Opium use and risk of colorectal cancer: a multi-center case-referent study in Iran. - Hadji M; Marzban M; Rashidian H; Naghibzadeh-Tahami A; Gholipour M; Mohebbi E; Safari-Faramani R; Seyyedsalehi MS; Hosseini B; Alizadeh-Navaei R; Rezaianzadeh A; Moradi A; et al. (Acta oncologica (Stockholm, Sweden), 2023)