Outcomes of Simultaneous Resection of Small Bowel Neuroendocrine Tumors with Synchronous Liver Metastases

Value of Surgical Cytoreduction in Patients with Small Intestinal Neuroendocrine Tumors Metastatic to the Liver and Peritoneum

BACKGROUND

Cytoreductive hepatectomy can improve survival and symptoms of hormonal excess in patients with small intestinal neuroendocrine tumor (siNET) liver metastases, but whether to proceed when peritoneal metastases are encountered at the time of planned cytoreductive hepatectomy is controversial.

METHODS

This was a retrospective review of patients who underwent surgical management of metastatic siNETs at Mayo Clinic between 2000 and 2020. Patients who underwent cytoreductive operation for isolated liver metastases or both liver and peritoneal metastases were compared.

RESULTS

Of 261 patients who underwent cytoreductive operation for siNETs, 211 had isolated liver metastases and 50 had liver and peritoneal metastases. Complete cytoreduction was achieved in 78% of patients with isolated liver metastases and 56% of those with liver and peritoneal metastases (p = 0.002). After complete cytoreduction, median overall survival (OS) was 11.5 years for isolated liver metastases and 11.2 years for liver and peritoneal metastases (p = 0.10), and relief of carcinoid syndrome was ≥ 97% in both groups. After incomplete cytoreduction with debulking of > 90% of hepatic disease and/or closing Lyon score of 1-2, median OS was 6.4 years for isolated liver metastases and 7.1 years for liver and peritoneal metastases (p = 0.12).

CONCLUSIONS

Patients with siNETs metastatic to both the liver and peritoneum have favorable outcomes after aggressive surgical cytoreduction, with the best outcomes observed after complete cytoreduction. Therefore, the presence of peritoneal metastases should not by itself preclude surgical cytoreduction in this population.

Management of neuroendocrine tumor liver metastases

BACKGROUND

Neuroendocrine Tumors (NETs) are a group of tumors that arise from neuroendocrine cells, and are increasing in incidence worldwide. These tumors often metastasize to the liver, and management of these neuroendocrine tumor liver metastases (NELMs) requires a multi-disciplinary approach. We aim to provide a comprehensive update for treatment of NELMs.

METHODS

We completed a comprehensive systemic review of papers involving the diagnosis, treatment, and outcomes of NELMs. We identified 1612 records via Scopus database literature search. Two independent authors reviewed these records, with 318 meeting criteria for inclusion in the final systemic review.

RESULTS

Primary tumor resection with resection of liver metastases is the treatment of choice for patients with NELMs. Liver-directed therapies and liver transplantation can be considered for patients with unresectable liver metastases. Systemic medical therapy is used for managing tumor burden and symptoms caused by NELMs.

CONCLUSIONS

Advancement in liver-directed and targeted systemic therapies provide improved options for patients with unresectable tumors. Given the complexity of NELMs, management of NELMs necessitates multidisciplinary teams at comprehensive health centers.

Management of Small Bowel Neuroendocrine Tumours: 10 Years' Experience at a Tertiary Referral Centre

BACKGROUND

Neuroendocrine tumours (NET) arising from the small bowel are clinically challenging and are often diagnosed at advanced stages. Disease control with surgery alone can be demanding. Multimodal treatment concepts integrating surgery and non-surgical modalities could be of benefit.

METHOD

Retrospective review of consecutive adult patients with SB NET treated at Imperial College Healthcare NHS Trust between 1 January 2010 and 31 December 2019. Data regarding clinicopathological characteristics, treatments, and disease trajectory were extracted and summarised. Overall and progression/recurrence-free survival were estimated at 5 and 10 years.

RESULTS

154 patients were identified, with a median age of 64 years (range 33-87); 135/154 (87.7%) had stage III/IV disease at diagnosis. Surgery was used in 125 individuals (81.2%), typically with either segmental small bowel resection (60.8%) or right hemicolectomy (33.6%) and mesenteric lymphadenectomy for the primary tumour. Systemic and/or liver-directed therapies were used in 126 (81.8%); 60 (47.6%) had more than one line of non-surgical treatment. Median follow-up was 67.2 months (range 3.1-310.4); overall survival at 5 and 10 years was 91.0% (95% CI: 84.9-94.7%) and 82.5% (95% CI: 72.9-88.9%), respectively. Imaging-based median progression-free survival was 42.7 months (95% CI: 24.7 to 72.4); 5-year progression-free survival was 63.4% (95% CI: 55.0-70.6%); 10-year progression-free survival was 18.7% (95% CI: 12.4-26.1). Nineteen patients (12.3%) reached 10 years follow-up without disease recurrence and therefore were considered cured.

CONCLUSIONS

Most patients with SB NET present in a metastasised stage. Multimodal treatment concepts may be associated with excellent clinical outcomes. Future work should explore optimal approaches to treatment sequencing and patient selection.

Association between surveillance imaging and survival outcomes in small bowel neuroendocrine tumors

BACKGROUND

Surveillance guidelines following the resection of small bowel neuroendocrine tumors (SB-NETs) are inconsistent. We evaluated the impact of surveillance imaging on SB-NET recurrence and overall survival (OS).

METHODS

Patients with completely resected SB-NETs referred to a provincial cancer center (2004-2015) were reviewed. Associations between imaging frequency, recurrence, post-recurrence treatment, and OS were determined using univariate and Cox-regression analyses.

RESULTS

Among 195 completely resected SB-NET patients, 31% were ≥70 years, 43% were female, and 80% had grade 1 disease. Imaging frequency was predictive of recurrence (hazard ratio 2.52, 95% confidence interval 1.84-3.46, p < 0.001). 72% underwent interventions for recurrent disease. Patients who were treated for the recurrent disease had comparable OS to those who did not recur (median 152 vs. 164 months; p = 0.25). Imaging frequency was not associated with OS in those with treated recurrent disease (p = 0.65). Patients who recurred underwent more computerized tomography (CT) scans than those who did not recur (CT: 1.47 ± 0.89 vs. 1.02 ± 0.81 scans/year, p < 0.001). Detection of disease recurrence was 5%-7% per year during the first 6 years of surveillance and peaked at 17% in Year 9.

CONCLUSION

Less frequent imaging over a longer duration should be emphasized to capture clinically relevant recurrences that can be treated to improve OS.

Molecular factors, diagnosis and management of gastrointestinal tract neuroendocrine tumors: An update

The prevalence of gastrointestinal neuroendocrine tumors (GI-NETs) is increasing, and despite recent advances in their therapy, it remains inadequate in patients with advanced well-differentiated neuroendocrine tumors. These tumors present many challenges concerning the molecular basis and genomic profile, pathophysiology, clinicopathological features, histopathologic classification, diagnosis and treatment. There has been an ongoing debate on diagnostic criteria and clinical behavior, and various changes have been made over the last few years. Neuroendocrine carcinoma of the gastrointestinal system is a rare but highly malignant neoplasm that is genetically distinct from gastrointestinal system neuroendocrine tumors (NETs). The diagnosis and management have changed over the past decade. Emerging novel biomarkers and metabolic players in cancer cells are useful and promising new diagnostic tools. Progress in positron emission tomography-computerized tomography and scintigraphy with new radioactive agents (⁶⁴Cu-DOTATATE or ⁶⁸Ga-DOTATATE) replacing enough octreoscan, has improved further the current diagnostic imaging. Promising results provide targeted therapies with biological agents, new drugs, chemotherapy and immunotherapy. However, the role of surgery is important, since it is the cornerstone of management. Simultaneous resection of small bowel NETs with synchronous liver metastases is a surgical challenge. Endoscopy offers novel options not only for diagnosis but also for interventional management. The therapeutic option should be individualized based on current multidisciplinary information.

Liver-Directed Therapy for Neuroendocrine Metastases: From Interventional Radiology to Nuclear Medicine Procedures

Neuroendocrine neoplasms (NENs) are rare and heterogeneous epithelial tumors most commonly arising from the gastroenteropancreatic (GEP) system. GEP-NENs account for approximately 60% of all NENs, and the small intestine and pancreas represent two most common sites of primary tumor development. Approximately 80% of metastatic patients have secondary liver lesions, and in approximately 50% of patients, the liver is the only metastatic site. The therapeutic strategy depends on the degree of hepatic metastatic invasion, ranging from liver surgery or percutaneous ablation to palliative treatments to reduce both tumor volume and secretion. In patients with grade 1 and 2 NENs, locoregional nonsurgical treatments of liver metastases mainly include percutaneous ablation and endovascular treatments, targeting few or multiple hepatic metastases, respectively. In the present work, we provide a narrative review of the current knowledge on liver-directed therapy for metastasis treatment, including both interventional radiology procedures and nuclear medicine options in NEN patients, taking into account the patient clinical context and both the strengths and limitations of each modality.

Head-to-head comparison between 18 F-DOPA PET/CT and 68 Ga-DOTA peptides PET/CT in detecting intestinal neuroendocrine tumours: A systematic review and meta-analysis

PURPOSE

The imaging of intestinal neuroendocrine tumours (NETs) relies on functional positron emission tomography (PET) tracers; these tumours can be studied by means of both ⁶⁸ Ga-DOTA peptides and ¹⁸ F-fluorodihydroxyphenyl- l-alanine (¹⁸ F-DOPA) PET/computed tomography (CT). As yet, it is unclear which of these two modalities offers the better sensitivity. We therefore conducted a meta-analysis to assess the available data.

METHODS

PubMed, CENTRAL, Scopus and Web of Science were searched for studies comparing the sensitivity of ⁶⁸ Ga-DOTA peptides and ¹⁸ F-DOPA PET/CT; papers up to February 2021 were considered. In each study, we considered sensitivity in terms of patient-based analysis (PBA), region-based analysis (RBA) and lesion-based analysis (LBA), and pooled the results yielded by each tracer. Multidisciplinary follow-up served as the standard of truth.

RESULTS

Of the 636 records identified, 6 articles published between 2008 and 2021 were finally selected, and 112 intestinal NETs patients were included. The pooled sensitivity of ¹⁸ F-DOPA PET/CT was 83%, 89% and 95% on PBA, RBA and LBA, respectively. ⁶⁸ Ga-DOTA peptides PET/CT showed sensitivity of 88%, 92% and 82% on PBA, RBA and LBA, respectively. No significant differences were found between the two tracers on PBA and RBA. By contrast, a clear trend towards significance in favour of ¹⁸ F-DOPA PET/CT was identified on LBA. The presence of a significant difference in favour of ¹⁸ F-DOPA PET/CT was confirmed in a subgroup analysis conducted only on the most recent and largest studies. In all three analyses, mild-to-high heterogeneity was found; however, no publication bias was observed.

CONCLUSION

Both ¹⁸ F-DOPA PET/CT and ⁶⁸ Ga-DOTA-peptides PET/CT are reliable diagnostic procedures in patients with intestinal NETs. However, in terms of lesion detection, a non-negligible difference in favour of ¹⁸ F-DOPA PET/CT was observed. Thus, the use of ¹⁸ F-DOPA PET/CT could be considered as a first-line molecular procedure in intestinal NETs.

Postoperative morbidity and mortality after surgical resection of small bowel neuroendocrine neoplasms: A systematic review and meta-analysis

Although small bowel resection is generally considered a low risk gastrointestinal procedure, this might not be true for small bowel neuroendocrine neoplasms (SB-NEN) as a result of potential central mesenteric involvement. We aimed to determine the reported morbidity and mortality after resection of SB-NEN in the literature and assess the effect of hospital volume on postoperative morbidity and mortality. A systematic review was performed by searching MEDLINE and Embase in March 2021. All studies reporting morbidity and/or mortality after SB-NEN resection were included. Pooled proportions of overall morbidity (Clavien-Dindo I-IV), severe morbidity (Clavien-Dindo III-IV), 30-day mortality, 90-day mortality and in-hospital mortality were calculated, as well as the association with hospital volume (high volume defined as the fourth quartile). Thirteen studies were included, with a total of 1087 patients. Pooled proportions revealed an overall morbidity of 13% (95% confidence interval [CI] = 7%-24%, I²  = 90%), severe morbidity of 7% (95% CI = 4%-14%, I²  = 70%), 30-day mortality of 2% (95% CI = 1%-3%, I²  = 0%), 90-day mortality of2% (95% CI = 2%-4%, I²  = 35%) and in-hospital mortality of 1% (95% CI = 0%-2%, I²  = 0%). An annual hospital volume of nine or more resections was associated with lower overall and severe morbidity compared to lower volume: 10% vs 15% and 4% vs 9%, respectively. Thirty-day mortality was similar (2% vs 1%) and 90-day mortality was higher in high-volume hospitals: 4% vs 1%. This systematic review with meta-analyses showed severe morbidity of 7% and low mortality rates after resection of SB-NEN. The currently available literature suggests a certain impact of hospital volume on postoperative outcomes, although heterogeneity among the included studies constrains interpretation.

Currently available treatment options for neuroendocrine liver metastases

Neuroendocrine neoplasms (NEN) are frequently characterized by a high propensity for metastasis to the liver, which appears to be a dominant site of distant-stage disease, affecting quality of life and overall survival. Liver surgery with the intention to cure is the treatment of choice for resectable neuroendocrine liver metastases (NELM), aiming to potentially prolong survival and ameliorate hormonal symptoms refractory to medical control. Surgical resection is indicated for patients with NELM from well-differentiated NEN, while its feasibility and complexity are largely dictated by the degree of liver involvement. As a result of advances in surgical techniques over the past decades, complex 1- and 2-stage, or repeat liver resections are performed safely and effectively by experienced surgeons. Furthermore, liver transplantation for the treatment of NELM should be anchored in a multimodal and multidisciplinary therapeutic strategy and restricted only to highly selected individual cases. A broad spectrum of interventional radiology treatments for NELM have recently been available, with expanding indications that are more applicable, as they are less limited by patient- and tumor-related parameters, being therefore important adjuncts or alternatives to surgery. Overall, liver-targeted treatment modalities may precede the administration of systemic molecular targeted agents and chemotherapy for patients with liver-dominant metastatic disease; these appear to be a crucial component of multimodal management of patients with NEN. In the present review, we discuss surgical and non-surgical liver-targeted treatment approaches for NELM, each complementing the other, with a view to assisting physicians in optimizing multimodal NEN patient care.

Intraindividual comparison of 18 F-FDOPA and 68 Ga-DOTATOC PET/CT detection rate for metastatic assessment in patients with ileal neuroendocrine tumours

INTRODUCTION

In patients with ileal neuroendocrine tumours (ileal NETs), head-to-head evaluation of diagnostic performances of ⁶⁸ Ga-DOTA-peptides and ¹⁸ F-fluorodihydroxyphenylalanine (¹⁸ F-FDOPA) positron emission tomography/computed tomography (PET/CT) has been performed in only few small patients' cohorts. The aim of this retrospective study was to compare ⁶⁸ Ga-DOTATOC and ¹⁸ F-FDOPA PET/CT for metastatic disease assessment in a homogeneous large series of patients with well-differentiated ileal NETs.

METHODS

All patients with ileal NETs who underwent both ¹⁸ F-FDOPA and ⁶⁸ Ga-DOTATOC PET/CT within a 3-month period and no therapeutic change between the two studies were retrospectively included. The detection rates of both modalities were calculated using per-patient, per-region and per-lesion analyses.

RESULTS

Forty one patients with ileal NETs were evaluated. ¹⁸ F-FDOPA and ⁶⁸ Ga-DOTATOC showed similar detection rates according to per-patient (97% for both) and per-region analyses (94% for ¹⁸ F-FDOPA vs 88% for ⁶⁸ Ga-DOTATOC, P = .35). For a total of 605 positive lesions, 458 (76%) were detected by both modalities, 122 (20%) exclusively by ¹⁸ F-FDOPA PET/CT, and 25 (4%) by ⁶⁸ Ga-DOTATOC PET/CT only. In a per-lesion analysis, ¹⁸ F-FDOPA PET/CT performed better than ⁶⁸ Ga-DOTATOC PET/CT (overall detection rates of 96% vs 80%; P < .001). ¹⁸ F-FDOPA PET/CT detected significantly more metastases than ⁶⁸ Ga-DOTATOC PET/CT in the liver, peritoneum, abdominal and supra-diaphragmatic lymph nodes.

CONCLUSION

¹⁸ F-FDOPA PET/CT seems not inferior than ⁶⁸ Ga-DOTATOC PET/CT for the delineation of metastatic spread of ileal NETs. Therefore, according to local expertise and technical availability, ¹⁸ F-FDOPA should be considered as a valid clinical diagnostic option for exhaustive metastatic assessment in patients with ileal NETs. Obviously, ⁶⁸ Ga-DOTATOC PET/CT remains mandatory for PRRT assessment. Further comparative studies are needed to determine the optimal approach in various clinical scenarios such as preoperative staging and primary tumour detection.

Examining Perioperative Risk Associated with Simultaneous Resection of Primary Neuroendocrine Tumors and Synchronous Hepatic Metastases

BACKGROUND

Surgical debulking of primary neuroendocrine tumors (NETs) and hepatic resection of metastatic NET disease may each independently improve overall survival. However, evidence for combined primary site debulking and metastasectomy on survival and impact on short-term perioperative outcomes is limited.

METHODS

The 2014-2016 ACS-NSQIP targeted hepatectomy database was queried for all patients undergoing liver resection for metastatic NET. Secondary procedure codes were evaluated for major concurrent operations. Multivariable analysis was performed to determine risk factors for 30-day morbidity and mortality.

RESULTS

A total of 472 patients were identified, of whom 153 (32.4%) underwent ≥1 additional concurrent major operation. The most common concurrent procedures were small bowel resection (14.6%), partial colectomy (8.9%), and radical lymphadenectomy (7.4%). Among all patients, overall 30-day mortality and morbidity were 1.5% and 25.6%, respectively. Modifiable and treatment-related factors associated with increased major postoperative morbidity risk included >10% weight loss within six months of surgery (p = 0.05), increasing number of hepatic lesions treated (p = 0.05), and biliary reconstruction (p = 0.001). No major concurrent procedure was associated with increased 30-day morbidity (all p > 0.05).

CONCLUSIONS

Approximately one-third of patients with stage IV NET underwent combined hepatic and multi-organ resection. Although modifiable and treatment-related factors predictive of perioperative morbidity were identified, performance of concurrent major procedures did not increase perioperative morbidity. These results support consideration of multi-organ resection in carefully selected patients with metastatic NET.

Surgery and Perioperative Management in Small Intestinal Neuroendocrine Tumors

Small-intestinal neuroendocrine tumors (SI-NETs) are the most prevalent small bowel neoplasms with an increasing frequency. In the multimodal management of SI-NETs, surgery plays a key role, either in curative intent, even if R0 resection is feasible in only 20% of patients due to advanced stage at diagnosis, or palliative intent. Surgeons must be informed about the specific surgical management of SI-NETs according to their hormonal secretion, their usual dissemination at the time of diagnosis and the need for bowel-preserving surgery to avoid short bowel syndrome. The aim of this paper is to review the surgical indications and techniques, and perioperative and postoperative management of SI-NETs.