Pancreatic neuroendocrine tumours: conservative versus surgical management

Minimally invasive versus open surgery for nonfunctioning pancreatic neuroendocrine tumors: a systematic review and meta-analysis

INTRODUCTION

Nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) have been diagnosed increasingly often but still represent rare pancreatic neoplasms. Surgery is a potentially curative approach for patients with NF-PNETs. In recent years, minimally invasive surgery (MIS) has been applied more frequently for surgical resection of NF-PNETs. The evidence for using MIS for NF-PNETs is still being determined and controversial.

MATERIALS AND METHODS

PubMed, Cochrane Library, and the Web of Science database were searched systematically from its inception to July 2023. All studies comparing MIS versus open surgery (OPS) of NF-PNETs were included. The primary outcomes were the incidence of overall postoperative complications and pancreas-specific complications [postoperative pancreatic fistula (POPF) and delayed gastric emptying (DGE)]. The secondary measures were duration of operation, intraoperative blood loss, and length of postoperative hospital stay. Pooled results are presented as odds ratios (OR) or mean difference (MD) with a 95% CI.

RESULTS

Five observational studies with a total of 1178 patients were included in the final analysis. The meta-analysis indicated that MIS attained less intraoperative blood loss (MD=-58.59, 95% CI [-92.76 to -24.41], P<0.01) and shorter length of hospital stay (MD=-3.07, 95% CI [-5.28 to -0.87], P<0.01) in contrast to open surgery for NF-PNETs. There were no significant differences concerning operative time (MD=52.04, 95% CI [-8.74 to 112.81], P=0.67), overall postoperative complications (OR=0.78, 95% CI [0.59-1.03], P=0.08), POPF (OR=0.99, 95% CI [0.66-1.47], P=0.94), and DGE (OR=0.58, 95% CI [0.58-1.42], P=0.67).

CONCLUSIONS

This study demonstrates that minimally invasive surgery for NF-PNETs is safe and associated with a considerably shorter postoperative hospital stay. Further studies are needed to verify the evidence.

Disease-free survival after pancreatectomy for pancreatic neuroendocrine tumors: A 17-year single-center experience of 223 patients

BACKGROUND

Metastasis or recurrence of pancreatic neuroendocrine tumors (pNETs) after pancreatectomy is an important source of postsurgical morbidity. This study aimed to define disease-free survival (DFS) in this population.

METHODS

Patients who underwent pancreatectomy for pNETs between January 2005 and January 2022 were included. Clinicopathologic and survival data were collected, and the primary endpoint was DFS. Kaplan-Meier survival analysis and Cox proportional hazards regression modeling were performed.

RESULTS

Of the 223 patients, 144 (65%) distal/subtotal/partial pancreatectomies, 71 (32%) pancreaticoduodenectomies, 6 (3%) total pancreatectomies, and 2 (1%) enucleations were performed. Of the 223 patients, 45 (20%) experienced disease recurrence or metastasis after index pancreatectomy during the 17 years of the study. Nonfunctional pNETs (162 [73%]) were more common than hormonally functional subtypes. The 2- and 5-year DFSs were 82% and 76%, respectively. Kaplan-Meier analysis demonstrated that N1 node positive disease, size of ≥ 4 cm, lymphovascular invasion, perineural invasion, Ki-67 of ≥ 20%, and nonfunctional pNETs are significantly associated with a lower DFS (P < .05). Univariate Cox analysis identified the following predictors to be significantly associated with poorer DFS: larger tumor size (hazard ratio [HR], 1.16; 95% CI, 1.04-1.28), Ki-67 index of ≥ 20% (HR, 4.93; 95% CI, 2.00-11.44), perineural invasion (HR, 3.23; 95% CI, 1.40-7.89), open surgery (HR, 3.34; 95% CI, 1.03-1.33), node-positive disease (HR, 5.27; 95% CI, 2.28-13.26), and increased body mass index (HR, 1.10; 95% CI, 1.03-1.17) (P < .05).

CONCLUSION

Of note, 1 in 5 patients who underwent resection developed recurrence or metastasis after pancreatectomy. Prognostic predictors of DFS in pNETs could help optimize treatment and enhance follow-up protocols to improve quality and reduce morbidity.

Surgical Management and Long-Term Evaluation of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) arise from neuroendocrine cells and are a rare class of heterogenous tumors with increasing incidence. The diagnosis, staging, treatment, and prognosis of PNETs depend heavily on identifying the histologic features and biological mechanisms. Here, the authors provide an overview of the diagnostic workup (biomarkers and imaging), grade, and staging of PNETs. The authors also explore associated genetic mutations and molecular pathways and describe updated guidelines on surgical and systemic treatment modalities.

Artificial Intelligence in Pancreatic Image Analysis: A Review

Pancreatic cancer is a highly lethal disease with a poor prognosis. Its early diagnosis and accurate treatment mainly rely on medical imaging, so accurate medical image analysis is especially vital for pancreatic cancer patients. However, medical image analysis of pancreatic cancer is facing challenges due to ambiguous symptoms, high misdiagnosis rates, and significant financial costs. Artificial intelligence (AI) offers a promising solution by relieving medical personnel's workload, improving clinical decision-making, and reducing patient costs. This study focuses on AI applications such as segmentation, classification, object detection, and prognosis prediction across five types of medical imaging: CT, MRI, EUS, PET, and pathological images, as well as integrating these imaging modalities to boost diagnostic accuracy and treatment efficiency. In addition, this study discusses current hot topics and future directions aimed at overcoming the challenges in AI-enabled automated pancreatic cancer diagnosis algorithms.

Survival after active surveillance versus upfront surgery for incidental small pancreatic neuroendocrine tumours

BACKGROUND

The safety of observing small non-functioning pancreatic neuroendocrine tumours (NF-Pan-NETs) remains under debate.

METHODS

This was a multicentre retrospective study of patients with small incidental NF-Pan-NETs. Survival of patients who underwent upfront surgery versus active surveillance was compared. The risk of death was matched with that in the healthy population. The excess hazard rate and probability of a normal lifespan (NLP) were calculated. Propensity score matching (PSM) with a 1 : 1 ratio was used to minimize the risk of selection bias.

RESULTS

Some 222 patients (43.7 per cent) underwent upfront surgery and 285 (56.3 per cent) were observed. The excess hazard rate for the entire cohort was quantifiable as 0.04 (95 per cent c.i. 0 to 0.08) deaths per 1000 persons per year, and the NLP was 99.7 per cent. Patients in the active surveillance group were older (median age 65 versus 58 years; P < 0.001), and more often had co-morbidity (45.3 versus 24.8 per cent; P = 0.001), and smaller tumours (median 12 versus 13 mm; P < 0.001), less frequently located in the pancreatic body-tail (59.5 versus 69.6 per cent; P = 0.008, 59.3 versus 73.9 per cent; P = 0.001). Median follow-up was longer for patients who underwent upfront surgery (5.6 versus 2.7 years; P < 0.001). After PSM, 118 patients per group were included. The excess hazard rates were 0.2 and 0.9 deaths per 1000 persons per year (P = 0.020) for patients in the active surveillance and upfront surgery groups respectively. Corresponding NLPs were 99.9 and 99.5 per cent respectively (P = 0.011).

CONCLUSION

Active surveillance of small incidental NF-Pan-NETs is a reasonable alternative to resection.

Surgical outcomes of gastro-entero-pancreatic neuroendocrine tumors G3 versus neuroendocrine carcinoma

BACKGROUND

To define surgical outcomes of patients with high-grade gastro-entero-pancreatic neuroendocrine neoplasm grade G3 (GEP-NEN G3).

METHODS

Patients who underwent surgical resection between 2000 and 2016 were identified. The overall survival (OS) and recurrence-free survival (RFS) of patients with gastro-entero-pancreatic neuroendocrine tumors grade G3 (GEP-NET G3) versus neuroendocrine carcinoma (NEC) were evaluated.

RESULTS

Fifty-one out of 2182 (2.3%) patients who underwent surgical resection were diagnosed as GEP-NEN G3. The pancreas was the most common primary site (n = 3772.5%). A majority of patients had lymph node metastasis (n = 3262.7%); one in three (n = 1631.4%) had distant metastasis. The median OS and RFS of the entire cohort were 56.4 and 34.5 months, respectively. Perineural invasion was a strong prognostic factor associate with OS after surgical resection. Patients with NEC had a worse survival outcome versus patients with NET G3 (median OS: 33.1 months vs. not attained, p = 0.088). In contrast, among patients who underwent curative-intent resection, patients with NEC had comparable RFS versus patients with NET G3 (median RFS: 35.6 vs. 33.9 months, p = 0.774).

CONCLUSIONS

Surgical resection provided acceptable short- and long-outcomes for well-selected patients with resectable GEP-NEN G3. NEC was associated with a worse OS versus NET G3.