Background: Targeting smokers at higher lung cancer risk can improve efficiency and reduce false positive detection in lung cancer screening. We evaluated whether time to first cigarette after waking (TTFC), a single-item measure of nicotine dependency, could improve stratification of lung cancer risk beyond standard smoking metrics (intensity, duration and pack-years).

Methods: In 3249 ever-smokers (1437 cases, 1812 controls) from a population-based case-control study in Italy, we examined the association between TTFC and lung cancer using logistic regression, and estimated lung cancer incidence by levels of TTFC, and smoking intensity, duration, and pack-years using absolute risk regression.

Results: Compared to smokers with TTFC>60 minutes, the lung cancer odds ratios (and 95% confidence intervals) for TTFC 31-60 minutes, 6-30 minutes and ≥5 minutes (i.e. by increasing dependency) were 2.57 (2.03-3.26), 2.27 (1.79-2.88), and 3.50 (2.64-4.64), respectively (p-trend<0.0001). The average lung cancer incidence rates for smokers of 1–10, 11–20, 21–30 and >30 cig/day were consistently and substantially higher among smokers with TTFC≥60 vs. >60 minutes (64.0 vs. 11.7, 125.6 vs. 28.6, 130.1 vs. 40.5, and 260.5 vs. 108.7 per 100,000 person-years, respectively). The slopes of increase in lung cancer rates with smoking duration and pack-years were significantly greater among smokers with higher dependency (p-interaction<0.001).

Conclusion: Lung cancer risk increases with shorter TTFC; this simple nicotine dependency measure substantially improves lung cancer risk stratification beyond standard smoking measures. Assessing TTFC may improve lung cancer risk prediction and could be useful in lung cancer screening and smoking cessation programs.

Citation Format: Fangyi Gu, Sholom Wacholder, Stephanie Kovalchik, Orestis A. Panagiotou, Carolyn Reyes-Guzman, Neal D. Freedman, Sara De Matteis, Dario Consonni, Pier Alberto Bertazzi, Andrew W. Bergen, Maria Teresa Landi, Neil E. Caporaso. Time to smoke first cigarette after morning awakening differentiates lung cancer risk beyond standard smoking measures. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr B52.