Using a genetic/clinical risk score to stop smoking (GeTSS): randomised controlled trial

As genetic tests become cheaper, the possibility of their widespread availability must be considered. This study involves a risk score for lung cancer in smokers that is roughly 50% genetic (50% clinical criteria). The risk score has been shown to be effective as a smoking cessation motivator in hospital recruited subjects (not actively seeking cessation services).

This was an RCT set in a United Kingdom National Health Service (NHS) smoking cessation clinic. Smokers were identified from medical records. Subjects that wanted to participate were randomised to a test group that was administered a gene-based risk test and given a lung cancer risk score, or a control group where no risk score was performed. Each group had 8 weeks of weekly smoking cessation sessions involving group therapy and advice on smoking cessation pharmacotherapy and follow-up at 6 months. The primary endpoint was smoking cessation at 6 months. Secondary outcomes included ranking of the risk score and other motivators.

67 subjects attended the smoking cessation clinic. The 6 months quit rates were 29.4%, (10/34; 95% CI 14.1-44.7%) for the test group and 42.9% (12/28; 95% CI 24.6-61.2%) for the controls. The difference is not significant. However, the quit rate for test group subjects with a "very high" risk score was 89% (8/9; 95% CI 68.4-100%) which was significant when compared with the control group (p = 0.023) and test group subjects with moderate risk scores had a 9.5% quit rate (2/21; 95% CI 2.7-28.9%) which was significantly lower than for above moderate risk score 61.5% (8/13; 95% CI 35.5-82.3; p = 0.03).

Only the sub-group with the highest risk score showed an increased quit rate. Controls and test group subjects with a moderate risk score were relatively unlikely to have achieved and maintained non-smoker status at 6 months. ClinicalTrials.gov ID NCT01176383 (date of registration: 3 August 2010).