1. Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150000, P.R. China
2. Department of Medical Oncology, Daqing Oilfield General Hospital, Daqing, Heilongjiang 163000, P.R. China
3. Department of Internal Medicine, Qiqihar First Factory Hospital, Qiqihar, Heilongjiang 161000, P.R. China
4. School of Basic Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang 161000, P.R. China