The role of pre-existing diabetes mellitus on hepatocellular carcinoma occurrence and prognosis: a meta-analysis of prospective cohort studies.
BACKGROUND
The impact of pre-existing diabetes mellitus (DM) on hepatocellular carcinoma (HCC) occurrence and prognosis is complex and unclear. The aim of this meta-analysis is to evaluate the association between pre-existing diabetes mellitus and hepatocellular carcinoma occurrence and prognosis.


METHODS
We searched PubMed, Embase and the Cochrane Library from their inception to January, 2011 for prospective epidemiological studies assessing the effect of pre-existing diabetes mellitus on hepatocellular carcinoma occurrence, mortality outcomes, cancer recurrence, and treatment-related complications. Study-specific risk estimates were combined by using fixed effect or random effect models.


RESULTS
The database search generated a total of 28 prospective studies that met the inclusion criteria. Among these studies, 14 reported the risk of HCC incidence and 6 studies reported risk of HCC specific mortality. Six studies provided a total of 8 results for all-cause mortality in HCC patients. Four studies documented HCC recurrence risks and 2 studies reported risks for hepatic decomposition occurrence in HCC patients. Meta-analysis indicated that pre-existing diabetes mellitus (DM) was significantly associated with increased risk of HCC incidence [meta-relative risk (RR) = 1.87, 95% confidence interval (CI): 1.15-2.27] and HCC-specific mortality (meta-RR = 1.88, 95%CI: 1.39-2.55) compared with their non-DM counterparts. HCC patients with pre-existing DM had a 38% increased (95% CI: 1.13-1.48) risk of death from all-causes and 91% increased (95%CI: 1.41-2.57) risk of hepatic decomposition occurrence compared to those without DM. In DM patients, the meta-RR for HCC recurrence-free survival was 1.93(95%CI: 1.12-3.33) compared with non-diabetic patients.


CONCLUSIONS
The findings from the current meta-analysis suggest that DM may be both associated with elevated risks of both HCC incidence and mortality. Furthermore, HCC patients with pre-existing diabetes have a poorer prognosis relative to their non-diabetic counterparts.
Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China.
Wan-Shui
WS
Yang
Puthiery
P
Va
Freddie
F
Bray
Shan
S
Gao
Jing
J
Gao
Hong-Lan
HL
Li
Yong-Bing
YB
Xiang
D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D015331:Cohort Studies; D048909:Diabetes Complications / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D018572:Disease-Free Survival; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D011446:Prospective Studies; D011786:Quality Control