Overweight, obesity and risk of liver cancer: a meta-analysis of cohort studies

Abstract

Cohort studies of excess body weight and risk of liver cancer were identified for a meta-analysis by searching MEDLINE and EMBASE databases from 1966 to June 2007 and the reference lists of retrieved articles. Results from individual studies were combined using a random-effects model. We identified 11 cohort studies, of which seven on overweight (with a total of 5037 cases) and 10 on obesity (with 6042 cases) were suitable for meta-analysis. Compared with persons of normal weight, the summary relative risks of liver cancer were 1.17 (95% confidence interval (CI): 1.02 -1.34) for those who were overweight and 1.89 (95% CI: 1.51 -2.36) for those who were obese. This meta-analysis finds that excess body weight is associated with an increased risk of liver cancer. Although relatively rare in the United States and other developed countries, liver cancer is the third most common cause of death from cancer worldwide (Parkin et al, 2005). It is rarely detected early and is often fatal within a few months of diagnosis. The 5-year survival rate is only about 6 -11% (Coleman et al, 2003;Ries et al, 2006). The age-adjusted incidence and mortality rates of liver cancer have been increasing rapidly in the United States since the mid-1980s (Ries et al, 2006). While approximately half of this increase can be attributable to hepatitis C virus infection, a minimal or no increase has been related to hepatitis B virus and alcoholic liver disease (El-Serag and Mason, 2000;Hassan et al, 2002). Given that about half of the increase in liver cancer incidence is not related to hepatitis, the major risk factor in a significant proportion of the cases has yet to be identified.Coinciding with the rising incidence of liver cancer, the prevalence of obesity has been increasing markedly over the past two decades worldwide (Larsson and Wolk, 2006). Obesity has been recognised as a risk factor for several malignancies, including cancer of the breast (in premenopausal women), endometrium, kidney (renal cell), colon, pancreas, gallbladder, and esophagus (adenocarcinoma) (IARC, 2002;. Accumulating epidemiologic evidence also indicates that excess body weight may be a risk factor for liver cancer, but the evidence has not been quantitatively summarised. We have therefore quantitatively assessed the associations of overweight and obesity with liver cancer risk in a meta-analysis of cohort studies. MATERIALS AND METHODS Study selectionA literature search was conducted in the MEDLINE and EMBASE databases for pertinent studies published in any language from 1966 to June 2007. We used the keywords 'body mass index', 'BMI', or 'obesity' in combination with 'hepatocellular carcinoma', 'liver cancer', or 'liver neoplasm'. Moreover, we manually reviewed the reference lists of retrieved articles to search for more studies.Studies were included in the meta-analysis if they fulfilled the following criteria: (1) cohort study in which liver cancer incidence or mortality was an outcome; (2) the exposure of interest was overweight and/or obesity defined by body ma...

Obesity and overweight in relation to liver disease mortality in men: 38 year follow-up of the original Whitehall study

“…The elevated risk of liver cancer mortality in obese men apparent herein also supports the findings of a recent meta-analysis of 10 published studies. 19 That adjustment for covariates, such as blood pressure and blood glucose, attenuated the strength of this relationship suggests that these metabolic factors may lie on the causal pathway linking obesity with fatal liver disease. Men with diabetes or impaired glucose tolerance (combined) experienced higher rates of liver cancer mortality (2.18; 1.02, 4.68) in multiply adjusted analyses (Table 1 available upon request) in comparison to other men, but there was no apparent association for non-liver cancer deaths (0.82; 0.29, 2.29).…”

Organ-Specific Cancer Metabolism and Its Potential for Therapy

“…Hepatocellular carcinoma (HCC) is one of the deadliest and most common cancers worldwide [69]. In the development of HCC, nutrition and metabolic related factors like alcohol consumption, aflatoxin contamination in food [70], the gut microbiota [71], diabetes [72] and bodyweight [73] influence initiation and progression of HCC. To treat HCC is difficult, because its onset often occurs on top of an underlying liver disease such as hepatitis B or C virus infection, alcoholic liver disease, or non-alcoholic fatty liver disease.…”

Overweight and obesity among Dutch workers: differences between occupational groups and sectors

“…The deWnitions of overweight kg/m 2 ) and obesity (BMI¸30 kg/m 2 ) are based on the literature showing an increased risk of morbidity and mortality from several diseases with a BMI above 25 kg/m 2 , and especially above 30 kg/m 2 (National Institutes of Health, National Heart Lung, and Blood Institute 1998; WHO 1998). For instance, overweight and obesity are associated with an increased risk of cardiovascular disease, hypertension, type 2 diabetes mellitus, stroke, osteoarthritis, gallbladder disease, and some cancers (Wannamethee et al 2005;Larsson and Wolk 2007;Flegal et al 2007;Yang et al 2009). Next to the public health impact, overweight and obesity have occupational consequences.…”