1. Department of Palliative Medicine, Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
2. Department of Critical Care Medicine, Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
3. Department of Tumor Research Institute, Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China