Tobacco and opium use and risk of liver and colorectal cancer mortality: Analysis of the Golestan Cohort Study (GCS).
BACKGROUND Tobacco and opium consumption are prevalent in Iran and have been linked to increased risk of upper GI cancers. To investigate their role in lower GI cancers, the associations of tobacco and opium use with liver and colorectal cancer mortality were examined in this study. METHODS From 2004-2008, participan...