Surgical and Oncologic Outcomes of Primary Tumor Resection in Patients with Small Intestinal Neuroendocrine Tumors: Results from a Single-Center Series Over a 15-Year Period.

BACKGROUND

The role of prophylactic primary tumor resection (PTR) in patients with small intestinal neuroendocrine tumors (SI-NETs) and unresectable liver metastases is a matter of debate.

OBJECTIVE

We aimed to evaluate outcomes in patients with SI-NETs who underwent PTR, according to the presence of metastasis and symptoms from primary.

MATERIAL AND METHODS

Data from patients who underwent PTR for SI-NETs from a single referral center (2007-2023) were prospectively collected. Patients were divided into three groups: non-metastatic (M0) and metastatic with primary tumor-related symptoms (MS) or metastatic asymptomatic (MA). Kaplan-Meier curves for overall survival (OS) and event-free survival (EFS) were generated and compared by group. Univariate and multivariable Cox regression analyses were performed to assess the significance of risk factors.

RESULTS

Of 147 patients, 53 were M0, 23 were MS, and 71 were MA. Median follow-up was 26 months. The 5- and 10-year OS estimates were 100% and 100% in M0 patients, 82 and 21% in MS patients, and 89 and 80% in MA patients, respectively (p < 0.001). Median EFS was 91 months overall and 43,126 months and not reached for the MS, MA, and M0 groups, respectively (p < 0.001). In multivariable analysis, MS (hazard ratio [HR] 3.92, 95% confidence interval [CI] 1.71-9.52), functioning tumors (HR 1.98, 95% CI 1.03-3.81), and G2 grade (HR 3.20, 95% CI 1.64-6.85) were associated with a shorter EFS.

CONCLUSIONS

In this large retrospective series, the MS group had a significantly worse OS and EFS compared with M0 and MA. This finding suggests that prophylactic PTR might benefit SI-NET patients with unresectable liver metastases, as symptom development could impair long-term prognosis after surgery.