Yamamoto 1996.

Methods	Randomised. Generation of the allocation sequence: not clear. Allocation concealment: post‐op central office telephone randomisation. Blinding: no. Follow‐up: treatment given until adverse events appeared. Intention‐to‐treat analysis: yes. Sample size calculations: no.
Participants	67 patients with UICC (see Notes) stage II hepatocellular carcinoma, stratified into three clinical stages of liver dysfunction.
Interventions	1. Surgery: 38 patients, curative resection as defined by the Liver Cancer Study Group of Japan (1992). 2. Adjuvant: 38 patients, two to four weeks postoperative twice daily oral HCFU 200 mg for as long as possible till severe adverse events appeared.
Outcomes	Follow‐up at least bimonthly with US and six‐monthly by CT, further investigations if recurrence suspected. 1. Survival: survival curves stratified for stage. 2. Disease‐free survival: survival curves stratified for stage.
Notes	Groups comparable at baseline. Radicality of resection judged by histopathology (Union Internationale Contre le Cancer (UICC) stage II curative criteria), none analysed had <1cm disease‐free margin. 16 patients were treated as withdrawn in the effectiveness (not ITT) analysis (eight for non‐curative resection and eight from adjuvant group for protocol violation). HCFU stopped in 12 patients because of adverse events ‐ neuropathy, liver dysfunction, exanthema, diarrhoea. Unspecified treatments were performed on all patients with recurrence. HR not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate