1. School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
2. School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
3. Guangdong Second Provincial General Hospital, Guangzhou, Guangdong 510317, P.R. China
4. Department of Oncology, Dongguan People's Hospital, Dongguan, Guangdong 523059, P.R. China