# Indications for Surgical Resection in Patients With Neuroendocrine Tumor Liver Metastases: An Intensive Surgical Experience of a High‐Volume Center

## TL;DR

This study identifies criteria for selecting patients with liver metastases from neuroendocrine tumors who may benefit from surgical resection based on tumor grade and number of metastases.

## Contribution

The study provides specific surgical indications for neuroendocrine liver metastases based on tumor grade and metastasis count to guide treatment decisions.

## Key findings

- Patients with fewer than 8 liver metastases and NET-G1/2 tumors have better recurrence-free survival after resection.
- Surgical resection for patients with 8 or more metastases or NET-G3 tumors is associated with very short recurrence-free survival.
- Multidisciplinary treatment is recommended for patients who do not meet the favorable criteria.

## Abstract

Surgical resection for neuroendocrine liver metastasis (NELM) is the key to long survival; however, the indications remain unclear due to the high recurrence rate. We aimed to identify candidates who would benefit from surgical resection for NELM.

Patients with NELM treated at our institution from January 2005 to December 2020 were included. Neuroendocrine carcinoma (NEC) was excluded. Risk factors for overall survival (OS) and recurrence‐free survival (RFS) were analyzed. The cut‐off value for the number of NELM predicting poor RFS was determined by minimum p‐value approach.

Of the total 126 patients, 67 patients underwent liver resection. The median follow‐up time from the date of initial diagnosis of NELM was 4.3 years. Surgical resection and NET‐G1/2 were associated with good OS in multivariate analysis (p < 0.001). In patients underwent R0/1 resection (n = 44), NET‐G3 [HR: 3.1 (95% CI 1.4–7.2)] and the number of NELM [HR: 1.1 (95% CI 1.0–1.1)] were associated with poor RFS in multivariate analysis. The optimal cut‐off value for the number of NELM was calculated as 8. The median RFS for patients with 8 or more liver metastases or NET‐G3 was 3.9 months, which was extremely short compared to patients with NET‐G1/2 (13.8 months) and to those who had fewer than 8 liver metastases (19.1 months).

This study suggests that fewer than 8 liver metastases and NET‐G1/2 are indications for surgical resection in patients with NELM considering the RFS. Surgical resection for patients with 8 or more liver metastases or NET‐G3 needs deliberate selection.

In patients with NELM, those with < 8 liver metastases and G1/2 tumors are the favorable candidates for liver resection. The important point of this study is that the patients who do not meet the above criteria should be considered for multidisciplinary treatment because of their extremely shorter recurrence‐free period.