Lung cancer is the deadliest cancer in the world.  It claims the lives of almost three million people a year.  This cancer is hard to cure, but clues about the most effective treatment seem to be in a patient's genes. VOA's Carol Pearson has more.

Connie West shares her reaction when she was diagnosed with lung cancer. "At that time, I thought the very worst," she acknowledges.  "Most people who have lung cancer have a very poor outcome."

But now, researchers say they have identified five genes that could give doctors clues about the chances patients have of surviving lung cancer.

The presence of these five genes could also help determine most lung cancer patients' best course of treatment.

The researchers first examined frozen tumor cells from patients with lung cancer.  

They noticed patients with this five-gene profile had better than an 85 percent chance of surviving four years after surgery, provided their cancers were detected early.

Patients with a high-risk profile, or those who did not have these five genes, have less than a 40 percent chance of living four years after surgery.

This genetic testing could help determine which treatments would work best.  Doctors might treat patients without the five-gene profile more aggressively.  They may spare patients with the five-gene profile from chemotherapy, its side effects and expense.

More study is needed to confirm these findings, but scientists say genetic testing could also lead to drugs that target particular genes.