[Cai, Quancai; Du, YQ; Li, Zhaoshen; Zhu, Chunping; Du, Yiqi] Naval Med Univ, Changhai Hosp, Dept Gastroenterol, Shanghai 200433, Peoples R China.
[Yuan, Yuan] China Med Univ, Tumor Etiol & Screening Dept, Shenyang, Liaoning, Peoples R China.
[Feng, Qi] Mianyang Cent Hosp, Dept Gastroenterol, Mianyang, Sichuan, Peoples R China.
[Feng, Yichao] Yanan Univ, Affiliated Hosp, Dept Gastroenterol, Yanan, Peoples R China.
[Hao, Yingxia] Baoding First Cent Hosp, Dept Gastroenterol, Baoding, Peoples R China.