Statins associate with lower risk of biliary tract cancers: A systematic review and meta-analysis

Squalene Epoxidase: Its Regulations and Links with Cancers

Squalene epoxidase (SQLE) is a key enzyme in the mevalonate-cholesterol pathway that plays a critical role in cellular physiological processes. It converts squalene to 2,3-epoxysqualene and catalyzes the first oxygenation step in the pathway. Recently, intensive efforts have been made to extend the current knowledge of SQLE in cancers through functional and mechanistic studies. However, the underlying mechanisms and the role of SQLE in cancers have not been fully elucidated yet. In this review, we retrospected current knowledge of SQLE as a rate-limiting enzyme in the mevalonate-cholesterol pathway, while shedding light on its potential as a diagnostic and prognostic marker, and revealed its therapeutic values in cancers. We showed that SQLE is regulated at different levels and is involved in the crosstalk with iron-dependent cell death. Particularly, we systemically reviewed the research findings on the role of SQLE in different cancers. Finally, we discussed the therapeutic implications of SQLE inhibitors and summarized their potential clinical values. Overall, this review discussed the multifaceted mechanisms that involve SQLE to present a vivid panorama of SQLE in cancers.

Long-term use of anti-cholesterol drugs and cancer risks in a Japanese population

Several studies have investigated the association between the use of anti-cholesterol drugs and cancer risks, of which results have been inconsistent. This study included 67,768 participants from the Japan Public Health Center-based Prospective Study. The data on anti-cholesterol drug use was collected using three questionnaires of the survey conducted every five years. We divided the participants into three groups according to the duration of the anti-cholesterol drug use. Multivariable-adjusted Cox proportional hazard regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). During the 893,009 person-years of follow-up from the 10-year follow-up survey, 8,775 participants (5,387 men and 3,388 women) were newly diagnosed with cancers. The duration of anti-cholesterol drug use was significantly associated with a decreased risk of liver cancer (HR:0.26, 95% CI 0.11-0.64 in > 5 y group) and with an increased risk of pancreatic cancer (HR:1.59, 95% CI 1.03-2.47 in > 5 y group). Moreover, a different trend was observed between men and women in the association with the risk of lung cancer. This study suggested that long-term use of anti-cholesterol drugs may have associations with a decreased incidence of liver cancer and with an increased incidence of pancreatic cancers.

The association of statin therapy and cancer: a meta-analysis

BACKGROUND

Statins are routinely prescribed to lower cholesterol and have been demonstrated to have significant benefits in atherosclerotic cardiovascular disease. However, whether statin therapy has effects on cancer risk remains controversial. In this study, we investigated the influence of statin therapy on cancer incidence and mortality by conducting a comprehensive meta-analysis of randomized controlled trials.

METHODS

Systematic searches by Cochrane, Embase, Medline, and PubMed were performed to locate data from eligible randomized controlled trials related to statin therapy and oncology. Our main endpoints were cancer incidence and mortality. Fixed-effects models were used in this study.

RESULTS

This meta-analysis comprised thirty-five randomized controlled studies. Twenty-eight included studies reported cancer incidence, and eighteen reported cancer mortality. The pooled results indicated no reduction in cancer incidence with statins compared to placebo [OR = 0.99, 95% CI (0.95, 1.03)]. In addition, statins did not decrease cancer mortality [OR = 0.99, 95% CI (0.91, 1.07)]. This study also performed a number of subgroup analyses, which showed no effect of statins on cancer subtypes such as genitourinary and breast cancer. Neither the type of statin nor long-term treatment with statins had an effect on cancer incidence and mortality.

CONCLUSION

Through comprehensive analysis, we found that statin therapy does not reduce cancer incidence or mortality while protecting the cardiovascular system.

TRIAL REGISTRATION

Prospero CRD42022377871.

Don't Judge a Book by Its Cover: The Role of Statins in Liver Cancer

Statins, which are inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, are an effective pharmacological tool for lowering blood cholesterol levels. This property makes statins one of the most popular drugs used primarily to prevent cardiovascular diseases, where hyperlipidemia is a significant risk factor that increases mortality. Nevertheless, studies conducted mainly in the last decade have shown that statins might prevent and treat liver cancer, one of the leading causes of cancer-related mortality worldwide. This narrative review summarizes the scientific achievements to date regarding the role of statins in liver tumors. Molecular biology tools have revealed that cell growth and proliferation can be inhibited by statins, which further inhibit angiogenesis. Clinical studies, supported by meta-analysis, confirm that statins are highly effective in preventing and treating hepatocellular carcinoma and cholangiocarcinoma. However, this effect may depend on the statin's type and dose, and more clinical trials are required to evaluate clinical effects. Moreover, their potential hepatotoxicity is a significant caveat for using statins in clinical practice. Nevertheless, this group of drugs, initially developed to prevent cardiovascular diseases, is now a key candidate in hepato-oncology patient management. The description of new drug-statin-like structures, e.g., with low toxicity to liver cells, may bring another clinically significant improvement to current cancer therapies.

[Metabolic syndrome and gastrointestinal cancer screening]

Cancer has become a leading cause of death among patients with metabolic syndrome (MetS). The more components of MetS a patient has, the higher his cancer risk is. MetS is causally associated with colorectal, pancreatic, gallbladder, biliary, hepatocellular, gastric and esophageal adenocarcinomas. MetS increases cancer mortality up to 2.4-fold. Intentional long-term weight loss reduces the excess cancer risk of obese MetS-patients. Preventing and treating the MetS together with GI cancer screening is effective and decreases the burden of GI cancer mortality significantly.

Assessing the role of lipid-lowering therapy on multi-cancer prevention: A mendelian randomization study

Background: Statin use for cancer prevention has raised wide attention but the conclusions are still controversial. Whether statins use have exact causal effects on cancer prevention remains unclear. Methods: Based on the Genome-Wide Association Studies (GWAS) datasets from the large prospective UK Biobank and other consortium databases, two-sample mendelian randomization (MR) analysis was conducted to explore the causal effects of statins use on varied site-specific cancer risks. Five MR methods were applied to investigate the causality. The stability, heterogeneity, and pleiotropy of MR results were also evaluated. Results: The atorvastatin use could increase the risk of colorectal cancer (odd ratio (OR) = 1.041, p = 0.035 by fixed-effects inverse variance weighted (IVW) method (IVW_FE), OR = 1.086, p = 0.005 by weighted median; OR = 1.101, p = 0.048 by weighted mode, respectively). According to the weighted median and weighted mode, atorvastatin could modestly decrease the risk of liver cell cancer (OR = 0.989, p = 0.049, and OR = 0.984, p = 0.004, respectively) and head and neck cancer (OR = 0.972, p = 0.020). Besides, rosuvastatin use could reduce the bile duct cancer risk by 5.2% via IVW_EF method (OR = 0.948, p = 0.031). No significant causality was determined in simvastatin use and pan-cancers via the IVW_FE or multiplicative random-effects IVW (IVW_MRE) method if applicable (p > 0.05). There was no horizontal pleiotropy observed in the MR analysis and the leave-one-out analysis proved the stability of the results. Conclusion: The causalities between statin use and cancer risk were only observed in colorectal cancer and bile duct cancer in the European ancestry population. Future works are warranted to provide more robust evidence for supporting statin repurposing for cancer prevention.