COVID-19(9) Hepatocellular carcinoma(8) Hepatectomy(5) surgery(5) Colorectal cancer(4) Impact(3) second(3) Wave(3) pandemic(3) complications(3) Perforated acute appendicitis(3) Hepatitis B virus(3) Colorectal(3) lesson(3) multicenter(3) nomogram(2) Prognosis(2) Gastric cancer(2) survival(2) Liver cancer(1) leadership(1) Smoke evacuation(1) FIB-4(1) enhanced recovery after surgery(1) artificial intelligence(1) overall survival(1) Hiatal hernia(1) Trial(1) Antiviral(1) surge(1)