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

Trans-arterial embolization versus chemoembolization for neuroendocrine liver metastases: a propensity matched analysis

INTRODUCTION

Locoregional therapies are a mainstay of treatment for patients with neuroendocrine liver metastases (NELM), yet the optimal transarterial approach remains undefined and recent studies have raised concern over the safety of transarterial chemoembolization (TACE).

METHODS

Patients with NELM who underwent TACE or transarterial embolization (TAE) at a single institution between 2000-2022 were retrospectively reviewed. Propensity score matching (PSM) controlling for age, sex, bilateral disease, tumor size, lobar embolization, grade, and extrahepatic disease was utilized to compare short- and long-term outcomes.

RESULTS

Among 412 patients with NELM, 329 underwent TACE and 83 TAE. Mean age was 60.7 ± 11.1 years. Patients primarily presented with synchronous (69.2%), bilateral (84.2%), and G1 disease (48.8%) and underwent staged procedures (55.8%). Following PSM, TACE was associated with slightly worse post-procedure laboratory values, but no difference in complications compared to TAE (23.3%vs29.3%, p = 0.247). TACE was associated with improved mean PFS (21.8vs10.7 months, p = 0.002), but no difference in radiographic size, chromogranin level, or median overall survival (50.0 months vs not met, p = 0.833).

CONCLUSION

Among patients with NELM, TACE was associated with similar short-term outcomes and improved PFS, but no difference in OS compared to TAE. These findings highlight the need for additional research on the optimal locoregional therapy for NELM.

Number of Hepatic Resections and Association with Complication after Metastatic Neuroendocrine Tumor Debulking: An American College of Surgeons NSQIP Database Study

BACKGROUND

Neuroendocrine tumor liver metastases (NELM) are a major source of morbidity and mortality in neuroendocrine tumor patients and can be treated with hepatic debulking surgery (HDS). This study aims to identify variables associated with postoperative morbidity in NELM HDS.

STUDY DESIGN

This analysis uses the American College of Surgeons NSQIP targeted hepatectomy-specific Participant User File from 2014 to 2020. Surgeries were grouped by number of hepatic resections performed (1 to 5, 6 to 10, greater than 10). Multivariable logistic regression and matching were used to identify prognostic factors of morbidity.

RESULTS

A total of 1,163 patients were included. A total of 1,011 (87%) had 1 to 5 hepatic resections, 101 (8.7%) had 6 to 10 resections, and 51 (4.4%) had greater than 10 resections. The overall complication rate was 35%, and surgical and medical complications reached 30% and 13%, respectively. Mortality occurred in 11 patients (0.9%). Significantly higher rates of any (34% vs 35% vs 53%, p = 0.021) and surgical complications (29% vs 28% vs 49%, p = 0.007) were noted for those undergoing greater than 10 resections (1 to 5 resections, 6 to 10, greater than 10). "Bleeding requiring transfusion" (p < 0.0001) occurred more frequently in the greater than 10 resection group. On multivariable logistic regression, greater than 10 resections were an independent risk factor for any (odds ratio [OR] 2.53, p = 0.002; OR 2.52, p =. 0013) and surgical (OR 2.53, p = 0.003; OR 2.88, p = 0.005) complications compared with 1 to 5 resections and 6 to 10 resections, respectively. Medical complications (OR 2.34, p = 0.020) and length of stay greater than 5 days (OR 1.98, p = 0.032) were also increased with greater than 10 vs 1 to 5 resections.

CONCLUSIONS

As reported by NSQIP, NELM HDS were performed safely with low mortality. However, more hepatic resections, especially greater than 10, were associated with increased postoperative morbidity and length of stay.

Surgery for metastatic pancreatic neuroendocrine tumors: a narrative review

Background and Objective

Pancreatic neuroendocrine tumors (PanNETs) are derived from the islet cells of the pancreas and have been increasing in incidence. Most of these tumors are nonfunctional although some can secrete hormones and lead to hormone-specific clinical syndromes. Surgery is the mainstay of treatment for localized tumors, however, surgical resection is controversial in metastatic PanNETs. This narrative review seeks to summarize the current literature surrounding surgery, specifically in the controversial area of metastatic PanNETs, review current treatment paradigms, and understand the benefits of surgery in this group of patients.

Methods

Authors searched PubMed using the terms "surgery pancreatic neuroendocrine tumor", "metastatic neuroendocrine tumor", and "liver debulking neuroendocrine tumor" from January 1990 to June 2022. Only English language publications were considered.

Key Content and Findings

There is no consensus among the leading specialty organizations regarding surgery for metastatic PanNETs. When considering surgery for metastatic PanNETs, tumor grade and morphology, location of the primary tumor, extra-hepatic or extra-abdominal disease, as well as liver tumor burden and metastatic distribution should be considered. Because the liver is the most common site of metastasis and liver failure is the most common cause of death in patients with hepatic metastases, attention is centered here on debulking and other ablative techniques. Liver transplantation is rarely used for hepatic metastases but could be beneficial in a small subset of patients. Retrospective studies have demonstrated improvement in survival and symptoms after surgery for metastatic disease, but the lack of prospective randomized control trials significantly limits analysis of surgical benefits in patients with metastatic PanNETs.

Conclusions

Surgery is the standard of care for localized PanNETs, while it remains controversial in metastatic disease. Many studies have shown a survival and symptomatic benefit to surgery and liver debulking in select groups of patients. However, most of the studies on which recommendations are based in this population are retrospective in nature and are subject to selection bias. This presents an opportunity for future investigation.

[Liver metastases of neuroendocrine tumors]

Neuroendocrine liver metastases (NELM) are very heterogeneous with respect to the clinical presentation and the prognosis. The treatment of NELMs requires a multidisciplinary approach and patients with NELM should be referred to a specialized center. When possible, the resection of NELMs provides the best long-term results. The general selection criteria for liver resection include an acceptable general physical condition for a large liver operation, tumors with a favorable differentiation grade 1 or 2, a lack of extrahepatic lesions, a sufficient residual liver volume and the possibility to resect at least 70% of the metastases. Supplementary treatment, including simultaneous liver ablation, are generally safe and can increase the number of patients who can be considered for surgery. For patients with resectable NELM, the resection of the primary tumor is recommended either in a 2-stage or combined procedure. In selected patients with nonresectable NELM a liver transplantation can be carried out, which can be associated with excellent long-term results.

Metastatic disease to the liver: Locoregional therapy strategies and outcomes

Secondary cancers of the liver are more than twenty times more common than primary tumors and are incurable in most cases. While surgical resection and systemic chemotherapy are often the first-line therapy for metastatic liver disease, a majority of patients present with bilobar disease not amenable to curative local resection. Furthermore, by the time metastasis to the liver has developed, many tumors demonstrate a degree of resistance to systemic chemotherapy. Fortunately, catheter-directed and percutaneous locoregional approaches have evolved as major treatment modalities for unresectable metastatic disease. These novel techniques can be used for diverse applications ranging from curative intent for small localized tumors, downstaging of large tumors for resection, or locoregional control and palliation of advanced disease. Their use has been associated with increased tumor response, increased disease-free and overall survival, and decreased morbidity and mortality in a broad range of metastatic disease. This review explores recent advances in liver-directed therapies for metastatic liver disease from primary colorectal, neuroendocrine, breast, and lung cancer, as well as uveal melanoma, cholangiocarcinoma, and sarcoma. Therapies discussed include bland transarterial embolization, chemoembolization, radioembolization, and ablative therapies, with a focus on current treatment approaches, outcomes of locoregional therapy, and future directions in each type of metastatic disease.

Neuroendocrine liver metastases: a contemporary review of treatment strategies

Well-differentiated neuroendocrine tumors (NETs) are globally increasing in prevalence and the liver is the most common site of metastasis. Neuroendocrine liver metastases (NELM) are heterogeneous in clinical presentation and prognosis. Fortunately, recent advances in diagnostic techniques and therapeutic strategies have improved the multidisciplinary management of this challenging condition. When feasible, surgical resection of NELM offers the best long-term outcomes. General indications for hepatic resection include performance status acceptable for major liver surgery, grade 1 or 2 tumors, absence of extrahepatic disease, adequate size and function of future liver remnant, and feasibility of resecting >90% of metastases. Adjunct therapies including concomitant liver ablation are generally safe when used appropriately and may expand the number of patients eligible for surgery. Among patients with synchronous resectable NELM, resection of the primary either in a staged or combined fashion is recommended. For patients who are not surgical candidates, liver-directed therapies such as transarterial embolization, chemoembolization, and radioembolization can provide locoregional control and improve symptoms of carcinoid syndrome. Multiple systemic therapy options also exist for patients with advanced or progressive disease. Ongoing research efforts are needed to identify novel biomarkers that will define the optimal indications for and sequencing of treatments to be delivered in a personalized fashion.