Genome Sciences & Policy (Durham, NC, USA) developed the panel of genomic tests that analyzes the unique molecular traits of cancerous tumors. They found that the tests were 80% accurate in predicting which drugs would be most effective in killing the tumor. Their findings were reported in the November 2006 issue of Nature Medicine. The Duke team plans to begin a clinical trial of the genomic tests in breast cancer patients next year.

"The tests have the potential to save lives and reduce patients' exposure to the toxic side effects of chemotherapy,” said Anil Potti, M.D., the study's lead investigator and assistant professor of medicine at the Duke Institute for Genome Sciences & Policy.



Related Links:
Duke University's Institute for Genome Sciences & Policy