Opium: an emerging risk factor for gastric adenocarcinoma.
Shakeri R, Malekzadeh R, Etemadi A, Nasrollahzadeh D, Aghcheli K, Sotoudeh M, Islami F, Pourshams A, Pawlita M, Boffetta P, Dawsey SM, Abnet CC, Kamangar F. Opium: an emerging risk factor for gastric adenocarcinoma. Int J Cancer. 2013 Jul 15; 133(2):455-61.