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

Chronological improvement of pancreatectomy for resectable but advanced pancreatic neuroendocrine neoplasms

BACKGROUND

Progress of non-surgical treatments in the last decade has improved the prognosis of pancreatic neuroendocrine neoplasms (PanNEN). However, the improvement of surgery for advanced PanNEN remains unknown. This study aimed to investigate the chronological changes of the clinical impact of pancreatectomy for PanNEN.

METHODS

Patients undergoing curative-intent pancreatectomy for PanNEN between 1991 and 2010 were categorized into the earlier period group, and those between 2011 and 2021 were into the later period group. Advanced PanNEN was defined as showing resectable synchronous liver metastases or invasion to portal venous systems or adjacent organs. The recurrence-free survival (RFS) and overall survival (OS) were analyzed among patients with non-advanced and advanced PanNENs. The independent prognostic risk factors were identified using a Cox proportional hazard model.

RESULTS

A total of 189 patients (n = 54 in the earlier period and n = 135 in the later period) were included. The proportion of advanced PanNEN increased from 15% to 30% (P = 0.027). The RFS and OS of non-advanced PanNEN were similar between the periods. Whereas, among patients with advanced PanNEN, the later period group showed improved prognosis; The 5-year RFS of the earlier period vs. the later period was 0% vs. 27%, and the 5-year OS was 38% vs. 82% (p = 0.013).

CONCLUSIONS

A radical surgical treatment for advanced PanNEN has shown prognostic improvement in this decade. However, more careful perioperative examinations and possibly, additional treatments are required for PanNEN with portal vein invasion.

The 3-Dimensional-Computed Tomography Texture Is Useful to Predict Pancreatic Neuroendocrine Tumor Grading

OBJECTIVES

The aim of this study is to evaluate the computed tomography texture parameters in predicting grading.

METHODS

This study analyzed 68 nonfunctioning pancreatic neuroendocrine neoplasms (Pan-NENs). Clinical and radiological parameters were studied. Four model models were built, including clinical and standard radiologic parameters (model 1), first- and second-order computed tomography features (models 2 and 3), all parameters (model 4). The diagnostic accuracy was reported as area under the curve. A score was computed using the best model and validated to predict progression-free survival.

RESULTS

The size of tumors and heterogeneous enhancement were related to the risk of "non-G1" Pan-NENs (coefficients 0.471, P = 0.012, and 1.508, P = 0.027). Four second-order parameters were significantly related to the presence of "non-G1" Pan-NENs: the gray level co-occurrence matrix correlation (6.771; P = 0.011), gray level co-occurrence matrix contrast variance (0.349; P = 0.009), the neighborhood gray-level different matrix contrast (-63.129; P = 0.001), and the gray-level zone length matrix with the low gray-level zone emphasis (-0.151; P = 0.049). Model 4 was the best, with a higher area under the curve (0.912; P = 0.005). The score obtained predicted the progression-free survival.

CONCLUSIONS

Computed tomography radiomics signature can be useful in preoperative workup.

County-Level Variation in Utilization of Surgical Resection for Early-Stage Hepatopancreatic Cancer Among Medicare Beneficiaries in the USA

INTRODUCTION

Geographic variations in access to care exist in the USA. We sought to characterize county-level disparities relative to access to surgery among patients with early-stage hepatopancreatic (HP) cancer.

METHODS

Data were extracted from the Surveillance, Epidemiology, and End Results (SEER)-Medicare Linked database from 2004 to 2015 to identify patients undergoing surgery for early-stage HP cancer . County-level information was acquired from the Area Health Resources Files (AHRF). Multivariable logistic regression analysis was performed to assess factors associated with utilization of HP surgery on the county level.

RESULTS

Among 13,639 patients who met inclusion criteria, 66.9% (n = 9125) were diagnosed with pancreatic cancer and 33.1% (n = 4514) of patients had liver cancer. Among patients diagnosed with early-stage liver and pancreas malignancy, two-thirds (n = 8878, 65%) underwent surgery. Marked county-level variation in the utilization of surgery was noted among patients with early-stage HP cancer ranging from 57.1% to more than 83.3% depending on which county a patient resided. After controlling for patient and tumor-related characteristics, counties with the highest quartile of patients living below the poverty level had 35% lower odds of receiving surgery for early stage HP cancer compared patients who lived in a county with the lowest proportion of patients below the poverty line (OR 0.65, 95% CI 0.55-0.77). In addition, patients residing in counties with the highest surgeon-to-population ratio (OR 2.01, 95% CI 1.52-2.65), as well as the highest hospital bed-to-population ratio (OR 1.29, 95% CI 1.07-1.54), were more likely to undergo surgical treatment for an early-stage HP malignancy.

CONCLUSION

Area-level variations among patients undergoing surgery for early-stage HP cancer were mainly due to differences in structural measures and county-level factors. Policies targeting high-poverty counties and improvement in structural measures may reduce variations in utilization of surgery among patients diagnosed with early-stage HP cancer.

Identifying Risk Factors and Patterns for Early Recurrence of Pancreatic Neuroendocrine Tumors: A Multi-Institutional Study

Simple Summary

Approximately 30% of patients with a pancreatic neuroendocrine tumor (pNET) will develop metastases. Curative-intent treatment largely involves resection. Identifying patients with early recurrence (ER) following resection might help tailor adjuvant therapies and the surveillance intensity. The aim of this retrospective study was to determine an evidence-based cut-off value for ER, and to explore risk factors associated with ER. ER was identified 18 months after surgery. Tumor size (OR 1.20, 95% CI 1.05–1.37, p = 0.007) and positive lymph nodes (OR 4.69, 95%CI 1.41–15.58, p = 0.01) were independently associated with ER. Patients with ER had lower post-recurrence free survival and overall survival than patients with late recurrence. These data support intensive follow-up shortly after surgery, and adjuvant therapy may help improve survival in pNET patients with ER after surgery.

Abstract

Background: Identifying patients at risk for early recurrence (ER) following resection for pancreatic neuroendocrine tumors (pNETs) might help to tailor adjuvant therapies and surveillance intensity in the post-operative setting. Methods: Patients undergoing surgical resection for pNETs between 1998–2018 were identified using a multi-institutional database. Using a minimum p-value approach, optimal cut-off value of recurrence-free survival (RFS) was determined based on the difference in post-recurrence survival (PRS). Risk factors for early recurrence were identified. Results: Among 807 patients who underwent curative-intent resection for pNETs, the optimal length of RFS to define ER was identified at 18 months (lowest p-value of 0.019). Median RFS was 11.0 months (95% 8.5–12.60) among ER patients (n = 49) versus 41.0 months (95% CI: 35.0–45.9) among non-ER patients (n = 77). Median PRS was worse among ER patients compared with non-ER patients (42.6 months vs. 81.5 months, p = 0.04). On multivariable analysis, tumor size (OR: 1.20, 95% CI: 1.05–1.37, p = 0.007) and positive lymph nodes (OR: 4.69, 95% CI: 1.41–15.58, p = 0.01) were independently associated with ER. Conclusion: An evidence-based cut-off value for ER after surgery for pNET was defined at 18 months. These data emphasized the importance of close follow-up in the first two years after surgery.

Prognostic Role of Examined and Positive Lymph Nodes after Distal Pancreatectomy for Non-Functioning Neuroendocrine Neoplasms

BACKGROUND

The most appropriate nodal staging system for non-functioning pancreatic neuroendocrine tumours (NF-PanNETs) remains unclear. Despite some evidence is available for pancreaticoduodenectomy, the adequate nodal staging is still unknown for distal pancreatectomy (DP). The aim of the present study was to evaluate the prognostic impact of the number of positive lymph nodes (PLNs) after DP for NF-PanNETs and to define the minimal number of lymph nodes to be harvested for an appropriate nodal staging.

METHODS

Data were retrospectively collected from patients who underwent DP with curative intent (R0-R1) for sporadic well-differentiated NF-PanNETs in 4 European high-volume centres. NF-PanNETs with nodal involvement (N+) were subclassified into N1 (1-3 PLNs) and N2 (4 or more PLNs). Univariate and multivariate analyses of disease-free survival (DFS) were performed.

RESULTS

Of 271 patients in the study, 62 (23%) had nodal involvement (N+). A higher probability of N+ was associated with the following factors: grading, resection margin status, perineural and microvascular invasion, and the number of examined lymph nodes. Three-year DFS rate for N0, N1, and N2 patients was 92, 72, and 50%, respectively (p < 0.001). At multivariate analysis, independent predictors of DFS were grading, T stage, presence of necrosis, and nodal status. For patients with ≥12 examined/resected lymph nodes, the N status remained a significant predictor of disease recurrence (p < 0.001), while it failed to predict recurrence in patients with <12 lymph nodes examined/resected (p = 0.116).

CONCLUSIONS

A minimal number of 12 nodes should be harvested in case of DP for NF-PanNET for an appropriate nodal staging. The number of positive lymph nodes is an independent predictor of DFS after DP for NF-PanNET, and the N0/N1/N2 nodal classification seems to be more relevant than the current N0/N+ staging.

Tumor burden score predicts tumor recurrence of non-functional pancreatic neuroendocrine tumors after curative resection

BACKGROUND

To investigate the feasibility of Tumor Burden Score (TBS) to predict tumor recurrence following curative-intent resection of non-functional pancreatic neuroendocrine tumors (NF-pNETs).

METHOD

The TBS cut-off values were determined by a statistical tool, X-tile. The influence of TBS on recurrence-free survival (RFS) was examined.

RESULTS

Among 842 NF-pNETs patients, there was an incremental worsening of RFS as the TBS increased (5-year RFS, low, medium, and high TBS: 92.0%, 73.3%, and 59.3%, respectively; P < 0.001). TBS (AUC 0.74) out-performed both maximum tumor size (AUC 0.65) and number of tumors (AUC 0.5) to predict RFS (TBS vs. maximum tumor size, p = 0.05; TBS vs. number of tumors, p < 0.01). The impact of margin (low TBS: R0 80.4% vs. R1 71.9%, p = 0.01 vs. medium TBS: R0 55.8% vs. R1 37.5%, p = 0.67 vs. high TBS: R0 31.9% vs. R1 12.0%, p = 0.11) and nodal (5-year RFS, low TBS: N0 94.9% vs. N1 68.4%, p < 0.01 vs. medium TBS: N0 81.8% vs. N1 55.4%, p < 0.01 vs. high TBS: N0 58.0% vs. N1 54.2%, p = 0.15) status on 5-year RFS outcomes disappeared among patients who had higher TBS.

CONCLUSIONS

TBS was strongly associated with risk of recurrence and outperformed both tumor size and number alone.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

A cure model survival analysis of patients affected by small intestinal neuroendocrine neoplasms: the Bologna ENETS center experience

PURPOSE

The primary end-point was to evaluate the cure fraction. Secondary end-points were to investigate the time to cure, the excess of death risk, the probability of cure and the factors related to these parameters.

METHODS

Retrospective study of an ENETS database regarding patients affected by Si-NENs. For each patients, clinical, pathological and follow-up data were collected. The survival analysis was made using a novel approach: the cure model approach.

RESULTS

The cure fraction was 92.1%. The death risk, time to cure and the probability of cure were 6/1000 person-years, 3.6 years and 98.2%, respectively. The independent factors influencing these parameters were the grading and the R status (P = 0.041 and P = 0.017, respectively). Patients affected by Si-NENs G2 increased the death risk and time to cure respect to Si-NENs G1 (51 versus 6 per 1000 person-years and 5.1 versus 3.6 years, respectively) as well as patients not operated respect to those radically resected (R0/1) (66 versus 1 per 1000 person-years and 4.8 versus 0.4 years, respectively). The probability of cure decreased (88.1 versus 97.8% and 80.4 versus 99.7%, respectively). R2 resection shows better results than no resection.

CONCLUSIONS

A large portion of patients affected by Si-NENs can be cured. The highest probability of cure regards patients with Si-NENs G1 who underwent to R0/R1 resection; the lower, those with Si-NENs G2 and no resection. R2 resection seems to be preferred respect to no resection.

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.