NEW YORK (CBS 2) – Researchers at New York Presbyterian-Weill Cornell Medical Center have discovered a breakthrough experimental treatment for lung cancer.

The treatment is part of a lung cancer vaccine that exposes the body to a protein that the lung cancer produces. This protein production helps the body build up protection against the cancer that’s attacking it.

“It’s huge because it proves the concept of engaging the immune system in the fight against cancer and I cannot tell you how important that is,” Dr. Nasser Altorki told CBS 2’s Dr. Holly Phillips.

Lung cancer is the leading cause of cancer deaths throughout the world, and if the vaccine works, countless lives could be saved.

In a cancer that can return in many cases, the vaccine could help fight to keep the deadly disease away permanently for some patients.

Carol Terry went to her doctor for swollen ankles last year, but after listening to her breathing, her physician ordered an X-ray.

“I had an extremely large tumor,” Terry said.

Terry, who smoked for 45 years, had stage-two lung cancer. She had surgery to remove the tumor, and then underwent four rounds of debilitating chemotherapy. She then joined the new vaccine trial to stop the cancer from coming back.

With the few side effects that it produces, patients are able to do more. While it’s still experimental, early vaccine test results have been promising, and Terry said she is hopeful the vaccine will add years to her life.

“My youngest grandchild is 11. She was in a parade, so to see her dancing was wonderful and hopefully I’ll be there to see her grow up,” Terry said.

More than 400 centers worldwide are taking part in the study, and Dr. Altorki remains optimistic about its future.

“It changes completely the way we treat lung cancer, it’s a game changer,” Dr. Altorki said.

The vaccine is given as a series of injections over two years, and researchers at New York Presbyterian Medical Center are still enrolling patients.