Prognostic role of metformin in diabetes mellitus type 2 patients with hepatocellular carcinoma: A systematic review and meta-analysis

Table 3 Characteristics of included studies for the risk of hepatocellular carcinoma recurrence

Ref.	City	Country	Study period	Design	N	Therapy	DM (no metformin)	Number of events	DM (metformin)	Number of events
Chen et al[29], 2011	Taichung	Taiwan	June 2003 to July 2009	Retro	53	RFA	32	18	21	12
Chan et al[33], 2017	Taipei	Taiwan	January 1995 to December 2011	Retro	4610	HR	2978	1615	1632	698
					7813	No surgery	5884	2668	1929	982
Cho et al[35], 2021	Kaohsiung	Taiwan	April 2001 to June 2016	Retro	222	HR	86	52	136	85
Total					12698		8980	4353	3718	1777

DM: Diabetes mellitus; Retro: Retrospective; RFA: Radiofrequency ablation; HR: Hepatic resection.