Indications and outcomes of enucleation versus formal pancreatectomy for pancreatic neuroendocrine tumors

Incidence and Prognostic Implications of Lymphovascular Invasion in Node-Negative Pancreatic Neuroendocrine Tumors: Results From the US Neuroendocrine Study Group

BACKGROUND

Despite the well-known prognostic role of lymph node metastasis (LNM) in pNETs, less is known about the importance of lymphovascular invasion (LVI) among patients with these tumors.

METHODS

Patients undergoing pancreatectomy for pNET between 2002 and 2020 were identified in the US Neuroendocrine Tumor Study Group database. Cox regression analysis was utilized to identify the impact of LVI on recurrence-free survival (RFS) among patients with node-negative pNET.

RESULTS

Among 853 patients who underwent resection for pNET, 214 patients (25.1%) had LNM, while 116 (13.6%) and 523 individuals (61.3%) were LVI + N0 and LVI - N0, respectively. The overall incidence of LVI among patients with N0 pNET was 18.1%; the incidence of LVI increased with increasing tumor size and Ki-67 levels (size < 2 cm and Ki-67 < 3%: 5.5%; size < 2 cm and Ki-67 ≥ 3%: 17.2%; size ≥ 2 cm and Ki-67 < 3%: 22.2%; size ≥ 2 cm and Ki-67 ≥ 3%: 43.1%, p < 0.001). Five-year RFS was highest among patients with LVI - N0 disease followed by individuals with LVI + N0 and N+ pNETs (92.8% vs. 61.6% vs. 58.3%, p < 0.001). On multivariable analysis, the presence of LVI on pathology remained independently associated with almost 2.5 times higher hazards of recurrence (HR 2.47, 05% CI 1.44-4.24) among individuals with N0 pNETs.

CONCLUSION

The incidence of LVI varied according to tumor size and Ki-67. LVI was associated with a higher likelihood of recurrence among individuals who underwent formal pancreatic resection for N0 pNETs. LVI is an important prognostic indicator among patients with node-negative pNETs.

Enucleation for Sporadic Nonfunctioning Pancreatic Neuroendocrine Tumors Larger than 2 Centimeters Is Associated with Equivalent Morbidity and Survival Compared to Smaller Tumors: A Multi-Institutional Study

INTRODUCTION

Nonfunctioning pancreatic neuroendocrine tumor (NF-PanNET) ≤2 cm can be observed or resected. Surgery remains recommended for NF-PanNET >2 cm but its extent, enucleation (EN) versus formal resection, remains controversial.

METHODS

Multicentric retrospective cohort of sporadic NF-PanNET patients treated with EN. Short- and long-term outcomes were compared according to tumor size on imaging ≤2 cm versus >2 cm.

RESULTS

131 patients underwent EN for NF-PanNET, including 103 (79.0%) ≤2 cm and 28 (21.0%) >2 cm (extremes, 4-55 mm). Patients' characteristics were comparable, and tumor characteristics only differed in their diameter. Clavien III-IV complications were similar (18.4% vs. 17.9%, p = 1.00) with one death in NF-PanNET ≤2 cm. Grade B/C pancreatic fistula were comparable (16.5% vs. 10.7%, p = 0.850). In NF-PanNET >2 cm there were more pT2/3 stage tumors (85.7% vs. 21.4%, p < 0.001), similar rates of grade G2/3 tumors (25% vs. 16.5%, p = 0.408) with a median Ki67 of 2 (interquartile range: 1-3), and of lymphovascular and perineural invasions. Lymph node picking was done in 46 (35.1%) patients, with a higher median number of harvested lymph nodes in NF-PanNET >2 cm (4 vs. 3, p = 0.01). All were pN0. R0 resection rate (78.6% vs. 82.5%, respectively; p = 0.670) was equivalent. Five-year overall (100% vs. 99%, p = 0.602) and 10-year disease-free (96% vs. 92%, respectively; p = 0.532) survivals were comparable.

CONCLUSIONS

EN for selected NF-PanNET >2 cm carries equivalent morbidity, overall and disease-free survivals compared to those observed with NF-PanNET ≤2 cm.

Solid Pseudopapillary Tumor of the Pancreas: Is Enucleation Safe?

BACKGROUND

While solid pseudopapillary tumor (SPT) of the pancreas are oncologically low-risk tumors, their resection with pancreaticoduodenectomy (PD) or partial pancreatectomy (PP) carries a significant risk for morbidity. To balance the favorable prognosis with the surgical morbidity of pancreas resection, this study explores the oncologic safety of enucleation (EN).

PATIENTS AND METHODS

The National Cancer Database (NCDB) was queried for resected SPT from January 2004 through December 2020. Perioperative outcomes and survival were analyzed with Kruskal-Wallis tests, and Kaplan-Meier analysis (with log-rank test). Survival analysis was performed to compare patients with and without lymph node (LN) metastases and binary logistic regression for predictors of LN metastasis.

RESULTS

A total of 922 patients met inclusion criteria; 18 patients (2%) underwent EN, 550 (59.6%) underwent PP, and 354 (38.4%) underwent PD. Mean tumor size was 57.6 mm. Length of hospital stay was significantly shorter for EN compared with PP and PD groups (3.8 versus 6.2 versus 9.4 days, p < 0.001). There was a nonsignificant improvement in unplanned readmission [0% versus 8% versus 10.7% (p = 0.163)], 30-day mortality [0% versus 0.5% versus 0% (p = 0.359)], and 90-day mortality [0% versus 0.5% versus 0% (p = 0.363)] between EN, PP, and PD groups. Survival analyses showed no difference in OS when comparing EN versus PP (p = 0.443), and EN versus PD (p = 0317). Patients with LN metastases (p < 0.001) fared worse, and lymphovascular invasion, higher T category (T3-4) and M1 status were found as predictors for LN metastasis.

CONCLUSIONS

EN may be considered for select patients leading to favorable outcomes. Because survival was worse in the rare cohort of patients with LN metastases, the predictors for LN metastasis identified here may aid in stratifying patients to EN versus resection.

Approach to the Patient: Insulinoma

Insulinomas are hormone-producing pancreatic neuroendocrine neoplasms with an estimated incidence of 1 to 4 cases per million per year. Extrapancreatic insulinomas are extremely rare. Most insulinomas present with the Whipple triad: (1) symptoms, signs, or both consistent with hypoglycemia; (2) a low plasma glucose measured at the time of the symptoms and signs; and (3) relief of symptoms and signs when the glucose is raised to normal. Nonmetastatic insulinomas are nowadays referred to as "indolent" and metastatic insulinomas as "aggressive." The 5-year survival of patients with an indolent insulinoma has been reported to be 94% to 100%; for patients with an aggressive insulinoma, this amounts to 24% to 67%. Five percent to 10% of insulinomas are associated with the multiple endocrine neoplasia type 1 syndrome. Localization of the insulinoma and exclusion or confirmation of metastatic disease by computed tomography is followed by endoscopic ultrasound or magnetic resonance imaging for indolent, localized insulinomas. Glucagon-like peptide 1 receptor positron emission tomography/computed tomography or positron emission tomography/magnetic resonance imaging is a highly sensitive localization technique for seemingly occult, indolent, localized insulinomas. Supportive measures and somatostatin receptor ligands can be used for to control hypoglycemia. For single solitary insulinomas, curative surgical excision remains the treatment of choice. In aggressive malignant cases, debulking procedures, somatostatin receptor ligands, peptide receptor radionuclide therapy, everolimus, sunitinib, and cytotoxic chemotherapy can be valuable options.

Ethanol Ablation for Benign Insulinoma: Intraoperative and Endoscopic Approaches

INTRODUCTION

Ethanol ablation can be utilized to manage insulinoma. We aimed to analyze our outcomes of endoscopic ultrasound (EUS) and intraoperative ultrasound (IOUS) guided Ethanol ablation of insulinoma.

METHODS

A single institution retrospective review of adults undergoing Ethanol ablation of benign pancreatic insulinoma (2007-2022) was performed. Outcomes were categorized as resolution of hypoglycemia, improvement, or no change at last follow-up.

RESULTS

A total of 16 patients underwent Ethanol ablation of benign insulinoma (N = 8 EUS, N = 8 IOUS): median age was 68 y, 8 (50%) were females, and 2 (12.5%) were associated with multiple endocrine neoplasia type-1. Median insulinoma size was 12 (range 7, 25) mm. Ethanol ablation was preferred over resection to avoid pancreaticoduodenectomy when it was not possible to enucleate the tumor in 10 (62.5%) patients while the rest underwent ablation due to being poor surgical candidates or because of a history of previous pancreatic resection. The median follow-up (interquartile range) was 43 (19.5, 81.5) mo. Resolution of hypoglycemia occurred in 11 patients (5 EUS, 6 IOUS), while the rest (3 EUS, 2 IOUS) experienced improvement in the severity and frequency of hypoglycemia. A single patient underwent resection following a previous ablation for symptomatic hypoglycemia 5 y after EUS guided ablation.

CONCLUSIONS

Ethanol ablation provides an alternative therapeutic option for patients with insulinoma. Both EUS and IOUS guided approaches are associated with a favorable resolution rate although EUS guided ablation may require multiple procedures to optimize outcomes.

Robotic enucleation & uncinectomy of complex lesions of the proximal pancreas

BACKGROUND

Malignant tumours within the proximal pancreas traditionally require pancreaticoduodenectomy (PD) for cure. For smaller lesions with borderline malignant potential the risk/benefit of PD becomes difficult to justify. Robotic approaches to these lesions allow for parenchymal preserving resection with reduced complication profile without oncological compromise.

METHODS

A review of a single surgeons prospectively collated database across two institutions of consecutive robotic enucleations or parenchyma preserving resections of the proximal pancreas was performed between July 2018 and October 2021. Standard demographic data, preoperative variables, intraoperative parameters, post-operative outcomes, morbidity and mortality were recorded.

RESULTS

Thirteen patients (8 female and 5 male) underwent robotic enucleation (EN) (8) and/or uncinectomy (UN) (5) in the proximal pancreas. Mean BMI was 32(kg/m2 ). Three patients (21%) underwent preoperative prophylactic pancreatic duct stenting. One patient required conversion to open. The median operative time in the EN group was 170 min (108-224 min) and the UN group was 160 min (110-204 min). The majority (8) of lesions were pNETs. Three lesions were IPMNs, with 1 solitary fibrous tumour and a serous cystic neoplasm (SCN) respectively. Median tumour size was 23 mm (11-58 mm) in the EN group, and 27 mm (17-38 mm) in the UN group. Ten of 13 patients had an R0 resection. There was no mortality in our series. Four (31%) patients across both groups developed clinically relevant POPF while none developed new endocrine or exocrine insufficiency. Average outpatient follow-up has been 6 months (1-18 months).

CONCLUSION

A robotic approach in proximal parenchymal preserving pancreatectomy is expanding, safe and feasible.

Effects of accelerated biological age on depressive symptoms in a causal reasoning framework

BACKGROUND

Depression in middle-aged and elderly individuals is multifaceted and heterogeneous, linked to biological age (BA) based on aging-related biomarkers. However, due to confounding with chronological age and the absence of subgroup analysis and causal reasoning, the association between BA and depressive symptoms (DS) might be unstable and requires further investigation.

METHODS

We utilized data from the China Health and Retirement Longitudinal Study (N = 9478) to perform association analysis, causal inference, and subgroup analysis. BA acceleration (BAA) was derived using machine learning and adjusted for chronological age. A generalized linear mixed-effects model (GLMM) tree algorithm was employed to identify subgroups. The causal reasoning frame included propensity score matching and fast large-scale almost matching exactly.

RESULTS

In the longitudinal analysis, BAA exhibited a consistent and significant positive association with DS, even after controlling for demographic characteristics, lifestyle factors, health status, and physical functions. This association remained unchanged within the causal framework. GLMM tree analysis identified three partitioning variables (sex, satisfaction, and BMI) and five subgroups. Further subgroup analysis revealed that BAA exerted the strongest effect on DS among women with less satisfying lives.

LIMITATIONS

Depressive symptoms were evaluated through scale measurements rather than clinical diagnosis. The sample was derived from the general population, not the clinically depressed population.

CONCLUSIONS

This study provided the first longitudinal evidence that biological age acceleration increases depressive symptoms under causal reasoning and subgroup analysis, particularly among less satisfied women. And the association between BAA and DS was independent of known risk factors.

Management Dilemma: Is Enucleation With Lymphadenectomy a Viable Choice for Large Pancreatic Neuroendocrine Tumors (p-NETs)?

Managing pancreatic neuroendocrine tumors (pNETs) has gradually taken a trend toward conservative management owing to its slow-growing and prolonged course. Though clear criteria exist regarding managing small tumors, the direction of a large tumor remains a dilemma. We present a case of a young 26-year-old lactating woman with a large 3.4 cm × 3.2 cm mass in the uncinate process, which is adjacent to the inferior vena cava (IVC) and has flimsy adhesions to the duodenum. She also had an enhancing adjacent lymph node measuring 1.2 cm × 0.7 cm, which showed enhancement with Ga-68 DOTANOC positron emission tomography/computed tomography (PET/CT) and raised serum gastrin levels. The dilemma was between pancreaticoduodenectomy (PD) or enucleation with lymphadenectomy (EL). Finally, EL was conducted. We discussed this case with relevant studies, which we had referred to because large-sized tumors are not usually enucleated.

Minimally-invasive versus open pancreatic enucleation: systematic review and metanalysis of short-term outcomes

BACKGROUND

Minimally Invasive Pancreatic Enucleation, either laparoscopic or robot-assisted, is rarely performed. The aim of this study was to offer the current available evidence about the outcomes of minimally invasive pancreatic enucleations and explore the possible advantage of this approach over traditional surgery.

METHODS

PubMed (MEDLINE), Cochrane Library and Embase (ELSEVIER) medical databases were searched for articles published from January 1990 to March 2022. Studies which included more than 10 cases of minimally-invasive pancreatic enucleation were included. Data on the outcomes were synthetized and meta-analyzed when appropriate.

RESULTS

Twenty studies published between 2009 and 2022 with a total of 552 patients were included in the systematic review: three hundred fifty-one patients (63.5%) had a laparoscopic intervention, two hundred and one (36.5%) robot-assisted with a cumulative incidence of conversion rate of 5%. Minimally-invasive surgery was performed in 63% of cases on the body/tail of the Pancreas and in 37% of the cases on the head/uncinate process of the Pancreas. The cumulative post-operative 30 days - mortality rate was 0.2% and the major postoperative morbidity (Clavien-Dindo III-IV-V) 35%. Clinically relevant pancreatic fistula was observed in 17% of the patients. Compared with the standardized open approach (n: 366 patients), mean length of hospital stay was significantly reduced in patients undergoing minimally invasive pancreatic enucleation (2.45 days, p = 0.003) with a favorable trend for post-operative major morbidity (Clavien-Dindo III-IV) (- 24% RR, p: 0.13). Operative time, blood loss and clinically relevant pancreatic fistula rate were comparable between the two groups. One hundred and fourteen robot-assisted enucleations entered in a subgroup analysis with comparable results to open surgery.

CONCLUSION

Minimally-Invasive approach for pancreatic enucleation is safe, feasible and offers short-term clinical outcomes comparable with open surgery. The potential benefit of robotic surgery will need to be verified in further studies.

[Enucleation of pancreatic tumors: a multiple-center study]

OBJECTIVE

To evaluate the immediate results of enucleation of pancreatic neuroendocrine tumors (pNETs).

MATERIAL AND METHODS

The results of enucleation of pancreatic neuroendocrine tumors (pNETs) were analyzed in 95 patients between 2016 and 2021. Functioning tumors (mean size 16.8 mm) were found in 70 patients, non-functioning (mean size 25 mm) - in 25 patients. Intraparenchymal tumors were found in 48 people, extraorganic lesion - in 47 patients.

RESULTS

There were 262 patients with pNETs who underwent various surgeries between 2016 and 2021. Various resections were performed in 167 (63.8%) cases, enucleations - in 95 (36.2%) patients. Traditional surgical approach was used in 65 patients. Pancreatic fistula occurred in 21 patients (type B - 17, type C - 4), while arrosive bleeding occurred in 6 patients with unfavorable outcomes in 2 cases. Minimally invasive surgeries were performed in 30 patients. Eight patients with intraparenchymal tumors required conversion to open surgery. Type B pancreatic fistula occurred in 5 patients that led to arrosive bleeding in 2 cases (hemostasis was provided by endovascular method). Comparison of intraparenchymal and extraorgan tumors regarding the incidence of pancreatic fistula revealed odds ratio 5.26 (95% CI 1.5355; 18.0323, p=0.0041). Postoperative mortality was 2.1%.

CONCLUSION

Enucleation is advisable for highly differentiated pancreatic neuroendocrine tumors up to 2 cm. Minimally invasive enucleation is indicated for extraorgan tumors. Intraparenchymal tumors significantly increase the risk of postoperative complications.

Laparoscopic pancreatic enucleation: cystic lesions and proximity to the Wirsung duct increase postoperative pancreatic fistula

BACKGROUND

Risk factors for postoperative pancreatic fistula (POPF) following pancreatic enucleation by the open approach (OpenEN) are well known. However, ENs are more frequently performed laparoscopically (LapEN). The aim of this study was to analyze the risk factors of POPF following LapEN.

METHODS AND PATIENTS

All patients in our prospective database who underwent LapEN were evaluated. We report the demographics, surgical, early and long-term outcomes. Numerous variables were analyzed to identify the risk factors of POPF.

RESULTS

From 2008 to 2020, 650 laparoscopic pancreatic resections were performed including 64 EN (10%). The median age was 51 years old (17-79), median BMI was 24 (19-48), and 44 patients were women (69%). The main presentation was an incidental diagnosis (n = 40; 62%), pain (n= 10;16%), and hypoglycemia (n = 8;12%). The main indications were neuroendocrine tumors (40; 63%), mucinous cystadenomas (15; 23%), intraductal papillary mucinous neoplasie (3; 5%), and other benign cysts (6; 9%). Lesions were located on the distal pancreas (43; 67%), head (n = 17; 27%), and neck (4; 6%). The median size was 20 mm (9-110); 30 mm (20-110) for mucinous cystadenoma and 18 mm (8-33) for NET. The median operative time was 90 mn (30-330), median blood loss was 20 ml (0-800) ml, and there were no transfusions and one conversion. There were no mortalities and overall morbidity (n = 22; 34%) included grades B and C POPF (10;16%) and post-pancreatectomy hemorrhage (4; 6%). The median hospital stay was 7 days (3-42). There were no invaded lymph nodes and all cystic lesions were nonmalignant. After a mean follow-up of 24 months, there was no recurrence. The risk factors for grades B/C POPF were mucinous cystadenoma and proximity to the Wirsung duct < 3 mm.

CONCLUSION

In this series, the outcome of LapEN was excellent with no mortality and a low rate of morbidity. However, the risk of POPF is increased with cystic lesions and those close to the Wirsung duct.

Lymph node metastases and recurrence in pancreatic neuroendocrine neoplasms

BACKGROUND

The impact of lymph node metastasis on survival in pancreatic neuroendocrine neoplasms as well as their best surgical treatment is controversial. We aimed to determine the frequency and prognostic impact of lymph node involvement in pancreatic neuroendocrine neoplasms.

METHODS

Patients undergoing pancreatic resections for pancreatic neuroendocrine neoplasms between 2001 and 2019 were retrospectively analyzed based on a prospective database. Clinicopathological parameters and perioperative outcome were assessed. Overall and disease-free survival was analyzed. Subgroup analysis was performed for sporadic, nonfunctional pancreatic neuroendocrine neoplasms without distant metastases and ≥4 analyzed lymph nodes.

RESULTS

Of 605 surgically resected pancreatic neuroendocrine neoplasms, 55% were G1, 36% were G2, and 9% were G3 differentiated. At the time of resection, 34% of patients had lymph node metastasis, and 16% had distant metastases. For subgroup analysis, 314 patients were analyzed. Lymph node metastases occurred in 36% of patients and were most frequent in G3 patients (67%). An increase in tumor size and advancement was associated with higher rates of lymph node metastasis, and disease-free survival was significantly impaired. Significant differences in disease-free survival were observed between 1 and 3 (5-year disease-free survival 52%) and ≥4 positive lymph nodes (5-year disease-free survival 28%), as well as when G3 tumors were excluded. In multivariable analysis, grading, tumor stage, and especially lymph node metastases as well as the proposed pN1 and pN2 categories were confirmed as independent predictors of recurrence.

CONCLUSION

The presence and extent of lymph node involvement has considerable prognostic impact in pancreatic neuroendocrine neoplasms. This study, for the first time, validated the proposed pN2 stage for well-differentiated pancreatic neuroendocrine neoplasms.

Robotic parenchymal-sparing pancreatectomy and pancreas-sparing duodenectomy avoid pancreaticoduodenectomy for benign and low-grade malignant tumours

BACKGROUND

Parenchymal-sparing pancreatectomy (PSP) or pancreas-sparing duodenectomy (PSD) is an alternative method for patients with benign or low-grade malignant tumours at the pancreatic head or duodenum. It avoids traumatic pancreaticoduodenectomy (PD) with pancreatic function preservation and improves quality of life. However, few studies have reported on robotic PSP (RPSP) or robotic PSD (RPSD).

METHODS

A retrospective analysis of 17 patients with benign and low-grade malignant pancreatic head and duodenal tumours who underwent RPSP or RPSD from January 2018 to February 2022 was conducted. The demographic, perioperative, and postoperative data of all patients were collected and analysed.

RESULTS

The operations were successful for all seventeen patients without conversion, including 10 cases of RPSP and 7 cases of RPSD. For RPSP, eight patients underwent pancreatic enucleation, and two patients underwent uncinate process resection. For RPSD, five patients underwent local duodenectomy, and two patients underwent segmental duodenectomy, with five simultaneous jejunostomies and two distal gastrectomies. The median OT and EBL were 135 min and 50 mL for RPSP and 220 min and 100 mL for RPSD, respectively. The median LOS was 8 days for RPSP and 19 days for RPSD. The main postoperative complications for RPSP included POPF (grade B, 6 cases), DGE (grade B, 1 case), PPH (1 case), and intra-abdominal infection (1 case). The main postoperative complications for RPSD included DGE (grade B, 1 case, grade C, 3 cases), postoperative haemorrhage (1 case), intra-abdominal infection (1 case), and duodenal fistula (1 case). One patient underwent interventional drain placement after RPSP because of POPF.

CONCLUSION

RPSP or RPSD is feasible for highly selected patients with benign and low-grade malignant pancreatic head and duodenal tumours, avoiding potential pancreaticoduodenectomy.

Evaluation of Risk Factors for Distant and Lymph Node Metastasis of Pancreatic Neuroendocrine Tumors

Purpose

Metastases of pancreatic neuroendocrine tumors (pNETs) can be found at the time of diagnosis in 20–50% of cases. Small asymptomatic tumors may be left for observation; however, they can metastasize. The aim of the study was to evaluate risk factors for distant and lymph node metastases of pNETs.

Patients and methods

One hundred and fourteen patients with postoperatively confirmed pNET were analyzed retrospectively in a single ENETS Center of Excellence. The relationship between location, size, differentiation of the tumor, and occurrence of lymph node and distant metastases was analyzed.

Results

pNETs’ location was pancreatic head – 38 (33.3%), body or tail – 68 (59.7%), and 8 (7.0%) involved the entire organ. Fifty-six (49.1%) tumors were graded G1, 50 (43.9%) G2, and 8 (7.0%) G3. Seventy-two (63.2%) tumors were ≥2 cm in diameter, and 42 (36.8%) <2 cm. Twenty-two (19.3%) patients had distant metastases and 47 (41.2%) had lymph node metastases. In ≥2 cm tumors distant and lymph node metastases were more frequent (p < 0.05). Distant metastases incidence was significantly higher in distally located tumors (p = 0.01) and in G2 and G3 tumors (p < 0.01). In 9.5% of <2cm tumors, distant metastases were present at diagnosis.

Conclusion

Distant metastases are more often found in larger, distally located pNETs grade G2 and G3, while a higher occurrence of lymph node metastases seems to be associated only with larger tumor size. A considerable number of tumors <2 cm in size have distant metastases already at the diagnosis, which might indicate the need for careful qualification of smaller lesions for observation.

Enucleation Is a Feasible Procedure for Well-Differentiated pNEN-A Matched Pair Analysis

The extent of surgical resection in the treatment of pancreatic neuroendocrine neoplasms (pNEN) is still controversial. This study aimed to evaluate the outcomes of enucleation for well-differentiated non-functional (nf) pNEN. Patients undergoing enucleation (2001−2020) were analyzed. Clinicopathological parameters, perioperative outcomes and survival were assessed. The analysis was performed as a nested case-control study and matched-pair analysis with formal resection. Sixty-one patients undergoing enucleation were identified. Compared to patients undergoing formal resection, enucleation was associated with a significantly shorter median length of operative time (128 (IQR 95−170) versus 263 (172−337) minutes, p < 0.0001) and a significantly lower rate of postoperative diabetes (2% versus 21%, p = 0.0020). There was no significant difference in postoperative pancreatic fistula rate (18% versus 16% type B/C, p = 1.0), Clavien−Dindo ≥ III complications (20% versus 26%, p = 0.5189), readmission rate (12% versus 15%, p = 0.6022) or length of hospital stay (8 (7−11) versus 10 (8−17) days, p = 0.0652). There was no 30-day mortality after enucleation compared to 1.6% (n = 1) after formal resection. 10-year overall survival (OS) and disease-free survival (DFS) was similar between the two groups (OS: 89% versus 77%, p = 0.2756; DFS: 98% versus 91%, p = 0.0873). Enucleation presents a safe surgical approach for well-differentiated nf-pNEN with good long-term outcomes for selected patients.

Comparison of Outcomes of Enucleation vs. Standard Surgical Resection for Pancreatic Neoplasms: A Systematic Review and Meta-Analysis

Background

With advancement in health technology, the detection rate of pancreatic neoplasms is increasing. Tissue sparing surgery (enucleation) as well as standard surgical resection are two commonly used modalities of management. There are studies comparing clinical outcomes between these two modalities; however, there is lack of studies that systematically pool the available findings to present conclusive and reliable evidence.

Methods

A systematic search was conducted using the PubMed, Scopus, and Google Scholar databases. Studies that were randomised controlled trials or cohort based or analysed retrospective data were considered for inclusion. Studies should have been done in adult patients with pancreatic neoplasms and should have examined the outcomes of interest by the two management modalities i.e., enucleation and standard surgical resection. Statistical analysis was performed using STATA software.

Results

A total of 20 studies were included in the meta-analysis. The operation time (in minutes) (WMD −78.20; 95% CI: −89.47, −66.93) and blood loss (in ml) (WMD −204.30; 95% CI: −281.70, −126.90) for enucleation was significantly lesser than standard surgical resection. The risk of endocrine (RR 0.32; 95% CI: 0.18, 0.56) and exocrine insufficiency (RR 0.16; 95% CI: 0.07, 0.34) was lower whereas the risk of post-operative pancreatic fistula (RR 1.46; 95% CI: 1.22, 1.75) was higher in enucleation, compared to standard surgical resection group. There were no differences in the risk of reoperation, readmission, recurrence, mortality within 90 days and 5-years overall mortality between the two groups.

Conclusions

Enucleation, compared to standard surgical resection, was associated with better clinical outcomes and therefore, might be considered for selected pancreatic neoplasms. There is a need for randomised controlled trials to document the efficacy of these two management techniques.

Resection of Non-Functional Pancreatic Neuroendocrine Neoplasms-A Single-Center Retrospective Outcome Analysis

Surgery remains the only curative treatment of pancreatic neuroendocrine neoplasms (pNEN). Here, we report the outcome after surgery for non-functional pNEN at a European Neuroendocrine Tumor Society (ENETS) center in Germany between 2000 and 2019; cases were analyzed for surgical (Clavien–Dindo classification; CDc) and oncological outcomes. Forty-nine patients (tumor grading G1 n = 25, G2 n = 22, G3 n = 2), with a median age of 56 years, were included. Severe complications (CDc ≥ grade 3b) occurred in 11 patients (22.4%) and type B/C pancreatic fistulas (POPFs) occurred in 5 patients (10.2%); in-hospital mortality was 2% (n = 1). Six of seven patients with tumor recurrence (14.3%) had G2 tumors in the pancreatic body/tail. The median survival was 5.7 years (68 months; [1–228 months]). Neither the occurrence (p = 0.683) nor the severity of complications had an influence on the relapse behavior (p = 0.086). This also applied for a POPF (≥B, p = 0.609). G2 pNEN patients (n = 22) with and without tumor recurrence had similar median tumor sizes (4 cm and 3.9 cm, respectively). Five of the six relapsed G2 patients (83.3%) had tumor-positive lymph nodes (N+); all G2 pNEN patients with recurrence had initially been treated with distal pancreatic resection. Pancreatic resections for pNEN are safe but associated with relevant postoperative morbidity. Future studies are needed to evaluate suitable resection strategies for G2 pNEN.

Recurrence of Non-functional Pancreatic Neuroendocrine Tumors After Curative Resection: A Tumor Burden-Based Prediction Model

BACKGROUND

Patients can experience recurrence following curative-intent resection of non-functional pancreatic neuroendocrine tumors (NF-pNETs). We sought to develop a nomogram to risk stratify patients relative to recurrence following resection of NF-pNETs.

METHODS

Patients who underwent curative-intent resection for NF-pNETs between 1997 and 2016 were identified from a multi-institutional database. The impact of clinicopathologic factors, including tumor burden score (TBS) (TBS² = (maximum tumor diameter)² + (number of tumors)²), was assessed relative to recurrence-free survival (RFS), and a nomogram was developed and internally validated.

RESULTS

With a median follow-up of 31.0 months (IQR 11.3-56.6 months), 66 (15.8%) out of 416 patients in the cohort experienced tumor recurrence. Overall, 3-, 5-, and 10-year RFS following curative-intent resection was 83.2%, 74.0%, and 44.7%, respectively. Several factors were associated with risk of recurrence including tumor grade (referent G1: G2, HR 4.07, 95% CI 2.29-7.26, p < 0.001; G3, HR 10.83, 95% CI 3.72-31.53, p < 0.001), lymph node metastasis (LNM) (HR 4.71, 95% CI 2.69-8.26, p < 0.001), as well as TBS (referent low: medium, HR 4.36, 95% CI 2.06-9.24, p < 0.001; high, HR 6.04, 95% CI 2.96-12.31, p < 0.001). A weighted nomogram including tumor grade (G1 0, G2 54.19, G3 100), LNM (N0 0, N1 42.06), and TBS (low 0, medium 44.07, high 56.48) was developed. The discriminatory power of the nomogram was very good with a C-index of 0.75 (95% CI, 0.66-0.79) in the training cohort and 0.71 (95% CI, 0.65-0.75) in the validation cohort. In addition, the nomogram performed better than the current 8th edition of AJCC TNM staging system, which had a C-index of 0.67 (95% CI, 0.60-0.73).

CONCLUSIONS

A nomogram that incorporated tumor grade, LNM, and TBS was established that had good discrimination and calibration. The nomogram may be an effective tool to stratify patients relative to recurrence risk following resection of NF-pNETs.