Low serum cholesterol and the risk of cancer: an analysis of the published prospective studies

Investigating the Relationship between Body Mass Index, Cholesterol, and Cancer in United States Adults: A Cross-Sectional Study

The purpose of this cross-sectional study was to investigate the relationship between Body Mass Index (BMI), cholesterol, and cancer in United States (US) adults. Data were collected from the 2020 Medical Expenditure Panel Survey (MEPS). Eligible participants were US adults (≥18 years) with data on BMI, cholesterol, and cancer status, who were alive at the end of the data collection period. An adjusted logistic regression model assessed associations between eight possible combinations of BMI and cholesterol status (independent variable) with cancer diagnosis (dependent variable). Among 27,805 individuals in the 2020 MEPS data, 20,818 met the eligibility criteria (weighted N = 252,340,615). Of these 2668 (weighted N = 29,770,359) had cancer and 18,150 (weighted N = 222,570,256) did not have cancer. In the adjusted logistic regression model, underweight and normal weight individuals with high cholesterol were associated with higher odds of cancer (odds ratio, OR = 2.002, and 95% confidence interval, CI = 1.032-3.885, and OR = 1.326 and 95% CI = 1.047-1.681, respectively), while obese individuals with normal cholesterol were associated with lower odds of cancer (OR = 0.681; 95% CI = 0.543-0.853) compared to normal weight individuals with normal cholesterol. This study offers insights into specific groups of individuals who may be prioritized for cancer prevention. Further research is required to investigate these findings in additional subpopulations.

Temporal Association of Total Serum Cholesterol and Pancreatic Cancer Incidence

Previous studies have suggested a “cholesterol-lowering effect” of preclinical pancreatic cancer, suggesting lower total cholesterol as a potential diagnostic marker. Leveraging repeated measurements of total cholesterol, this study aims to examine the temporal association of total cholesterol and pancreatic cancer incidence. We conducted a nested case-control study based on a Korean National Health Insurance Service−Health Screening Cohort, including 215 pancreatic cancer cases and 645 controls matched on age and sex. Conditional logistic regression was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the associations of pancreatic cancer incidence with total cholesterol levels across different time windows over 11 years before pancreatic cancer diagnosis (recent, mid, distant). We found that, compared to participants with total cholesterol < 200 mg/dL in the recent 3 years prior to diagnosis, those having total cholesterol ≥ 240 mg/dL showed a significantly lower pancreatic cancer incidence (OR = 0.50 (0.27−0.93)). No significant association was found in relation to total cholesterol measured in the mid and distant past. When changes in total cholesterol over the three time periods were analyzed, compared with those with total cholesterol levels consistently below 240 mg/dL over the entire period, the OR of pancreatic cancer was 0.45 (0.20−1.03) for participants with recent-onset hypercholesterolemia, 1.89 (0.95−3.75) for recent-resolved hypercholesterolemia, and 0.71 (0.30−1.66) for consistent hypercholesterolemia. In conclusion, while high total cholesterol in the recent past may indicate a lower pancreatic cancer incidence, a recent decrease in total cholesterol may suggest an elevated incidence of pancreatic cancer.

Nationwide cohort study: cholesterol level is inversely related with the risk of gastric cancer among postmenopausal women

BACKGROUND

Recent studies showed inverse relationship between hypercholesterolemia and the risk of gastric cancer, especially among male. However evidence among female is inconsistent. We aimed to investigate the relationship between cholesterol level and the risk of gastric cancer among female according to menopausal status.

METHODS

We analyzed the data from a population-based prospective cohort of female ≥ 30 years old who underwent cancer screening and general health screening provided by the Korean National Health Insurance Corporation in 2009. Under quartile stratification of the level of cholesterol components, we calculated the hazard ratio (HR) for gastric cancer incidence until 2018 for each level group according to the menopausal status at 2009.

RESULTS

Among total 2,722,614 individuals, 17,649 gastric cancer cases developed after mean 8.26 years of follow-up (premenopausal 3746/1180666; postmenopausal 13,903/1541948). Total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) showed inverse relationship with the risk of gastric cancer among postmenopausal women (adjusted HR (95% confidence interval) for the highest quartile vs. lowest quartile and p-for-trend: 0.88 (0.84-0.92) and < 0.001 for total cholesterol; 0.89 (0.85-0.92) and < 0.001 for HDL-C; 0.92 (0.89-0.97) and 0.001 for LDL-C), whereas none showed statistically significant risk relationship among premenopausal women. Triglyceride was not independently related with gastric cancer risk among both pre- and postmenopausal women.

CONCLUSIONS

Cholesterol levels, including total cholesterol, HDL-C, and LDL-C, are inversely related with the risk of gastric cancer among postmenopausal women, but not among premenopausal women.

PCSK9 as a new player in cancer: New opportunity or red herring?

Initially described as a factor involved in liver regeneration and neuronal differentiation, proprotein convertase subtilisin/kexin type 9 (PCSK9) has become one of the key regulators of low-density lipoprotein cholesterol. Besides that, a number of studies have suggested PCSK9 may play a role in cancer biology. This is particularly true for gastroenteric (gastric and liver cancers) and lung cancers, where higher PCSK9 levels were associated with the increased ability of the tumor to develop and give metastasis as well as with reduced overall survival. Accordingly, monoclonal antibodies blocking PCSK9 were recently shown to synergize with immunotherapy in different types of cancers to achieve tumor growth suppression through an increased intratumoral infiltration of cytotoxic T cells. Anti-PCSK9 vaccines have been tested in animal models with encouraging results only in colon carcinoma. As most of this evidence is based on pre-clinical studies, this has led to some controversies and inconsistencies, thus suggesting that additional research is needed to clarify the topic. Finally, modulation of intracellular PCSK9 levels by silencing RNA (siRNA) may help understand the physiological and pathological mechanisms of PCSK9.

Association between low density lipoprotein cholesterol and all-cause mortality: results from the NHANES 1999-2014

The association between low density lipoprotein cholesterol (LDL-C) and all-cause mortality has been examined in many studies. However, inconsistent results and limitations still exist. We used the 1999–2014 National Health and Nutrition Examination Survey (NHANES) data with 19,034 people to assess the association between LDL-C level and all-cause mortality. All participants were followed up until 2015 except those younger than 18 years old, after excluding those who died within three years of follow-up, a total of 1619 deaths among 19,034 people were included in the analysis. In the age-adjusted model (model 1), it was found that the lowest LDL-C group had a higher risk of all-cause mortality (HR 1.708 [1.432–2.037]) than LDL-C 100–129 mg/dL as a reference group. The crude-adjusted model (model 2) suggests that people with the lowest level of LDL-C had 1.600 (95% CI [1.325–1.932]) times the odds compared with the reference group, after adjusting for age, sex, race, marital status, education level, smoking status, body mass index (BMI). In the fully-adjusted model (model 3), people with the lowest level of LDL-C had 1.373 (95% CI [1.130–1.668]) times the odds compared with the reference group, after additionally adjusting for hypertension, diabetes, cardiovascular disease, cancer based on model 2. The results from restricted cubic spine (RCS) curve showed that when the LDL-C concentration (130 mg/dL) was used as the reference, there is a U-shaped relationship between LDL-C level and all-cause mortality. In conclusion, we found that low level of LDL-C is associated with higher risk of all-cause mortality. The observed association persisted after adjusting for potential confounders. Further studies are warranted to determine the causal relationship between LDL-C level and all-cause mortality.

Proprotein convertase subtilisin/kexin type 9 (PCSK9): A potential multifaceted player in cancer

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a novel pharmacological target for hypercholesterolemia and associated cardiovascular diseases owing to its function to mediate the degradation of low-density lipoprotein receptor (LDLR). Findings over the past two decades have identified novel binding partners and cellular functions of PCSK9. Notably, PCSK9 is aberrantly expressed in a broad spectrum of cancers and apparently contributes to disease prognosis, indicating that PCSK9 could be a valuable cancer biomarker. Experimental studies demonstrate the contribution of PCSK9 in various aspects of cancer, including cell proliferation, apoptosis, invasion, metastasis, anti-tumor immunity and radioresistance, strengthening the idea that PCSK9 could be a promising therapeutic target. Here, we comprehensively review the involvement of PCSK9 in cancer, summarizing its aberrant expression, association with disease prognosis, biological functions and underlying mechanisms in various malignancies. Besides, we highlight the potential of PCSK9 as a future therapeutic target in personalized cancer medicine.

PCSK9 and cancer: Rethinking the link

BACKGROUND

Cancer is emerging as a major problem globally, as it accounts for the second cause of death despite medical advances. According to epidemiological and basic studies, cholesterol is involved in cancer progression and there are abnormalities in cholesterol metabolism of cancer cells including prostate, breast, and colorectal carcinomas. However, the importance of cholesterol in carcinogenesis and thereby the role of cholesterol homeostasis as a therapeutic target is still a debated area in cancer therapy. Proprotein convertase subtilisin/kexin type-9 (PCSK9), a serine protease, modulates cholesterol metabolism by attachment to the LDL receptor (LDLR) and reducing its recycling by targeting the receptor for lysosomal destruction. Published research has shown that PCSK9 is also involved in degradation of other LDLR family members namely very-low-density-lipoprotein receptor (VLDLR), lipoprotein receptor-related protein 1 (LRP-1), and apolipoprotein E receptor 2 (ApoER2). As a result, this protein represents an interesting therapeutic target for the treatment of hypercholesterolemia. Interestingly, clinical trials on PCSK9-specific monoclonal antibodies have reported promising results with high efficacy in lowering LDL-C and in turn reducing cardiovascular complications. It is important to note that PCSK9 mediates several other pathways apart from its role in lipid homeostasis, including antiviral activity, hepatic regeneration, neuronal apoptosis, and modulation of various signaling pathways. Furthermore, recent literature has illustrated that PCSK9 is closely associated with incidence and progression of several cancers. In a number of studies, PCSK9 siRNA was shown to effectively suppress the proliferation and invasion of the several studied tumor cells. Hence, a novel application of PCSK9 inhibitors/silencers in cancer/metastasis could be considered. However, due to poor data on effectiveness and safety of PCSK9 inhibitors in cancer, the impact of PCSK9 inhibition in these pathological conditions is still unknown.

SEARCH METHODS

A vast literature search was conducted to find intended studies from 1956 up to 2020, and inclusion criteria were original peer-reviewed publications.

PURPOSE OF REVIEW

To date, PCSK9 has been scantly investigated in cancer. The question that needs to be discussed is "How does PCSK9 act in cancer pathophysiology and what are the risks or benefits associated to its inhibition?". We reviewed the available publications highlighting the contribution of this proprotein convertase in pathways related to cancer, with focus on the potential implications of its long-term pharmacological inhibition in cancer therapy.

[Research Progress on the Relationship between Blood Lipids and Lung Cancer Risk and Prognosis]

近年来，肺癌成为导致癌症相关死亡的主要原因。越来越多证据表明，许多脂类和脂类类似物是肿瘤发生的关键调节因子，吸烟、饮食及肥胖等影响血脂水平的因素可能与癌症的风险相关。目前随着脂质与肿瘤发生过程关系的研究逐渐深入，探索血脂与肺癌风险及预后相关性已成为研究的热点。本文就血脂水平与肺癌发病风险、血脂水平与肺癌患者预后相关性及调整血脂药物与防治肺癌方向的研究进展进行综述。

Lipid profile and risk of ovarian tumours: a meta-analysis

BACKGROUND

Existing data from several reports on the association between lipid profile and ovarian tumour (OT) suggests divergent conclusions. Our aim was to examine whether circulating lipid profile: total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) differed between cases and non-cases of OT.

METHODS

Electronic repositories; PUBMED, EMBASE and Cochrane library were explored through December 2019 to retrieve published articles for inclusion in the meta-analysis after quality assessment. Heterogeneity was assessed using I2 statistics, the effect of individual studies on the overall effect size was tested using sensitivity analysis and funnel plot was used to evaluate publication bias.

RESULTS

Twelve studies, involving 1767 OT cases and 229,167 non-cases of OT were included in this meta-analysis and I2 statistics ranged between 97 and 99%. Mean circulating TC (- 16.60 [- 32.43, - 0.77]mg/dL; P = 0.04) and HDL (- 0.25[- 0.43, - 0.08]mmol/L; P = 0.005) were significantly lower among OT cases compared to non-OT cases.

CONCLUSION

Decreased TC and HDL profiles were observed among subjects with OT in this collection of reports. The implications of TC and HDL in tumour manifestations and growth need to be validated in a large multi-ethnic longitudinal cohort adjusting for relevant confounders.

Cholesterol, Oxysterols and LXRs in Breast Cancer Pathophysiology

Breast cancer is the most frequent cancer among women. In 2018, it is estimated that 627,000 women died from breast cancer. This is approximately 15% of all cancer deaths among women (WHO 2018). Breast cancer is a multifactorial chronic disease. While important progress has been made to treat patients, many questions regarding aspects of this disease relating to carcinogenesis are still open. During carcinogenesis, cells exhibit cholesterol homeostasis deregulation. This results in an accumulation of intracellular cholesterol, which is required to sustain their high growth rate. Cholesterol efflux and influx are two metabolic pathways that are necessary to prevent cholesterol accumulation in the cells. Liver X receptors (LXRs) are nuclear receptors that, upon activation, induce the expression of ABC transporters, responsible for promoting cholesterol efflux, and the expression of IDOL (inducible degrader of low-density lipoprotein receptor), in charge of reducing cholesterol influx. Oxysterols, oxygenated derivatives of cholesterol formed through different pathways, have been discovered as LXR-specific ligands. Some oxysterols are involved in tumor formation while others are considered anti-tumor agents. In the present review, we discuss the involvement of cholesterol, oxysterols and LXRs in breast cancer pathophysiology, with an emphasis on the biological effects of LXR ligands.

Low Levels of Low-Density Lipoprotein Cholesterol and Mortality Outcomes in Non-Statin Users

We aimed to test the association between low-density lipoprotein cholesterol (LDL-C) and cardiovascular disease (CVD), cancer, and all-cause mortality in non-statin users. A total of 347,971 subjects in Kangbuk Samsung Health Study (KSHS.57.4% men, mean follow up: 5.64 ± 3.27 years) were tested. To validate these associations, we analyzed data from another cohort (Korean genome and epidemiology study, KoGES, 182,943 subjects). All subjects treated with any lipid-lowering therapy and who died during the first 3 years of follow up were excluded. Five groups were defined according to baseline LDL-C concentration (<70, 70–99, 100–129, 130–159, ≥160 mg/dL). A total of 2028 deaths occurred during follow-up in KSHS. The lowest LDL-C group (LDL < 70 mg/dL) had a higher risk of all-cause mortality (HR 1.95, 1.55–2.47), CVD mortality (HR 2.02, 1.11–3.64), and cancer mortality (HR 2.06, 1.46–2.90) compared to the reference group (LDL 120–139 mg/dL). In the validation cohort, 2338 deaths occurred during follow-up. The lowest LDL-C group (LDL < 70 mg/dL) had a higher risk of all-cause mortality (HR 1.81, 1.44–2.28) compared to the reference group. Low levels of LDL-C concentration are strongly and independently associated with increased risk of cancer, CVD, and all-cause mortality. These findings suggest that more attention is needed for subjects with no statin-induced decrease in LDL-C concentrations.

Updating the role of obesity and cholesterol in breast cancer

BACKGROUND

Breast cancer is the second most common cause of cancer-related death among women. Advances in our understanding of the disease have translated into better diagnostics and more effective therapeutics, leading to earlier detection and improved outcomes. Several studies have pointed at lifestyle and environmental factors as contributory for the onset and progression of the disease. Obesity and cholesterol stand out for their potential causal relationship with breast cancer and ease of modification.

MAIN TEXT

Obesity and cholesterol represent risk factors for breast cancer, but their impact is largely affected by cofounding variables including menopausal status, disease subtype, and inflammation. Establishing a causal relationship between lifestyle factors and clinical outcomes may be challenging. Epidemiological studies and meta-analyses have rendered conflicting or sometimes contradictory results, possibly owing to the multifactorial nature of the disease. We discuss the supporting evidence and limitations in our understanding of obesity and cholesterol as risk factors for breast cancer.

CONCLUSIONS

There is sufficient evidence that obesity and cholesterol impact clinical outcomes. Physicians are advised to take steps to help patients with their weight, such as recommending dietary and lifestyle interventions.

Total Serum Cholesterol and Pancreatic Cancer: A Nested Case-Control Study

BACKGROUND

Pancreatic cancer is the third leading cause of cancer-related death in the United States. Total serum cholesterol (TSC) may predict cancer risk, although its role independent of statins remains elusive. We examined the association between TSC and pancreatic cancer risk independent of statins.

METHODS

A nested case-control analysis was conducted among statin-naïve patients within The Health Improvement Network (THIN), a United Kingdom-based general practice database. Cases were >40 years old and diagnosed with pancreatic cancer after at least 6 months of follow-up. Controls were selected by incidence density sampling and matched by age, sex, practice site, and follow-up. Primary exposure was TSC (mmol/L) prior to index date. Conditional logistic regression estimated ORs for pancreatic cancer risk associated with TSC. Sensitivity analyses were conducted among nondiabetics.

RESULTS

Among 1,241 cases and 3,307 matched controls, an average 8% reduction was observed in pancreatic cancer risk per mmol/L increase in TSC [OR 0.92, 95% confidence interval (CI): 0.85-1.00; nondiabetics: OR 0.91, 95% CI: 0.83-0.99]. When TSC was measured at 12-month intervals prior to diagnosis, the OR between TSC and pancreatic cancer was 0.88 at 0 to 12 months (95% CI: 0.77-1.00; nondiabetics: OR 0.81, 95% CI: 0.68-0.96). No significant association was seen at subsequent discrete intervals before index date.

CONCLUSIONS

TSC is a significant predictor of short-term risk for pancreatic cancer. This risk increase associated with lower TSC was independent of statins.

IMPACT

TSC could serve as a biomarker for risk stratification, screening, and early diagnosis of pancreatic cancer in future clinical prediction models.

Statin use, high cholesterol and prostate cancer progression; results from HCaP-NC

BACKGROUND

Statin use is associated with lower advanced prostate cancer risk and reduced prostate cancer-specific mortality, but prior studies were conducted mainly in white men. We examined the effect of statin use on risk of prostate cancer progression in a population-based, minority-enriched cohort.

METHODS

We used data from prostate cancer cases (45% African American) diagnosed between 2004 and 2007 who participated in the Health Care Access and Prostate Cancer Treatment in North Carolina cohort (HCaP-NC). We abstracted statin use at diagnosis. Men reported if they had ever been diagnosed with high cholesterol. Multivariable Cox proportional hazards analysis was used to examine associations between statin use and risk of prostate cancer progression (biochemical recurrence or secondary treatment), overall and by race. In secondary analysis, we examined the association between high cholesterol and risk of progression, overall, and by statin use.

RESULTS

Of 669 men, 244 (36%) were statin users at diagnosis. During 3.8 years median follow-up, 138 men experienced prostate cancer progression. There was no association between statin use and risk of progression, either overall (HR 1.03; 95%CI 0.72-1.46) or stratified by race. High cholesterol was inversely associated with risk of progression, particularly among statin users (HR 0.43; 95%CI 0.20-0.94; p-interaction = 0.22) and in men with higher perceived access to care (HR 0.57; 95%CI 0.36-0.90; p-interaction = 0.03). Study limitations included a relatively small sample size, short follow-up, and lack of data regarding post diagnosis statin use.

CONCLUSIONS

Statin use at diagnosis was not associated with prostate cancer progression in the population-based, minority-enriched HCaP-NC. Greater healthcare engagement, including actively controlling serum cholesterol, may be linked to better prostate cancer-specific outcomes.

Benefits of Statin Therapy in Patients With Acute Myocardial Infarction With Serum Low-Density Lipoprotein Cholesterol ≤ 50 mg/dl

Previous trials have found that statin therapy reduces low-density lipoprotein cholesterol (LDL-C) level and the risk of cardiovascular events. However, the benefit of statin therapy in patients with baseline LDL-C levels ≤ 50 mg/dl is less clear. Therefore, the aim of this study was to assess whether patients with acute myocardial infarction (AMI) who have baseline LDL-C levels ≤ 50 mg/dl would benefit from statin therapy in real-world clinical practice. We analyzed the clinical data of 1,048 patients (67.3 ± 12.6 years, 69.6% men) with AMI, who had baseline LDL-C levels ≤ 50 mg/dl from the Korean Acute Myocardial Infarction Registry data between November 2005 and May 2014. They were divided into 2 groups based on whether they were prescribed statins or not at discharge (statin and nonstatin group, n = 738 and 310, respectively). The primary end point was the major adverse cardiac event (MACE), defined as the composite of all-cause mortality, recurrent myocardial infarction, and repeated percutaneous coronary intervention or coronary artery bypass grafting. MACE occurred in 9.2% of the statin group versus 19.6% in the nonstatin group during the 12-month follow-up. Statin therapy significantly reduced the risk of MACE (hazard ratio [HR] 0.60, 95% CI 0.39 to 0.94, p = 0.025) and coronary artery bypass grafting (HR 0.27, 95% CI 0.08 to 0.96, p = 0.043). There was a trend of reduced cardiac death in the statin group compared with the nonstatin group (HR 0.52, 95% CI 0.26 to 1.02, p = 0.059). Statin therapy for patients with AMI with LDL-C levels ≤ 50 mg/dl was associated with improved outcomes. Therefore, statin therapy is feasible and effective, even in AMI patients with extremely low levels of LDL-C.

Blood lipids profile and lung cancer risk in a meta-analysis of prospective cohort studies

BACKGROUND

Emerging evidence has connected lipid metabolism disturbance with lung diseases, but the relationship between blood lipid profile and lung cancer risk is controversial and inconclusive.

OBJECTIVE

We conducted a meta-analysis of prospective cohort studies to evaluate the relationship between blood lipids profile and lung cancer incidence.

METHODS

Relevant studies were identified by searching PubMed, Cochrane Library, Web of Science, EBSCO, Ovid, CNKI, VIP, and WANGFANG MED through August 2016. Nine prospective cohort studies were included in the meta-analysis, and fixed or random effects model was used to calculate pooled relative risk (RRs). The RR was calculated using either highest vs lowest categories, or upper quantile vs lowest quantile. The thresholds were determined by the authors of each original publication, based on either predefined cut-offs or the distributions within their study population.

RESULTS

Analysis of 18,111 lung cancer cases among 1,832,880 participants showed that serum total cholesterol levels were inverse associated with lung cancer risk (RR = 0.93, 95% confidence interval [CI]: 0.85-1.03). Further analysis considered the lag time and excluded the effects of preclinical cancer, with totally 1,239,948 participants and 14,052 lung cancer cases, found a significantly inverse association between total cholesterol and lung cancer risk (RR = 0.89, 95% CI: 0.83-0.94). Analysis of 3067 lung cancer cases among 59,242 participants found that the high-density lipoprotein cholesterol levels (RR = 0.76, 95% CI: 0.59-0.97) was negatively associated with lung cancer risk and 4673 lung cancer cases among 685,852 participants showed that the total triglyceride (RR = 1.68, 95% CI: 1.44-1.96) was positively associated with lung cancer risk.

CONCLUSION

Cholesterol and fatty acid metabolism might present different and specific mechanism on lung cancer etiology and needs further elucidation.

Prognostic Role of Preoperative Serum Lipid Levels in Patients Undergoing Radical Prostatectomy for Clinically Localized Prostate Cancer

BACKGROUND

The prognostic role of preoperative serum lipid levels in patients undergoing radical prostatectomy (RP) for clinically localized prostate cancer (PCa) is unclear. The aim of the present study was to investigate preoperative serum lipid levels in patients with clinically localized PCa undergoing RP and their association with clinicopathological features and oncological outcome.

METHODS

Preoperative lipid levels (total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides) and statin use from consecutive patients with clinically localized PCa undergoing RP in a tertiary referral center between 2008 and 2015 were recorded and patients were followed prospectively. Logistic regression analysis was used to test the association between lipid levels and clinicopathological parameters. Lipid values were analyzed both as continuous and dichotomized variables. Univariable and multivariable Cox regression analyses were performed to identify predictors for recurrence-free survival (RFS). Recurrence was defined as rising and verified PSA levels >0.1 ng/ml.

RESULTS

Our cohort consisted of 371 men with a median age of 63 years (range 41-78 years) and a median preoperative PSA value of 6.79 ng/ml (0.43-81.4 ng/ml). Median follow-up was 28 months (1-64). No association was found between lipid levels and adverse pathological characteristics such as ≥pT3, Gleason score ≥8, positive nodal status and positive surgical margins. Recurrence occurred in 49 patients (15.4%) at a median time of 18 months (2-51 month). Compared to low LDL cholesterol, high LDL cholesterol was associated with longer RFS in univariable analysis (continuous: Hazard Ratio (HR): 0.67, 95%-Confidence Interval (CI): 0.47-0.96, P = 0.03; 3 mM cut-point: HR: 0.44, 95%-CI: 0.24-0.79, P = 0.006). Neither levels of other lipids, nor statin use were associated with RFS. Preoperative LDL cholesterol remained an independent predictor for PCa recurrence in a multivariable model adjusted for age, preoperative PSA, statin use, tumor stage, Gleason score, nodal status and surgical margin status (continuous: HR: 0.66, 95%-CI: 0.44-0.99, P = 0.04; 3 mM cut-point: HR: 0.41, 95%-CI: 0.21-0.78, P = 0.007).

CONCLUSIONS

This is the first prospective study showing the potential adverse and independent prognostic role of low preoperative LDL cholesterol levels in patients with localized PCa undergoing RP. Prostate 77:549-556, 2017. © 2017 Wiley Periodicals, Inc.

Evidence-based goals in LDL-C reduction

The evidence from trials of statin therapy suggests that benefits in cardiovascular disease (CVD) event reduction are proportional to the magnitude of low-density lipoprotein cholesterol (LDL-C) lowering. The lack of a threshold at which LDL-C lowering is not beneficial, in terms of CVD prevention observed in these trials, is supported by epidemiological and genetic studies reporting the cardio-protective effects of lifelong low exposure to atherogenic cholesterol in a graded fashion. Providing that intensive LDL-C lowering is safe, these observations suggest that many individuals even at current LDL-C treatment targets could benefit. Here, we review recent safety and efficacy data from trials of adjunctive therapy, with LDL-C lowering beyond that achieved by statin therapy, and their potential implications for current guideline targets. Finally, the application of current guidance in the context of pre-treatment LDL-C concentration and deployment of statin therapy is also discussed. The number of patients requiring treatment to prevent a CVD event with statin treatment has been shown to differ markedly according to the pre-treatment LDL-C concentration even when absolute CVD risk is similar. It produces more likelihood of benefit when absolute LDL-C reduction is greater which is largely dependent on pre-treatment LDL-C concentration. This also has to be taken in consideration when deploying new agents like proprotein convertase subtilisin/kexin type 9 monoclonal antibodies. Patients with highest LDL-C concentration despite maximum statin and ezetimibe therapy will attain most absolute LDL-C reduction when treated with proprotein convertase subtilisin/kexin type 9 monoclonal antibodies, hence benefit most in term of CVD risk reduction.

Associations between serum lipids and breast cancer incidence and survival in the E3N prospective cohort study

PURPOSE

Several mechanistic studies support a role of cholesterol or its metabolites in breast cancer etiology, but associations have been inconsistent in epidemiological studies. In observational studies, possible reverse causation must be accounted for using a prospective design. We investigated prospective associations between pre-diagnostic serum lipid concentrations [total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides], and both breast cancer risk and survival in the E3N cohort study.

METHODS

Analyses were performed on 583 cases from the E3N prospective cohort diagnosed between 1994 and 2005, and 1,043 controls matched on date, age, recruitment center and menopausal status at blood collection. Odds ratios (OR) and 95% confidence intervals were estimated using conditional logistic regression. Risks of recurrence were estimated among cases using Cox proportional hazards model. Models were adjusted for lifestyle risk factors and mutually adjusted for lipid concentrations. Survival analyses were additionally adjusted for tumor characteristics.

RESULTS

Overall, there was no association between any serum lipid and breast cancer risk or survival. In stratified analyses, statistically significant interaction was observed between TC and menopausal status (P interaction = 0.05) and between TC and waist circumference (P interaction = 0.03), although the ORs did not reach statistical significance in any of the strata. There was no statistically significant effect modification by BMI, time between blood donation and diagnosis or ER status.

CONCLUSIONS

Our results suggest that serum lipids are not associated with breast cancer risk overall, but that menopausal status and waist circumference should be considered in further studies.

The current evidence on statin use and prostate cancer prevention: are we there yet?

An increasing amount of data supports an inverse association between statin use and cancer risk. The findings for prostate cancer, particularly advanced disease, are the most promising of all cancers studied. Use of these agents seems to also be associated with improved prostate- cancer-specific survival, particularly in men undergoing radiotherapy, suggesting usefulness of statins in secondary and tertiary prevention. Some study results might be influenced by increased PSA screening and health-conscious behaviour in statin users but these factors are unlikely to completely account for observed beneficial effects. The epidemiological evidence is supported by preclinical studies that show that statins directly inhibit prostate cancer development and progression in cell-based and animal-based models. The antineoplastic effect of statins might arise from a number of cholesterol-mediated and non-cholesterol-mediated mechanisms that affect pathways essential for cancer formation and progression. Understanding these mechanisms is instrumental in drug discovery research for the development of future prostate cancer therapeutics, as well as in designing clinical trials to test a role for statins in prostate cancer prevention. Currently, sufficient data are lacking to support the use of statins for the primary prevention of prostate cancer and further research is clearly warranted. Secondary and tertiary prevention trials in men who have been diagnosed with prostate cancer might soon be performed.

Long-Term Effectiveness and Safety of Pravastatin in Patients With Coronary Heart Disease

Background—

We aimed to assess the long-term effects of treatment with statin therapy on all-cause mortality, cause-specific mortality, and cancer incidence from extended follow-up of the Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) trial.

Methods and Results—

LIPID initially compared pravastatin and placebo over 6 years in 9014 patients with previous coronary heart disease. After the double-blind period, all patients were offered open-label statin therapy. Data were obtained over a further 10 years from 7721 patients, by direct contact for 2 years, by questionnaires thereafter, and from mortality and cancer registries. During extended follow-up, 85% assigned pravastatin and 84% assigned placebo took statin therapy. Patients assigned pravastatin maintained a significantly lower risk of death from coronary heart disease (relative risk [RR] 0.89; 95% confidence interval [CI], 0.81−0.97; P =0.009), from cardiovascular disease (RR, 0.88; 95% CI, 0.81−0.95; P =0.002), and from any cause (RR, 0.91; 95% CI, 0.85−0.97; absolute risk reduction, 2.6%; P =0.003).Cancer incidence was similar by original treatment group during the double-blind period (RR, 0.94; 95% CI, 0.82–1.08; P =0.41), later follow-up (RR, 1.02; 95% CI, 0.91–1.14; P =0.74), and overall (RR, 0.99; 95% CI, 0.91–1.08; P =0.83). There were no significant differences in cancer mortality, or in the incidence of organ-specific cancers. Cancer findings were confirmed in a meta-analysis with other large statin trials with extended follow-up.

Conclusions—

In LIPID, the absolute survival benefit from 6 years of pravastatin treatment appeared to be maintained for the next 10 years, with a similar risk of death among survivors in both groups after the initial period. Treatment with statins does not influence cancer or death from noncardiovascular causes during long-term follow-up.

Disentangling the Association between Statins, Cholesterol, and Colorectal Cancer: A Nested Case-Control Study

BACKGROUND

Several prior studies have found an association between statin use and reduced risk of colorectal cancer. We hypothesized that these findings may be due to systematic bias and examined the independent association of colorectal cancer risk with statin use, serum cholesterol, and change in cholesterol concentration.

METHODS AND FINDINGS

22,163 colorectal cancer cases and 86,538 matched controls between 1995 and 2013 were identified within The Health Improvement Network (THIN) a population-representative database. Conditional logistic regression models estimated colorectal cancer risk with statin use, serum total cholesterol (mmol/L), and change in total cholesterol level. We confirmed a decreased risk of colorectal cancer with statin use (long-term: odds ratio [OR], 0.95; 95% confidence interval [CI], 0.91-0.99; short-term: OR, 0.92; 95% CI, 0.85-0.99). However, to assess whether the observed association may result from indication bias, a subgroup analysis was conducted among patients prescribed a statin. In this subgroup (n = 5,102 cases, n = 19,032 controls), 3.1% of case subjects and 3.1% of controls discontinued therapy. The risk of colorectal cancer was not significantly different among those who continued statin therapy and those who discontinued (OR, 0.98; 95% CI, 0.79-1.22). Increased serum cholesterol was independently associated with decreased risk of colorectal cancer (OR, 0.89 per mmol/L increase; 95% CI, 0.87-0.91); the association was only present if serum cholesterol was measured near the cancer diagnosis (<6 mo: OR, 0.76; 95% CI, 0.47-0.61; >24 mo: OR, 0.98; 95% CI, 0.93-1.03). Decreases in serum total cholesterol >1 mmol/L ≥1 year prior to cancer diagnosis were associated with subsequent colorectal cancer (statin users: OR, 1.25; 95 CI%, 1.03-1.53; nonusers: OR, 2.36; 95 CI%, 1.78-3.12). As an observational study, limitations included incomplete data and residual confounding.

CONCLUSIONS

Although the risk of colorectal cancer was lower in statin users versus nonusers, no difference was observed among those who continued versus discontinued statin therapy, suggesting the potential for indication bias. The association between decreased serum cholesterol and colorectal cancer risk suggests a cholesterol-lowering effect of undiagnosed malignancy. Clinical judgment should be used when considering causes of cholesterol reduction in patients, including those on statin therapy.

Apolipoprotein E epsilon 2 allele and low serum cholesterol as risk factors for gastric cancer in a Chinese Han population

Apolipoprotein E (apoE) mediates lipid metabolism both in peripheral and in the brain. The human APOE gene has three polymorphic alleles that influence the risk for various types of cancer and neurodegenerative diseases. A potential association between APOE allele and the risk for gastric cancer has been implicated, but the specific allele involved and potential associations with the subtype and the grade of cancer malignancy need further clarification. We screened the APOE genotype in 550 gastric cancer patients and 550 non-cancer control individuals and found that the presence of the APOE ε2 and lower serum total cholesterol are associated with an increased risk for gastric cancer (all P ≤ 0.0005). Interestingly, APOE ε2 is also correlated with increased risk for both intestinal and diffuse histotypes but not with TN classification or stage in gastric cancer patients, suggesting that APOE polymorphic alleles are associated with the risk of development but unlikely the progression of gastric cancer. Since ε2 carriers have lower levels of serum total cholesterol than non-ε2 carriers, our findings suggest that the increased risk for gastric cancer by APOE ε2 allele might be mediated through lowered serum total cholesterol levels.

Cholesterol and breast cancer risk: a systematic review and meta-analysis of prospective studies

The objective of the present study was to conduct the first systematic review and meta-analysis of prospective studies investigating the associations between total cholesterol (TC), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) levels and the risk of breast cancer. Relevant studies were identified in PubMed (up to January 2014). Inclusion criteria were original peer-reviewed publications with a prospective design. Random-effects models were used to estimate summary hazard ratios (HR) and 95% CI. Distinction was made between studies that did or did not exclude cancer cases diagnosed during the first years of follow-up, thereby eliminating potential preclinical bias. Overall, the summary HR for the association between TC and breast cancer risk was 0.97 (95% CI 0.94, 1.00; dose-response per 1 mmol/l increment, thirteen studies), and that between HDL-C and breast cancer risk was 0.86 (95% CI 0.69, 1.09; dose-response per 1 mmol/l increment, six studies), with high heterogeneity (I2= 67 and 47%, respectively). For studies that eliminated preclinical bias, an inverse association was observed between the risk of breast cancer and TC (dose-response HR 0.94 (95% CI 0.89, 0.99), seven studies, I2= 78%; highest v. lowest HR 0.82 (95% CI 0.66, 1.02), nine studies, I2= 81%) and HDL-C (dose-response HR 0.81 (95% CI 0.65, 1.02), five studies, I2= 30 %; highest v. lowest HR 0.82 (95% CI 0.69, 0.98), five studies, I2= 0%). There was no association observed between LDL-C and the risk of breast cancer (four studies). The present meta-analysis confirms the evidence of a modest but statistically significant inverse association between TC and more specifically HDL-C and the risk of breast cancer, supported by mechanistic plausibility from experimental studies. Further large prospective studies that adequately control for preclinical bias are needed to confirm the results on the role of cholesterol level and its fractions in the aetiology of breast cancer.

Alteration of Lipid Profile in Patients with Head and Neck Malignancy

Lipids are the major cell membrane components, essential for various biological functions including cell growth and division for the maintenance of cell integrity of normal and malignant tissues. The changes in lipid profile have been associated since long with cancer and hypocholesterolemia has been observed in patients with cancers of various organs. The objective of the present study is to evaluate the alterations and clinical significance of plasma lipid profiles in untreated head and neck malignancies. The present case-control study comprises of newly diagnosed and histologically confirmed, 100 head and neck malignancy cases diagnosed between 1st July 2013 and 30th June 2014 in the Department of Otorhinolaryngology and Head and Neck Surgery, Gandhi Medical College, Bhopal. Fasting blood samples were collected and the lipid profile studied. In present study, the authors found that there is a preponderance of head and neck malignancy in the age group of 41-60 years, males having the higher incidence. Malignancy involving oral cavity were the commonest and majority were well differentiated. Statistically, there was a highly significant reduction of mean serum total cholesterol (TC), triglycerides and high density lipoproteins (HDL) in the subjects of head and neck malignancy as compared to the control group. TC and HDL were also found significantly lower among those with habit of tobacco consumption.

Dyslipidemia and colorectal cancer risk: a meta-analysis of prospective studies

PURPOSE

The findings from epidemiologic studies of dyslipidemia and colorectal cancer risk have been conflicting. We performed a dose-response meta-analysis of published prospective studies to assess the aforementioned association.

METHODS

Relevant studies that reported the association between the components of dyslipidemia (serum triglyceride, total cholesterol, and high-/low-density lipoprotein cholesterol) and colorectal cancer risk were identified by searching PubMed until the end of May 2014. We pooled the relative risks (RRs) from individual studies using a random- and fixed-effects models and performed dose-response, heterogeneity, and publication bias analyses.

RESULTS

Seventeen prospective studies, including 1,987,753 individuals with 10,876 colorectal cancer events, were included in the meta-analysis. The overall pooled RR for high versus low concentrations for triglyceride (n = 9 studies) was 1.18 (95 % CI 1.04-1.34; I (2) = 47.8 %), for total cholesterol (n = 10 studies) was 1.11 (95 % CI 1.01-1.21; I (2) = 46.7 %), for high-density lipoprotein cholesterol (n = 6 studies) was 0.84 (95 % CI 0.69-1.02; I (2) = 42.5 %), and for low-density lipoprotein cholesterol (n = 3 studies) was 1.04 (95 % CI 0.60-1.81; I (2) = 82.7 %). In the dose-response analysis, the overall pooled RR was 1.01 (95 % CI 1.00-1.03; I (2) = 0 %) per 50 mg/dL of triglyceride and 1.01 (95 % CI 0.97-1.05; I (2) = 64.3 %) per 100 mg/dL of total cholesterol.

CONCLUSIONS

This meta-analysis of prospective studies suggests that dyslipidemia, especially high levels of serum triglyceride and total cholesterol, is associated with an increased risk of colorectal cancer, whereas high-density lipoprotein cholesterol might associate with a decreased risk of colorectal cancer. Further studies are warranted to determine whether altering the concentrations of these metabolic variables may reduce colorectal cancer risk.

HMG-CoA reductase inhibitors as adjuvant treatment for hematologic malignancies: what is the current evidence?

Statins have been shown to possess properties that go beyond their lipid-lowering effects. These agents act on the mevalonate pathway and inhibit synthesis of cholesterol, geranylgeranyl pyrophosphate, and farnesyl pyrophosphate, which are necessary for posttranslational modification of the Rho, Rac, and Ras superfamily of proteins. Early phase studies have demonstrated that this modulation of cellular signaling can ultimately exert pro-apoptotic, anti-angiogenic, and immunomodulatory effects, and might even restore chemosensitivity in several hematologic cancers. Nonetheless, these promising preclinical results have not yet migrated from the bench to the bedside as their effectiveness as adjuvant agents in hematologic malignancies is currently uncertain. In the present review, we summarize the existing evidence stemming from preclinical and clinical studies pertaining to the use of statins as adjuvant therapies in hematologic malignancies, and discuss the new insights gained from the ongoing translational research.

Cholesterol-induced mammary tumorigenesis is enhanced by adiponectin deficiency: role of LDL receptor upregulation

Adiponectin is an adipokine that can suppress the proliferation of various human carcinoma cells. Although its anti-tumor activities have been suggested by many clinical investigations and animal studies, the underlying mechanisms are not fully characterized. In MMTV-polyomavirus middle T antigen (MMTV-PyVT) transgenic mice models, reduced- or complete loss-of-adiponectin expression promotes mammary tumor development. The present study demonstrated that while tumor development in control MMTV-PyVT mice is associated with a progressively decreased circulating cholesterol concentration, adiponectin deficient MMTV-PyVT mice showed significantly elevated total- and low density lipoprotein (LDL)-cholesterol levels. Cholesterol contents in tumors derived from adiponectin deficient mice were dramatically augmented. High fat high cholesterol diet further accelerated the tumor development in adiponectin deficient PyVT mice. The protein levels of LDL receptor (LDLR) were found to be upregulated in adiponectin-deficient tumor cells. In human breast carcinoma cells, treatment with LDL-cholesterol or overexpressing LDLR elevates nuclear beta-catenin activity and facilitates tumor cell proliferation. On the other hand, adiponectin decreased LDLR protein expression in breast cancer cells and inhibited LDL-cholesterol-induced tumor cell proliferation. Both in vivo and in vitro evidence demonstrated a stimulatory effect of adiponectin on autophagy process, which mediated the down-regulation of LDLR. Adiponectin-induced reduction of LDLR was blocked by treatment with a specific inhibitor of autophagy, 3-methyladenine. In conclusion, the study demonstrates that adiponectin elicits tumor suppressive effects by modulating cholesterol homeostasis and LDLR expression in breast cancer cells, which is at least in part attributed to its role in promoting autophagic flux.

Association between apolipoprotein E genotype and cancer susceptibility: a meta-analysis

BACKGROUND

Apolipoprotein E (ApoE), a protein primarily involved in lipoprotein metabolism, occurs in three isoforms (E2, E3 and E4). Studies evaluating the association between APOE genotype and incidence of malignancies have given inconclusive results.

OBJECTIVE

The objective of the present study was to analyze the association between APOE genotype and incidence of cancer by a meta-analysis.

METHODS

We conducted a literature search in the electronic databases for studies with information on APOE genotype in malignancies. Sixteen studies (14 case-control and 2 cohort; 77,970 controls and 12,010 cases) were included for the present meta-analysis. Pooled odds ratios (OR) with 95 % confidence intervals (CI) were calculated assuming a random-effect model for all the genotypes and alleles. Subgroup analyses based on study design, ethnicity of populations, site of cancer and source of controls were performed as a post hoc measure. Appropriate tests to detect heterogeneity, publication bias and sensitivity were done at all stages. The review protocol is registered with the PROSPERO database vide registration number CRD42013006496.

RESULTS

The pooled effect measure for the comparisons did not reveal an association in primary analyses. In the subgroup analyses, we observed a negative association between APOE4+ genotypes and overall risk of cancer in the cohort study subgroup (pooled OR 0.86; 95 % CI 0.82-0.91; p < 0.00001; I (2) = 0 %). Sensitivity analyses did not alter the overall pooled effect measure, and there were no evidences to suggest a publication bias.

CONCLUSION

Overall, the present meta-analysis did not show any association between APOE alleles and genotypes with incidence of cancer in general.

Colorectal cancer risk and dyslipidemia: a case-cohort study nested in an Italian multicentre cohort

BACKGROUND

Dyslipidemia is an established risk factor for many diseases, but its effect on colorectal cancer risk is less clear. We investigated the association of colorectal cancer risk with plasma triglycerides, total, HDL, and LDL cholesterol in four Italian EPIC centers.

METHODS

We conducted a case-cohort study on participants recruited to four Italian EPIC centers (Turin, Varese, Naples, and Ragusa; 34,148 subjects). A random subcohort of 850 subjects was obtained and 286 colorectal cancer cases were diagnosed. Triglycerides, total and HDL cholesterol were determined in plasma samples obtained at baseline and stored at -196°C; LDL cholesterol was calculated. Hazard ratios (HR) with 95% confidence intervals (CI), adjusted for potential confounders, were estimated by Cox regression models using the Prentice method.

RESULTS

The highest tertiles of total (HR 1.66, 95%CI 1.12-2.45) and LDL cholesterol (HR 1.87, 95%CI 1.27-2.76) were associated with increased colorectal cancer risk compared to lowest tertiles. Risks were greater for men than women, and for postmenopausal than premenopausal women. Highest tertiles of total and LDL cholesterol were also significantly associated with increased risks of colon cancer, distal colon cancer, and rectal cancer, but not proximal colon cancer.

CONCLUSIONS

Our findings suggest that high levels of total and LDL cholesterol increase colorectal cancer risk, particularly in men and postmenopausal women. However additional studies are needed to clarify the role of plasma lipids in these cancers, particularly in view of the conflicting findings of previous studies.

Prospective associations between serum biomarkers of lipid metabolism and overall, breast and prostate cancer risk

Experimental studies provided evidence about mechanisms by which cholesterol, especially high density lipoprotein cholesterol (HDL-C), could influence carcinogenesis, notably through antioxidant and anti-inflammatory properties. However, prospective studies that investigated the associations between specific lipid metabolism biomarkers and cancer risk provided inconsistent results. The objective was to investigate the prospective associations between total cholesterol (T-C), HDL-C, low density lipoprotein cholesterol, apolipoproteins A1 (apoA1) and B, and triglycerides and overall, breast and prostate cancer risk. Analyses were performed on 7,557 subjects of the Supplémentation en Vitamines et Minéraux Antioxydants Study, a nationwide French cohort study. Biomarkers of lipid metabolism were measured at baseline and analyzed regarding the risk of first primary incident cancer (N = 514 cases diagnosed during follow-up, 1994-2007), using Cox proportional hazards models. T-C was inversely associated with overall (HR(1mmol/L increment) = 0.91, 95 % CI 0.82-1.00; P = 0.04) and breast (HR(1mmol/L increment) = 0.83, 95 % CI 0.69-0.99; P = 0.04) cancer risk. HDL-C was also inversely associated with overall (HR(1mmol/L increment) = 0.61, 95 % CI 0.46-0.82; P = 0.0008) and breast (HR(1mmol/L increment) = 0.48, 95 % CI 0.28-0.83; P = 0.009) cancer risk. Consistently, apoA1 was inversely associated with overall (HR(1g/L increment) = 0.56, 95 % CI 0.39-0.82; P = 0.003) and breast (HR(1g/L increment) = 0.36, 95 % CI 0.18-0.73; P = 0.004) cancer risk. This prospective study suggests that pre-diagnostic serum levels of T-C, HDL-C and ApoA1 are associated with decreased overall and breast cancer risk. The confirmation of a role of cholesterol components in cancer development, by further large prospective and experimental studies, may have important implications in terms of public health, since cholesterol is already crucial in cardiovascular prevention.

Safety and effect of very low levels of low-density lipoprotein cholesterol on cardiovascular events

Based on the cardiovascular (CV) outcomes data derived predominantly from 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor (statin) trials, guidelines have set low-density lipoprotein (LDL) cholesterol targets at successively lower levels over time. Recent data have demonstrated that more-intensive statin therapy (and, consequently, lower LDL cholesterol level) is more effective at reducing CV events than less-intensive statin therapy. Although the average LDL cholesterol level for a United States adult is 119 mg/dl, within the "normal" range (90 to 130 mg/dl) per the United States National Cholesterol Education Program-Adult Treatment Panel III guidelines, data from fetal studies, diet studies, contemporary hunter-gatherer populations, and other mammals have suggested that the "normal" physiologic range for LDL cholesterol in humans is likely 50 to 70 mg/dl. Low LDL cholesterol levels have been sporadically associated with an increased risk of cancer, hemorrhagic stroke, and other complications in population studies and clinical trials. However, statin clinical trials have generally not demonstrated correlations between on-treatment LDL cholesterol levels and safety. Clinical data have suggested a linear relation between LDL cholesterol lowering and CV risk reduction, supporting a favorable risk/benefit ratio for attaining very low levels of LDL cholesterol to minimize the risk of CV events. In conclusion, clinical trial evidence demonstrating the efficacy and safety of LDL cholesterol lowering to a very low level is essential to ascertain the benefits and risks in reducing the residual risk of vascular disease.

Total serum cholesterol and cancer incidence in the Metabolic syndrome and Cancer Project (Me-Can)

OBJECTIVE

To investigate the association between total serum cholesterol (TSC) and cancer incidence in the Metabolic syndrome and Cancer project (Me-Can).

METHODS

Me-Can consists of seven cohorts from Norway, Austria, and Sweden including 289,273 male and 288,057 female participants prospectively followed up for cancer incidence (n = 38,978) with a mean follow-up of 11.7 years. Cox regression models with age as the underlying time metric were used to estimate hazard ratios (HR) and their 95% confidence intervals (CI) for quintiles of cholesterol levels and per 1 mmol/l, adjusting for age at first measurement, body mass index (BMI), and smoking status. Estimates were corrected for regression dilution bias. Furthermore, we performed lag time analyses, excluding different times of follow-up, in order to check for reverse causation.

RESULTS

In men, compared with the 1st quintile, TSC concentrations in the 5th quintile were borderline significantly associated with decreasing risk of total cancer (HR = 0.94; 95%CI: 0.88, 1.00). Significant inverse associations were observed for cancers of the liver/intrahepatic bile duct (HR = 0.14; 95%CI: 0.07, 0.29), pancreas cancer (HR = 0.52, 95% CI: 0.33, 0.81), non-melanoma of skin (HR = 0.67; 95%CI: 0.46, 0.95), and cancers of the lymph-/hematopoietic tissue (HR = 0.68, 95%CI: 0.54, 0.87). In women, hazard ratios for the 5th quintile were associated with decreasing risk of total cancer (HR = 0.86, 95%CI: 0.79, 0.93) and for cancers of the gallbladder (HR = 0.23, 95%CI: 0.08, 0.62), breast (HR = 0.70, 95%CI: 0.61, 0.81), melanoma of skin (HR = 0.61, 95%CI: 0.42, 0.88), and cancers of the lymph-/hematopoietic tissue (HR = 0.61, 95%CI: 0.44, 0.83).

CONCLUSION

TSC was negatively associated with risk of cancer overall in females and risk of cancer at several sites in both males and females. In lag time analyses some associations persisted, suggesting that for these cancer sites reverse causation did not apply.

Statins and the risk of cancer after heart transplantation

BACKGROUND

Although newer immunosuppressive agents, such as mTOR (mammalian target of rapamycin) inhibitors, have lowered the occurrence of malignancies after transplantation, cancer is still a leading cause of death late after heart transplantation. Statins may have an impact on clinical outcomes beyond their lipid-lowering effects. The aim of the present study was to delineate whether statin therapy has an impact on cancer risk and total mortality after heart transplantation.

METHODS AND RESULTS

A total of 255 patients who underwent heart transplantation at the University Hospital Zurich between 1985 and 2007 and survived the first year were included in the present study. The primary outcome measure was the occurrence of any malignancy; the secondary end point was overall survival. During follow-up, a malignancy was diagnosed in 108 patients (42%). The cumulative incidence of tumors 8 years after transplantation was reduced in patients receiving a statin (34% versus 13%; 95% confidence interval, 0.25-0.43 versus 0.07-0.18; P<0.003). Statin use was associated with improved cancer-free and overall survival (both P<0.0001). A Cox regression model that analyzed the time to tumor formation with or without statin therapy, adjusted for age, male sex, type of cardiomyopathy, and immunosuppressive therapy (including switch to mTOR inhibitors or tacrolimus), demonstrated a superior survival in the statin group. Statins reduced the hazard of occurrence of any malignancy by 67% (hazard ratio, 0.33; 95% confidence interval, 0.21-0.51; P<0.0001).

CONCLUSIONS

Although it is not possible to adjust for all potential confounders because of the very long follow-up period, this registry suggests that statin use is associated with improved cancer-free and overall survival after cardiac transplantation. These data will need to be confirmed in a prospective trial.

Lack of effect of lowering LDL cholesterol on cancer: meta-analysis of individual data from 175,000 people in 27 randomised trials of statin therapy

Background

Statin therapy reduces the risk of occlusive vascular events, but uncertainty remains about potential effects on cancer. We sought to provide a detailed assessment of any effects on cancer of lowering LDL cholesterol (LDL-C) with a statin using individual patient records from 175,000 patients in 27 large-scale statin trials.

Methods and Findings

Individual records of 134,537 participants in 22 randomised trials of statin versus control (median duration 4.8 years) and 39,612 participants in 5 trials of more intensive versus less intensive statin therapy (median duration 5.1 years) were obtained. Reducing LDL-C with a statin for about 5 years had no effect on newly diagnosed cancer or on death from such cancers in either the trials of statin versus control (cancer incidence: 3755 [1.4% per year [py]] versus 3738 [1.4% py], RR 1.00 [95% CI 0.96-1.05]; cancer mortality: 1365 [0.5% py] versus 1358 [0.5% py], RR 1.00 [95% CI 0.93–1.08]) or in the trials of more versus less statin (cancer incidence: 1466 [1.6% py] vs 1472 [1.6% py], RR 1.00 [95% CI 0.93–1.07]; cancer mortality: 447 [0.5% py] versus 481 [0.5% py], RR 0.93 [95% CI 0.82–1.06]). Moreover, there was no evidence of any effect of reducing LDL-C with statin therapy on cancer incidence or mortality at any of 23 individual categories of sites, with increasing years of treatment, for any individual statin, or in any given subgroup. In particular, among individuals with low baseline LDL-C (<2 mmol/L), there was no evidence that further LDL-C reduction (from about 1.7 to 1.3 mmol/L) increased cancer risk (381 [1.6% py] versus 408 [1.7% py]; RR 0.92 [99% CI 0.76–1.10]).

Conclusions

In 27 randomised trials, a median of five years of statin therapy had no effect on the incidence of, or mortality from, any type of cancer (or the aggregate of all cancer).

Cancer mortality according to lipid-lowering drugs and lipoproteins in a general population

OBJECTIVE

The beneficial effect of lipid-lowering drugs (LLD) on cardiovascular risk is established, but long term safety data remain scarce. Our aim was to assess 10-year risk of cancer mortality according to blood lipoprotein levels and LLD exposure, in a general population.

METHODS

Our analysis was based on the Third French MONICA survey on cardiovascular risk factors (1994-1997). Participants were randomly recruited from the general population of three French areas and were aged 35-64 years. Subjects with a history of cancer at baseline were excluded from the analysis. Vital status and cause of mortality were obtained 10 years after inclusion.

RESULTS

There were 3262 participants and 177 deaths were recorded over the 10-year period (78 due to a cancer). The sample comprised 64% of normolipidaemic, 25% of untreated dyslipidaemic and 11% of dyslipidaemic subjects treated with LLD (4% statins, 6% fibrates and 1% other hypolipidaemic drugs). After adjustment for centre, age, gender, smoking, gamma-glutamyl transpeptidase and mean corpuscular volume, the hazard ratios (HR) for cancer mortality in subjects with non-HDL cholesterol <3.5 mmol/L (135 mg/dL) and in those with HDL cholesterol <0.90 mmol/L (35 mg/dL) were 2.74 (95% confidence interval: 1.66-4.52, p < 0.001) and 2.83 (1.62-4.96, p < 0.001), respectively. The adjusted HR for cancer mortality was 0.31 (0.11-0.86, p = 0.025) in people on LLD compared to untreated subjects.

CONCLUSIONS

In the present study, we confirm the significant association between low cholesterol and cancer mortality without finding any harmful signal regarding cancer risk associated with the use of LLD. The main limitations are remaining baseline differences between treated and untreated subjects (due to the observational design but minimized by the use of extensive adjustments and propensity score methods), and the lack of re-assessment of LLD exposure and cholesterol levels during follow-up, possibly leading to a misclassification bias.

Low-density lipoprotein cholesterol and the risk of cancer: a mendelian randomization study

BACKGROUND

Low plasma levels of low-density lipoprotein (LDL) cholesterol are associated with an increased risk of cancer, but whether this association is causal is unclear.

METHODS

We studied 10 613 participants in the Copenhagen City Heart Study (CCHS) and 59 566 participants in the Copenhagen General Population Study, 6816 of whom had developed cancer by May 2009. Individuals were genotyped for PCSK9 R46L (rs11591147), ABCG8 D19H (rs11887534), and APOE R112C (rs429358) and R158C (rs7412) polymorphisms, all of which are associated with lifelong reduced plasma LDL cholesterol levels. Plasma LDL cholesterol was calculated using the Friedewald equation in samples in which the triglyceride level was less than 354 mg/dL and measured directly by colorimetry for samples with higher triglyceride levels. Risk of cancer was estimated prospectively using Cox proportional hazards regression analyses and cross-sectionally by logistic regression analyses. Causality was studied using instrumental variable analysis. All statistical tests were two-sided.

RESULTS

In the CCHS, compared with plasma LDL cholesterol levels greater than the 66th percentile (>158 mg/dL), those lower than the 10th percentile (< 87 mg/dL) were associated with a 43% increase (95% confidence interval [CI] = 15% to 79% increase) in the risk of cancer. The polymorphisms were associated with up to a 38% reduction (95% CI = 36% to 41% reduction) in LDL cholesterol levels but not with increased risk of cancer. The causal odds ratio for cancer for a 50% reduction in plasma LDL cholesterol level due to all the genotypes in both studies combined was 0.96 (95% CI = 0.87 to 1.05), whereas the hazard ratio of cancer for a 50% reduction in plasma LDL cholesterol level in the CCHS was 1.10 (95% CI = 1.01 to 1.21) (P for causal odds ratio vs observed hazard ratio = .03).

CONCLUSION

Low plasma LDL cholesterol levels were robustly associated with an increased risk of cancer, but genetically decreased LDL cholesterol was not. This finding suggests that low LDL cholesterol levels per se do not cause cancer.

Functional polymorphisms to modulate luminal lipid exposure and risk of colorectal cancer

PURPOSE

Fat absorption may play a crucial role in colorectal carcinogenesis by determining intra-colonic exposure to potentially carcinogenic lipid metabolites.

METHODS

We conducted a population-based case-control study that included 1163 cases and 1501 controls to examine whether individuals who carry genetic variants associated with lower lipid absorption have a higher risk of colorectal cancer. Using Taqman assay, we determined FABP2 alanine (A)/threonine (T) polymorphism at codon 54 in exon-2 and APOE isoforms. Multivariable odds ratios (OR) and 95% confidence intervals (CI) were calculated by unconditional logistic regression models, assuming FABP2 A54 and APO non-E4 as high risk alleles.

RESULTS

We found no associations with either of the polymorphisms. The OR associated with FABP2 A54 homozygotes compared with the others was 1.01 (95% CI; 0.86-1.45) and that for non-ApoE4 carriers compared with carries was 0.95 (95% CI; 0.80-1.13). However, there was a statistically significant negative interaction between total fat intake and FABP2 AA genotypes (p=0.025), indicating that the risk of colorectal cancer associated with this polymorphism is higher in the subjects with lower fat intake.

CONCLUSIONS

These results suggest that these SNPs may not be useful in predicting colorectal cancer risk in populations with high fat intake.

Multivariate explanatory model for sporadic carcinoma of the colon in Dukes' stages I and IIa

OBJECTIVE

We obtained before an explanatory model with six dependant variables: age of the patient, total cholesterol (TC), HDL cholesterol (HDL-C), VLDL cholesterol (VLDL-C), alkaline phosphatase (AP) and the CA 19.9 tumour marker. Our objective in this study was to validate the model by means of the acquisition of new records for an additional analysis.

DESIGN

Non-paired case control study.

SETTING

Urban and rural hospitals and primary health facilities in Western Andalusia and Extremadura (Spain).

PATIENTS

At both the primary care facilities and hospital level, controls were gathered in a prospective manner (n= 275). Cases were prospective and retrospective manner collected on (n=126).

MAIN OUTCOME MEASURES

Descriptive statistics, logistic regression and bootstrap analysis.

RESULTS

The AGE (odds ratio 1.02; 95% CI 1.003-1.037) (p= 0.01), the TC (odds ratio 0.986; 95% C.I. 0.980-0.992) (p< 0.001) and the CA 19.9 (odds ratio 1.023; 95% C.I. 1.012- 1.034) (p<0.001) were the variables that showed significant values at logistic regression analysis and bootstrap. Berkson's bias was statistically assessed.

CONCLUSIONS

The model, validated by means of logistic regression and bootstrap analysis, contains the variables AGE, TC, and CA 19.9 (three of the original six) and has a level 4 over 5 according to the criteria of Justice et al. (multiple independent validations) [Ann. Intern. Med.1999; 130: 515].

Serum lipid levels and the risk of biliary tract cancers and biliary stones: A population-based study in China

Biliary tract cancers, encompassing the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Gallstones, the predominant risk factor for biliary cancers, are linked with hyperlipidemia. As part of a population-based case-control study conducted in Shanghai, China, we examined the associations of serum lipid levels with biliary stones and cancers. We included 460 biliary cancer cases (264 gallbladder, 141 extrahepatic bile duct, and 55 ampulla of Vater), 981 biliary stone cases and 858 healthy individuals randomly selected from the population. Participants completed an in-person interview and gave overnight fasting blood samples. Participants in the highest quintile of triglycerides (>/=160 mg/dl) had a 1.4-fold risk of biliary stones (95% CI = 1.1-1.9), a 1.9-fold risk of gallbladder cancer (95% CI = 1.3-2.8), and a 4.8-fold risk of bile duct cancer (95% CI = 2.8-8.1), compared to the reference group (third quintile: 90-124 mg/dl). Participants in the lowest quintile of high-density lipoprotein (HDL) (<30 mg/dl) had a 4.2-fold risk of biliary stones (95% CI = 3.0-6.0), an 11.6-fold risk of gallbladder cancer (95% CI = 7.3-18.5), and a 16.8-fold risk of bile duct cancer (95% CI = 9.1-30.9), relative to the reference group (third quintile: 40-49 mg/dl). In addition, total cholesterol, low-density lipoprotein (LDL) and apolipoprotein A (apo A) were inversely associated with biliary stones; whereas low levels as well as high levels of total cholesterol, LDL, apo A and apolipoprotein B (apo B) were associated with excess risks of biliary tract cancers. Our findings support a role for serum lipids in gallstone development and biliary carcinogenesis.