Trial Information

Longitudinal Study of Prostate, Lung, Colon, and Ovarian Cancer (PLCO) Screen Trial

Lung cancer is the leading cause of cancer death in the United States. Approximately 90% of
lung cancer is caused by cigarette smoking. While most lung cancer cases occur in smokers or
ex-smokers, only 15-25% of smokers will get lung cancer. Currently it remains impossible to
predict which smokers will get cancer.

Each puff of a cigarette delivers, along with nicotine, a mixture of over 60 known
carcinogens. Most of these carcinogens require metabolic activation before they can
negatively affect cell DNA and cause cancer. Biomarkers that quantify carcinogen levels and
metabolic activity of carcinogens are a useful tool and available to use. The purpose of
this study is to assess the variability of tobacco smoke carcinogen biomarker levels over
one year in a group of smokers.

This longitudinal observational study will involve a repeated measure analysis of 6
different tobacco carcinogen biomarkers. Fifty current smokers who intend to continue
smoking for the duration of the study will be recruited through advertisements. Participants
will be compensated for their time. Blood samples will be collected every two months for one
year. All samples will be analyzed for the 6 different carcinogen biomarkers and individual
variability in biomarker levels will be assessed.