A multicentre, multinational study of clinical characteristics and prognosis of hepatocellular carcinomaAhmet Dirican, Dogan Uncu, Marina Sekacheva, Mehmet Artaç, Archil Aladashvil, Atike Erdogan, Muhammet Kaplan, Ahmet Alacacıoğlu, Ioannis Boukovinas and Nazim Turhal