Why are non-smokers with little exposure to second-hand smoke diagnosed with the disease while others are not? Why do some heavy smokers never develop lung cancer, while other lighter smokers do?
These are some of the questions the team behind a highly successful early detection lung cancer project is aiming to answer as they expand their research to include air pollution and genetic susceptibility.
“In the original project, we looked at the use of a risk prediction algorithm to identify people that would benefit from screening, but the best available model still only catches about 50 per cent of people that may develop lung cancer,” said principal investigator Dr. Stephen Lam, chair of B.C.’s Provincial Lung Tumour Group at the BC Cancer and a professor of medicine at the University of British Columbia.
“That’s why we decided to look at other risk factors like air pollution - a major thing that nobody has ever looked at - and we also are looking at genetic susceptibility factors to try and improve the prediction model that way.”
Lung cancer is the most common cause of cancer death around the world, with 1.6 million deaths and 1.8 million new cases a year. The five-year for survival rate for patients is currently less than 18 per cent, but if caught early enough the disease can be cured for 70 per cent of cases.
The original early detection project validates a lung cancer prediction algorithm that uses age, smoking history, family history of lung cancer, history of chronic obstructive pulmonary disease, education level and body mass index to calculate risk. The project also developed a lung nodule cancer risk calculator software that accurately classifies which spots or lesions are benign and which are malignant on an initial lung computed tomography (CT) scan among individuals at high-risk for lung cancer.
The current project will be taking this research one step further, expanding to include air pollution and genetics in the early-screening criteria. The team will also be developing advanced computer analytic imaging tools to determine the likelihood of small lung nodules found on screening CT being cancerous to improve the efficiency, accuracy, and cost-effectiveness of reading the large number of scans generated in a screening program.
Unlike the previous project, the expansion will be international: recruiting patients from the British Columbia and comparing data with similar research ongoing across Canada, as well separately funded research in the U.S., Australia, the UK and Hong Kong (where the research will be supported by funds raised by the Hong Kong Terry Fox Runs).
Over 200 people are currently enrolled, and Dr. Lam is hoping to screen more than 2,000 B.C. patients in total. Participants need to have smoked for at least 20 years, and be between the ages of 55 and 80 to take part.
“By the end of the project we hope to achieve a refined risk prediction model and automate lung screening and CT reading, as well as implement routine screening for high-risk patients in B.C. across Canada and world-wide” said Dr. Lam, noting he also hopes the screening will become as common practice as mammograms and colonoscopies. “With early detection, lung cancer can be a curable cancer.”
*This project is co-funded by the TFRI ($1,800,000), BC Cancer ($488,500), National Sanitarium Association ($58,011), University of Queensland ($3,057,884) and Vancouver Coastal Health ($1,326,542)