Epidemiologists who analyzed survey questionnaire responses came up with a new way to predict risk of lung cancer - the time you spent before lighting up the first time.

Lung cancer prediction is tricky business - though it is commonly assume that people who smoke will get lung cancer, shockingly few smokers do and almost half of lung cancer patients didn't smoke. There are standard markers that epidemiologists have used to match cancer risk - how many cigarettes per day and even cumulative exposure (pack-years).

The new survey results lead them to suggest that time before first light up may be a predictor for both light and heavy smokers. 

Writing in the JNCI: Journal of the National Cancer Institute, Fangyi Gu, Sc.D., M.D., of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, and colleagues discusss their analysis of questionnaire data from the Environment and Genetics in Lung Cancer Etiology (EAGLE) study of current and former smokers in Italy and the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer screening trial in the US.

Subjects were asked about their smoking history and habits and to answer the question, "How soon after you wake up do you usually smoke your first cigarette of the day?" The responses were categorized as 5 or fewer, 6-30, 31-60, and more than 60 minutes.  

In the sample of 3249 ever smokers from the EAGLE study, 1812 were lung cancer patients and 1437 were control subjects matched by residence, sex and age. In analyses adjusted for smoking intensity, duration and other lung cancer risk factors, compared to those with "time to first cigarette" (TTFC) of more than 1 hour, the risk of lung cancer was statistically significantly higher in those with shorter TTFC. The association of TTFC with lung cancer risk was stronger in current vs. former smokers and, surprisingly, in lighter vs heavier smokers but not different between men and women. In analyses of the PLCO study, lung cancer risk increased in a borderline statistically significant trend.  

The researchers conclude that although their results support the association of
"time to first cigarette"
with lung cancer risk, prospective and screening studies are needed. They write, "Assessing TTFC may improve lung cancer risk prediction and could be useful in lung cancer screening and smoking cessation programs."