Alberta researchers have launched a new study to figure out how to screen current and former smokers for lung cancer, to see if they can spot the disease in its earliest stages.

While other forms of cancer might get more attention, lung cancer remains the leading cause of cancer death among men and women in Canada. That’s in part because by the time lung cancer causes symptoms, it’s often too advanced to cure, says Dr. Alain Tremblay, the Calgary-based principal investigator in the new study.

For years, researchers have searched for a way to screen former and current smokers for early lung cancer, but have had little success. Screening with chest X-rays has been shown in studies not to reduce the number of people dying of the cancer, and spit tests have not fared any better either.

But spiral CT scans do appear effective at spotting early cases. Research in the U.S. has shown that the scans can find early cancer cases and reduce deaths. But it’s still unclear which patients benefit from the scans the most, since it isn't feasible to offer scans to all smokers.

CT scans are not only costly, they produce a small amount of radiation that may raise the risk of cancer on its own. As well, the screening tests can lead to false negative results (meaning some cancers are missed), or false-positives, which can lead to unneeded follow-up tests and surgeries.

Tremblay said in an announcement that CT scan screening has the potential to reduce the number of deaths, “but the challenge is to determine who is most at risk.”

The study, funded by the Alberta Cancer Foundation, will screen older smokers once a year, for three years. So far, 70 people have agreed to take part in the study in Calgary and Edmonton, but researchers want to recruit a total of 800 current and former smokers over the age of 55.

The Alberta researchers want to test a lung cancer risk "calculator" to determine who is most likely to benefit from screening. They will look at a number of risk factors, including:

  • smoking history, including number of cigarettes smokedand for how long
  • family cancer history
  • educational level and ethnicity

They also want to see if combining a smoking cessation counselling program within the screening can help more current smokers quit. And they hope to determine the actual costs of a potential lung cancer screening program in Alberta.

Edmonton-based thoracic surgeon Dr. Eric Bédard, who is leading one arm of the study, says his team will also determine who does not benefit from screening.

“We’re trying to really hone in on the highest risk population,” says Bedard.

Already, the study has helped identify one participant who had early stage cancer. That person has now had surgery to remove it.

“Now that they’ve gone through surgery they have a much better chance at survival,” says Daniel Salamon of the Alberta Cancer Foundation.

With a report from CTV Calgary’s Kevin Green