Preoperative serum-gamma-glutamyltransferase (GGT) does not represent an independent prognostic factor in a European cohort of patients with non-metastatic renal cell carcinoma

A Systematic Review of Serum γ-Glutamyltransferase as a Prognostic Biomarker in Patients with Genitourinary Cancer

γ-Glutamyltransferase (GGT), a membrane-bound enzyme, contributes to the metabolism of glutathione (GSH), which plays a critical physiological role in protecting cells against oxidative stress. GGT has been proposed as a biomarker of carcinogenesis and tumor progression given that GGT activity is important during both the promotion and invasion phases in cancer cells. Moreover, GGT expression is reportedly related to drug-resistance possibly because a wide range of drugs are conjugated with GSH, the availability of which is influenced by GGT activity. While serum GGT activity is commonly used as a quick, inexpensive, yet reliable means of assessing liver function, recent epidemiological studies have shown that it may also be an indicator of an increased risk of prostate cancer development. Moreover, elevated serum GGT is reportedly an adverse prognostic predictor in patients with urologic neoplasms, including renal cell carcinoma, prostate cancer, and urothelial carcinoma, although the background mechanisms have still not been well-characterized. The present review article summarizes the possible role of GGT in cancer cells and focuses on evidence evaluation through a systematic review of the latest literature on the prognostic role of serum GGT in patients with genitourinary cancer.

Impact of Serum γ-Glutamyltransferase on Overall Survival in Patients with Metastatic Renal Cell Carcinoma in the Era of Targeted Therapy

BACKGROUND

γ-Glutamyltransferase (GGT) is a marker of oxidative stress. Elevated serum GGT is linked to poor survival in various malignancies; however, there are no data on metastatic renal cell carcinoma (mRCC). Additionally, GGT expression in cancer tissues remains largely unknown.

OBJECTIVE

The present study was designed to determine the prognostic role of serum GGT in patients with mRCC and the association between systemic and local GGT levels.

PATIENTS AND METHODS

Pretherapeutic serum GGT and other clinicopathological parameters were retrospectively compared with overall survival (OS) in 146 consecutive patients with mRCC receiving tyrosine kinase inhibitor therapy. GGT expression was analyzed in 65 resected specimens using immunohistochemistry.

RESULTS

A total of 82 patients (56%) died during the follow-up period (median 34.9 months). Median OS was 16.0 months and 36.8 months in patients with elevated GGT levels and without elevated GGT, respectively (P < 0.001). On multivariable analysis, elevated serum GGT was an independent adverse prognostic factor (hazard ratio [HR] 4.04, P < 0.001), together with high neutrophils (HR 2.06, P = 0.041), low albumin (HR 2.00, P = 0.006), high lactate dehydrogenase (HR 2.68, P < 0.001), and high De Ritis ratio (HR 1.97, P = 0.004). Preoperative serum GGT levels were 29, 48, and 109 U/l in patients whose renal cancer cells showed negative to weak, moderate, and strong GGT expression, respectively (P = 0.004).

CONCLUSIONS

Elevated serum GGT was an unfavorable prognostic factor in mRCC, and overexpression of GGT in renal cancer cells might be responsible for elevation of serum GGT.

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.

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.

ɤ-glutamyl hydroxymethyl rhodamine green fluorescence as a prognostic indicator for lung cancer

OBJECTIVE

ɤ-glutamyltranspeptidase is an enzyme expressed in various malignancies including lung cancer. It rapidly activates non-fluorescent ɤ-glutamyl hydroxymethyl rhodamine green to highly fluorescent hydroxymethyl rhodamine green. The resultant tumor fluorescence is therefore an indicator of cellular ɤ-glutamyltranspeptidase activity. We have explored the use of ɤ-glutamyl hydroxymethyl rhodamine green as an intraoperative imaging tool for visualizing cancers. Herein, we evaluated the potential of the tumor fluorescence as a postoperative prognostic indicator.

METHODS

We included patients with non-small cell lung cancer who had undergone radical resection from 2012 to 2014 in the study. We assessed the fluorescence intensity of the resected tumor and normal lung tissue by ex vivo imaging using ɤ-glutamyl hydroxymethyl rhodamine green.

RESULTS

Sixty-seven patients were eligible for the study (adenocarcinomas, n = 44; squamous cell carcinoma, n = 14; other histologies, n = 8). The pathological stages were I, II, III, and IV in 39, 15, 12, and 1 patient, respectively. Based on the fluorescence of the tumor tissue, the patients were divided into high fluorescence (n = 33) and low fluorescence (n = 34) groups. The 5-year overall survival rate was significantly higher in the high fluorescence group (72.7%) compared to the low fluorescence group (47.1%, P = 0.025). Similarly, pathological stage I patients of the high fluorescence group had higher 5-year overall survival (85.7% vs. 44.4%, P = 0.009) and recurrence-free survival (76.2% vs. 44.4% P = 0.044) rates compared to those of the low fluorescence group.

CONCLUSIONS

ɤ-glutamyl hydroxymethyl rhodamine green fluorescence is a good postoperative prognostic indicator in patients with non-small cell lung cancer.

BioScore (B7-H1, survivin, and Ki-67) does not predict cancer-specific mortality in surgically treated patients with renal cell carcinoma: An external validation study

BACKGROUND

To externally validate' BioScore', a biomarker-based scoring system using immunohistochemical tumor expression levels of B7-H1, survivin, and Ki-67, in a single-center cohort of renal cell carcinoma (RCC) patients. Additionally, we investigated the potential benefit of BioScore as compared to the Mayo Clinic stage, size, grade, and necrosis (SSIGN) score.

MATERIALS AND METHODS

The validation cohort comprised 393 nonmetastatic RCC patients treated with radical nephrectomy or nephron-sparing surgery from 1999 to 2004. Kaplan-Meier estimators, the log-rank test, uni- and multivariable Cox regression models, and measures of discrimination were used to quantify the prognostic performance of BioScore regarding cancer-specific mortality (CSM).

RESULTS

During a median follow-up of 7.8 years, 69/132 (52%) deaths were adjudicated to progressive disease. BioScore was weakly associated with CSM in univariable analysis (hazard ratio per 1 point increase = 1.12, 95% confidence interval = 1.02-1.23, P = 0.023). However, this association did not prevail after adjusting for other adverse prognostic factors as represented by the SSIGN score. The discriminative performance of BioScore was very modest (Harrell's C-Index = 0.60) and did not improve the SSIGN score (P = 0.341), which already showed an excellent discrimination, as evidenced by Harrell's C-Index of 0.81. In a sensitivity analysis regarding clear cell RCC patients only, B7-H1 positivity did not emerge as a statistically significant predictor of CSM.

CONCLUSION

Although a higher BioScore was significantly associated with a higher CSM, the magnitude of this association was weak and not independent from other prognosticators. Moreover, BioScore did not improve the prognostic accuracy of the SSIGN score.

Prognostic and clinicopathological significance of Gamma-Glutamyltransferase in patients with hepatocellular carcinoma: A PRISMA-compliant meta-analysis

BACKGROUND

Many studies explored the prognostic and clinicopathological significance of pretreatment serum Gamma-Glutamyltransferase (GGT) level in hepatocellular carcinoma (HCC). However, there are inconsistent results in the prognostic and clinicopathological significance of pretreatment serum GGT level in HCC. Thus, we conducted this meta-analysis to comprehensively assess the prognostic and clinicopathological significance of pretreatment serum GGT level in HCC patients.

METHODS

We systematically searched PubMed, EMBASE and Web of Science for relevant studies (up to June 14, 2018). The estimated hazard ratios (HRs) were used to assess the association between pretreatment serum GGT level and survival in HCC patients. The estimated odds ratios (ORs) were applied to evaluate the correlation between pretreatment serum GGT and clinicopathological features in HCC.

RESULTS

Our results showed that high pretreatment serum GGT level was significantly correlated with poor overall survival (OS) (HR = 1.70, 95% CI: 1.54-1.87; P < .01) and disease-free survival/relapse-free survival (DFS/RFS) (HR = 1.56, 95% CI: 1.42-1.71; P < .01). Additionally, our results also revealed that there was a close correlation between GGT level and several clinicopathological features in HCC patients, including vascular invasion, tumor size, tumor number and Alpha-fetoprotein (AFP) level.

CONCLUSIONS

This meta-analysis shows that high pretreatment serum GGT level is significantly correlated with poor survival and unfavorable clinicopathological features in HCC patients, suggesting that pretreatment serum GGT may be an economical and effective prognostic biomarker for HCC patients. However, more high-quality studies are still warranted to further validate our findings, considering there are several limitations in this meta-analysis.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Prognostic significance of the pretreatment serum gamma-glutamyltransferase levels in Chinese patients with non-metastatic cervical cancer

This study was performed to evaluate the prognostic significance of the pretreatment serum gamma-glutamyltransferase (GGT) levels in a Chinese cohort of patients with early-stage or locally advanced cervical cancer. The pretreatment serum GGT levels were examined in 290 cervical cancer patients with stage I-III disease and 230 healthy controls selected from a cancer-free population in the same region. Patients were assigned to normal or high-risk GGT groups, as previously described, and the GGT levels were correlated to clinicopathologic parameters and survival data. The GGT levels in cervical cancer patients were significantly higher than those in healthy controls (35.6 ± 29.1 vs. 24.1 ± 14.7 U/L, P < 0.001). In addition, the pretreatment serum GGT levels were associated with the histology type (P = 0.023), lymph node involvement (P = 0.040), stage (P = 0.029), recurrence (P = 0.015) and death (P = 0.005), but not with age (P = 0.432), tumor size (P = 0.067) or degree of differentiation (P = 0.901). Moreover, univariate survival analysis revealed that patients with high GGT levels tended to have poorer disease-free survival (DFS) [hazard ratio (HR), 1.721; 95% confidence interval (CI), 1.189–2.491; P = 0.004] and overall survival (OS) (HR, 1.929; 95% CI, 1.294–2.876; P = 0.001) compared to those with normal GGT levels. However, a multivariate Cox-regression model did not support these data (HR, 1.373; 95% CI, 0.925–2.039; P = 0.116 for DFS and HR, 1.357; 95% CI, 0.887–2.078; P = 0.160 for OS, respectively) after adjusting for other confounding variables. High pretreatment serum GGT was associated with more advanced tumor behavior, but could not serve as an independent prognostic indicator in patients with early-stage or locally advanced cervical cancer.

Preoperative Gamma-Glutamyltransferase Is Associated with Cancer-Specific Survival and Recurrence-Free Survival of Nonmetastatic Renal Cell Carcinoma with Venous Tumor Thrombus

Introduction. To evaluate the prognostic significance of preoperative gamma-glutamyltransferase (GGT) on the subgroup of nonmetastatic renal cell carcinoma (RCC) with venous tumor thrombus. Materials and Methods. We retrospectively reviewed the institutional database and collected the medical data of 156 patients with nonmetastatic RCC with venous tumor thrombus between March 2004 and December 2014. Kaplan-Meier and Cox regression analyses were applied to determine the prognostic factors for cancer-specific survival (CSS) and recurrence-free survival (RFS). Results. The median value and optimal cutoff point of preoperative GGT were 23.0 and 37.5 IU/L, respectively. In the entire cohort, 67 (42.9%) patients experienced disease recurrence, and 46 (29.5%) patients died. Kaplan-Meier analysis revealed that the CSS and RFS rates were lower in patients with preoperative GGT ≥ 37.5 IU/L than in those with preoperative GGT < 37.5 IU/L. Multivariate Cox proportional hazard analysis demonstrated that high preoperative GGT was significantly associated with shorter CSS (hazard ratio [HR]: 2.115; 95% CI: 1.164–3.843; p = 0.014) and RFS (HR: 1.955; 95% CI: 1.166–3.276; p = 0.011), after adjusting other covariates. Conclusions. Preoperative GGT can serve as an independent prognostic biomarker of nonmetastatic RCC patients with venous tumor thrombus. Further prospective study is warranted to confirm our results.

Elevated Preoperative Serum Gamma-glutamyltranspeptidase Predicts Poor Prognosis for Hepatocellular Carcinoma after Liver Transplantation

Gamma-glutamyltransferase (γ-GGT) is a membrane-bound enzyme that is involved in biotransformation, nucleic acid metabolism, and tumourigenesis. Elevated serum γ-GGT levels are related to an increased cancer risk and worse prognosis in many cancers. In the present study, we evaluated the prognostic value of preoperative serum γ-GGT in patients with hepatocellular carcinoma (HCC) who underwent liver transplantation (LT). A total of 130 HCC patients after LT were included in the study. The optimal cut-off value of γ-GGT was 128U/L by receiver operating characteristic analysis, with a sensitivity and specificity of 60.0% and 72.9%, respectively. Elevated preoperative serum γ-GGT was significantly associated with high alpha-fetoprotein (AFP), large tumor size, and macro- and micro-vascular invasion. The 1-, 3-, 5-year disease-free survival (DFS) and overall survival (OS) rates of HCC patients in the γ-GGT > 128U/L group were poorer than those in the γ-GGT ≤ 128U/L group. Stratification analysis revealed that γ-GGT exhibited a greater predictive value for DFS and OS in HCC patients beyond the Milan criteria and no macro-vascular invasion. In conclusion, elevated preoperative serum γ-GGT was significantly associated with advanced tumor stage and aggressive tumor behaviors, and serum γ-GGT can be considered as a prognostic factor for HCC patients after LT, especially for patients beyond the Milan criteria or without macro-vascular invasion.