The Terry Fox Research Institute is injecting an additional $1.5 million into a lung cancer screening study that is proving successful in detecting early cancers.

The study conducts annual screening CT scans to look for lung cancer in a curable stage in current and former smokers aged 50 to 75. The additional funding will allow researchers to conduct a third scan in the 2,500 participants.

Researchers know that the scans improve the odds of catching cancer early, but are trying to determine how often scanning is required and what its most beneficial and cost-effective uses are.

To date researchers have been very pleased with their findings, according to Dr. John Goffin, associate professor in the Department of Oncology at McMaster and one of the study researchers.

"The number of cancers we have detected has been double what we expected," said Goffin.

"Our use of blood markers to help determine who may have cancer has also been very good."

The current findings have the potential to significantly reduce lung cancer mortality through early detection and simple breath and blood testing.

Goffin added that the study’s efforts to improve the assessment of CT scans in determining which tumors are benign and which are cancerous have produced significant results and an academic paper.

Lung cancer kills some 20,000 Canadians every year and is the most common cause of cancer death world wide, according to the Terry Fox Research Institute.

"We already know our study is helping to save lives. This additional funding will enable us to collect and analyze new data that will help us to evaluate individuals with high risk," said Dr. Stephan Lam, lead investigator of the study, in a press release.

"We anticipate it will contribute to important recommendations about a potential screening program, its benefits and its costs."

The donation will extend the study to June 2015.