Opium use and subsequent incidence of cancer: results from the Golestan Cohort Study oleh Mahdi Sheikh, MD, Ramin Shakeri, PhD, Hossein Poustchi, PhD, Akram Pourshams, ProfMD, Arash Etemadi, PhD, Farhad Islami, PhD, Masoud Khoshnia, MD, Abdolsamad Gharavi, MD, Gholamreza Roshandel, PhD, Hooman Khademi, MD, Sadaf G Sepanlou, PhD, Maryam Hashemian, PhD, Abdolreza Fazel, MD, Mahdi Zahedi, MD, Behnoush Abedi-Ardekani, MD, Paolo Boffetta, ProfPhD, Sanford M Dawsey, MD, Paul D Pharoah, ProfPhD, Masoud Sotoudeh, ProfMD, Neal D Freedman, PhD, Christian C Abnet, PhD, Nicholas E Day, ProfPhD, Paul Brennan, PhD, Farin Kamangar, ProfPhD, Reza Malekzadeh, ProfMD