Predicting lung cancer
A new screening prediction model proves much more effective at identifying at-risk patients
Judy Wiebe found out she had lung cancer after signing up for a University of Calgary clinical trial researching the effectiveness of screening for lung cancer. She thought she was in great shape for a woman in her 70s and had no signs that anything was wrong with her health.
“I stopped smoking a number of years ago. I didn’t have any symptoms that I would have associated with lung cancer; I wasn’t coughing or feeling tired. I felt good,” says Wiebe. “If it hadn’t been for the study, I never would have known that tumours were forming in my lungs.” Wiebe underwent surgery to have the tumours removed and is now cancer free.
Dr. Alain Tremblay, professor of medicine in the departments of Medicine and Oncology at the Cumming School of Medicine (CSM) and member of the Arnie Charbonneau Cancer Institute, recently led the Calgary arm of a Pan-Canadian study researching the effectiveness of a new lung cancer screening risk predication model. The model takes a number of factors into account including age, smoking duration, pack-years smoked, body mass index, and level of education.
Lung cancers were detected in 6.5 per cent of the participants, a much higher number than in other studies, demonstrating the usefulness of the risk prediction model. Of those, 75 per cent were Stage 1 or Stage 2, which is considered to be the early stage of the disease and is often curable whereas without screening, only 20 per cent of cases are this early.
“As a Canadian study, these results are very important; each province is trying to decide whether lung cancer screening is something that should be funded by the health care system,” says Tremblay. “Through this research, we’ve been able to prove the risk selection model works. We can identify a very high risk group of people who may have lung cancer and save money by not screening people unnecessarily.”
Those identified as being at high risk would undergo a low dose CT scan every one to two years. “We estimate that over 100,000 people in Alberta qualify for the screening program”, adds Tremblay. “Screening can enable an earlier diagnosis when tumours are more likely to be at a more curable stage, just like we saw in Weibe’s case.”
Preventive screening programs are in place for breast, colon and prostate cancer even though lung cancer is the number one cancer killer in both men and women in Canada. In Alberta alone, more than 2,000 people will be diagnosed with this disease this year, the majority at an incurable stage.
This is the first big study to use a risk calculator to determine individual participants' risk of lung cancer. The questionnaire-based survey developed by a Brock University scientist predicts your risk of developing lung cancer in the next six years. Results are published in The Lancet Oncology.