Conservative management and parenchyma-sparing resections of pancreatic neuroendocrine tumors: Literature review

Maximum Value on Arterial Phase Computed Tomography Predicts Prognosis and Treatment Efficacy of Sunitinib for Pancreatic Neuroendocrine Tumours

PURPOSE

This study was designed to assess the computed tomography maximum (CTmax) value on pretherapeutic arterial phase computed tomography (APCT) images to predict pancreatic neuroendocrine tumours (pNETs) recurrence and clarify its role in predicting the outcome of tumour therapy.

METHODS

This retrospective study enrolled 250 surgical patients and 24 nonsurgical patients with sunitinib-based treatment in our hospital from 2008 to 2019. CT images were assessed, the maximum value was defined as "CTmax," and recurrence-free survival (RFS) or progression-free survival (PFS) was compared between a high-CTmax group and a low-CTmax group among patients who underwent surgical resection or nonsurgical, sunitinib-based treatment according to the CTmax cutoff value.

RESULTS

In ROC curve analysis, a CTmax of 108 Hounsfield units, as the cutoff value, achieved an AUC of 0.796 in predicting recurrence. Compared with the low-CTmax group, the high-CTmax group had a longer RFS (p < 0.001). Low CTmax was identified as an independent factor for RFS (p < 0.001) in multivariate analysis; these results were confirmed using the internal validation set. The CTmax value was significantly correlated with the microvascular density (MVD) value (p < 0.001) and the vascular endothelial growth factor receptor 2 (VEGFR2) score (p < 0.001). Furthermore, the high-CTmax group had a better PFS than the low-CTmax group among the sunitinib treatment group (p = 0.007).

CONCLUSIONS

The tumour CTmax on APCT might be a potential and independent indicator for predicting recurrence in patients who have undergone surgical resection and assessing the efficacy of sunitinib for patients with advanced metastatic pNETs.

Long-term Outcomes of Parenchyma-sparing and Oncologic Resections in Patients With Nonfunctional Pancreatic Neuroendocrine Tumors <3 cm in a Large Multicenter Cohort

INTRODUCTION

The role of parenchyma-sparing resections (PSR) and lymph node dissection in small (<3 cm) nonfunctional pancreatic neuroendocrine tumors (PNET) is unlikely to be studied in a prospective randomized clinical trial. By combining data from 4 high-volume pancreatic centers we compared postoperative and long-term outcomes of patients who underwent PSR with patients who underwent oncologic resections.

METHODS

Retrospective review of prospectively collected clinicopathologic data of patients who underwent pancreatectomy between 2000 and 2021 was collected from 4 high-volume institutions. PSR and lymph node-sparing resections (enucleation and central pancreatectomy) were compared to those who underwent oncologic resections with lymphadenectomy (pancreaticoduodenectomy, distal pancreatectomy). Statistical testing was performed using χ 2 test and t test, survival estimates with Kaplan-Meier method and multivariate analysis using Cox proportional hazard model.

RESULTS

Of 810 patients with small sporadic nonfunctional PNETs, 121 (14.9%) had enucleations, 100 (12.3%) had central pancreatectomies, and 589 (72.7%) patients underwent oncologic resections. The median age was 59 years and 48.2% were female with a median tumor size of 2.5 cm. After case-control matching for tumor size, 221 patients were selected in each group. Patients with PSR were more likely to undergo minimally invasive operations (32.6% vs 13.6%, P <0.001), had less intraoperative blood loss (358 vs 511 ml, P <0.001) and had shorter operative times (180 vs 330 minutes, P <0.001) than patients undergoing oncologic resections. While the mean number of lymph nodes harvested was lower for PSR (n=1.4 vs n=9.9, P <0.001), the mean number of positive lymph nodes was equivalent to oncologic resections (n=1.1 vs n=0.9, P =0.808). Although the rate of all postoperative complications was similar for PSR and oncologic resections (38.5% vs 48.2%, P =0.090), it was higher for central pancreatectomies (38.5% vs 56.6%, P =0.003). Long-term median disease-free survival (190.5 vs 195.2 months, P =0.506) and overall survival (197.9 vs 192.6 months, P =0.372) were comparable. Of the 810 patients 136 (16.7%) had no lymph nodes resected. These patients experienced less blood loss, shorter operations ( P <0.001), and lower postoperative complication rates as compared to patients who had lymphadenectomies (39.7% vs 56.9%, P =0.008). Median disease-free survival (197.1 vs 191.9 months, P =0.837) and overall survival (200 vs 195.1 months, P =0.827) were similar for patients with no lymph nodes resected and patients with negative lymph nodes (N0) after lymphadenectomy.

CONCLUSION

In small <3 cm nonfunctional PNETs, PSRs and lymph node-sparing resections are associated with lower blood loss, shorter operative times, and lower complication rates when compared to oncologic resections, and have similar long-term oncologic outcomes.

The clinicopathologic and operative characteristics of patients with small nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND

Incidentally detected, small nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) are increasingly diagnosed on imaging modalities. This retrospective investigation evaluated the clinicopathologic characteristics and perioperative and oncologic outcomes in patients with small NF-PNETs undergoing curative resection.

METHODS

The medical records of 444 patients who underwent pancreatic resection for NF-PNETs at a single, large-volume institution between January 2000 and December 2018 were retrospectively reviewed. Patients were divided into those with small (≤2 cm) and large (>2 cm) tumors based on the largest tumor diameter on preoperative computed tomography (CT). Outcomes were also evaluated in subgroups of patients with small NF-PNET who did and did not undergo lymphadenectomy.

RESULTS

Of the 444 patients with NF-PNETs, 195 (43.9%) had small (≤2 cm) and 249 (56.1%) had large (>2 cm) NF-PNETs. The rate of parenchyma-preserving surgery (14.4% vs. 7.2%, p = 0.014) and the ratio of spleen preservation for left-sided pancreatectomy (65.6% vs. 38.3%, p < 0.001) were higher in the small NF-PNET group. Size on CT >2 cm (p < 0.001, hazard ratio [HR]: 5.836, 95% confidence interval [CI]: 2.474-13.769), presence of perineural invasion (p < 0.001, HR: 3.025, 95% CI: 1.640-5.577), World Health Organization (WHO) Grade 2 (p = 0.007, HR: 2.861, 95% CI: 1.325-6.176), and WHO Grade 3 (p < 0.001, HR: 11.537, 95% CI: 5.282-25.199) were independent predictors of disease-free survival (DFS). DFS did not differ significantly in patients with small NF-PNETs who did and did not undergo lymphadenectomy (p = 0.886).

CONCLUSIONS

Assessment of long-term oncologic outcomes suggests that surgical resection may cure small NF-PNETs. Minimally invasive surgery and organ-preserving surgery are acceptable treatment options for select patients with small NF-PNETs. The effect on survival outcomes of lymph node dissection for small NF-PNETs remains unclear.

Management and surveillance of non-functional pancreatic neuroendocrine tumours: Retrospective review

BACKGROUND

/Objective. To determine the outcomes of a non-operative management approach for sporadic, small, non-functional pancreatic neuroendocrine tumours.

METHODS

A retrospective chart review of patients with non-functional pancreatic neuroendocrine tumours initially managed non-operatively at a single institution was performed. Patients were identified through a search of radiologic reports, and individuals with ≥2 cross-sectional imaging studies performed >6 months apart from Jan. 1, 2000 to Dec. 31, 2013 were included. Data on tumour size, radiologic characteristics at diagnosis, interval radiologic growth, and surgical outcomes were recorded.

RESULTS

Over the thirteen-year study period, 95 patients met inclusion criteria and were followed radiologically for a median of 36 months (18-69 months). Median initial tumour size on first imaging was 14.0 mm (IQR 10-19 mm). Median overall tumour growth rate was 0.03 mm/month (IQR: 0.00-0.14 mm/month). There was no significant relationship between initial tumour size and growth rate for tumours ≤ 2 cm or for lesions between 2 and 4 cm. Thirteen (14%) patients initially managed non-operatively underwent resection during the follow-up period. Reasons for surgery included interval tumour growth, patient anxiety or preference, or diagnostic uncertainty. Median time to surgery was 14 months (IQR 8-19 months). No patients progressed beyond resectability or developed metastatic disease during the observation period.

CONCLUSION

For patients with sporadic, small, non-functional pancreatic neuroendocrine tumours, radiologic surveillance appears to be a safe initial approach to management.

Rare case of adult pancreatic haemangioma and literature review

Pancreatic haemangiomas are benign vascular tumours very rare in adults. Twenty-two cases are described in the literature. The symptoms are non-specific, and therefore rarely clinically suspected, and the vast majority are incidental findings in imaging tests such as ultrasound, CT, angiography or MRI. They appear on CT as a cystic lesion with contrast enhancement in the arterial phase. We present the case of a 36-year-old male patient with no history of disease, referred with lumbar pain and suspected renal calculus after tomography showing hypervascular enhancement in the pancreatic body and infiltrative lesion (possible neuroendocrine neoplasia) on MRI and biliopancreatic echoendoscopy. He was submitted to laparotomy with subtotal pancreatectomy and splenectomy and satisfactory evolution.

The prognostic impact of primary tumor resection in pancreatic neuroendocrine tumors with synchronous multifocal liver metastases

BACKGROUND

Whether primary tumor resection benefits patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors remains controversial. We investigated whether primary tumor resection significantly affects survival in this study.

METHODS

A retrospective study of patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors between 1998 and 2016 was performed. Patient demographics, operation details, adjuvant treatment, and pathological and survival information were collected, and relevant clinical-pathological parameters were assessed in univariate and multivariate survival analyses.

RESULTS

Sixty-three patients were included in this study, including 35 who underwent primary tumor resection. The median survival time and 5-year survival rate of this cohort were 50 months and 44.5%, respectively. Median survival time in the resected group was significantly longer at 72 months than that of 32 months in the nonresected group (p = 0.010). Multivariate analysis showed that primary tumor surgery was a significant independent prognostic factor (HR 0.312, 95% CI: 0.128-0.762, p = 0.011).

CONCLUSIONS

Primary tumor resection significantly benefits patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors.

[Early endocrine neoplasia of the pancreas]

Pancreatic endocrine neoplasias (pNENs) are uncommon but fascinating tumors with a rising incidence. In accordance to its location, size and grading, the decision to operate the patient should always be made in an interdisciplinary approach. This article provides a comprehensive review of the current literature addressing the current challenges in pNEN surgery and shows that patients with completely resected small pNENs generally have an excellent prognosis, but also that surveillance may be a powerful tool.

Robotic Enucleation for Benign or Borderline Tumours of the Pancreas: A Retrospective Analysis and Comparison from a High-Volume Centre in Asia

BACKGROUND

Enucleation is increasingly performed for benign or borderline tumours of the pancreas because it is a parenchyma-sparing and less invasive procedure compared to conventional pancreatectomy, which reduces the risk of exocrine and endocrine insufficiency. This study retrospectively evaluated and compared the pre-, intra-, and post-operative clinical characteristics after open and robotic approaches for pancreatic enucleation.

METHODS

Fifty-six cases of enucleation for benign or borderline tumours of the pancreas treated from March 2010 to July 2015 were identified by a retrospective search. These included 25 patients who underwent an open approach and 31 patients who underwent a robotic approach. The clinical characteristics were extracted and compared.

RESULTS

The two groups had a similar location and pathology of the tumour. The robotic group had a significantly shorter operation time and significantly less blood loss than the open group. The rates of clinical pancreatic fistula (PF) formation and major complications were similar. The robotic approach could be applied for a tumour on the right side of the pancreas without increasing the incidence of clinical PF or other major complications. The patients with clinical PF had a significantly shorter distance between the lesion and the main pancreatic duct (MPD).

CONCLUSION

Robotic enucleation appears to be a feasible and safe approach for benign or borderline tumours of the pancreas and was associated with similarly favourable surgical outcomes as the open approach. Identifying and avoiding the MPD is an important step during enucleation.

Surgical resection of a primary tumor improves survival of metastatic pancreatic cancer: a population-based study

INTRODUCTION

Pancreatic cancer is a lethal disease with a very poor prognosis. This study investigates survival of patients diagnosed with metastatic pancreatic cancer (mPC) based on local treatment of the primary tumor.

METHODS

Patients diagnosed with stage IV mPC between 2004 and 2013 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Cancer-specific survival (CSS) and overall survival (OS) were examined. CSS and OS were examined by using the Kaplan-Meier method with the log-rank test. Multivariable survival analyses of CSS and OS were conducted using the Cox proportional hazard model.

RESULTS

A total of 28918 patients with mPC were included in this analysis. There were 467 patients who received surgical resection (1.6%) and 28451 patients who did not (98.4%). Patients who were younger than 70 years (odds ratio [OR]=1.45, 95% CI=1.04-2.03, p=0.03), diagnosed from 2004 to 2008 (OR=1.49, 95% CI=1.25-1.80, p<0.001), female (OR=1.31, 95% CI=1.08-1.58, p<0.001), married (OR=1.56, 95% CI=1.27-1.90, p<0.001), at T3 stage (OR=3.53, 95% CI=1.10-11.37, p=0.035), at N1 stage (OR=2.05, 95% CI=1.68-2.50, p<0.001), presenting histological types other than adenocarcinoma (OR=2.04, 95% CI=1.43-2.94, p<0.001), and with tumor of the pancreatic head (OR=1.90, 95% CI=1.27-2.82, p=0.002) were more likely to be treated with surgical resection. The results of multivariate analysis showed that surgical resection of the primary tumor was associated with CSS (hazard ratio [HR]=0.58, 95% CI=0.52-0.64, p<0.001) and OS (HR=0.59, 95% CI=0.53-0.65, p<0.001) benefits. In addition, not receiving chemotherapy (HR=2.33, 95% CI=2.27-2.39, p<0.001), age >50 years (HR=1.25, 95% CI=1.09-1.42, p=0.001), male (HR=1.121, 95% CI=1.09-1.15, p<0.001), black ethnicity (HR=1.11, 95% CI=1.1-1.15, p<0.001), unmarried (HR=1.20, 95% CI=1.17-1.23, p<0.001), histological type of adenocarcinoma (HR=1.18, 95% CI=1.14-1.22, p<0.001), and primary site other than the pancreatic head (HR=1.08, 95% CI=1.05-1.11, p<0.001) are factors associated with poor survival.

CONCLUSION

This study reveals that local treatment has the primary benefit of both CSS and OS in patients with mPC. These results may guide the management of this patient population.

Pancreatic stump closure after pancreatoduodenectomy in elderly patients: a retrospective clinical study

BACKGROUND

Pancreatic fistula (PF) after pancreatoduodenectomy (PD) represents the major source of morbidity. Derivative procedures are preferred by pancreatic surgeons, but the optimal management of remnant pancreatic stump remains controversial.

AIMS

The purpose of this retrospective study is to evaluate the efficacy and safety of pancreatic stump closure in selected elderly patients (>65 years).

METHODS

Clinical data of 44 PD undergone mechanical closure of the pancreatic stump performed between 2001 and 2014 in two department of general and oncologic surgery were retrospectively collected. Considering the age, patients were divided into two groups: 21 patients of less than 65 years (Group A) and 23 patients of more than 65 years (Group B).

RESULTS

A soft pancreatic parenchyma with a not-dilated duct (diameter <3 mm) was reported in all the 44 patients. A grade-A PF, which did not required further treatments, developed in 20 cases (45.4%; 13 in group A and 7 in group B; p < 0.05), grade-B in 5 patients (11.4%; 3 in group A and 2 in group B; statistically not significant) and a grade-C PF was observed only in one patient (2.2%; 1 in group A and 0 in group B).

DISCUSSION

In selected "high risk" elderly patients (>65 years) with soft pancreatic texture, the closure of the pancreatic stump can be a useful tool in the surgical armamentarium with the aim to reduce the incidence of age-related complications.

CONCLUSIONS

Prospective randomized controlled trial to better evaluate PF risk factors is needed.

Outcomes of Pancreaticoduodenectomy for Pancreatic Neuroendocrine Tumors: Are Combined Procedures Justified?

Efficacy and outcomes of resection for pancreatic neuroendocrine tumors (pNET) are well established; specific data on outcomes for pancreaticoduodenectomy (PD), either alone or with combined procedures, are limited. A retrospective review of PDs for pNET (1998-2014) at our institution was conducted. Patients were categorized into standard PD (SPD) alone or combined PD (CPD) defined as patients undergoing concurrent vascular reconstruction or additional organ resection for curative intent. Kaplan-Meier survival analyses were performed. PD for pNET was performed for 95 patients. Tumors were functional in 11 patients (9 %). Twenty-six patients (28 %) underwent CPD. The 30/90-day mortality was 1.1/5.3 % respectively and similar between SPD and CPD (p = 0.61/p = 0.24). Five-year overall survival after PD for pNET was 85.1/71.9 % and similar between SPD/CPD groups (p = 0.17). Recurrence-free and overall survival for low-grade tumors was 74.7/93.9 % at 5 years compared to only 14.8/49.7 % for high-grade tumors (p < 0.001) and not predicted by extent of resection (SPD/CPD, respectively). PD with or without concurrent resection provides an acceptable, perioperative and long-term oncologic, outcome for pNET. CPD is justified treatment modality, particularly for patients with low-grade tumors. The need for combinatorial procedures during PD is not contraindication alone for otherwise resectable patients with pNET.