Current status of Interventional Radiology in the management of Gastro-Entero-Pancreatic Neuroendocrine Tumours (GEP-NETs). Cardiovasc Intervent Radiol. 2015;38:13-24. [PMID: 25366087 DOI: 10.1007/s00270-014-1005-z]

[Radiologically guided interventional therapies for the treatment of neuroendocrine tumors]

BACKGROUND

The majority of patients with neuroendocrine tumors (NET) develop liver metastases during the course of the disease, significantly impacting prognosis and quality of life.

CLINICAL ISSUE

Radiologically guided interventional therapies, such as thermal ablation, transarterial embolization (TAE)/chemoembolization (TACE), and selective internal radiotherapy (TARE), can play a crucial role in the treatment of metastatic NET.

DATA

Due to the rarity of the disease, the majority of evidence is based on retrospective studies. For thermal ablation, the complete response rates ranging from 31.6 to 95.3% depending on the study. No significant differences in outcomes were found between TAE, TACE, and TARE. In several studies, all intra-arterial procedures led to a reduction of tumor-related symptoms and achieved disease control.

CONCLUSION

Thermal ablation can be used as a curative therapy in oligometastatic patients with nonresectable liver metastases from NETs. In cases of disseminated liver metastases, intra-arterial therapy using TAE, TACE, or TARE can be employed.

Clinical Outcomes of DEB-TACE in Hepatic Metastatic Neuroendocrine Tumors: A 5-Year Single-Institutional Experience

RATIONALE AND OBJECTIVES

To evaluate single-institution outcomes of drug-eluting bead transarterial chemoembolization (DEB-TACE) in the treatment of locally advanced neuroendocrine tumor (NET) hepatic metastases with a focus on safety and efficacy of treatment.

MATERIALS AND METHODS

A single-center retrospective cohort study of the outcomes of consecutive patients with NELM who underwent DEB-TACE between 2014 and 2019 was performed. Clinicopathologic characteristics, radiologic response (modified Response Evaluation Criteria in Solid Tumors) at 1-month follow-up, adverse events, progression-free survival (PFS), and overall survival were calculated.

RESULTS

Among 287 patients (mean age of 62 years; 39% male: 61% female), disease burden was bilobar (90.2%) with mean largest tumor diameter measuring 4.9 ± 2.8 cm. Of these patients, 14.6% had no evidence of tumor in other organs or lymph nodes. Complete response occurred in 60 (20.9%) patients while 133 (46.3%) had partial responses. Major complication occurred in 2.4%. Liver function tests including total bilirubin and AST were overall stable at the 1-month follow-up, with only a small increase in the ALT at +8.9% (p < 0.01). Overall survival was 80.1% at 1 year, 49.1% at 3 years, and 12.3% at 5 years with a mean PFS of 14.4 ± 12.5 months.

CONCLUSION

Based on this institutional experience, DEB-TACE is an acceptable locoregional therapy choice for hepatic metastases of NET due to its tolerable safety profile and relative efficacy.

Contemporary indications for and outcomes of hepatic resection for neuroendocrine liver metastases

BACKGROUND

Although surgical resection is associated with the best long-term outcomes for neuroendocrine liver metastases (NELM), the current indications for and outcomes of surgery for NELM from a population perspective are not well understood.

AIM

To determine the current indications for and outcomes of liver resection (LR) for NELM using a population-based cohort.

METHODS

A retrospective review of the 2014-2017 American College of Surgeons National Surgical Quality Improvement Program and targeted hepatectomy databases was performed to identify patients who underwent LR for NELM. Perioperative characteristics and 30-d morbidity and mortality were analyzed.

RESULTS

Among 669 patients who underwent LR for NELM, the median age was 60 (interquartile range: 51-67) and 51% were male. While the number of metastases resected ranged from 1 to 9, the most common (45%) number of tumors resected was one. The majority (68%) of patients had a largest tumor size of < 5 cm. Most patients underwent partial hepatectomy (71%) while fewer underwent a right or left hepatectomy or trisectionectomy. The majority of operations were open (82%) versus laparoscopic (17%) or robotic (1%). In addition, 30% of patients underwent intraoperative ablation while 45% had another concomitant operation including cholecystectomy (28.8%), bowel resection (20.2%), or partial pancreatectomy (3.4%). Overall 30-d morbidity and mortality was 29% and 1.3%, respectively. On multivariate analysis, American Society of Anesthesiologists class ≥ 3 [odds ratios (OR), OR = 2.089, 95% confidence intervals (CI): 1.197-3.645], open approach (OR = 1.867, 95%CI: 1.148-3.036), right hepatectomy (OR = 1.618, 95%CI: 1.014-2.582), and prolonged operative time of > 230 min (OR = 1.731, 95%CI: 1.168-2.565) were associated with higher 30-d morbidity while intraoperative ablation and concomitant procedures were not.

CONCLUSION

LR for NELM was performed with relatively low postoperative morbidity and mortality. Concomitant procedures performed at the time of LR did not increase morbidity.

Non-Pharmacological Therapeutic Options for Liver Metastases in Advanced Neuroendocrine Tumors

The incidence of liver metastasis in digestive neuroendocrine tumors is high. Their presence appears as an important prognostic factor in terms of quality of life and survival. These tumors may be symptomatic because of the tumor burden itself and/or the hormonal hyper-secretion induced by the tumor. Surgery is the treatment of choice for resectable tumors and metastasis. Nevertheless, surgery is only possible in a small number of cases. The management of non-resectable liver metastasis is a challenge. The literature is rich but consists predominantly in small retrospective series with a low level of proof. Thus, the choice of one technique over another could be difficult. Local ablative techniques (radiofrequency) or trans-catheter intra-arterial liver-directed treatments (hepatic artery embolization, chemo-embolization, and radio-embolization) are frequently considered for liver metastasis. In the present review, we focus on these different therapeutic approaches in advanced neuroendocrine tumors, results (clinical and radiological), and overall efficacy, and summarize recommendations to help physicians in their clinical practice.

Pretreatment hematologic markers as prognostic predictors of gastroenteropancreatic neuroendocrine tumors: a systematic review and meta-analysis

Background

Systemic inflammation can be reflected by peripheral hematologic parameters and combined index like the lymphocyte count, neutrophil count, platelet count, neutrophil-to-lymphocyte (NLR), and platelet-to-lymphocyte ratio (PLR). This systematic review and meta-analysis aimed to summarize the association between the hematologic markers and prognosis of gastroenteropancreatic neuroendocrine tumors (GEP–NETs).

Methods

A computerized systematic search of PubMed, Embase, and Web of Science was conducted up to August 2016. Studies evaluating prognosis value of hematologic parameters in patients with GEP–NETs were retrieved. For meta-analysis, hazard ratios (HRs) with 95% confidence intervals (95% CIs) were extracted and synthesized using Review Manager software.

Results

We identified eight retrospective cohort studies comprising a total of 724 cases. The majority of included studies focused on pancreatic neuroendocrine tumors (PNETs). The prognostic values of NLR, PLR, and platelet count were reported in six studies, two studies, and one study, respectively. All the parameters were associated with prognostic outcomes in patients with GEP–NETs. A high NLR was significantly associated with poor prognosis in GEP–NETs (pooled HR 3.05, 95% CI 1.96–4.76, I² = 0%, P < 0.00001 for overall survival (OS); pooled HR 3.30, 95% CI 2.04–5.32, I² = 0%, P < 0.00001 for recurrence-free survival [RFS]). In PNETs, pooled-analyses also showed significant superiority of a low NLR on OS (pooled HR 4.21, 95% CI 1.95–9.13, I² = 0%, P = 0.0003) and RFS (pooled HR 5.37, 95% CI 2.14–13.47, I² = 0%, P = 0.003).

Conclusions

These findings suggest that the elevated NLR could be an adverse prognosis factor for GEP–NETs. The conclusion should be mainly limited to PNETs as the majority of included cases were PNET patients. The prognostic value of other hematologic parameters deserves further investigation. We recommend that further studies should use a continuous NLR variable and adopt a prospective and matched study design.

Current and emerging therapies for PNETs in patients with or without MEN1

Pancreatic neuroendocrine tumours (PNETs) might occur as a non-familial isolated endocrinopathy or as part of a complex hereditary syndrome, such as multiple endocrine neoplasia type 1 (MEN1). MEN1 is an autosomal dominant disorder characterized by the combined occurrence of PNETs with tumours of the parathyroids and anterior pituitary. Treatments for primary PNETs include surgery. Treatments for non-resectable PNETs and metastases include biotherapy (for example, somatostatin analogues, inhibitors of receptors and monoclonal antibodies), chemotherapy and radiological therapy. All these treatments are effective for PNETs in patients without MEN1; however, there is a scarcity of clinical trials reporting the efficacy of the same treatments of PNETs in patients with MEN1. Treatment of PNETs in patients with MEN1 is challenging owing to the concomitant development of other tumours, which might have metastasized. In recent years, preclinical studies have identified potential new therapeutic targets for treating MEN1-associated neuroendocrine tumours (including PNETs), and these include epigenetic modification, the β-catenin-wingless (WNT) pathway, Hedgehog signalling, somatostatin receptors and MEN1 gene replacement therapy. This Review discusses these advances.

Liver transarterial embolizations in metastatic neuroendocrine tumors

The management of patients with well-differentiated neuroendocrine tumors (NET) and non-resectable liver metastases is challenging. Liver-directed transarterial embolization (TAE), transarterial chemo-embolization (TACE) and selective internal radiation therapy (SIRT) have a place of choice among other treatment modalities. However, their utilization relies on a low level of proof, due to the lack of prospective data, the absence of comparative studies and considerable heterogeneity between local practices. TAE and TACE generally achieve average symptomatic, biological and radiological responses of 75%, 56% and 50%, with progression-free survival of 12-18 months, with acceptable tolerance. Although not clearly demonstrated, TACE may be more effective than TAE in pancreatic NET, but not in small-intestine NET. SIRT has been developed more recently and may achieve similar results, with improved tolerance, but decreased cost-effectiveness, although no prospective comparison has been published to date. There is currently no strong argument to choose between TAE, TACE and SIRT, and they have not been compared to other treatment modalities. The evaluation of their efficacy has mostly relied on criteria based on size variations, which do not take into account tumor viability and metabolism, and thus may not be relevant. These techniques may be especially effective when performed as first-line therapies, in patients with non-major liver involvement (<75%) and with hypervascular metastases. Finally, studies exploring their combination with systemic therapies are ongoing.

Radiolabeled Somatostatin Analogue Therapy Of Gastroenteropancreatic Cancer

Peptide receptor radionuclide therapy (PRRT) has been utilized for more than two decades and has been accepted as an effective therapeutic modality in the treatment of inoperable or metastatic gastroenteropancreatic neuroendocrine neoplasms (NENs) or neuroendocrine tumors (NETs). The two most commonly used radiopeptides for PRRT, (90)Y-octreotide and (177)Lu-octreotate, produce disease-control rates of 68%-94%, with progression-free survival rates that compare favorably with chemotherapy, somatostatin analogues, and newer targeted therapies. In addition, biochemical and symptomatic responses are commonly observed. In general, PRRT is well tolerated with only low to moderate toxicity in most individuals. In line with the need to place PRRT in the therapeutic sequence of gastroenteropancreatic NENs, a recently sponsored phase III randomized trial in small intestine NENs treated with (177)Lu-octreotate vs high-dose octreotide long-acting release demonstrated that (177)Lu-octreotate significantly improved progression-free survival. Other strategies that are presently being developed include combinations with targeted therapies or chemotherapy, intra-arterial PRRT, and salvage treatments. Sophisticated molecular tools need to be incorporated into the management strategy to more effectively define therapeutic efficacy and for an early identification of adverse events. The strategy of randomized controlled trials is a key issue to standardize the treatment and establish the position of PRRT in the therapeutic algorithm of NENs.