Small doses of radiation meant to ease the symptoms of incurable lung cancer may actually save the lives of a few patients, surprised Australian researchers reported on Monday.

About one in a hundred patients with apparently incurable non-small cell lung cancer survived five or more years after the treatments, and 18 patients were apparently cured, the researchers said.

Dr. Michael Mac Manus, a radiation oncologist at the Peter MacCallum Cancer Center in Melbourne, Australia, and colleagues followed 2,337 apparently incurable lung cancer patients who had received palliative doses of radiation.

Writing in the journal Cancer, they said 1.1 percent of the 2,337 patients lived five or more years after treatment - considered remission.

“Our data show that close to 1 percent of patients with NSCLC have prolonged survival with doses of palliative radiation therapy that would not normally be considered sufficient for long-term disease control,” they wrote.

NSCLC, the most common type of lung cancer, has an average five-year survival rate of only 40 percent. The five-year survival rate in advanced disease is only about 15 percent.

Patients diagnosed with NSCLC that is too advanced to be cured can be given palliative therapies to ease pain and discomfort, including radiation.

Lung cancer is by far the biggest cancer killer globally. Each year ten million people are diagnosed with lung cancer, according to the Global Lung Cancer Coalition, and half of all patients die within a year of diagnosis.

Most cases are linked to smoking.