The role of lymph node ratio in recurrence after curative surgery for pancreatic endocrine tumours

Prognostic Nomogram Based on the Metastatic Lymph Node Ratio for T1-4N0-1M0 Pancreatic Neuroendocrine Tumors After Surgery

Purpose

This study aimed to investigate the prognostic significance of the metastatic lymph node ratio (LNR) in patients with pancreatic neuroendocrine tumors (pNETs) and to develop and validate nomograms to predict 5-, 7-, and 10-year overall survival (OS) and cancer-specific survival (CSS) rates for pNETs after surgical resection.

Methods

The demographics and clinicopathological information of T_1-4N_0-1M₀ pNET patients between 2004 and 2018 were extracted from the Surveillance, Epidemiology and End Results database. X-tile software was used to determine the best cutoff value for the LNR. Patients were randomly divided into the training and the validation groups. A Cox regression model was used in the training group to obtain independent prognostic factors to develop nomograms for predicting OS and CSS. The concordance index (C-index), calibration curves, area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA) were used to assess the nomograms. Patients were divided into four groups according to the model scores, and their survival curves were generated by the Kaplan–Meier method.

Results

A total of 806 patients were included in this study. The best cutoff value for the LNR was 0.16. The LNR was negatively correlated with both OS and CSS. Age, sex, marital status, primary site, grade, the LNR and radiotherapy were used to construct OS and CSS nomograms. In the training group, the C-index was 0.771 for OS and 0.778 for CSS. In the validation group, the C-index was 0.737 for OS and 0.727 for CSS. The calibration curves and AUC also indicated their good predictability. DCA demonstrated that the nomograms displayed better performance than the American Joint Committee on Cancer (AJCC) TNM staging system (8th edition). Risk stratification indicated that patients with higher risk had a worse prognosis.

Conclusions

The LNR is an independent negative prognostic factor for pNETs. The nomograms we built can accurately predict long-term survival for pNETs after surgery.

C-reactive protein independently predicts survival in pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (pNEN) are highly variable in their postresection survival. Determination of preoperative risk factors is essential for treatment strategies. C-reactive protein (CRP) has been implicated in the pathogenesis of pNEN and shown to be associated with survival in different tumour entities. Patients undergoing surgery for pNEN were retrospectively analysed. Patients were divided into three subgroups according to preoperative CRP serum levels. Clinicopathological features, overall and disease-free survival were assessed. Uni- and multivariable survival analyses were performed. 517 surgically resected pNEN patients were analysed. CRP levels were significantly associated with relevant clinicopathological parameters and prognosis and were able to stratify subgroups with significant and clinically relevant differences in overall and disease-free survival. In univariable sensitivity analyses CRP was confirmed as a prognostic factor for overall survival in subgroups with G2 differentiation, T1/T2 and T3/T4 tumour stages, patients with node positive disease and with and without distant metastases. By multivariable analysis, preoperative CRP was confirmed as an independent predictor of postresection survival together with patient age and the established postoperative pathological predictors grading, T-stage and metastases. Preoperative serum CRP is a strong predictive biomarker for both overall and disease free survival of surgically resected pNEN. CRP is associated with prognosis independently of grading and tumour stage and may be of additional use for treatment decisions.

Prognostic factors for relapse in resected gastroenteropancreatic neuroendocrine neoplasms: A systematic review and meta-analysis

BACKGROUND

Gastroenteropancreatic neoplasms (GEP-NENs)can potentially be cured through surgical resection, but only 42-57% achieve 5-year disease-free survival.There is a lack of consensus regarding the factorsassociated withrelapse followingresection ofGEP-NENs.

METHODS

Asystematic review identified studies reporting factors associated with relapse in patients with GEP-NENs following resection of a primary tumour. Meta-analysis was performed to identify the factors prognostic for relapse-free survival (RFS)oroverall survival (OS).

RESULTS

63 studies comprising 13,715 patients were included; 56 studies reported on pancreatic NENs (12,418 patients), 24 reported on patients with grade 1-2 tumours (4,735 patients). Median follow-up was 44.2 months, median RFS was 32 months. Pooling of multivariable analyses of GEP-NENs (all sites and grades) found the following factors predicted worse RFS (all p values < 0.05): vascular resection performed, metastatic disease resected, grade 2 disease, grade 3 disease, tumour size > 20 mm, R1 resection, microvascular invasion, perineural invasion, Ki-67 > 5% and any lymph node positivity. In a subgroup of studies comprising exclusively of grade 1-2 GEP-NENs, R1 resection, perineural invasion, grade 2 disease, any lymph node positivity and tumour size > 20 mm predicted worse RFS (all p values < 0.05). Few OSdata were available for pooling; in univariableanalysis(entire cohort), grade 2 predicted worse OS (p = 0.007), whileR1 resectiondid not (p = 0.14).

CONCLUSIONS

The factors prognostic for worse RFS following resection of a GEP-NEN identified in this meta-analysis could be included in post-curative treatment surveillance clinical guidelines and inform the stratification and inclusion criteria of future adjuvant trials.

Number of Positive Lymph Nodes Is Superior to LNR and LODDS for Predicting the Prognosis of Pancreatic Neuroendocrine Neoplasms

BACKGROUND

The American Joint Committee on Cancer (AJCC) staging for pancreatic neuroendocrine neoplasms (PanNENs) based on the number of positive lymph nodes (PLNs) is the most widely accepted nodal staging system. New nodal staging schemes that take both the number of PLNs and the number of examined lymph nodes into consideration have emerged as useful prognostic tools. The aim of the current study was to determine the most effective nodal staging system, among the 8th edition AJCC N staging (or PLN staging), lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS), for predicting the cause-specific survival of patients with PanNENs.

METHODS

The clinicopathological and prognostic data of 2,295 patients from the Surveillance, Epidemiology, and End Results (SEER) database, diagnosed with PanNENs between 1988 and 2015, were reviewed retrospectively.

RESULTS

A multivariate analysis identified PLN and LNR staging as independent prognostic factors, but not LODDS. The PLN staging exhibited higher C-index and area under the curve values than those of the LNR and LODDS, indicating better predictive discriminatory capacity. No significant difference in the survival of patients was observed within the same PLN staging subgroup according to the number (high or low) of examined lymph nodes. In contrast, intra-group heterogeneity was seen with use of LNR and LODDS staging, due to overestimation of the risk of insufficient examined lymph nodes, and LODDS failed to stratify patients without lymph nodes metastasis into different risk groups.

CONCLUSIONS

The PLN staging is more reliable than LNR and LODDS staging for predicting the cause-specific survival of PanNENs.

The eighth version of American Joint Committee on Cancer nodal classification for high grade pancreatic neuroendocrine tumor should be generalized for the whole population with this disease

Several indexes evaluating the lymph node metastasis of pancreatic neuroendocrine tumor (pNET) have been raised. We aimed to compare the prognostic value of the indexes via the analysis of Surveillance, Epidemiology, and End Results (SEER) database.We identified pNETs patients from SEER database (2004-2015). The prognostic value of N classification which adopted the 8th American Joint Committee on Cancer (AJCC) N classification for well differentiated pNET, revised N classification (rN) which adopted the AJCC 8th N classification for exocrine pancreatic cancer (EPC) and high grade pNET, lymph node ratio and log odds of positive nodes were analyzed.A total of 1791 eligible patients in the SEER cohort were included in this study. The indexes N, rN, lymph node ratio, and log odds of positive nodes were all significant independent prognostic factors for the overall survival. Specifically, the rN had the lowest akaike information criterion of 4050.19, the highest likelihood ratio test (χ) of 48.87, and the highest C-index of 0.6094. The rN was significantly associated with age, tumor location, tumor differentiation, T classification and M classification (P < .05 for all).The 8th version of AJCC N classification for high grade pNET could be generalized for the pNET population.

Systematic Review and Metaanalysis of Lymph Node Metastases of Resected Pancreatic Neuroendocrine Tumors

BACKGROUND

The optimal surgical strategy for pancreatic neuroendocrine tumors (PNETs) is unknown. However, current guidelines recommend a watch-and-wait strategy for small nonfunctional PNETs (NF-PNETs). The aim of this study is to investigate the risk stratification and prognostic significance of lymph node metastasis (LNM) of PNETs to guide decision-making for lymphadenectomy.

PATIENTS AND METHODS

The MEDLINE and Web of Science databases were systematically searched for studies reporting either risk factors of LNM in resected PNETs or survival of patients with LNM. The weighted average incidence of LNM was calculated according to tumor characteristics. Random-effects metaanalyses were performed, and pooled hazard ratios (HR) and their 95% confidence intervals (CI) were calculated to determine the impact of LNM on overall survival (OS). In subgroup analyses, NF-PNETs were assessed.

RESULTS

From a total of 5883 articles, 98 retrospective studies with 13,374 patients undergoing resection for PNET were included. In all PNETs, the weighted median rates of LNM were 11.5% for small (≤ 2 cm) PNETs and 15.8% for G1 PNETs. In NF-PNETs, the rates were 11.2% for small PNETs and 10.3% for G1 PNETs. LNM of all PNETs (HR 3.87, 95% CI 3.00-4.99, P < 0.001) and NF-PNETs (HR 4.98, 95% CI 2.81-8.83, P < 0.001) was associated with worse OS.

CONCLUSIONS

LNM is potentially prevalent even in small and well-differentiated PNETs and is associated with worse prognosis. A watch-and-wait strategy for small NF-PNETs should be reappraised, and oncologic resection with lymphadenectomy can be considered. Prospective and controlled studies are needed in the future.

Impact of tumour size on metastasis and survival in patients with pancreatic neuroendocrine tumours (PNETs): A population based study

Background: The relationship between tumour size and metastasis rate is poorly recognized in patients with pancreatic neuroendocrine tumours (PNETs). The impact of tumour size on prognosis was controversial in previous investigations.

Methods: PNETs cases diagnosed from 1988 to 2013 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Clinicopathologic features were retrospectively analyzed. Survival was calculated by the Kaplan-Meier method. Multivariable Cox regression models with hazard ratios (HRs) were constructed to analyze survival outcomes and risk factors. Cubic spline analysis was used to assess relationship between tumor size and probability of metastasis.

Results: A total of 5424 patients were identified, 1226 (22.6%) with tumour size of 20mm or less. The probability of metastasis increased in a non-linear fashion with increasing tumour size. Univariate analysis showed that tumour size was significantly correlated with survival (P<0.001), no matter surgery was performed or not. However, subgroup analysis suggested this association to be linear for patients with localized and regional tumours (P<0.001), but stochastic in patients with distant stages (P=0.703). On multivariate analysis, tumour size was an indicator for metastasis (HR=1.010, 95%CI: 1.008-1.013, P<0.001) and size≤20mm was an independent prognostic factor for good survival. For tumours≤20mm, surgical treatment was associated with significantly improved survival (P<0.001).

Conclusions: Tumour size affects the probability of metastasis. Its prognostic impact on survival is restricted to patients with localized and regional disease. For patients with tumour size ≤20mm, surgical treatment should be considered preferably.

Predictive Value of Chromogranin A and a Pre-Operative Risk Score to Predict Recurrence After Resection of Pancreatic Neuroendocrine Tumors

INTRO

Chromogranin A (CgA) may be prognostic for patients with neuroendocrine tumors; however, the clinical utility of this test is unclear.

METHODS

Patients undergoing resection for pancreatic neuroendocrine tumors (pNET) were selected from the eight institutions of the US Neuroendocrine Tumor Study Group database. Cox regression was used to identify pre-operative variables that predicted recurrence-free survival (RFS), and those with p < 0.1 were included in a risk score. The risk score was tested in a unique subset of the overall cohort.

RESULTS

In the entire cohort of 287 patients, median follow-up time was 37 months, and 5-year RFS was 73%. Cox regression analysis identified four variables for inclusion in the risk score: CgA > 5x ULN (HR 4.3, p = 0.01), tumor grade 2/3 (HR 3.7, p = 0.01), resection for recurrent disease (HR 6.2, p < 0.01), and tumor size > 4 cm (HR 4.5, p = 0.1). Each variable was assigned 1 point. Risk-score testing in the unique validation cohort of 63 patients revealed a 95% negative predictive value for recurrence in patients with zero points.

DISCUSSION

This simple pre-operative risk scoring system resulted in a high degree of specificity for identifying patients at low-risk for tumor recurrence. This test can be utilized pre-operatively to aid informed decision-making.

Lymphadenectomy in pancreatic neuroendocrine neoplasms: Why are we still debating?

Pancreatic Neuroendocrine Neoplasms (PNEN) are rare tumours exhibiting very heterogeneous behaviour. For these reasons, studies with high level of evidence are lacking. Whether lymphadenectomy should be performed for PNEN is a matter of debate. In this review, we perform a critical analysis of the available literature regarding the clinical significance of lymphnode metastases, the importance of lymphadenectomy, and the implications on disease-specific survival.

Current Management of Pancreatic Neuroendocrine Tumors: From Demolitive Surgery to Observation

Incidental diagnosis of pancreatic neuroendocrine tumors (PanNETs) greatly increased in the last years. In particular, more frequent diagnosis of small PanNETs leads to many challenging clinical decisions. These tumors are mostly indolent, although a percentage (up to 39%) may reveal an aggressive behaviour despite the small size. Therefore, there is still no unanimity about the best management of tumor smaller than 2 cm. The risks of under/overtreatment should be carefully evaluated with the patient and balanced with the potential morbidities related to surgery. The importance of the Ki-67 index as a prognostic factor is still debated as well. Whenever technically feasible, parenchyma-sparing surgeries lead to the best chance of organ preservation. Lymphadenectomy seems to be another important prognostic issue and, according to recent findings, should be performed in noninsulinoma patients. In the case of enucleation of the lesion, a lymph nodal sampling should always be considered. The relatively recent introduction of minimally invasive techniques (robotic) is a valuable option to deal with these tumors. The current management of PanNETs is analysed throughout the many available published guidelines and evidences with the aim of helping clinicians in the difficult decision-making process.

Is radical surgery always curative in pancreatic neuroendocrine tumors? A cure model survival analysis

BACKGROUND

Adjuvant therapy after curative surgery for sporadic pancreatic neuroendocrine tumor (pNETs) is not currently recommended, assuming that all patients could be cured by a radical resection. The aim of our study is to establish how many and which kind of patients remained uncured after radical resection of pNET.

METHODS

Retrospective study involving 143 resected sporadic pNETs. The survival analysis was carried out using the cure model, describing the cure fraction and the excess of risk recurrence. Multivariate analyses were made in order to evaluate the non negligible effect of demographics, clinical and pathological factors on survival parameters. The results were reported as percentages, fractions, ORs and HRs with 95% confidence interval (95 CI %).

RESULTS

The cure fraction and the excess of hazard rate of the whole population were 57.1% (37.4-74.6, 95% CI) and 0.06 (0.03-0.07, 95% CI), respectively. Two independent factors were related to the cure fraction: TNM stage (OR 0.27 ± 0.17; P = 0.002) and grading (OR 0.11 ± 0.18; P = 0.004). Considering the excess of hazard rate, only two independent factors were related to an increased risk of recurrence: TNM stage (HR 3.49 ± 1.12; P = 0.004) and grading (HR 4.93 ± 1.82; P < 0.001).

CONCLUSION

The radical surgery has a high probability of cure in stages I-II or in grading 1 while, in stages III-IV or in grading 3 tumors, surgery alone failed to achieve a "cure". A multimodal treatment should be employed in order to avoid a recurrence of the disease.

Grading Using Ki-67 Index and Mitotic Rate Increases the Prognostic Accuracy of Pancreatic Neuroendocrine Tumors

OBJECTIVES

To measure the usefulness of Ki-67 proliferative index (Ki-67 index) as a prognostic variable for grading pancreatic neuroendocrine tumors.

METHODS

A multi-institutional prospective database comprising 350 patients. Grading based on mitotic activity (<2 mitoses/10 high-power fields, 2-20 and >20) and Ki-67 index (<3% per 10 high-power fields, 3%-20% and >20%). Final grade selected based on higher grade of either variable.

RESULTS

Most patients were in the less than 3% (n = 158) and 3% to 20% Ki-67 category (n = 107), with a minority being high-grade (Ki-67 > 20%, n = 27). Discordance between Ki-67 and mitotic rate was noted in 58 patients. On multivariate analysis, final-grade (grade 2: P = 0.010, hazard ratio [HR], 1.2; grade 3: P = 0.002; HR, 2.8), Ki-67, mitotic rate, and lymph node status were significant prognostic markers for overall survival (OS). For disease-free survival (DFS), only final-grade (grade 2: P = 0.05; HR, 1.4; grade 3: P = 0.009; HR, 2.3), Ki-67, mitotic rate, and margin status significantly predicted DFS. Ki-67 was a better model for OS and mitotic rate for DFS. Overall combined final grade was the best model based on HR.

CONCLUSION

Ki-67 is a strong prognostic factor for OS and DFS and should be included in all pancreatic neuroendocrine tumor pathology.

A Lymph Node Ratio-Based Staging Model Is Superior to the Current Staging System for Pancreatic Neuroendocrine Tumors

CONTEXT

The incidence of pancreatic neuroendocrine tumors (PNETs) is increasing. Current staging systems include nodal positivity, but the association of lymph node status and worse survival is controversial.

OBJECTIVE

The study aim was to determine the prognostic significance of lymph node ratio (LNR) and compare it with nodal positivity for PNET.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

A retrospective analysis of the Surveillance, Epidemiology, and End Results database between 2004 and 2011 was performed in patients who underwent a pancreatectomy with lymphadenectomy. The primary outcome was disease-specific survival (DSS).

RESULTS

Of the 896 patients analyzed, T stage, N stage, distant metastasis, grade, extent of resection, sex, and age ≥57 years were significantly associated with worse DSS on univariate analysis. On multivariate analysis, age ≥57 [hazard ratio (HR) 1.75, 95% confidence interval (CI), 1.12 to 2.74, P = 0.015], male sex (HR 1.58; 95% CI, 1.01 to 2.48; P = 0.046), grade (poorly differentiated/undifferentiated: HR 7.59; 95% CI, 4.71 to 12.23; P < 0.001), distant metastases (HR 2.45; 95% CI, 1.58 to 3.79; P < 0.001), and partial pancreatectomy (HR 2.55; 95% CI, 1.2 to 5.4; P = 0.015) were associated with worse DSS. Comparison between staging models constructed based on LNR cutoffs and the American Joint Committee on Cancer (AJCC) eighth edition staging system revealed that a model based on LNR ≥0.5 was superior.

CONCLUSIONS

LNR ≥0.5 is independently associated with worse DSS. A staging system with LNR ≥0.5 was superior to the current AJCC eighth edition staging system.

Intrinsic Contact Between T and N Classifications in Resected Well-Moderately Differentiated Locoregional Pancreatic Neuroendocrine Neoplasms

BACKGROUND

The role of N classification is controversial in several prognostication systems proposed for pancreatic neuroendocrine neoplasms (pNENs). The widely accepted modified European Neuroendocrine Tumor Society (mENETS) system suggests this contradiction may be related to T classification.

METHODS

Data were collected retrospectively from 981 patients in the Surveillance, Epidemiology, and End Results (SEER) database (1973-2012; cohort 1) and 140 patients from the Pancreatic Cancer Institute of Fudan University (2006-2016; cohort 2). All patients had resected well- to moderately differentiated locoregional pNENs, whereby the mENETS system was adopted. Factors related to N1 classification and the association between N and T classifications were analyzed, and N classification prognosis based on T classification was assessed.

RESULTS

In cohorts 1 and 2, tumor size (2-4 cm: p < 0.001 and p = 0.037, respectively; > 4 cm: p < 0.001 and p = 0.012, respectively) and tumors extending beyond the pancreas (p < 0.001 and p = 0.016, respectively), which are factors for T classification, affected N1 classification. For tumors limited to the pancreas, the N1 classification was associated with tumor size (p < 0.001 and p = 0.046, respectively) and predicted poor disease-specific survival (DSS), while for tumors extending beyond the pancreas, the N1 classification did not affect patient outcomes. Findings obtained with data from the SEER database were reproducible with our institutional data.

CONCLUSIONS

N classification is associated with T classification, limiting the value of N1 classification for the pNENs tumor-node-metastasis system. A new risk model is necessary to predict patient outcomes and guide clinical practice for the prognosis of pNENs.

Lymph node ratio, but not the total number of examined lymph nodes or lymph node metastasis, is a predictor of overall survival for pancreatic neuroendocrine neoplasms after surgical resection

Aim

To evaluate the prognostic significance of lymph node metastasis, extent of examined lymph nodes (ELNs) and lymph node ratio (LNR) for resected pancreatic neuroendocrine neoplasms (pNENs).

Materials and Methods

Surgically resected pNENs were assimilated from the Surveillance, Epidemiology, and End Results database. Kaplan-Meier and Cox proportional hazard models were used to examine the prognostic effect of clinicopathological characteristics on overall survival; Harrell's concordance index was performed to assess the prognostic accuracy of all independent prognostic factors; and the Spearman's rank correlation was used to assess the correlation between LNR and other clinicopathological characteristics.

Results

Totally, 1,273 pathologically confirmed pNENs were included in our study. The extent of ELNs failed to show any survival benefit in entire cohort (ELNs ≤ 12 vs. ELNs > 12, P = 0.072) or pNENs without lymph node metastasis (ELNs ≤ 28 vs. ELNs > 28, P = 0.108). Lymph node metastasis and LNR > 0.40 were significantly (both P < 0.001) adverse prognostic factors of overall survival. However, only LNR > 0.40 was the independent predictor of survival after adjusted for other clinicopathological characteristics. Besides LNR, the age, gender, primary tumor site, grade and stage also were the independent predictors of overall survival; and this survival model had an acceptable predictive power (Harrell's concordance index, 0.731).

Conclusions

The current study suggested that the LNR, not the total number of ELNs and the lymph node metastasis, is an independent prognostic indicator of overall survival for pNENs after surgical resection.

Is surgery the best treatment for sporadic small (≤2 cm) non-functioning pancreatic neuroendocrine tumours? A single centre experience

BACKGOUND

There is currently there is substantial controversy regarding the best management of non-functioning pancreatic neuroendocrine tumours ≤2 cm.

METHODS

Retrospective study involving 102 surgically treated patients affected by non-functioning pancreatic neuroendocrine tumours. Patients having small tumours (≤2 cm) (Group A) and those having large tumours (>2 cm) (Group B) were compared regarding demographics, clinical and pathological factors with the aim of evaluating the risk of malignancy and survival times.

RESULTS

The small tumours were T3-4 in 11% and G2-3 in 36.6% of cases; lymph node and distant metastases were present in 31% and 8% of the cases, respectively. When small and large tumours were compared, significant differences were found in relation to the presence of symptoms (P = 0.012), tumour status (P > 0.001), grading (P > 0.001) and years lost due to disability (P = 0.002). Multivariate analysis of the factors predicting malignancy and survival times showed that tumour size was related only to grading (P < 0.001). The years of life lost and disability adjusted life years were influenced by age at of diagnosis, the presence of symptoms and years lost due to disability only by grading.

CONCLUSIONS

Tumour size alone did not seem to be reliable in predicting malignancy because, first, small tumours (≤2 cm) could present lymph node or distant metastases, and could be G2-3 in a non-negligible percentage of cases and second, their risk of malignancy and survival time are similar to large tumours. Additional parameters have to be considered in order to establish the proper management of small tumours, such as age at diagnosis, presence of symptoms and grading.

Pathology and Surgical Treatment of High-Grade Pancreatic Neuroendocrine Carcinoma: an Evolving Landscape

Pancreatic neuroendocrine neoplasms (PNENs) are rare, accounting for less than 5% of all pancreatic tumors. High-grade pancreatic neuroendocrine carcinomas (hgPNECs) represent about 5% of all PNENs. They show highly aggressive behavior with dismal prognosis. Throughout the last two decades, there has been a notable progress in basic and clinical research of PNENs and a therapeutic trend towards both more aggressive and minimally invasive surgery. Despite these advances, hgPNECs as a distinct clinical entity remains largely unexplored among surgeons. This review of current development in pathology reporting and surgical treatment of hgPNECs aims at increasing the awareness of an evolving field in pancreatic surgery.

Prognostic factors for disease relapse in patients with neuroendocrine tumours who underwent curative surgery

AIM

Surgery is the only modality of cure in patients diagnosed with neuroendocrine tumours (NETs). The aim of this study was to identify prognostic factors associated with disease relapse in patients with NETs treated by potentially-curative surgery.

METHODS

Sequential patients registered in The Christie European NET Society (ENETS) Centre of Excellence, with grade (G)1 or G2 NETs who had undergone curative surgery (February 2002-June 2014) were included. Investigated prognostic factors for relapse were: age, gender, TNM stage, tumour-localisation, functionality, genetic predisposition, presence of multiple NETs, second malignancy, grade (Ki-67-based), presence of vascular and/or perineural invasion, necrosis, surgical margin (R0/R1), Eastern Cooperative Oncology Group performance status and Adult Comorbidity Evaluation co-morbidity score.

RESULTS

One hundred and eighty-eight patients were identified [median age of 60 years (range 16-89)]. With a median follow-up of 2.6 years, 43 relapses occurred. The estimated median relapse-free survival (RFS) for the entire cohort was 8.0 years (95% confidence interval [CI] 5.9-10.0 years). In univariate analysis, primary NET location (p = 0.01), ENETS T-(HR-1.4; 95%-CI 1.0-2.0, p = 0.026), N-(HR-2.0, 95%-CI 1.1-3.9, p = 0.026) and M-stage (HR-2.6, 95%-CI 1.1-6.3, p = 0.052), grade (Ki-67%-based) (HR-2.5; 95%-CI 1.4-4.7; p = 0.003) and perineural invasion (HR-2.1; 95%-CI 1.1-3.9; p = 0.029) were prognostic for relapse. Factors remaining significant after multivariable analysis were tumour size (HR-1.67; 95%-CI 1.04-2.70; p = 0.03), nodal involvement (HR-2.61; 95%-CI 1.17-5.83; p = 0.013) and Ki-67 at the time of diagnosis (HR-1.93; 95%-CI 1.24-3.0; p = 0.002).

CONCLUSION

Size of tumour, lymph node involvement and Ki-67 were independent prognostic factors for relapse after potentially curative surgery in NET.

Ki-67 prognostic and therapeutic decision driven marker for pancreatic neuroendocrine neoplasms (PNENs): A systematic review

BACKGROUND

We systematically evaluate the current evidence regarding Ki-67 as a prognostic factor in pancreatic neuroendocrine neoplasms to evaluate the differences of this marker in primary tumors and in distant metastases as well as the values of Ki-67 obtained by fine needle aspiration and by histology.

METHODS

The literature search was carried out using the MEDLINE/PubMed database, and only papers published in the last 10 years were selected.

RESULTS

The pancreatic tissue suitable for Ki-67 evaluation was obtained from surgical specimens in the majority of the studies. There was a concordance of 83% between preoperative and postoperative Ki-67 evaluation. Pooling the data of the studies which compared the Ki-67 values obtained in both cytological and surgical specimens, we found that they were not related. The assessment of Ki-67 was manual in the majority of the papers considered for this review. In order to eliminate manual counting, several imaging methods have been developed but none of them are routinely used at present. Twenty-two studies also explored the role of Ki-67 utilized as a prognostic marker for pancreatic neuroendocrine neoplasms and the majority of them showed that Ki-67 is a good prognostic marker of disease progression. Three studies explored the Ki-67 value in metastatic sites and one study demonstrated that, in metachronous and synchronous liver metastases, there was no significant variation in the index of proliferation.

CONCLUSIONS

Ki-67 is a reliable prognostic marker for pancreatic neuroendocrine neoplasms.

Validation of the 2010 WHO classification and a new prognostic proposal: A single centre retrospective study of well-differentiated pancreatic neuroendocrine tumours

BACKGOUND

In 2010, the World Health Organization (WHO) modified the classification for pancreatic neuroendocrine tumours (NETs). Recently, some modifications were proposed to improve its prognostic value. The aim of this study was to test the prognostic value of both the original and the modified 2010 WHO grading systems.

METHODS

One hundred and twenty consecutive patients surgically resected for well-differentiated NETs were evaluated in multivariate Cox regression models. Age, sex, hormonal status, size, lymph node ratio, stage, margin status and grading were evaluated in order to predict disease-free survival (DFS). Four models were evaluated: model 1: grading according to the 2010 WHO; model 2: modified grading with cut-off at 5% of the Ki-67 index; model 3: modified grading in which the G2 category was divided into two subgroups (2-5% and 5-20%) and model 4: the Ki-67 index as a continuous variable. Decision curve analysis (DCA) was carried out to evaluate the clinical utility of the various cut-offs.

RESULTS

All the grading systems remained independent factors in predicting DFS. Model 2 (c index = 0.814 and P = 0.012) and model 3 (c index = 0.865 and P = 0.015) showed higher predictive powers with respect to model 1 (c index = 0.799). Model 4 had a high predictive value (c index 0.848, P = 0.013). Decision curve analysis confirmed that biological behaviour represented the best prognostic parameter.

CONCLUSION

This study presented some limitations: single centre, retrospective design and a long period of enrolment. The result showed that, by increasing the cut-off of the G2 category to 5% or by creating two subgroups in the G2 category, it was possible to obtain a better stratification of patients.

Well-differentiated neuroendocrine neoplasia: relapse-free survival and predictors of recurrence after curative intended resections

BACKGROUND

Resection with curative intention is the cornerstone of treatment in patients with neuroendocrine tumors. A proportion of patients will relapse after R0 resection, but the factors predictive of recurrence are not well understood.

METHODS

A database established 1998 at the University Hospital Marburg was queried for all patients with documented R0 resection. Recurrence-free survival and overall survival were estimated using the Kaplan-Meier method. Uni- and multivariate analyses were performed.

RESULTS

180 patients with a median age of 52 years entered the analysis. We observed 77 recurrences after a median time of 2.9 years. 24% of the recurrences occurred later than 5 years after operation. Median recurrence-free survival of the whole cohort was 101 months. In univariate analysis grade by Ki-67, stage, high lymph node ratio and microangioinvasion were significant predictors of recurrence. On multivariate analysis these parameters were confirmed as independent prognostic parameters with stage and microangioinvasion being the most important predictors.

CONCLUSIONS

After R0 resection of neuroendocrine tumors, postoperative surveillance should be extended to at least 10 years. Patients with distant metastases and microangioinvasion are at high risk of recurrence. Clinical trials of adjuvant treatment protocols are indicated in these patients.