New test may help guide cancer treatment

/ Source: Reuters

A new test that looks at genetic material from a patient’s tumor is 80 percent accurate in predicting which drugs would be most effective against that particular cancer, researchers reported.

The test can be used to predict not only whether a single drug can work to stop a tumor but whether a specific combination of drugs will work, the team at Duke University in North Carolina reported.

Writing in the journal Nature Medicine, the researchers said they used a “gene chip” made by Affymetrix as the basis of the test, done in lab dishes using tumor samples from several hundred different patients with leukemia and ovarian, breast and lung cancers.

They said they would start testing their assay in breast cancer patients next year.

“With the new test, we think that physicians will be able to personalize chemotherapy in a way that should improve outcomes,” said Dr. Anil Potti, an assistant professor of medicine in the Duke Institute for Genome Sciences & Policy who led the study.

“Over 400,000 patients in the United States are treated with chemotherapy each year, without a firm basis for which drug they receive,” said genetics professor Joseph Nevins.

“We believe these genomic tests have the potential to revolutionize cancer care by identifying the right drug for each individual patient,” Nevins said in a statement.

“Importantly, we believe this research can improve the efficiency of chemotherapy without changing the drugs currently used in standard practice. Rather, the tests simply provide an approach to better selection within a repertoire of available drugs.”

The gene chip is used to scan the messenger RNA from thousands of genes in a tumor.

Messenger RNA translates a gene’s DNA code into proteins that run the cell’s activities and can indicate how active a particular gene is inside the cell.

Such testing is done to a limited degree now to see if patients can qualify for so-called targeted therapies such as Tarceva, Herceptin and other drugs. The Duke team looked at older and less-specific cancer drugs such as paclitaxel, topotecan and 5-fluorouracil.

The research team compared their assay’s results against the actual results that the patients had with chemotherapy and said their test was 80 percent accurate in predicting whose tumors would be stopped by a particular agent or combination of agents.