Outcome of nonfunctioning pancreatic neuroendocrine tumors after initial surveillance or surgical resection: a single-center observational study

Background

Current guidelines consider observation a reasonable strategy for G1 or G2 nonfunctional pancreatic neuroendocrine tumors (nf pNETs) ≤2 cm. We aimed to characterize their natural behavior and confront the data with the outcomes of patients undergoing upfront surgery.

Methods

Data from patients with histologically confirmed nf pNETs ≤2 cm, managed at a single tertiary referral center between 2002 and 2020, were retrospectively reviewed.

Results

Thirty-nine patients (mean age 62.1 years, 56% male) with 43 lesions (mean size 12.7±3.9 mm; 32 grade 1 [G1] and 7 grade 2 lesions [G2]) were managed by careful surveillance. Progression was observed in 15 lesions (35%; mean follow up 47 months). Six patients (18%) underwent secondary surgery because of an increase in tumor size or dilation of the main pancreatic duct; 3 of them had lymph node metastasis in the resected specimen. Surgery was followed by pancreatic fistula in 2/6 patients, 1 of whom died. Fourteen patients (mean age 59 years, 64.3% female, mean size of lesions 11.4±3.1 mm) underwent pancreatic surgery immediately after diagnosis. The surgery-associated complication rate was 57.1% (8/14). Of the 14 patients, 13 remained recurrence free (mean follow up 67 months). Recurrent metastatic disease was observed 3 years after pancreaticoduodenectomy (R0, 15 mm G2 lesion, 0 N+/8 N) in 1 patient.

Conclusions

The behavior of small nf pNETs is difficult to predict, as there is evidence for malignant behavior in a subgroup of patients, even after surgical treatment. Optimal management remains challenging, as pancreatic surgery is associated with significant morbidity.

Long-term clinical and radiological outcomes of endoscopic ultrasound-guided radiofrequency ablation of benign insulinomas

OBJECTIVE

In recent years, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has emerged as an alternative nonsurgical treatment for pancreatic neuroendocrine tumours. The aim of our study was to assess the long-term follow-up of patients treated with EUS-RFA for a sporadic insulinoma in our centre in terms of efficacy, safety and risk of recurrence.

DESIGN, PATIENTS AND MEASUREMENTS

We retrospectively analysed the data of 11 patients with an insulinoma treated by EUS-RFA in our tertiary centre between June 2018 and April 2022. Clinical and biological, as well as imaging, follow-up was planned at 3, 6, 12 months and then annually.

RESULTS

In our series, there were nine women and two men with a median age of 65 years. All tumours were sporadic, with a mean size of 11 mm. The procedure allowed an immediate and complete symptomatic and biological remission in all patients without notable complications. Complete radiological resolution of the tumour after ablation was observed in seven patients, and persistence of an asymptomatic tumour residue was observed in four patients. During the mean follow-up period of 26 months, two patients presented a significant but asymptomatic increase of the tumour residue; a second EUS-RFA session was performed in one patient and the other patient is being closely monitored.

CONCLUSIONS

EUS-RFA treatment of benign insulinomas provides a long-term complete clinical resolution of hypoglycaemia. A long-term follow-up is essential if residual tumour persists after initial EUS-RFA treatment.

Management of non-functional pancreatic neuroendocrine tumors by endoscopic ultrasound-guided radiofrequency ablation: Retrospective study in two tertiary centers

BACKGROUND

Recently, there has been growing interest in investigating endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) for the management of small non-functional pancreatic neuroendocrine tumors (nf pNETs).

PATIENTS AND METHODS

A bicentric retrospective study was performed that included patients with histologically confirmed nf pNETs who were consecutively treated by EUS-RFA between December 2015 and March 2021 at two tertiary referral centers.

RESULTS

In 27 patients (mean age 65.0 years, 52% male), EUS-RFA was successfully performed. All patients had sporadic G1 lesions (mean size 14.0 ± 4.6 mm, 7% uncinated process, 22% head, 11% body, 19% body/tail junction, and 41% tail). Overall, 9/27 lesions (33%) were cystic. The mean hospital stay was 3.2 days. Complete treatment response was confirmed in 25/27 patients (93%) on cross-sectional imaging (mean follow-up 15.7 ± 12.2 months, range 2-41 months). Two patients had two EUS-RFA sessions until complete necrosis was observed. Periprocedural acute pancreatitis occurred in 4/27 (14.8%), three of them were treated by endoscopic cystogastrostomy (11.1%). One patient underwent secondary surgery. The histopathology of the resected specimen revealed 3 mm of residual tumor tissue.

CONCLUSION

EUS-RFA seems to be a promising treatment strategy for the management of small nf pNETs with excellent efficacy. Further evidence focusing on long-term survival, safety profile and recurrence is needed.

Endoscopic ultrasound-guided ethanol and radiofrequency ablation of pancreatic insulinomas: a systematic literature review

BACKGROUND

Insulinoma is the most common neuroendocrine neoplasm of the pancreas, characterised by hypoglycaemic symptoms. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) and ethanol ablation (EUS-EA) are novel methods for treating insulinoma.We aimed to perform a systematic review to assess the efficacy and safety of EUS-guided ablation techniques for pancreatic insulinomas.

METHODS

We systematically searched for articles detailing EUS-guided ablations of insulinomas. We performed a qualitative analysis and summarised data on the efficacy and safety of EUS-RFA and EUS-EA techniques.

RESULTS

In total, we identified 35 case reports and case series describing 75 patients with insulinomas treatment with EUS-guided ablation. Twenty-seven patients were treated with EUS-RFA, 47 patients with EUS-EA, and 1 patient received EUS-EA and EUS-RFA in the same session. In total, 84 insulinomas were ablated (EUS-RFA: 31, EUS-EA: 53). Most insulinomas were in the head of the pancreas (40%). The clinical success rate for EUS-guided ablation techniques was 98.5%. The median glucose level was 1.95 (Q1-Q3: 1.69-2.13) mmol/L before ablation compared to 6.20 (Q1-Q3: 5.30-7.05) mmol/L after treatment. The median insulin and C-peptide levels before and after RFA/EA were 230 (Q1-Q2: 120-257) pmol/L and 41 (Q1-Q2 35-42) pmol/L; 2077 (Q1-Q2 1644-2459) pmol/L and 819 (Q1-Q2 696-1072) pmol/L, respectively. There were eleven adverse events: seven abdominal pain, two mild acute pancreatitis, one necrotising acute pancreatitis and one local hematoma. All patients recovered, and there were no periprocedural deaths.

CONCLUSIONS

EUS-guided ablation of insulinoma seems to be a safe and effective treatment and is an alternative to surgical resection in selected cases.