Prospective study of the association of gamma-glutamyltransferase with cancer incidence in women

The predictive value of γ-glutamyl transferase to serum albumin ratio in hepatocellular carcinoma patients after liver transplantation

Background

Elevated preoperative γ-glutamyl transferase (GGT) levels or reduced serum albumin levels have been established as negative prognostic factors for patients with hepatocellular carcinoma (HCC) and various other tumors. Nonetheless, the prognostic significance of the GGT to serum albumin ratio (GAR) in liver transplantation (LT) therapy for HCC is still not well-defined.

Methods

A retrospective analysis was conducted on the clinical data of 141 HCC patients who underwent LT at Shulan (Hangzhou) Hospital from June 2017 to November 2020. Using the receiver operating characteristic (ROC) curve, the optimal GAR cutoff value to predict outcomes following LT was assessed. Univariate and multivariate Cox proportional hazards regression analyses were used to identify independent risk factors associated with both overall survival (OS) and recurrence-free survival (RFS).

Results

A GAR value of 2.04 was identified as the optimal cutoff for predicting both OS and RFS, with a sensitivity of 63.2% and a specificity of 74.8%. Among these patients, 80 (56.7%) and 90 (63.8%) met the Milan and the University of California San Francisco (UCSF) criteria, respectively. Univariate Cox regression analysis showed that microvascular invasion (MVI), maximum tumor size (>5 cm), total tumor size (>8 cm), liver cirrhosis, TNM stage (III), and GAR (≥2.04) were significantly associated with both postoperative OS and RFS in patients with HCC (all p < 0.05). Multivariate Cox regression analysis indicated that GAR (≥2.04) was independently linked with RFS and OS.

Conclusion

Pre-transplant GAR ≥2.04 is an independent correlate of prognosis and survival outcomes after LT for HCC and can be used as a prognostic indicator for both mortality and tumor recurrence following LT.

Associations between Liver Enzymes, Lifestyle Risk Factors and Pre-Existing Medical Conditions in a Population-Based Cross-Sectional Sample

While alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) enzymes are commonly used indicators of liver dysfunction recent studies have suggested that these may also serve as predictive biomarkers in the assessment of extrahepatic morbidity. In order to shed further light on the interactions between serum liver enzyme abnormalities, factors of lifestyle and health status we examined ALT and GGT activities in a population-based sample of 8743 adult individuals (4048 men, 4695 women from the National FINRISK 2002 Study, mean age 48.1 ± 13.1 years) with different levels of alcohol drinking, smoking, physical activity, body weight and the presence or absence of various pre-existing medical conditions. The assessments also included laboratory tests for inflammation, lipid status and fatty liver index (FLI), a proxy for fatty liver. The prevalence of ALT and GGT abnormalities were significantly influenced by alcohol use (ALT: p < 0.0005 for men; GGT: p <0.0005 for both genders), smoking (GGT: p <0.0005 for men, p =0.002 for women), adiposity (p < 0.0005 for all comparisons), physical inactivity (GGT: p <0.0005; ALT: p <0.0005 for men, p <0.05 for women) and coffee consumption (p <0.0005 for GGT in both genders; p <0.001 for ALT in men). The total sum of lifestyle risk factor scores (LRFS) influenced the occurrence of liver enzyme abnormalities in a rather linear manner. Significantly higher LRFS were observed in the subgroups of individuals with pre-existing medical conditions when compared with those having no morbidities (p <0.0005). In logistic regression analyses adjusted for the lifestyle factors, both ALT and GGT associated significantly with fatty liver, diabetes and hypertension. GGT levels also associated with coronary heart disease, angina pectoris, cardiac insufficiency, cerebrovascular disease, asthma and depression. Combinations of abnormal ALT and GGT activities significantly increased the odds for hypertension coinciding with abnormalities in biomarkers of inflammation, lipid status and FLI. The data indicates that ALT and GGT activities readily respond to unfavorable factors of lifestyle associating also with a wide array of pre-existing medical conditions. The data supports close links between both hepatic and extrahepatic morbidities and lifestyle risk factors and may open new insights on a more comprehensive use of liver enzymes in predictive algorithms for assessing mechanistically anchored disease conditions.

Predictive risk markers in alcoholism

The medical disorders of alcoholism rank among the leading public health problems worldwide and the need for predictive and prognostic risk markers for assessing alcohol use disorders (AUD) has been widely acknowledged. Early-phase detection of problem drinking and associated tissue toxicity are important prerequisites for timely initiations of appropriate treatments and improving patient's committing to the objective of reducing drinking. Recent advances in clinical chemistry have provided novel approaches for a specific detection of heavy drinking through assays of unique ethanol metabolites, phosphatidylethanol (PEth) or ethyl glucuronide (EtG). Carbohydrate-deficient transferrin (CDT) measurements can be used to indicate severe alcohol problems. Hazardous drinking frequently manifests as heavy episodic drinking or in combinations with other unfavorable lifestyle factors, such as smoking, physical inactivity, poor diet or adiposity, which aggravate the metabolic consequences of alcohol intake in a supra-additive manner. Such interactions are also reflected in multiple disease outcomes and distinct abnormalities in biomarkers of liver function, inflammation and oxidative stress. Use of predictive biomarkers either alone or as part of specifically designed biological algorithms helps to predict both hepatic and extrahepatic morbidity in individuals with such risk factors. Novel approaches for assessing progression of fibrosis, a major determinant of prognosis in AUD, have also been made available. Predictive algorithms based on the combined use of biomarkers and clinical observations may prove to have a major impact on clinical decisions to detect AUD in early pre-symptomatic stages, stratify patients according to their substantially different disease risks and predict individual responses to treatment.

Gamma-glutamyl-transferase is associated with incident hip fractures in women and men ≥ 50 years: a large population-based cohort study

The association of serum gamma-glutamyl-transferase (GGT) with hip fracture risk has not been examined in women and men ≥ 50 years. We show that elevated GGT was associated with increased hip fracture risk, particularly in men. GGT could be a candidate serum marker of long-term hip fracture risk in the elderly.

INTRODUCTION

We herein examined a possible relation between serum levels of GGT and hip fracture risk in women and men aged ≥ 50 years, which has not been investigated before.

METHODS

In this population-based prospective cohort study, approximately 41,000 women and nearly 33,000 men ≥ 50 years participating in a medical prevention program 1985-2005 in western Austria were followed up for the occurrence of osteoporotic hip fractures during 2003-2013. ICD-10 based discharge diagnoses for hip fracture included S72.0, S72.1, and S72.2 available from all regional hospitals. GGT-related hip fracture risk was ascertained at each participant´s first and last examination during the prevention program. In a subset of 5445 participants, alcohol consumption could be included as a covariate.

RESULTS

In men, hip fracture risk rose significantly by 75% and 86% for every tenfold increase of GGT measured at the first and last examination, respectively, and in women, hip fracture risk rose by 22% from the last examination. Elevated GGT (≥ 36 U/l in women, ≥ 56 U/l in men) at the first examination was associated with increased hip fracture risk only in men (HR 1.51, 95% CI 1.25-1.82), and at the last examination in both women (HR 1.14, 95% CI 1.02-1.28) and men (HR 1.61, 95% CI 1.33-1.95). Alcohol consumption had no significant influence on GGT-mediated hip fracture risk in women and men.

CONCLUSIONS

Our findings identified an association of elevated GGT and hip fracture in women and men ≥ 50 years and suggest GGT as a candidate serum marker of long-term hip fracture risk in an elderly population.

Big and Free Fractions of Gamma-Glutamyltransferase: New Diagnostic Biomarkers for Malignant Mesothelioma?

Malignant pleural mesothelioma (MPM) is a cancer mainly caused by asbestos fiber inhalation, characterized by an extremely long latency and poor prognosis. Recently, researchers have focused on testing the diagnostic ability of several biomarkers. Gamma-Glutamyltransferase (GGT) has been demonstrated to be the sum of several GGT sub-fractions activity, classified based on their molecular weight in big-GGT, medium-GGT, small-GGT, and free-GGT. This work aims to evaluate whether specific GGT fractional enzymatic activity patterns could be helpful in MPM diagnosis. We analyzed blood samples from 175 workers previously exposed to asbestos, 157 non-exposed healthy subjects, and 37 MPM patients through a molecular exclusion chromatographic method. We found a specific profile of GGT fractions activity, significantly associated with MPM, resulting in an increase in b-, m- activity, along with an evident, yet not significant, decrease in f-activity. Receiver-operating characteristic (ROC) analysis showed that the best Area Under Curve (AUC) value resulted from the combined index b/f (0.679, 95% CI: 0.582–0.777). Combining the b-/f-GGT activity with the levels of serum mesothelin-related protein (SMRP; another promising MPM biomarker) improved the diagnostic accuracy, increasing the AUC value to 0.875 (95% CI: 0.807–0.943, p = <0.0001). Since MPM has a specific pattern of GGT enzymatic activity, we could hypothesize that GGT fractions play different specific biochemical roles. The improvement in the diagnostic power given by the combination of these two biomarkers confirms that the strategy of biomarkers combination might be a better approach for MPM diagnosis.

The association between serum liver enzymes and cancer mortality

Interpreting levels of liver enzymes is often challenging because they may be influenced by metabolic processes beyond the liver. Given their pathophysiologic roles in inflammation and oxidative stress, higher levels of these enzymes may be associated with increased risk of mortality. However, studies have found inconsistent results. Thus, we examined the association of liver enzymes levels with cancer mortality in the general US adult population. We used the US National Health and Nutrition Examination Survey from 1999 to 2016. Kaplan-Meier survival curve comparisons were examined across quartiles of liver enzymes. Cox proportional hazards models were built to examine the relationship between cancer mortality and liver enzymes quartiles without and with adjustment for potential confounding factors. During the 338,882 person-years follow-up, 1059 participants had cancer-related deaths. There was a nonlinear U-shaped relationship between serum alanine and aspartate aminotransferase (ALT and AST) levels and cancer mortality. There was no relationship between cancer mortality and gamma-glutamyltransferase (GGT); however, each 10 IU/L increase in GGT after median was associated with 1% higher mortality risk (HR = 1.01; 95% CI = 1.00, 1.02; P = 0.001). Only subjects with high levels of alkaline phosphatase (ALP) had higher cancer mortality (HR = 1.63; 95CI = 1.30, 2.05; P < 0.001 and HR = 1.52; 95%CI = 1.20, 1.94; P = 0.001, respectively). Only the lowest and highest serum ALT and AST levels are associated with increased cancer mortality. For ALP, the relationship is present at higher levels. The association with GGT was not robust to different analyses. The mechanisms underlying the observed relationships need further exploration.

Enhanced Susceptibility to Breast Cancer in Korean Women With Elevated Serum Gamma-Glutamyltransferase Levels: A Nationwide Population-Based Cohort Study

Background

The incidence of breast cancer has been gradually increasing in Korea. Recently, the elevated level of serum gamma-glutamyltransferase (GGT) has emerged to be associated with the development and progression of some malignancies. This study aimed to determine the effect of serum GGT levels on the risk of developing breast cancer in Korean women.

Methods

We used National Health Insurance Service Health Checkup data to examine the association between serum GGT levels and breast cancer development in Korean women. Women aged 40 years or older who participated in the Korean National Health Screening Examination between January 2009 and December 2009 and who did not develop any cancer within 1-year post examination were included in this analysis (n = 3,109,506). Cox proportional hazard regression analysis was conducted to calculate hazard ratios (HRs) with 95% confidence intervals (CIs).

Results

Overall, an elevated serum GGT level was associated with the increased risk of developing breast cancer; compared to the Q1 group, the Q4 group showed a significantly increased breast cancer risk (HR: 1.120,95% CI: 1.08-1.162). Such a relationship was stronger in post-menopausal women than pre-menopausal women (HR: 1.173, 95% CI: 1.107-1.243; HR: 1.070, 95% CI:1.019-1.124). Women with a high GGT level (Q4) were also at an increased risk of developing carcinoma in situ (CIS) (HR: 1.114, 95% CI: 1.04-1.192). In post-menopausal women, the Q4 group also exhibited higher CIS risk (HR: 1.266, 95% CI: 1.132-1.416). However, no significant difference in the risk of developing CIS was observed between the Q1 and Q4 groups in pre-menopausal women. Further analysis revealed that obese, post-menopausal women with a high GGT level (Q4) were associated with an increased risk of developing breast cancer (HR: 1.214, 95% CI: 1.125-1.31) and CIS (HR: 1.348, 95% CI: 1.159-1.569).

Conclusions

Our study results demonstrate that increased serum GGT level is a risk factor for developing breast cancer. The post-menopausal women group with obesity and elevated serum GGT level showed the highest incidence of breast cancer. Thus, serum GGT concentration could be a novel and potential risk factor for breast cancer. Further validation in different ethnic groups would be warranted.

Determining the association between repeatedly elevated serum gamma-glutamyltransferase levels and risk of respiratory cancer: A nationwide population-based cohort study

Background

Although elevated serum gamma‐glutamyltransferase (GGT) is a known indicator of increased risk of several cancers, the clinical value of repeated measurements of GGT has not been determined. Therefore, we aimed to investigate whether repeatedly elevated serum GGT levels are associated with the risk of respiratory cancer incidence.

Methods

We included participants who had undergone the Korean Health screening four times during 2009–2012 and had previously undergone four consecutive examinations. Those who were diagnosed with respiratory cancer before the date of examination were excluded. The participants obtained one GGT point if their GGT levels were in the highest quartile (the quartile 4 group). We analyzed the association between GGT points and respiratory cancer incidence by Cox proportional hazard models.

Results

During mean follow‐up of 6.39 ± 1.2 years, 3,559,109 participants were enrolled. Of them, 8,944 (0.34%) men and 1,484 (0.14%) women were newly diagnosed with respiratory cancer. In multivariate analysis adjusted for confounding factors, male participants with 4 GGT points had a significantly higher hazards of developing respiratory cancer than those with 0 GGT points (hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.31–1.48). Among female, participants with the highest points of GGT also had sixfold increased risk of developing laryngeal cancer. However, no significant association was observed between GGT points and lung cancer incidence among women (HR: 0.95; 95% CI: 0.81–1.11).

Conclusion

Repeatedly elevated serum levels of GGT were associated with a higher risk of respiratory cancer incidence, especially in men. This finding suggests that physicians can identify a person with a higher risk of respiratory cancer through a simple repeated measurement of GGT.

Risk of gastrointestinal cancer in patients with an elevated level of gamma-glutamyltransferase: A nationwide population-based study

Emerging evidence that an elevated serum gamma-glutamyltransferase (GGT) level is associated with an increased risk of gastrointestinal cancer, but still controversial. The aim of this study to assess the relationship between GGT level and risk of gastrointestinal cancer, and the contribution of the interaction of hyperglycemia with elevated GGT level to the incidence of gastrointestinal cancer by the stratified analysis. A total of 8,120,665 Koreans who received medical checkups in 2009 were included. Subjects were classified according to the quartile of GGT level for women and men. The incidence rates of gastrointestinal cancer for each group were analyzed using Cox proportional hazards models. During follow-up, 129,853 cases of gastrointestinal cancer newly occurred (esophagus, 3,792; stomach, 57,932; and colorectal, 68,789 cases). The highest GGT quartile group showed an increased risk of gastrointestinal cancer (esophagus, hazard ratio = 2.408 [95% confidence interval, 2.184–2.654]; stomach, 1.121 [1.093–1.149]; and colorectal, 1.185 [1.158–1.211]). The risk increased significantly with the rise in GGT quartile level, regardless of the site of cancer. The stratified analysis according to glycemic status showed that the effect of elevated GGT was predominant in the risk of esophageal cancer. The effect of elevated GGT further increased the risk of stomach and colorectal cancers in diabetic patients. An elevated level of GGT was associated with an increased risk of gastrointestinal cancer, regardless of the site of cancer. The effect of the increase in GGT level on the risk of gastrointestinal cancer depended on the type of cancer and glycemic status.

Repeatedly elevated γ-glutamyltransferase levels are associated with an increased incidence of digestive cancers: A population-based cohort study

BACKGROUND

The association between elevated γ-glutamyltransferase (GGT) at a certain point and incident cancer has been suggested; however, no study has evaluated the association between repeatedly elevated GGT and cancer incidence.

AIM

To investigate the effects of repeatedly elevated GGT on the incidence of digestive cancers.

METHODS

Participants who had undergone health screening from 2009 to 2012 and 4 consecutive previous examinations were enrolled. GGT points were calculated as the number of times participants met the criteria of quartile 4 of GGT in four serial measurements (0-4 points). Multivariable Cox proportional hazard regression models were applied.

RESULTS

In total, 3559109 participants were included; among them, 43574 digestive cancers developed during a median of 6.8 years of follow-up. The incidence of total digestive cancers increased in a dose-response manner in men [adjusted hazard ratio (aHR) compared with those with 0 GGT points = 1.28 and 95% confidence interval (CI) = 1.24-1.33 in those with 1 point; aHR = 1.40 and 95%CI = 1.35-1.46 in those with 2 points; aHR = 1.52 and 95%CI = 1.46-1.58 in those with 3 points; aHR = 1.88 and 95%CI = 1.83-1.94 in those with 4 points; P for trend < 0.001]. This trend was more prominent in men than in women and those with healthy habits (no smoking, no alcohol consumption, and a low body mass index) than in those with unhealthy habits.

CONCLUSION

Repeatedly elevated GGT levels were associated with an increased risk of incident digestive cancer in a dose-responsive manner, particularly in men and those with healthy habits. Repeated GGT measurements may be a good biomarker of incident digestive cancer and could help physicians identify high-risk populations.

Prognostic value of γ-glutamyl transpeptidase to albumin ratio combined with aspartate aminotransferase to lymphocyte ratio in patients with hepatocellular carcinoma after hepatectomy

Hepatocellular carcinoma (HCC) is a malignant tumor associated with a high recurrence rate after hepatectomy. Recently, preoperative inflammatory and liver function reserve indices were found to predict increased risk of recurrence and decreased survival in HCC patients. This study aims to evaluate the ability of the γ-glutamyl transpeptidase-to-albumin ratio (GAR) and aspartate aminotransferase-to-lymphocyte ratio (ALRI), individually and in combination, to predict the prognosis of HCC patients after hepatectomy.We retrospectively reviewed 206 HCC patients who underwent radical resection at the General Hospital of Ningxia Medical University from January 2011 to November 2016. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off value for GAR and ALRI. The Pearson Chi-Squared test was used to analyze the correlations between GAR, ALRI and clinicopathological characteristics. Univariate and multivariate analyses were used to determine the predictive value of these factors for disease-free survival (DFS) and overall survival (OS). Survival rates were drawn according to the Kaplan-Meier method and differences between subgroups were compared by the log-rank statistics.GAR and ALRI were significantly correlated with gender, history of smoking, prothrombin time, tumor diameter, T stage and early intrahepatic recurrence by the Pearson Chi-Squared test (all P < .05). Univariate analysis indicated that T stage, GAR and ALRI were significantly correlated with DFS and OS in HCC patients after hepatectomy. Multivariate analysis illustrated that GAR and ALRI were independently related to DFS and OS in HCC patients. Preoperative GAR > 0.946 or ALRI > 18.734 predicted poor prognosis in HCC patients after hepatectomy. Additionally, the predictive scope of GAR combined with ALRI was more sensitive than that of either individual measurement alone.Our data indicate that there is a close association between the clinicopathological characteristics in HCC patients and increased GAR or ALRI. Higher levels of GAR and ALRI could sensitively and specifically predict a poor prognosis in HCC patients after hepatectomy. Furthermore, combined usage of GAR and ALRI could improve the accuracy of this prediction.

The dark side of gamma-glutamyltransferase (GGT): Pathogenic effects of an 'antioxidant' enzyme

Having long been regarded as just a member in the cellular antioxidant systems, as well as a clinical biomarker of hepatobiliary diseases and alcohol abuse, gamma-glutamyltransferase (GGT) enzyme activity has been highlighted by more recent research as a critical factor in modulation of redox equilibria within the cell and in its surroundings. Moreover, due to the prooxidant reactions which can originate during its metabolic function in selected conditions, experimental and clinical studies are increasingly involving GGT in the pathogenesis of several important disease conditions, such as atherosclerosis, cardiovascular diseases, cancer, lung inflammation, neuroinflammation and bone disorders. The present article is an overview of the laboratory findings that have prompted an evolution in interpretation of the significance of GGT in human pathophysiology.

Circulating liver function markers and colorectal cancer risk: A prospective cohort study in the UK Biobank

Evidence links the liver to development of colorectal cancer (CRC). However, it remains unknown how liver function may influence CRC risk in the general population. We conducted a prospective cohort study in the UK Biobank of 375 693 participants who provided blood samples in 2006 to 2010. Circulating levels of liver function markers (alanine transaminase [ALT], aspartate transaminase [AST], total bilirubin [TBIL], gamma glutamyltransferase [GGT], alkaline phosphatase [ALP], total protein [TP] and albumin [ALB]) were measured. Incident cancer cases were identified through linkage to the national cancer registry up to 2019. Repeated biomarker measurements were available from a subset of 11 320 participants who were re-assessed in 2012 to 2013. After a median follow-up of 10.0 years, we documented 2662 cases of CRC. Circulating levels of ALT, AST, TBIL, GGT, TP and ALB at baseline were inversely associated with CRC risk (P < .01), with multivariable hazard ratio (95% confidence interval) comparing decile 10 vs 1 of 0.62 (0.51-0.75), 0.63 (0.53-0.75), 0.85 (0.72-1.02), 0.74 (0.61-0.89), 0.70 (0.59-0.84) and 0.66 (0.55-0.79), respectively. Strengthened associations were found after recalibration for repeated measurements. The associations appeared stronger for proximal colon cancer than distal colon cancer and rectal cancer, but consistent for early-, mid- and late-onset CRC. In a large cohort of general population, the UK Biobank, higher circulating levels of ALT, AST, TBIL, GGT, TP and ALB, largely within the normal range, were associated with a lower risk of CRC. The findings support a link between liver function and CRC, and may spur future research on the gut-microbiota-liver axis.

Predictive role of γ-glutamyltransferase in patients receiving nivolumab therapy for metastatic renal cell carcinoma

INTRODUCTION

γ-Glutamyltransferase is reportedly associated with survival in local and metastatic renal cell carcinoma patients; however, its predictive role among patients treated with immune-checkpoint inhibitors are unknown. This study aimed to investigate the role of γ-glutamyltransferase as a predictive marker among metastatic renal cell carcinoma patients undergoing nivolumab therapy.

METHODS

We retrospectively evaluated 69 nivolumab-treated metastatic renal cell carcinoma patients upon failure of one or more systematic therapies. Serum γ-glutamyltransferase levels were determined at baseline and 2 months after nivolumab treatment initiation. Patients were classified as high (≥ 49 U/L) and low (< 49 mg/dL) from baseline GGT levels and the outcomes were compared between the two groups. Furthermore, increased (after/baseline ≥ 2) and non-increased (after/baseline < 2) groups were compared. Progression-free survival and overall survival were evaluated after nivolumab initiation.

RESULTS

Overall survival was significantly shorter in the high baseline γ-glutamyltransferase group (20.3%) than in the low group (79.7%) (median 2.33 vs not reached [months], p = 0.0051). Progression-free survival and the overall survival were significantly shorter in the increased than in the non-increased group (24.6% and 75.4%, respectively) (median PFS: 4.43 vs 7.23 [months], p = 0.0373/OS: 24.00 vs not reached, p = 0.0467). On multivariate analyses, high baseline γ-glutamyltransferase was an independent factor for overall survival (p = 0.0345) and increased γ-glutamyltransferase was an independent factor for progression-free survival (p = 0.0276) and overall survival (p = 0.0160).

CONCLUSIONS

High baseline γ-glutamyltransferase and its early increase are associated with a poor prognosis in metastatic renal cell carcinoma patients receiving nivolumab. Serum γ-glutamyltransferase levels may help predict treatment outcomes.

The Predictive Value of Pre-therapeutic Serum Gamma-glutamyl transferase in Efficacy and Adverse Reactions to Neoadjuvant Chemotherapy among Breast Cancer Patients

Purpose

Gamma-glutamyl transferase (GGT) has been reported as being involved in tumor progression. Previous studies documented a potential relationship between serum GGT level and survival outcome in several types of human malignancies. However, the association between serum GGT levels and response to neoadjuvant chemotherapy (NAC) has not yet been reported. The present study aimed to evaluate the association between pre-therapeutic serum GGT level and the efficacy, long-term survival, and adverse reactions of NAC and to investigate its role in predicting NAC sensitivity in patients with breast cancer.

Methods

A total of 129 patients were recruited and stratified into 2 groups according to serum GGT level (< 29 U/L and ≥ 29 U/L). The association between pre-therapeutic serum GGT levels and clinicopathological parameters was examined. The correlation between pre-therapeutic serum GGT levels and pathological complete response (pCR) was analyzed using univariate and multivariate logistic regression. Survival analyses of relapse-free survival (RFS) and disease-free survival (DFS) were performed. Pearson's χ² test and multivariate logistic regression model were used to analyze the correlation between pre-therapeutic serum GGT levels and adverse reactions.

Results

Pre-therapeutic serum GGT levels were associated with pCR among breast cancer patients treated with NAC. Multivariate analysis showed that low-level GGT significantly increased pCR rate. Patients in the high-level GGT group had poorer survival than those in the low-level GGT group. Subgroup analysis demonstrated that serum GGT level was potentially related to RFS and DFS in the hormone receptor-positive group. Low levels of GGT are significantly associated with a higher incidence of neutropenia.

Conclusion

Pre-therapeutic serum GGT level is an independent and novel biomarker for predicting the efficiency, prognosis, and adverse reactions to NAC in breast cancer patients. Patients with low pre-therapeutic serum GGT levels are more likely to have higher pCR rates, better RFS and DFS, and higher hematologic toxicity.

Trial Registration

ClinicalTrials.gov Identifier: NCT02199418, NCT02221999

γ-Glutamyltranspeptidase as a Prognostic Biomarker in Advanced Hepatocellular Carcinoma Treated with Transarterial Chemoembolization

PURPOSE

To evaluate the prognostic value of pretreatment serum γ-glutamyltransferase (GGT) level in patients with advanced hepatocellular carcinoma (HCC) receiving transarterial chemoembolization.

MATERIALS AND METHODS

This retrospective study included 140 patients (123 male, 17 female; mean age, 56.9 y ± 12.0; range, 22.0-82.0 y) with Barcelona Clinic Liver Cancer class C HCC who received first-line conventional chemoembolization between December 2013 and March 2018. Patients were divided into low and high GGT groups based on a cutoff value calculated with a receiver operating characteristic curve. Overall survival (OS) was compared between groups by log-rank test. Univariate and multivariate survival analyses were performed.

RESULTS

The optimal cutoff values of GGT were 119.5 U/L in men and 175.0 U/L in women. The 6-, 9-, and 12-mo OS rates were 81.7%, 72.4%, and 62.9%, respectively, for patients in the low GGT group (n = 44) and 58.8%, 35.7%, and 28.8%, respectively, for patients in the high GGT group (n = 96; P < .001). Multivariable Cox regression analysis identified high pretreatment serum GGT level (hazard ratio [HR], 2.71; 95% confidence interval [CI], 1.67-4.40; P < .001), multiple tumors (HR, 3.05; 95% CI, 1.23-7.53; P = .02), and performance of target treatment (ie, sorafenib; HR, 0.41; 95% CI, 0.24-0.72; P = .002) or ablation (HR, 0.35; 95% CI, 0.18-0.66; P = .001) as independent prognostic factors for OS.

CONCLUSIONS

Pretreatment serum GGT level was an independent prognostic factor for OS in patients with advanced HCC treated with chemoembolization, suggesting that GGT is a useful prognostic biomarker for advanced HCC.

Relationship between serum gamma-glutamyl transferase level and colorectal adenoma

Background and aims

Cost-effective serology tests may increase the predictive accuracy of colonoscopy for colorectal cancer screening. Reportedly, gamma-glutamyl transferase (GGT) is associated with oxidative stress and carcinogenesis and has been found to be elevated in the serum of cancer patients and colorectal adenoma tissue. We aimed to investigate the association between serum GGT levels and colorectal adenoma.

Methods

This single-center, health examination-based cohort enrolled 2475 subjects from 2006 to 2015. Baseline characteristics, laboratory data, bidirectional gastrointestinal endoscopy, and transabdominal ultrasonography were used to evaluate the severity of fatty liver.

Results

We found an elevated median GGT level in subjects with tubular adenoma compared with those without (23 IU/L and 20 IU/L, p<0.001). A GGT cutoff of ≥20 IU/L reached a maximal Youden index in receiver operating curve (ROC) analyses. Subsequent regression analyses showed an odds ratio of 1.46 (95% CI 1.17–1.82, p<0.001) for age, body mass index, diabetes diagnosis, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and positive Helicobacter pylori urease test, all being associated with an increased incidence of colon adenoma. Subgroup analysis showed that the odds ratio (OR 1.27, 95% CI 1.15–1.68, p<0.001) is only significant and highest in patients with a negative or mild fatty liver and an ALT level of ≤40 IU/L.

Conclusions

The results suggested a positive correlation of GGT with colon adenoma incidence and a predictive value with a cutoff point of >20 IU/L, which is within the normal range. The effect may be most prominent for those without steatohepatitis.

Gamma-glutamyl transferase variability and risk of dementia: A nationwide study

OBJECTIVES

Variability in various biomarkers has emerged as a new clinical indicator for diseases including neurodegenerative disorders. Gamma-glutamyl transferase (GGT) has a potential to be involved in the pathogenesis of dementia due to its function as a marker of oxidative stress and atherosclerosis. We investigated the association between baseline GGT, GGT variability, and dementia risk for the first time in a large population.

METHODS

The Korean National Health Insurance Service datasets of claims and preventive health check-ups from 2004 to 2016 were used for this retrospective longitudinal study. The risk of incident dementia (all-cause dementia, Alzheimer's disease, and vascular dementia) was analyzed according to sex-specific quartiles of baseline GGT and GGT variability, and groups categorized by baseline GGT and GGT variability in ≥40-year-old individuals without baseline dementia (N = 6 046 442; mean follow-up 6.32 years).

RESULTS

During follow-up, 166 851 cases of new dementia developed. The fully adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia increased in the higher quartiles of baseline GGT and GGT variability (HR [95% CI]: Q2, 1.034 [1.019-1.049]; Q3, 1.090 [1.075-1.105]; Q4, 1.212 [1.196-1.229]). The association between GGT variability quartiles and dementia risk remained significant even after adjusting for log-transformed baseline GGT level. The fully adjusted HRs for dementia was highest in the group with high baseline GGT concentration and the highest GGT variability quartile [HR (95% CI): 1.273 (1.250-1.296)].

CONCLUSIONS

Not only baseline GGT level, but also GGT variability may be an independent predictor of dementia, and might be used for risk stratification for future dementia.

Cell-Membrane-Localizing, Two-Photon Probe for Ratiometric Imaging of γ-Glutamyl Transpeptidase in Cancerous Cells and Tissues

γ-Glutamyl transpeptidase (GGT), a cell surface-bound protease, is associated with various diseases including cancer. The detection of the enzyme activity is an important subject, leading to about 40 activatable fluorescent probes so far. All of them, however, lack the membrane-localizing ability, raising a reliability issue in the quantitative analysis. Disclosed is the first fluorescent probe that senses the cell surface-bound enzyme, which, furthermore, is capable of ratiometric as well as two-photon imaging with desirable features. Ratiometric imaging of cancer cell lines reveals a 6.4-8.4-fold higher GGT levels than those in normal cell lines. A comparison of the enzyme activity in organ tissues of normal and tumor xenograft mice reveals notably different levels of enzyme activity depending on the kind of tissue. Normal tissues exhibited comparable levels of enzyme activity, except the kidney that has significantly higher GGT activity (2.7-4.0-fold) than the other organs. Compared with the normal tissues, considerably higher enzyme activity was observed in the tumor tissues of the thigh (4.0-fold), colon (2.5-fold), lung (3.6-fold), and liver (2.1-fold), but essentially no enhanced activity in the tumor tissues of the spleen, stomach, and pancreas and a comparable level in both the tumor and normal kidney tissues were observed. The probe offers practical means for studying GGT-associated biology in cells and tissues by one- as well as two-photon ratiometric imaging.

Serum Exosomal Gamma-Glutamyltransferase Activity Increased in Patients with Renal Cell Carcinoma with Advanced Clinicopathological Features

BACKGROUND

There has been no clinically useful diagnostic or prognostic biomarker for renal cell carcinoma (RCC). Serum γ-glutamyltransferase (GGT) activity has been reported to be a prognostic marker for several types of cancer including RCC. Exosomes or small extracellular vesicles present in body fluids have potential as a biomarker. We have recently demonstrated that GGT activity on exosomes isolated from serum is useful for the differential diagnosis of prostate cancer and benign prostate hyperplasia. In this study, we aimed to examine if serum exosomal GGT activity could be a marker for RCC.

METHODS

We examined GGT1 expression and GGT activity in cell lysates and exosomes from culture medium of HK-2 proximal tubule epithelial and RCC cell lines. GGT activity was measured using a fluorescent probe for GGT, γ-glutamyl hydroxymethyl rhodamine green. Serum and serum exosomal GGT activities were measured in patients with RCC. GGT1 expression in RCC tissues was evaluated by immunohistochemical staining.

RESULTS

GGT1 levels in exosomes from KMRC-1, OS-RC-2 and 786-O cells were elevated compared with those from HK-2 cells. In exosomes, GGT1 expression correlated with GGT activity determined using a fluorescent probe for GGT. In RCC patients, serum exosomal GGT activity was elevated in those with advanced stages (III/IV vs. I/II, p = 0.037) and those with microvascular invasion (with vs. without, p = 0.034). Immunohistochemical analysis showed that membranous GGT1 expression was increased in RCC with microvascular invasion. Notably, preoperative serum exosomal GGT activity could predict the likelihood of having microvascular invasion diagnosed by pathological examination of surgically resected specimens.

CONCLUSIONS

Our results suggest that serum exosomal GGT activity could be a clinically useful marker for advanced clinicopathological features of RCC patients, and its combined use with conventional diagnostic modalities may improve the diagnosis and treatment of patients.

Prognostic Significance of Serum Uric Acid and Gamma-Glutamyltransferase in Patients with Advanced Gastric Cancer

PURPOSE

In this study, we aim to evaluate the prognostic role of serum uric acid and gamma-glutamyltransferase in advanced gastric cancer patients.

METHODS

A total of 180 patients pathologically diagnosed with advanced gastric cancer were included in this retrospective study. We used time-dependent receiver operating characteristic (ROC) curves to identify the optimal cut-off value of serum uric acid (UA) and gamma-glutamyltransferase (GGT). Survival analysis was performed using the Kaplan-Meier method and log-rank test, and multivariate Cox regression analyses were applied. A nomogram was formulated, and the calibration and discrimination of the nomogram were determined by calibration curve and concordance index (C-index). We validated the results using bootstrap resampling and a separate study on 60 patients collected from 2015 to 2017 using the same criteria in other medical center.

RESULTS

Both higher serum uric acid (>228 μmol/L) and higher gamma-glutamyltransferase (>14 U/L) had worse OS and PFS. Univariate analysis indicated that serum uric acid (UA) (p < 0.001 and p < 0.001) and gamma-glutamyltransferase (GGT) (p < 0.001 and p = 0.044) were significantly related to overall survival (OS) and progression-free survival (PFS), respectively. Multivariate analysis revealed serum uric acid (UA) and gamma-glutamyltransferase (GGT) were independent prognostic factors for OS (p = 0.012, p = 0.001). The optimal agreement between actual observation and nomogram prediction was shown by calibration curves. The C-indexes of the nomogram for predicting OS and PFS were 0.748 (95% CI: 0.70-0.79) and 0.728 (95% CI: 0.6741-0.7819), respectively. The results were confirmed in the validation cohort.

CONCLUSION

We observed that both serum UA and GGT were poor prognostic factors in patients with advanced gastric cancer. And we also formulated and validated a nomogram which can predict individual survival for advanced gastric cancer patients.

Metabolic profiles to predict long-term cancer and mortality: the use of latent class analysis

BACKGROUND

Metabolites are genetically and environmentally determined. Consequently, they can be used to characterize environmental exposures and reveal biochemical mechanisms that link exposure to disease. To explore disease susceptibility and improve population risk stratification, we aimed to identify metabolic profiles linked to carcinogenesis and mortality and their intrinsic associations by characterizing subgroups of individuals based on serum biomarker measurements. We included 13,615 participants from the Swedish Apolipoprotein MOrtality RISk Study who had measurements for 19 biomarkers representative of central metabolic pathways. Latent Class Analysis (LCA) was applied to characterise individuals based on their biomarker values (according to medical cut-offs), which were then examined as predictors of cancer and death using multivariable Cox proportional hazards models.

RESULTS

LCA identified four metabolic profiles within the population: (1) normal values for all markers (63% of population); (2) abnormal values for lipids (22%); (3) abnormal values for liver functioning (9%); (4) abnormal values for iron and inflammation metabolism (6%). All metabolic profiles (classes 2-4) increased risk of cancer and mortality, compared to class 1 (e.g. HR for overall death was 1.26 (95% CI: 1.16-1.37), 1.67 (95% CI: 1.47-1.90), and 1.21 (95% CI: 1.05-1.41) for class 2, 3, and 4, respectively).

CONCLUSION

We present an innovative approach to risk stratify a well-defined population based on LCA metabolic-defined subgroups for cancer and mortality. Our results indicate that standard of care baseline serum markers, when assembled into meaningful metabolic profiles, could help assess long term risk of disease and provide insight in disease susceptibility and etiology.

Gamma-glutamyltransferase as a preoperative differential diagnostic marker in patients with adnexal mass

OBJECTIVE

Gamma-glutamyltransferase (GGT) is involved in tumor development, progression and chemotherapy resistance. The present study evaluated GGT serum levels as a preoperative predictive marker for ovarian cancer in patients with adnexal mass.

STUDY DESIGN

Preoperative GGT serum levels of 2235 patients with adnexal mass and subsequent surgery were ascertained (patients with benign ovarian tumors: n = 1811; borderline tumor of the ovary [BTO]: n = 85; epithelial ovarian cancer [EOC]: n = 339). Standardized expert transvaginal ultrasound was documented.

RESULTS

Median (interquartile range) GGT serum levels in patients with benign ovarian tumors, BTO, and EOC were 15.0 U/l (11.0-23.0), 17.0 U/l (10.0-23.5), and 20.0 U/l (13.0-34.0), respectively (p = 0.002). Elevated GGT serum levels were associated with the presence of BTO/EOC in univariate analysis (p < 0.0001, hazard ratio 1.8, confidence interval 1.5-2.3). GGT did not outperform established tools for preoperative prediction of BTO/EOC in patients with adnexal mass, such as CA-125 measurement or transvaginal ultrasound.

CONCLUSION

Elevated GGT serum levels were not associated with the presence of BTO/EOC in women with suspicious adnexal mass in multivariate analysis. GGT serum levels did not outperform established risk factors and therefore might add only limited additional value to CA-125 serum levels in the differential diagnosis between benign and malignant adnexal masses.

Prognostic value of γ-glutamyltransferase-to-albumin ratio in patients with pancreatic ductal adenocarcinoma following radical surgery

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with poor prognosis. Many preoperative biomarkers can predict postoperative survival of PDAC patients. In this study, we created a novel ratio index based on preoperative liver function test, γ‐glutamyltransferase‐to‐albumin ratio (GAR), and evaluated its prognostic value in predicting clinical outcomes of PDAC patients following radical surgery. We retrospectively enrolled 833 PDAC patients who had underwent radical surgery at our institution between January 2010 and January 2017. Patients were divided into two groups according to the cut‐off value of GAR. Univariate and multivariate survival analysis between the groups were evaluated. TNM stage, GAR, preoperative serum carbohydrate antigen 19‐9 (CA19‐9) and tumor differentiation were combined to generate a more accurate prognostic model. The optimal cut‐off value of GAR was 0.65. Significant correlations were found between GAR and tumor location, tumor size, vascular invasion, obstructive jaundice, biliary drainage and parameters of liver function test. Univariate and multivariate analysis showed that high level of GAR independently predicted poorer postoperative overall survival (OS, P < 0.001) and recurrence‐free survival (RFS, P < 0.001). Subgroup analysis demonstrated that GAR was predictive of survival in patients without biliary obstruction or severely impaired liver function. In addition, integration of GAR, preoperative serum CA19‐9, and tumor differentiation into TNM staging system could better stratify the prognosis for PDAC patients compared with TNM stage alone. Our study demonstrates that preoperative GAR is an independent prognostic factor for prediction of surgical outcomes in PDAC patients. Combination of TNM stage, GAR, preoperative serum CA19‐9, and tumor differentiation can enhance the prognostic accuracy.

A novel mitochondrial-targeting near-infrared fluorescent probe for imaging γ-glutamyl transpeptidase activity in living cells

γ-Glutamyl transpeptidase (GGT) plays an essential role in regulating cellular glutathione and cysteine homeostasis, and its abnormal elevation is associated with different diseases including cancers. Here a novel mitochondrial-targeting near-infrared fluorescent probe was designed for GGT by conjugating glutamate acid to a newly synthesized amine hemicyanine fluorophore. The fluorescent probe was initially non-emissive due to the formation of an amide bond which destroyed the electronic-donating ability of the amine moiety and disrupted the push-pull structure. GGT-mediated cleavage of the γ-glutamyl bond regenerated the initial fluorophore with distinct intramolecular charge transfer (ICT) and activated the fluorescence signal. The fluorescent probe displayed a linear relationship to the concentration of GGT in the range of 1.0-90 U L-1, with an estimated limit of detection (LOD) of 0.4 U L-1. Its ability to target and image mitochondrial GGT activity was demonstrated in living cells with high specificity and fast response. We believe our near-infrared fluorescent probe could have great potential in imaging mitochondrial GGT activity and elucidating GGT-associated pathological consequences in living cells and even small animal models.

Noninvasive scoring systems predict hepatic and extra-hepatic cancers in patients with nonalcoholic fatty liver disease

BACKGROUND

Liver fibrosis predicts liver-related morbidity and mortality in patients with non-alcoholic fatty liver disease (NAFLD). Non-invasive scores correlate with the degree of liver fibrosis in these patients.

AIMS AND METHODS

To investigate the accuracy of noninvasive scoring systems in predicting long-term outcomes and cancer incidence of patients with NAFLD, we performed a single-center retrospective study of patients with biopsy proven NAFLD. Mean follow up period was 100 months. Outcomes included liver-related complications, hospitalizations, overall mortality and the development of any malignancies.

RESULTS

32 patients had advanced fibrosis (F3-F4) per biopsy at baseline and 121 patients had mild to moderate fibrosis (F0-F2). Both advanced histologic fibrosis stage as well as higher non-invasive scores predicted repeated hospitalizations and longer hospitalization stays. In a multivariate analysis, liver fibrosis (p = 0.002), FIB-4 score (p<0.001), NFS (p<0.001) but not APRI score (p = 0.07) were predictors of overall mortality, and the occurrence of malignancies was associated with higher APRI (p<0.001), FIB-4 (p<0.001) and NFS (p = 0.008) scores, but not with advanced fibrosis, as determined by liver biopsy (p = 0.105).

CONCLUSIONS

In NAFLD patients, noninvasive scoring systems are good predictors of morbidity and mortality and may have an additive value in predicting the development of hepatic and extra-hepatic cancers.

Gamma-glutamyltransferase, possible novel biomarker in colon diverticulosis: a case-control study

The gamma-glutamyltransferase (GGT) is recognized in medical practice as a useful indicator for the detection of liver lesions, especially those induced by the excessive consumption of alcoholic or cholesterol-associated drinks. The present study, although it includes a very small number of cases diagnosed with colon diverticulosis-diverticulitis associated with polyposis at the same intestinal level, identifies the presence of increased circulating concentrations of this enzyme in the serum. Its serum levels are tracked “dynamically” throughout a year after the diagnosis and start of the therapy. The study calls into question the release of the enzyme from the edge of the enterocytes’ brush-like edge, leading to the pathogenic disturbance of regional redox homeostasis. The hypothesis gives the circulating values of GGT predictive value for cellular oxidative stress, as well as for indirectly expressing the glutathione level in cytosol.

Prognostic significance of preoperative gamma-glutamyltransferase to lymphocyte ratio index in nonfunctional pancreatic neuroendocrine tumors after curative resection

Various inflammation-based prognostic scores have been associated with reduced survival in patients with nonfunctional pancreatic neuroendocrine tumor (NF-PNET). However, few studies have illuminated the relationship between the preoperative gamma-glutamyltransferase (GGT) to lymphocyte ratio index (GLRI) and the prognosis of NF-PNET. A retrospective review of 125 NF-PNET patients following curative resection was conducted. The cut-off values for the inflammation-based prognostic scores, including GLRI, were selected using receiver operating characteristic curve analysis. Univariate, multivariate and Kaplan-Meier analyses were used to calculate overall survival (OS) and disease-free survival (DFS). The optimal cut-off value for GLRI was 10.3. Multivariate analysis showed that GLRI was an independent predictor of OS (P = 0.001) and DFS (P = 0.007) for NF-PNET. Kaplan-Meier analysis also showed that preoperative GLRI had significant prognostic value in various subgroups of patients with NF-PNET. The discriminatory capability of GLRI was superior to that of other inflammation-based scores in OS prediction. Furthermore, the predictive range was expanded by incorporating GLRI into the conventional stratification systems, including AJCC staging and WHO classification. These results indicated that preoperative GLRI was an independent predictor for NF-PNET patients undergoing curative resection. The incorporation of GLRI into the existing conventional stratification systems resulted in improved predictive accuracy.

High pretreatment serum gamma-glutamyl transpeptidase predicts an inferior outcome in nasopharyngeal carcinoma

Background

Gamma-glutamyl transpeptidase (GGT) which plays an important role in tumor initiation, invasion, drug resistance is strongly associated with poor prognosis in patients with cancers. This study was designed to estimate whether pretreatment serum GGT could predict the clinical outcome of nasopharyngeal carcinoma (NPC) patients.

Results

An optimal cutoff value was identified as 23 U/L for GGT. Univariate analysis and multivariate analysis demonstrated that elevated GGT was correlated with shorter local recurrence-free survival (LRFS) (HR, 4.163; 95% CI, 1.690-10.251; p=0.023), progression-free survival (PFS) (HR, 3.119; 95% CI, 1.955-4.976; p=0.031) and overall survival (OS) (HR, 2.811; 95% CI, 1.614-4.896; p=0.007).

Materials and Methods

We retrospectively analyzed data from 374 patients with NPC. Kaplan–Meier method was used to calculate and compare the prognosis. The Cox proportional hazards model was applied to carry out univariate and multivariate analyses.

Conclusion

Pretreatment GGT can be a novel and independent prognostic biomarker for patients with NPC.

Elevated serum gamma-glutamyltransferase is associated with an increased risk of oesophageal carcinoma in a cohort of 8,388,256 Korean subjects

Gamma-glutamyltransferase (GGT) is a marker for hepatic injury and alcohol consumption. However, the association of GGT with the risk of oesophageal carcinoma (OC) has not been fully recognized to date. Therefore, this study aimed to determine the association between elevated GGT and OC, by also considering the body mass index (BMI) of the subjects. Clinical data from 8,388,256 Korean individuals, who were aged 40 years and over and who received healthcare check-ups arranged by the national insurance program in 2007 and 2008, were analysed. Newly diagnosed OC was identified using claims data during a median follow-up duration of 8.72 years. During the study period, 6,863 individuals (0.08%) developed OC. We found that there was an increased risk of OC in subjects with serum GGT values >18 IU/L. Furthermore, a BMI <18.5 kg/m² (underweight) was associated with increased OC risk, while a BMI ≥23.0 kg/m² was associated with a reduced OC risk. Individuals who were both underweight and in the highest GGT quartile (≥40 IU/L) had a far greater risk of OC compared to other individuals (hazard ratio: 3.65, 95% confidence interval: 3.10–4.30). In conclusion, increased serum GGT was associated with an increased risk of developing OC in the general Korean population, regardless of age, sex, smoker status, or alcohol consumption.

Gamma-glutamyltransferase activity in exosomes as a potential marker for prostate cancer

Background

Exosomes or extracellular vesicles have the potential as a diagnostic marker for various diseases including cancer. In order to identify novel exosomal markers for prostate cancer (PC), we performed proteomic analysis of exosomes isolated from PC cell lines and examined the usefulness of the marker in patients.

Methods

Exosomes isolated by differential centrifugation from the culture medium of androgen-dependent LNCaP prostate cancer cell line and its sublines of partially androgen-independent C4, androgen-independent C4–2 and bone metastatic C4–2B were subjected to iTRAQ-based proteomic analysis. Exosomes were also isolated by immunocapture and separated by size exclusion chromatography and density gradient centrifugation. Protein expression was determined by Western blot analysis. GGT activity was measured using a fluorescent probe, γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG). Immunohistochemical analysis of tissues was performed using anti-GGT1 antibody.

Results

Among proteins upregulated in C4–2 and C4–2B cells than in LNCaP cells, we focused on gamma-glutamyltransferase 1 (GGT1), a cell-surface enzyme that regulates the catabolism of extracellular glutathione. The levels of both GGT1 large and small subunits were elevated in exosomes isolated from C4–2 and C4–2B cells by differential centrifugation and by immunocapture with anti-CD9 or -prostate-specific membrane antigen (PSMA) antibody. In cell lysates and exosomes, GGT1 expression correlated with GGT activity. Size exclusion chromatography of human serum demonstrated the presence of GGT activity and GGT1 subunits in fractions positive for CD9. Density gradient centrifugation revealed the co-presence of GGT1 subunits with CD9 in exosomes isolated by differential centrifugation from human serum. Since GGT activity correlated with GGT1 expression in serum exosomes isolated by differential centrifugation, we measured serum exosomal GGT activity in patients. Unexpectedly, we found that serum exosomal GGT activity was significantly higher in PC patients than in benign prostatic hyperplasia (BPH) patients. In support of this finding, immunohistochemical analysis showed increased GGT1 expression in PC tissues compared with BPH tissues.

Conclusions

Our results suggest that serum exosomal GGT activity could be a useful biomarker for PC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3301-x) contains supplementary material, which is available to authorized users.

Long-term stability of cancer biomarkers in human serum: biomarkers of oxidative stress and redox status, homocysteine, CRP and the enzymes ALT and GGT

AIM

Five frequently used biomarkers in cancer research and epidemiological studies were tested for their assay stability upon storage of serum for 12 months at -20 and -70/-80°C.

MATERIALS & METHODS

The biomarker assays include reactive oxygen metabolites (ROM), the total thiol levels (TTL), homocysteine (HCy), C-reactive protein (HS-CRP) and two liver enzymes, alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT).

RESULTS

The assays for ROM, HCy, HS-CRP and GGT were stable in human serum samples at the two temperatures tested. The two other assays TTL and ALT, however, showed statistically significant differences in their stability between -20 and -80°C.

CONCLUSION

Therefore, storage at -80°C is advised to maintain a reliable assay outcome when serum samples have to be stored for longer periods.

γ-Glutamyltransferase and Breast Cancer Risk Beyond Alcohol Consumption and Other Life Style Factors - A Pooled Cohort Analysis

Objective

Elevated γ-Glutamyltransferase serum levels are associated with increased risk of overall cancer incidence and several site-specific malignancies. In the present prospective study we report on the associations of serum γ-Glutamyltransferase with the risk of breast cancer in a pooled population-based cohort considering established life style risk factors.

Methods

Two cohorts were included in the present study, i.e. the Vorarlberg (n = 97,268) and the Malmoe cohort (n = 9,790). Cox proportional hazards regression models were fitted to estimate HRs for risk of breast cancer.

Results

In multivariate analysis adjusted for age, body mass index and smoking status, women with γ-Glutamyltransferase levels in the top quartile were at significantly higher risk for breast cancer compared to women in the lowest quartile (HR 1.21, 95% CI 1.09 to 1.35; p = 0.005). In the subgroup analysis of the Malmoe cohort, γ-Glutamyltransferase remained an independent risk factor for breast cancer when additionally considering alcohol intake. A statistically significant increase in risk was seen in women with γ-Glutamyltransferase-levels in the top versus lowest quartile in a multivariate model adjusted for age, body mass index, smoking status, physical activity, parity, oral contraceptive-use and alcohol consumption (HR 1.37, 95% CI 1.11–1.69, p = 0.006).

Conclusion

Our findings identified γ-Glutamyltransferase as an independent risk factor for breast cancer beyond the consumption of alcohol and other life style risk factors.

Biomarker-Based Approaches for Assessing Alcohol Use Disorders

Although alcohol use disorders rank among the leading public health problems worldwide, hazardous drinking practices and associated morbidity continue to remain underdiagnosed. It is postulated here that a more systematic use of biomarkers improves the detection of the specific role of alcohol abuse behind poor health. Interventions should be initiated by obtaining information on the actual amounts of recent alcohol consumption through questionnaires and measurements of ethanol and its specific metabolites, such as ethyl glucuronide. Carbohydrate-deficient transferrin is a valuable tool for assessing chronic heavy drinking. Activities of common liver enzymes can be used for screening ethanol-induced liver dysfunction and to provide information on the risk of co-morbidities including insulin resistance, metabolic syndrome and vascular diseases. Conventional biomarkers supplemented with indices of immune activation and fibrogenesis can help to assess the severity and prognosis of ethanol-induced tissue damage. Many ethanol-sensitive biomarkers respond to the status of oxidative stress, and their levels are modulated by factors of life style, including weight gain, physical exercise or coffee consumption in an age- and gender-dependent manner. Therefore, further attention should be paid to defining safe limits of ethanol intake in various demographic categories and establishing common reference intervals for biomarkers of alcohol use disorders.

Mitochondria-targeting ratiometric fluorescent probe for γ-glutamyltranspeptidase and its application to colon cancer

An indocyanine-based probe for γ-glutamyltranspeptidase exhibited ratiometric fluorescence in mitochondria through an enzyme-mediated amide-to-amine transformation reaction applicable for colon cancer detection.

Obesity and the extent of liver damage among adult New Zealanders: findings from a national survey

Objective

Non‐alcoholic fatty liver disease (NAFLD), defined as excessive fat accumulation in hepatocytes when no other pathologic causes are present, is an increasingly common obesity‐related disorder. We sought to describe the prevalence of elevated liver enzymes, a marker of liver damage, among New Zealand adults, and high‐risk subgroups including those with an elevated body mass index and those with pre‐diabetes or diabetes, to gain a better understanding of the burden of liver disease.

Methods

A total of 4,721 New Zealanders aged 15+ years participated in a nationally representative nutrition survey. Liver enzymes, alanine transaminase (ALT) and gamma glutamyl transpeptidase (GGT) were measured in serum. Results were available for 3,035 participants, of whom 10.8% were Māori and 4.5% Pacific.

Results

Overall, the prevalence of elevated ALT and elevated GGT was 13.1% (95% confidence interval [CI]: 11.2 – 15.0) and 13.7% (95% CI: 12.0 – 15.4), respectively. Odds ratios for an elevated ALT or GGT markedly increased with increasing body mass index. Men with obesity had the highest elevated ALT prevalence (28.5%; 95% CI: 21.7–35.4), and women with diabetes had the highest elevated GGT prevalence (36.5%; 95% CI: 26.0–47.0). Adding alcohol consumption categories to each of the adjusted models did not meaningfully change any results, although for women, heavy alcohol consumption was associated with an elevated GGT (overall p = 0.03).

Conclusions

Obesity‐related liver disease is likely to increasingly burden the New Zealand health sector and contribute to health disparities unless effective obesity treatment and prevention measures are given high priority. © 2015 The Authors. Obesity Science & Practice published by John Wiley & Sons Ltd, World Obesity and The Obesity Society.

Gamma-Glutamyltransferase: A Predictive Biomarker of Cellular Antioxidant Inadequacy and Disease Risk

Gamma-glutamyltransferase (GGT) is a well-established serum marker for alcohol-related liver disease. However, GGT's predictive utility applies well beyond liver disease: elevated GGT is linked to increased risk to a multitude of diseases and conditions, including cardiovascular disease, diabetes, metabolic syndrome (MetS), and all-cause mortality. The literature from multiple population groups worldwide consistently shows strong predictive power for GGT, even across different gender and ethnic categories. Here, we examine the relationship of GGT to other serum markers such as serum ferritin (SF) levels, and we suggest a link to exposure to environmental and endogenous toxins, resulting in oxidative and nitrosative stress. We observe a general upward trend in population levels of GGT over time, particularly in the US and Korea. Since the late 1970s, both GGT and incident MetS and its related disorders have risen in virtual lockstep. GGT is an early predictive marker for atherosclerosis, heart failure, arterial stiffness and plaque, gestational diabetes, and various liver diseases, including viral hepatitis, other infectious diseases, and several life-threatening cancers. We review literature both from the medical sciences and from life insurance industries demonstrating that serum GGT is a superior marker for future disease risk, when compared against multiple other known mortality risk factors.

Serum Gamma-Glutamyltransferase Levels Predict Clinical Outcomes in Hemodialysis Patients

BACKGROUND

Gamma-glutamyltransferase (GGT) is a biomarker of liver injury. GGT has also been reported to be a marker of oxidative stress and a predictor of mortality in the general population. Hemodialysis (HD) patients suffer from oxidative stress. The aim of our study was to investigate the relationship between serum GGT levels and clinical outcomes in HD patients.

METHODS

A total of 1,634 HD patients were enrolled from the Clinical Research Center registry for end-stage renal disease, a prospective cohort in Korea. Patients were categorized into three groups by tertiles of serum GGT levels. The primary outcome was all-cause, cardiovascular, or infection-related mortality and hospitalization.

RESULTS

During the median follow-up period of 30 months, the highest tertile of serum GGT levels had a significantly higher risk for all-cause mortality (hazard ratio (HR) 2.39, 95% confidence interval (CI), 1.55-3.69, P<0.001), cardiovascular mortality (HR 2.14, 95% CI, 1.07-4.26, P = 0.031) and infection-related mortality (HR 3.07, 95% CI, 1.30-7.25, P = 0.011) using tertile 1 as the reference group after adjusting for clinical variables including liver diseases. The highest tertile also had a significantly higher risk for first hospitalization (HR 1.22, 95% CI, 1.00-1.48, P = 0.048) and cardiovascular hospitalization (HR 1.42, 95% CI, 1.06-1.92, P = 0.028).

CONCLUSIONS

Our data demonstrate that high serum GGT levels were an independent risk factor for all-cause, cardiovascular, and infection-related mortality, as well as cardiovascular hospitalization in HD patients. These findings suggest that serum GGT levels might be a useful biomarker to predict clinical outcomes in HD patients.

Metabolic serum biomarkers for the prediction of cancer: a follow-up of the studies conducted in the Swedish AMORIS study

The Swedish Apolipoprotein MOrtality RISk study (AMORIS) contains information on more than 500 biomarkers collected from 397,443 men and 414,630 women from the greater Stockholm area during the period 1985–1996. Using a ten-digit personal identification code, this database has been linked to Swedish national registries, which provide data on socioeconomic status, vital status, cancer diagnosis, comorbidity, and emigration. Within AMORIS, 18 studies assessing risk of overall and site-specific cancers have been published, utilising a range of serum markers representing glucose and lipid metabolism, immune system, iron metabolism, liver metabolism, and bone metabolism. This review briefly summarises these findings in relation to more recently published studies and provides an overview of where we are today and the challenges of observational studies when studying cancer risk prediction.

Overall, more recent observational studies supported previous findings obtained in AMORIS, although no new results have been reported for serum fructosamine and inorganic phosphate with respect to cancer risk. A drawback of using serum markers in predicting cancer risk is the potential fluctuations following other pathological conditions, resulting in non-specificity and imprecision of associations observed. Utilisation of multiple combination markers may provide more specificity, as well as give us repeated instead of single measurements. Associations with other diseases may also necessitate further analytical strategies addressing effects of serum markers on competing events in addition to cancer. Finally, delineating the role of serum metabolic markers may generate valuable information to complement emerging clinical studies on preventive effects of drugs and supplements targeting metabolic disorders against cancer.

γ-Glutamyltransferase and cancer risk: The Korean cancer prevention study

Elevated serum γ-glutamyltransferase (GGT) is a marker of hepatic injury and is associated with risk of chronic disease. However, the value of GGT as a biomarker for cancer risk remains unclear. Therefore, we evaluated the association of serum GGT with cancer incidence among more than 1.6 million Koreans. We included 1,662,087 Koreans (1,108,121 men and 553,966 women aged 20-95 years) who received health insurance from the National Health Insurance Service and had a biennial medical evaluation between 1995 and 1998. Follow-up was through December 2012. Using Cox proportional hazards models, we adjusted for age, smoking status, alcohol consumption, exercise and body mass index after exclusion of early cases (cancer diagnosis or death within 5 years of starting follow-up) and estimated hazard ratios (HRs) of overall and organ-specific cancer incidence by GGT quintiles. During the 17-year follow-up, 129,087 new cancer cases occurred among the participants. Across levels of GGT, there was a positive gradient of HR and the highest quintile of GGT (≥ 60 IU/L) had the highest HR for all cancers in both men and women. By cancer site, the association was strongest for liver cancer, comparing the highest and lowest strata in men [HR, 6.67; 95% confidence interval (95%CI), 5.88-7.57] and in women (HR, 7.57; 95%CI, 6.41-8.94). Significant associations were also observed for cancers of the esophagus, larynx, stomach, colorectal, bile duct and lung in men and of the bile duct in women. Increased serum GGT level is independently associated with risk of cancer.

Prognostic significance of gamma-glutamyltransferase in patients with resectable esophageal squamous cell carcinoma

Gamma-glutamyltransferase (GGT) is a membrane-bound enzyme involved in the glutathione metabolism. Studies suggested that GGT was a marker of apoptotic balance and modulated tumor progression, invasion and drug resistance. Recently, GGT was shown to be associated with the progression of high-grade esophageal epithelial dysplasia to invasive carcinoma. This study was conducted to investigate the value of pre-therapeutic serum GGT levels as prognostic parameter in esophageal squamous cell carcinoma. Six hundred thirty-nine resectable esophageal squamous cell carcinoma patients were recruited in this study and were stratified into two GGT risk groups. The association of pre-therapeutic serum GGT levels and clinical-pathological parameters was examined. Univariate and multivariate survival analyses were performed. GGT serum levels were associated with gender, smoking status, TNM stage and lymph node involvement. Higher pre-therapeutic serum GGT was found in males, smoker, advanced TNM stage and lymph node positive patients. Patients assigned to the low-risk group had higher 5-year overall survival rate (53.1% vs. 33.0%, P < 0.01) and disease-free survival rate (45.2% vs. 23.4%, P < 0.01) than the high-risk group. Patients with high-risk group of GGT had 1.568 (95% confidence interval [CI], 1.259 ∼ 1.952) times the risk of death and 1.582 (95% CI, 1.286 ∼ 1.946) times the risk of disease recurrence contrast with those with low-risk group of GGT. The pre-therapeutic serum GGT is a novel independent prognostic parameter for disease-free survival and overall survival in resectable esophageal squamous cell carcinoma.

Prognostic relevance of pretherapeutic gamma-glutamyltransferase in patients with primary metastatic breast cancer

Background

Gamma-glutamyltransferase (GGT) is a known marker for apoptotic balance and cell detoxification. Recently, an association of baseline GGT levels and breast cancer incidence, tumor progression and chemotherapy resistance was shown. The purpose of this study was to evaluate the association of pre-therapeutic GGT levels, clinical-pathological parameters and survival in patients with primary metastatic breast cancer (PMBC).

Methods

In this multicenter analysis, pre-therapeutic GGT levels and clinical-pathological parameters of 114 patients diagnosed with PMBC between 1996 and 2012 were evaluated. The association between GGT levels and clinical-pathological parameters were analysed. Patients were stratified into four GGT risk-groups (GGT < 18.00 U/L: normal low, 18.00 to 35.99 U/L: normal high, 36.00 to 71.99 U/L: elevated and ≥ 72.00 U/L: highly elevated) and survival analyses were performed.

Findings

Patients in the high risk GGT group had a poorer overall survival, when compared to the low risk group with five-year overall survival rates of 39.5% and 53.7% (p = 0.04), respectively. Patients with larger breast tumors had a trend towards higher GGT levels (p = 0.053). Pre-therapeutic GGT levels were not associated with indicators of aggressive tumor biology such as HER2-status, triple negative histology, or poorly differentiated cancers.

Conclusion

Pre-therapeutic GGT serum level might serve as a novel prognostic factor for overall-survival in patients with PMBC.

Emerging regulatory paradigms in glutathione metabolism

One of the hallmarks of cancer is the ability to generate and withstand unusual levels of oxidative stress. In part, this property of tumor cells is conferred by elevation of the cellular redox buffer glutathione. Though enzymes of the glutathione synthesis and salvage pathways have been characterized for several decades, we still lack a comprehensive understanding of their independent and coordinate regulatory mechanisms. Recent studies have further revealed that overall central metabolic pathways are frequently altered in various tumor types, resulting in significant increases in biosynthetic capacity and feeding into glutathione synthesis. In this review, we will discuss the enzymes and pathways affecting glutathione flux in cancer and summarize current models for regulating cellular glutathione through both de novo synthesis and efficient salvage. In addition, we examine the integration of glutathione metabolism with other altered fates of intermediary metabolites and highlight remaining questions about molecular details of the accepted regulatory modes.

The WOMED model of benign thyroid disease: Acquired magnesium deficiency due to physical and psychological stressors relates to dysfunction of oxidative phosphorylation

BACKGROUND

The aim of this study was to discern whether a relation between biochemical parameters, sonography and musculoskeletal data exists in cases of hyperthyroidism and whether they are modifiable through supplementation with selenomethionine and magnesium citrate as well as by acupuncture and manual medicine methods.

RESULTS

A direct correlation between whole blood selenium and serum magnesium was found in subjects without thyroid disease and in menopausal women while it was reversed in cases of thyroid diseases as well as in patients with depression, infection, and in infertile women. Vascularization indices were elevated in cases of newly diagnosed benign thyroid diseases. Musculoskeletal changes i.e. lateral tension and idiopathic moving toes, as well as situations of physical and psychological stress and minor trauma and infection led to an increase of vascularization. Magnesium levels correlated negatively with these two conditions. The supplementation brought a reduction of the vascularization indices and reduced the incidence of idiopathic moving toes. Treatment of lateral tension required manual medicine methods and acupuncture (gastrocnemius). A small subgroup of patients showed a further reduction of hyper-vascularization after receiving coenzyme Q10.

CONCLUSIONS

We interpret the elevated thyroid vascularization and low magnesium levels as signs of an inflammatory process related to the musculoskeletal changes. Improvement of thyroid function and morphology can be achieved after correcting the influence of stressors together with the supplementation regime. We hypothesize that the central biochemical event in thyroid disease is that of an acquired, altered mitochondrial function due to deficiency of magnesium, selenium, and coenzyme Q10.

Alpha-1-fucosidase as a prognostic indicator for hepatocellular carcinoma following hepatectomy: a large-scale, long-term study

Background:

Preoperative alpha-L-fucosidase (AFU) has been used as a diagnostic biomarker for hepatocellular carcinoma (HCC), but its role as a prognostic predictor after partial hepatectomy has not been well defined. The study aimed to investigate the prognostic significance of preoperative serum AFU for HCC patients after hepatic resection.

Methods:

A retrospective training data set and a prospective validation data set were used to evaluate the prognosis of HCC after partial hepatectomy. A total of 669 patients with histopathologically confirmed HCC were enrolled. Univariate and multivariate analyses were used to identify the prognostic significance of preoperative serum AFU.

Results:

The retrospective training data set showed a preoperative AFU>35 u l⁻¹ should be used. The prospective validation data set showed preoperative AFU was an independent prognostic factor of overall survival (OS) (P=0.008; hazard ratio: 2.333; 95% confidence interval: 1.249–4.369). Patients with a preoperative AFU>35 u l⁻¹ had a lower recurrence-free survival rate and an OS rate than those with AFU⩽35 u l⁻¹, and they have a higher tendency to form macrovascular invasion. Furthermore, the prognostic significance of AFU>35 u l⁻¹ could also be applied to patients with alpha-fetoprotein levels of ⩽400 ng ml⁻¹.

Conclusions:

Preoperative serum AFU is a prognostic predictor of HCC.

Gamma-glutamyl transpeptidase level is a novel adverse prognostic indicator in human metastatic colorectal cancer

AIM

Biomarkers have been utilized for prognosis in colorectal cancer; however, relatively few have been identified. We compared the prognostic value of serum alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma-glutamyl transpeptidase (GGT) with carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in patients with metastatic colorectal cancer (mCRC).

METHOD

Blood samples were collected from 239 patients with mCRC presenting between 2005 and 2010 in the Sun Yat-sen University Cancer Center.

RESULTS

CEA (P < 0.001), CA19-9 (P < 0.001), GGT (P < 0.001), ALP (P < 0.001) and LDH (P = 0.001) were statistically significant prognostic factors of overall survival (OS). CEA (P = 0.002) and GGT (P = 0.021) were validated as independent predictors. On univariate analysis, CEA (P = 0.003), CA19-9 (P = 0.006), GGT (P < 0.001) and ALP (P = 0.001) were statistically significant predictive factors of progression-free survival (PFS) in patients having first-line chemotherapy. CEA (P = 0.011) and GGT (P = 0.027) were independent predictors. GGT (P = 0.001), ALP (P = 0.016) and LDH (P = 0.039) levels were correlated with the tumour response rate assessed by CT, whilst CEA (P = 0.724) and CA19-9 (P = 0.822) were not. There was a statistically significant difference in OS (P < 0.001) and PFS (P < 0.001) among patients who had elevations of both CEA and GGT compared with those in whom only one or neither was elevated.

CONCLUSION

Among GGT, LDH and ALP, only GGT plays an independent role with CEA in predicting OS and PFS in mCRC. When coupled with CEA, GGT may lead to improved prognostic predictors.

Association of gamma-glutamyltransferase with severity of disease at diagnosis and prognosis of ovarian cancer

Background:

Gamma-glutamyltransferase (GGT) – a membrane-bound enzyme crucially involved in the cell's detoxification pathway and apoptotic balance – is involved in tumour development, progression and chemotherapy resistance. Elevated GGT serum levels are associated with increased cancer risk in women and worse prognosis in gynaecologic cancers. The present study investigated the prognostic role of GGT in ovarian cancer patients.

Methods:

In this multicenter study, pre-therapeutic GGT levels were ascertained in 634 consecutive patients with epithelial ovarian cancer (EOC, n=567) and borderline tumour of the ovary (BTO, n=67). Gamma-glutamyltransferase serum levels were associated with clinicopathological parameters and uni- and multivariate survival analyses were performed. Immunohistochemistry of GGT was performed in ovarian cancer tissue and correlated with GGT serum levels.

Results:

Pre-therapeutic GGT serum levels were higher in patients with EOC (28.56 (38.24) U l⁻¹) than in patients with BTO (20.01 (12.78) U l⁻¹, P=0.01). High GGT serum levels were associated with advanced FIGO stage (P<0.001) and with worse overall survival in univariate (P<0.001) and multivariable analysis (P=0.02, HR 1.2 (1.1–1.5)). We further investigated the association between systemic GGT serum levels and local GGT expression in EOC tumour tissue and observed an association between these two parameters (P=0.03).

Conclusion:

High pre-therapeutic GGT serum levels are associated with advanced tumour stage and serve as an independent prognostic marker for worse overall survival in patients with EOC. Gamma-glutamyltransferase expression in ovarian cancer tissue is reflected in GGT serum levels.

Variation in the γ-glutamyltransferase 1 gene and risk of chronic pancreatitis

OBJECTIVE

Individuals with chronic pancreatitis are at increased risk for pancreatic cancer. We hypothesized that genetic variation in the γ-glutamyltransferase 1 (GGT1) gene, which was recently reported associated with pancreatic cancer risk in a genome-wide association study, is also associated with risk of chronic pancreatitis.

METHODS

Associations between common polymorphisms in GGT1 and chronic pancreatitis were evaluated using data and samples from the North American Pancreatitis Study 2. Patients (n = 496) and control subjects (n = 465) were genotyped for 4 single-nucleotide polymorphisms: rs4820599, rs2017869, rs8135987, and rs5751901. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) for chronic pancreatitis risk were calculated using multiple logistic regression models. Interactions with cigarette smoking and alcohol use were explored.

RESULTS

Single-nucleotide polymorphisms rs8135987 and rs4820599 were both statistically significantly associated with risk of chronic pancreatitis; compared with common allele homozygotes, individuals with at least 1 minor allele were at increased risk (rs8135987: OR, 1.36; 95% CI, 1.03-1.80 [P(trend) = 0.01]; rs4820599: OR, 1.39; 95% CI, 1.04-1.84 [P(trend) = 0.0]; adjusted for age, sex, race, smoking status, and alcohol use). No significant interactions with cigarette smoking and alcohol use were observed.

CONCLUSION

Our results suggest that common variation in the GGT1 gene may also affect risk of chronic pancreatitis.