Body mass index, serum total cholesterol, and risk of gastric high-grade dysplasia: A case-control study among Chinese adults

Ethnic-specific associations between body mass index and gastric cancer: a Mendelian randomization study in European and Korean populations

BACKGROUND

Given the uncertainties surrounding the associations in previous epidemiological studies, we conducted linear and nonlinear Mendelian randomization (MR) studies to evaluate whether body mass index (BMI) associated with gastric cancer (GC) risk in European and Korean.

METHODS

Genome-wide association study-summary statistics were used from the Pan-UK Biobank, the Genetic Investigation of Anthropometric Traits consortium, the K-CHIP consortium, and BioBank Japan. BMI-associated single nucleotide polymorphisms (SNPs) were used as instrumental variables (IVs) in MR to identify the association between BMI and GC. Both linear and nonlinear MR analyses were performed. Sensitivity analyses were also conducted for individuals below or above a BMI of 24 kg/m2.

RESULTS

The study used 22 and 55 SNPs as IVs for BMI in European and Korean populations, respectively. Genetically predicted BMI was positively associated with GC risk in the European population (Odds ratio per 1 kg/m2 increase; 95% CI = 1.17; 1.01-1.36 using simple median method), but no significant association was observed in the Korean population. However, the nonlinear MR identified a U-shaped association between BMI and GC in the Korean population, with both low and high BMIs associated with increased GC risk. A BMI of 24 kg/m2 presented the lowest risk. Sensitivity analyses did not yield any genome-wide significant SNPs.

CONCLUSION

While MR analysis suggests a linear association between BMI and GC in those of European ancestry, nonlinear MR hints at a U-shaped association in Koreans. This suggests the association between BMI and GC risk may vary according to ethnic ancestry.

Postoperative high-density lipoprotein cholesterol level: an independent prognostic factor for gastric cancer

Objective

The relationship between serum lipids and prognosis of gastric cancer has not been confirmed. Our purpose in the study was to investigate the associations between preoperative and postoperative serum lipids level and prognosis in patients with gastric cancer.

Methods

A retrospective study was performed on 431 patients who received radical (R0) gastrectomy from 2011 to 2013. Preoperative and postoperative serum lipids level were recorded. Clinical-pathological characteristics, oncologic outcomes, disease-free survival (DFS) and overall survival (OS) were collected. The prognostic significance was determined by Kaplan-Meier analysis and Cox proportional hazards regression model.

Results

There was no significant difference in DFS and OS according to preoperative serum lipids level. Regarding postoperative serum lipids level, compared to normal high-density lipoprotein cholesterol (HDL-C), low postoperative HDL-C level indicated a shorter OS (hazard ratio: 1.76, 99% confidence interval: 1.31–2.38; P=0.000) and a shorter DFS (hazard ratio: 2.06, 99% confidence interval: 1.55–2.73; P=0.000). However, other postoperative serum lipid molecules were not associated with DFS and OS.

Conclusion

Postoperative HDL-C might be an independent prognostic factor of gastric cancer.

Influence of cholesterol on cancer progression and therapy

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Abnormality in blood cholesterol level is significantly correlated with risk of different cancers.

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Majority of tumor tissue from cancer patient exhibits overexpression of LDLR and ACAT for supporting rapid cancer cell proliferation.

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Alteration of the cholesterol metabolism in cancer cells hampers therapeutic response.

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Targeting cholesterol metabolism for treatment of cancer with other conventional chemotherapeutic drugs appears to be beneficial.

Cholesterol is a fundamental molecule necessary for the maintenance of cell structure and is vital to various normal biological functions. It is a key factor in lifestyle-related diseases including obesity, diabetes, cardiovascular disease, and cancer. Owing to its altered serum chemistry status under pathological states, it is now being investigated to unravel the mechanism by which it triggers various health complications. Numerous clinical studies in cancer patients indicate an alteration in blood cholesterol level (either decreased or increased) in comparison to normal healthy individuals. This article elaborates on our understanding as to how cholesterol is being hijacked in the malignancy for the development, survival, stemness, progression, and metastasis of cancerous cells. Also, it provides a glimpse of how cholesterol derived entities, alters the signaling pathway towards their advantage. Moreover, deregulation of the cholesterol metabolism pathway has been often reported to hamper various treatment strategies in different cancer. In this context, attempts have been made to bring forth its relevance in being targeted, in pre-clinical and clinical studies for various treatment modalities. Thus, understanding the role of cholesterol and deciphering associated molecular mechanisms in cancer progression and therapy are of relevance towards improvement in the management of various cancers.

Associations of Serum Lipid Level with Gastric Cancer Risk, Pathology, and Prognosis

Purpose

The association of serum lipids with gastric cancer is controversial. We clarified the role of serum lipids in the development, progression, and prognosis of gastric cancer.

Materials and Methods

In total, 412 patients diagnosed with gastric cancer were prospectively recruited, and 2,934 control subjects who underwent screening endoscopy were enrolled from December 2013 to March 2017 to conduct a case-control study in a tertiary center. Serum lipid profiles, including total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), apolipoprotein A-I (apoA-I), and apolipoprotein B, and clinicopathologic characteristics were analyzed.

Results

The gastric cancer group showed significantly lower HDL-C, higher LDL-C, and lower apoA-I level than the control group. In multivariate analysis, old age (odds ratio [OR], 1.051; p < 0.001), smoking (OR, 1.337; p < 0.001), a family history of gastric cancer (OR, 2.038; p < 0.001), Helicobacter pylori seropositivity (OR, 4.240; p < 0.001), lower HDL-C (OR, 0.712; p=0.020), and higher LDL-C (p=0.002) were significant risk factors for gastric cancer. Lower HDL-C and higher LDL-C remained significant after adjustments for covariates, including age and sex. In a subgroup analysis of the gastric cancer group, lower TG levels were associated with undifferentiated histology. No serum lipids were associated with overall survival.

Conclusion

Lower HDL-C and higher LDL-C were associated with the risk of gastric cancer, even after adjusting for age, sex, and other factors. In the gastric cancer group, undifferentiated histology was associated with lower TG levels.

The U-shaped association between body mass index and gastric cancer risk in the Helicobacter pylori Biomarker Cohort Consortium: A nested case-control study from eight East Asian cohort studies

The association between body mass index (BMI) and noncardia gastric cancer (NCGC) risk remains controversial. The purpose of our study was to examine the association of BMI with NCGC risk with consideration of Helicobacter pylori (HP) biomarkers. This international nested case-control study, composed of 1,591 incident NCGC cases and 1,953 matched controls, was established from eight cohorts in China, Japan and Korea, where the majority of NCGCs are diagnosed worldwide. HP antibody biomarkers were measured in blood collected at cohort enrollment by multiplex serology. The NCGC risk according to baseline BMI was estimated using logistic regression to produce odds ratios (ORs) and 95% confidence intervals (CIs). We found a U-shaped association between BMI category and NCGC risk. Compared to those with reference BMI (22.6-25.0 kg/m² ), those with lower and higher BMI had an increased NCGC risk (BMI <18.5 kg/m² , OR = 1.56, 95% CI = 1.04-2.34; BMI >27.5 kg/m² , OR = 1.48, 95% CI = 1.15-1.91; adjusted for age, sex and smoking). The U-shaped association was persistent among subjects with HP infection and high-risk biomarkers (HP+ CagA+: BMI <18.5 kg/m² , OR = 1.60, 95% CI = 1.00-2.55; BMI >27.5 kg/m² , OR = 1.59, 95% CI = 1.21-2.11; and Omp+ HP0305+: BMI <18.5 kg/m² , OR = 1.88, 95% CI = 1.04-3.42; BMI >27.5 kg/m² , OR = 1.70, 95% CI = 1.20-2.42, respectively). Our study provides evidence of significantly increased NCGC risk among individuals with low or high BMI, including in subjects with high-risk HP biomarkers (HP+ CagA+, Omp+ HP0305+) in the high-risk area of East Asia.