Trial Information

A Protocol for an RCT of Smoking Cessation Success Rate With or Without a Genetic Test (Respiragene) to Assess Lung Cancer Risk - an Exploratory Study

Despite the 5-10% probability of lung cancer in smokers, 50% do not believe they are at
significantly increased risk Despite this, over 80% of smokers would like to know their
personal risk of lung cancer. RP Young, a clinician at University of Auckland, has show a
three way link between biomarkers for COPD, a set of 20 single nucleotide polymorphisms
(SNPs) and lung cancer. He has demonstrated a strong correlation between a risk score
(derived from FH of cancer, the 20 SNPs & clinical COPD) and the development of lung cancers
whereas healthy smokers (who had not developed lung cancer) matched for age, gender and
lifetime smoking habits had a relatively low risk score (n=446 lung cancer subjects, 484
healthy current smokers. The odds ratio for lung cancer risk varied from 0.2-3.2 depending
on the genetic risk (p<0.001). The Auckland lung cancer risk score has a 90% sensitivity for
a score of >4. The validity of 20 SNP gene test has also been confirmed in populations in
Barcelona, Spain and Liverpool, UK. The test has been given the trade name "Respiragene".

Small uncontrolled trials of use of Respiragene in smoking cessation clinics in New Zealand
and USA show an improvement in smoking cessation at six months after a Respiragene
intervention with quit rates of 30-35%. The trial hypothesis is that smokers who have the
Respiragene test and a full explanation of their risk score will have a better quit rate at
4 weeks and at six months (after completion of their eight weekly smoking cessation clinic
sessions) than controls. Smoking cessation at the six month follow up will bw confirmed by
testing for salivary cotinine. Based on data from Young's small trial, we also hypothesise
that this uplift of quit rate will be seen for subjects with both high risk scores and
average risk scores (there is no low risk category for smokers). These hypotheses are the
basis of the primary end points.

The investigators will also be administering the same questionnaire to each subject and
control twice, at 4 weeks and six months (after the smoking cessation course) that is
primarily designed to evaluate the impact of the Respitagene test in relation to other
influences:

- other components of the smoking cessation clinic sessions (salivary cotinine testing,
carbon monoxide breath analyser, general clinic help and advice, clinic fact sheets)

- general environmental factors (cost of cigarettes, family pressure, work regulations,
doctor's advice)

The results will be analysed using SPSS Statistics 17.0 computer programme.