Lung cancer is the most common cancer in the world, both in terms of incidence and mortality. The European Early Lung Cancer project (EU ELC) will determine if specific genetic changes occurring in lung carcinogenesis are detectable in the respiratory epithelium of individuals who have an increased risk of developing lung cancer. This paper reports preliminary epidemiological results from the EU ELC project (www.euelc.com).

The study has a case-control design, conducted in 13 areas in eight European countries. Incident cases of lung cancer between the ages of 35 and 79 years were identified through the main hospitals in participating centres. Controls were frequency matched to cases by geographic area (13 centres), 5-year age group and gender. In-person structured interviews were conducted to obtain information on demographic characteristics, tobacco use, medical history and history of lung-related diseases, family history of cancer and occupational history.

891 incident lung cancer cases and 1370 controls were recruited between November 2002 and October 2006. Caucasians represent approximately 98% of both the cases and the controls. There were significant differences between cases and controls in age finished full-time education (p=0.02) with a borderline protective effect of education (p=0.05). The proportion of smokers (including ex smokers) was higher in cases (93.1%) compared with controls (74.7%). Approximately 48% of cases were self-reported current smokers and 45% were former smokers, as compared with 32% and 43%, respectively, for the controls (p<0.0001). There were significant increases in lung cancer risk in terms of pack-years of smoking (p<0.0001) and duration of smoking (p<0.0001). Smoking adjusted increases in risk were also observed for a panel of epidemiological factors including a prior history of bronchitis (p=0.02), chronic obstructive pulmonary disease (p=0.01) and pneumonia (p=0.05). Approximately 22% of the cases and 13% of the controls self-reported a history of occupational exposure to asbestos, whilst a further 10% of cases and 6% of controls reported that they had possibly been exposed to asbestos as a result of their job (p<0.0001).

In conclusion, we observed significant differences in distributions between cases and controls for a range of demographic and epidemiological factors, with corresponding increases in lung cancer risk. Further analyses will elucidate the role of environmental or lifestyle factors in determining specific acquired genetic alterations in the process leading to lung cancer.

Funded by EU Framework V

98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA