Genetic Test Predicts Benefits of Chemotherapy
A newly developed genetic test can predict with up to 90% accuracy which early stage lung cancer patients are likely to experience recurrence and therefore would benefit from chemotherapy, according to a Duke University study published in the New England Journal of Medicine, the Wall Street Journal reports. Currently, patients diagnosed with early stage non-small-cell lung cancer undergo surgery followed by observation, without chemotherapy. About one-third of such patients experience a relapse.
For the study, funded by NIH and Duke's Institute for Genome Sciences and Policy, Anil Potti and researchers examined tissue from 198 early stage tumors that had been removed in surgery (Levitz, Wall Street Journal, 8/10). The samples considered were both from patients who had relapsed and from those who were cancer-free for five years (Cook, Boston Globe, 8/10).
Researchers extracted RNA representing thousands of genes. When examined under a slide and a special light, researchers say florescent RNA "emits a telltale luminescence" that determines which genes are most active in a tumor.
The researchers then analyzed 133 active genes while considering tumor diameter and a patient's age, sex, smoking history and subtype of cancer in order to assign a risk "number" to each patient (Wall Street Journal, 8/10). The predicted risks were then compared with the outcomes of each patient's treatment.
The test was 93% accurate on tumor samples that came from Duke and 75% accurate on the rest. Current risk estimate tests are about 60% accurate, according to Potti.
Potti called the test "a fingerprint unique to the individual patient (that) predicts survival changes," he added (Johnson, AP/Long Island Newsday, 8/9).
Tom Lynch, director of the Center for Thoracic Cancers at Massachusetts General Hospital, said, "I think this is a very, very exciting tool. The future of cancer therapy is going to be based on exactly what this paper is about."
The results have spurred researchers to launch a broader NIH-funded trial of the test within the next six months. The study will include about 1,200 patients in 60 locations in the U.S. and Canada (Boston Globe, 8/10).
In the meantime, Potti says researchers have already requested that the Blue Cross & Blue Shield plan of North Carolina approve chemotherapy for at-risk early stage lung cancer even before the trials are completed.
Company spokesperson Mark Stinneford said, "Until we examine their research, we can't predict when or if we might provide medical coverage for such a test" (Wall Street Journal, 8/10).