The use of the drug Osimertinib after surgery reduces the risk of death in lung cancer patients by 51 percent.

"Thirty years ago, we couldn't do anything for such patients. Now we have this powerful drug," said Roy Herbst, deputy director of the Yale Cancer Center and lead author of the study on the effects of osimertinib, the Guardian reported.

He said the 50 percent figure is a big deal, especially in the case of lung cancer, which is very resistant to therapies.

Speaking at the World Lung Cancer Conference in Chicago, Herbst said the "exciting results" added even more weight to earlier findings that showed the drug could cut the risk of the disease coming back in half.

He pointed out that some patients in the UK, US and other countries already have access to the drug. A report by AstraZeneca, which makes the drug Osimertinib, said the drug showed an unprecedented and highly significant benefit in terms of patient survival.

It added that after five years, 88 percent of patients who took the daily pill were still alive after the tumor was removed. Lung cancer is the deadliest cancer, killing almost two million people annually.