[1] Chinese Acad Med Sci & Peking Union Med Coll, Canc Hosp, Off Canc Screening, Natl Clin Res Ctr Canc,Natl Canc Ctr, 17 Pan jia yuan South Lane, Chaoyang 100021, Peoples R China
[2] Gansu Wuwei Tumor Hosp, Dept Gastroenterol, Wuwei, Peoples R China
[3] Hosp Ci Cty, Dept Epidemiol, Canc Inst, Handan, Peoples R China
[4] Linzhou Canc Hosp, Dept Gen Surg, Linzhou, Peoples R China
[5] China Med Univ, Affiliated Hosp 1, Off Natl Canc Reg Med Ctr Liaoning Prov, Shenyang, Peoples R China
[6] Univ Med Ctr, Erasmus MC, Dept Publ Hlth, Rotterdam, Netherlands