(SAN FRANCISCO) -- In 2011, 220,000 Americans were diagnosed with lung cancer. Eighty percent of those Americans had a form of the disease known as non-small cell lung cancer.
In its early stages, doctors usually decide to remove the tumor surgically. But as Dr. Edward Kim, chief of head and neck medical oncology at MD Anderson Cancer Center in Houston, explained, what to do next is often a difficult question to answer.
"Patients with this early stage of lung cancer pose a real dilemma for clinicians," he said in an email to ABC News. "The current literature is less than definitive when deciding between the benefit of the chemotherapy against the risk of chemotherapy side effects for the patient."
The reason the early stage of this kind of lung cancer is so tricky to treat is because about 50 percent of people with it will see it return after surgery. That means that half of all patients with it might have been helped with chemotherapy, while the other half would have experienced no benefit from chemo, but considerable side effects and cost. So, for years, the question has been, "How can we tell these patients apart?"
Dr. David Jablons, chief of thoracic surgery at the University of California at San Francisco, believes he has found the answer.
In a study published in the journal Lancet on Thursday, Jablons, in collaboration with a large consortium in China, described a new genetic test to determine which of the surgically removed lung cancers will return.
"This is the largest molecular study done on lung cancer so far, and the results are really encouraging for lung cancer patients," Jablons says.
Developed by Pinpoint Genomics, the gene test was used to analyze lung cancer cells of more than 1,500 patients in the United States and China. Researchers examined 14 specific genes that are thought to make cancer more likely to return. They then compared the results to see which patients actually had a recurrence and which patients did not.
Not only were they able to predict which patients had a return of their lung cancer, they found that this genetic test outperformed traditional methods used to predict the return of this cancer, opening the door to the possibility that the test will make it possible to decide who should get chemotherapy and who should not.
Copyright 2012 ABC News Radio