Biochemical prognostic indicators for pancreatic neuroendocrine tumors and small bowel neuroendocrine tumors

Neuroendocrine Neoplasms: Identification of Novel Metabolic Circuits of Potential Diagnostic Utility

The incidence of neuroendocrine neoplasms (NEN) is increasing, but established biomarkers have poor diagnostic and prognostic accuracy. Here, we aim to define the systemic metabolic consequences of NEN and to establish the diagnostic utility of proton nuclear magnetic resonance spectroscopy (¹H-NMR) for NEN in a prospective cohort of patients through a single-centre, prospective controlled observational study. Urine samples of 34 treatment-naïve NEN patients (median age: 59.3 years, range: 36-85): 18 had pancreatic (Pan) NEN, of which seven were functioning; 16 had small bowel (SB) NEN; 20 age- and sex-matched healthy control individuals were analysed using a 600 MHz Bruker ¹H-NMR spectrometer. Orthogonal partial-least-squares-discriminant analysis models were able to discriminate both PanNEN and SBNEN patients from healthy control (Healthy vs. PanNEN: AUC = 0.90, Healthy vs. SBNEN: AUC = 0.90). Secondary metabolites of tryptophan, such as trigonelline and a niacin-related metabolite were also identified to be universally decreased in NEN patients, while upstream metabolites, such as kynurenine, were elevated in SBNEN. Hippurate, a gut-derived metabolite, was reduced in all patients, whereas other gut microbial co-metabolites, trimethylamine-N-oxide, 4-hydroxyphenylacetate and phenylacetylglutamine, were elevated in those with SBNEN. These findings suggest the existence of a new systems-based neuroendocrine circuit, regulated in part by cancer metabolism, neuroendocrine signalling molecules and gut microbial co-metabolism. Metabonomic profiling of NEN has diagnostic potential and could be used for discovering biomarkers for these tumours. These preliminary data require confirmation in a larger cohort.

Prognostic value of chromogranin A in patients with GET/NEN in the pancreas and the small intestine

The aim of this study was to evaluate the clinical usefulness of the chromogranin A (CgA) determination in patients with neuroendocrine neoplasms (NENs) of the digestive system and to analyse the association between concentration of the marker and progression-free survival (PFS) and overall survival (OS). Serum concentrations of CgA were determined before the treatment in 131 patients with NENs, including patients with tumours located in the pancreas, the small intestine, caecum, appendix and in the colon. No significant associations were identified in CgA concentrations between the control group and patients with NENs in appendix and colon. In patients with NENs of the pancreas and NENs of the small intestine and caecum, increased CgA levels were associated with lymph node involvement, distant metastases and a baseline liver involvement. Analyses revealed significantly higher CgA concentrations in patients with active disease compared to those without symptoms of NEN. In patients with NENs of the pancreas, CgA concentration was correlated with tumour grade and Ki67. Significantly higher CgA levels were also found in patients who died compared to those who lived. Analyses of PFS and OS revealed that CgA concentration was not a prognostic factor in patients with NENs of the pancreas. In patients with NENs of the small intestine and caecum, increased CgA concentrations are independent, poor prognostic factors for both PFS and OS. In conclusion, in patients with NENs in pancreas, CgA levels are associated with disease progression, while in patients with NENs in small intestine and caecum, its concentration is a predictive indicator for PFS and OS.

Pretreatment hematologic markers as prognostic predictors of gastroenteropancreatic neuroendocrine tumors: a systematic review and meta-analysis

Background

Systemic inflammation can be reflected by peripheral hematologic parameters and combined index like the lymphocyte count, neutrophil count, platelet count, neutrophil-to-lymphocyte (NLR), and platelet-to-lymphocyte ratio (PLR). This systematic review and meta-analysis aimed to summarize the association between the hematologic markers and prognosis of gastroenteropancreatic neuroendocrine tumors (GEP–NETs).

Methods

A computerized systematic search of PubMed, Embase, and Web of Science was conducted up to August 2016. Studies evaluating prognosis value of hematologic parameters in patients with GEP–NETs were retrieved. For meta-analysis, hazard ratios (HRs) with 95% confidence intervals (95% CIs) were extracted and synthesized using Review Manager software.

Results

We identified eight retrospective cohort studies comprising a total of 724 cases. The majority of included studies focused on pancreatic neuroendocrine tumors (PNETs). The prognostic values of NLR, PLR, and platelet count were reported in six studies, two studies, and one study, respectively. All the parameters were associated with prognostic outcomes in patients with GEP–NETs. A high NLR was significantly associated with poor prognosis in GEP–NETs (pooled HR 3.05, 95% CI 1.96–4.76, I² = 0%, P < 0.00001 for overall survival (OS); pooled HR 3.30, 95% CI 2.04–5.32, I² = 0%, P < 0.00001 for recurrence-free survival [RFS]). In PNETs, pooled-analyses also showed significant superiority of a low NLR on OS (pooled HR 4.21, 95% CI 1.95–9.13, I² = 0%, P = 0.0003) and RFS (pooled HR 5.37, 95% CI 2.14–13.47, I² = 0%, P = 0.003).

Conclusions

These findings suggest that the elevated NLR could be an adverse prognosis factor for GEP–NETs. The conclusion should be mainly limited to PNETs as the majority of included cases were PNET patients. The prognostic value of other hematologic parameters deserves further investigation. We recommend that further studies should use a continuous NLR variable and adopt a prospective and matched study design.

Neutrophil-lymphocyte ratio predicts survival in pancreatic neuroendocrine tumors

Although the prognostic role of neutrophil-lymphocyte ratio (NLR) has been confirmed in a variety of tumors, the prognostic role of NLR in pancreatic neuroendocrine tumors (PNETs) has not been examined. The present study was performed to assess the role of NLR as a prognostic factor in patients with PNETs. Clinical data were retrospectively retrieved from a single institution. The best cut-off value for baseline NLR levels was determined by the receiver operating characteristic (ROC) curve and area under the ROC curve. The primary event was overall survival and event times were assessed by the Kaplan-Meier method. Potential factors associated with the elevation of NLR in PNETs were examined. A total of 165 consecutive patients with pathologically confirmed PNETs were included in this study. The cutoff value of NLR was 2.4 by ROC curve (area under ROC curve, 0.70). NLR >2.4 was found to be a poor prognostic factor in the univariate and multivariate analyses. Patients with a NLR value >2.4 had a higher proportion of tumor size at >3 cm (P=0.001), TNM stage III or IV (P=0.019), and G2/G3 (P=0.003). We concluded that NLR is an independent predictor of overall survival for patients with PNETs. Aberrant elevation of NLR identifies high-risk patients with aggressive characteristics.

Analysis of the factors affecting lymph node metastasis and the prognosis of rectal neuroendocrine tumors

OBJECTIVE

To analyze the factors affecting lymph node metastasis and the prognosis of rectal neuroendocrine tumors after surgical treatment.

METHODS

A retrospective analysis was conducted using the clinical data from 156 cases of rectal neuroendocrine tumors during the period of January 1999 to December 2013. The Kaplan-Meier method was used to calculate the survival time, Cox regression analysis was performed for statistical analysis of clinicopathological factors that may be associated with lymph node metastasis and prognosis, and correlation analysis was carried out using binary logistic regression.

RESULTS

The overall 5-year survival rate of the entire group was 95.7%. Multivariate analysis showed that the depth of invasion was an independent prognostic factor (P < 0.001). The incidence of lymph node metastasis was 7.7% (12/156), and logistic regression analysis showed that lymph node metastasis was related to the depth of invasion (P = 0.003) and tumor diameter (P = 0.006).

CONCLUSION

The surgical approach of rectal neuroendocrine tumors should be selected based on a comprehensive consideration of factors such as tumor size, depth of invasion and lymph node metastasis.