[1] Shandong Univ, Cheeloo Coll Med, Sch Publ Hlth, Dept Biostat, Jinan 250012, Shandong, Peoples R China
[2] Kunming Med Univ, Affiliated Hosp 3, Yunnan Canc Hosp, Dept Radiol,Yunnan Canc Ctr, Kunming 650118, Peoples R China
[3] Kunming Med Univ, Affiliated Hosp 3, Yunnan Canc Hosp, Dept Colorectal Surg,Yunnan Canc Ctr, Kunming 650118, Peoples R China
[4] Kunming Med Univ, Affiliated Hosp 3, Yunnan Canc Hosp, Dept Clin Lab Med,Yunnan Canc Ctr, Kunming 650118, Peoples R China
[5] Kunming Med Univ, Sch Publ Hlth, Kunming 650500, Yunnan, Peoples R China
[6] Kunming Med Univ, Yunnan Prov Key Lab Publ Hlth & Biosafety, Kunming 650500, Yunnan, Peoples R China