Moossavi S, Mohamadnejad M, Pourshams A, Poustchi H, Islami F, Sharafkhah M, Mirminachi B, Nasseri-Moghaddam S, Semnani S, Shakeri R, Etemadi A, Merat S, Khoshnia M, Dawsey SM, Pharoah PD, Brennan P, Abnet CC, Boffetta P, Kamangar F, Malekzadeh R. Opium Use and Risk of Pancreatic Cancer: A Prospective Cohort Study. Cancer Epidemiol Biomarkers Prev. 2018 03; 27(3):268-273.