Clinical implication of ectopic liver lipid accumulation in renal cell carcinoma patients without visceral obesity

Metabolic dysfunction-associated steatotic liver disease and urinary system cancers: Mere coincidence or reason for concern?

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a systemic disease characterized by insulin resistance and lipotoxicity. Its association with type 2 diabetes, cardiovascular disease, liver cirrhosis, and hepatocellular carcinoma are well described. However, the association of MASLD and extra-hepatic cancers has received significantly less attention. This narrative review will summarize the conflicting evidence regarding the association between MASLD and cancers of the urinary system, including renal cell carcinoma, urothelial carcinoma, and prostate adenocarcinoma. It will explore potential mechanisms that could be responsible for a higher risk of urinary system cancers in patients with MASLD. We hope that our comprehensive assessment of the literature will help the readers to better interpret the available evidence.

Extrahepatic Outcomes of Nonalcoholic Fatty Liver Disease: Nonhepatocellular Cancers

Nonalcoholic fatty liver disease (NAFLD) encompasses the entire spectrum of fatty liver disease in individuals without significant alcohol consumption, including isolated steatosis, steatohepatitis, and cirrhosis. The overall global prevalence of NAFLD is estimated to be 30%, and the associated clinical and economic burden will continue to increase. NAFLD is a multisystemic disease with established links to cardiovascular disease, type 2 diabetes, metabolic syndrome, chronic kidney disease, polycystic ovarian syndrome, and intra- and extrahepatic malignancies. In this article the authors review the potential mechanisms and current evidence for the association between NAFLD and extrahepatic cancers and the resultant impact on clinical outcomes.

Association between nonalcoholic fatty liver disease and extrahepatic cancers: a systematic review and meta-analysis

BACKGROUND

NAFLD is tightly associated with various diseases such as diabetes, cardiovascular disease, kidney disease, and cancer. Previous studies had investigated the association between NAFLD and various extrahepatic cancers, but the available data to date is not conclusive. The aim of this study was to investigate the association between NAFLD and various extrahepatic cancers comprehensively.

METHODS

Searches were conducted of various electronic databases (PubMed, EMBASE, Medline, and the Cochrane Library) to identify observational studies published between 1996 and January 2020 which investigated the association between NAFLD and extrahepatic cancers. The pooled OR/HR/IRR of the association between NAFLD and various extrahepatic cancers were analyzed.

RESULTS

A total of 26 studies were included to investigate the association between NAFLD and various extrahepatic cancers. As the results shown, the pooled OR values of the risk of colorectal cancer and adenomas in patients with NAFLD were 1.72 (95%CI: 1.40-2.11) and 1.37 (95%CI: 1.29-1.46), respectively. The pooled OR values of the risk of intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma in patients with NAFLD were 2.46 (95%CI: 1.77-3.44) and 2.24 (95%CI: 1.58-3.17), respectively. The pooled OR value of the risk of breast cancer in patients with NAFLD was 1.69 (95%CI: 1.44-1.99). In addition, NAFLD was also tightly associatied with the risk of gastric cancer, pancreatic cancer, prostate cancer, and esophageal cancer.

CONCLUSIONS

NAFLD could significantly increase the development risk of colorectal adenomas and cancer, intrahepatic and extrahepatic cholangiocarcinoma, breast, gastric, pancreatic, prostate, and esophageal cancer. NAFLD could be considered as one of the influencing factors during the clinical diagnosis and treatment for the extrahepatic cancers.

The association between BMI and kidney cancer risk: An updated dose-response meta-analysis in accordance with PRISMA guideline

OBJECTIVE

Obesity is considered as one of the risk factors of kidney cancer. However, the results are not consistent in reported original studies, as well as in published meta-analysis. This study aims to clarify the relationship between overweight/obesity and kidney cancer by an updated overall and dose-response meta-analysis.

METHODS

This meta-analysis was conducted in accordance with PRISMA guideline. Relevant studies were searched using PubMed, Embase, and Web of Science databases. The studies were limited to human cohort studies in English and Chinese language. Random-effect models and dose-response meta-analysis were used to synthesize the results. Subgroup analyses were also conducted based on the characteristics of participants.

RESULTS

Twenty-four cohort studies with 8,953,478 participants were included in our meta-analysis. Compared to the normal weight, the pooled RRs of kidney cancer was 1.35 (1.27-1.43) in overweight and 1.76 (1.61-1.91) in obese participants. An increased kidney cancer risk of 1.06 (1.05-1.06) for each 1 kg/m increase in BMI was showed in dose-response meta-analysis. No significant heterogeneity was found across studies with I = 39.4% for overweight, and I = 43.3% for obesity.

CONCLUSION

The overall and dose-response meta-analysis suggested that overweight/obesity increases the risk of kidney cancer both in men and women.