Management Strategies and Outcomes for Type 1 Gastric Neuroendocrine Tumors Measuring More Than 1 cm.

INTRODUCTION

Type 1 gastric neuroendocrine tumors (T1g-NETs) are well-differentiated lesions with excellent survival but frequent recurrence. Tumor size is the main prognostic factor, yet optimal management for tumors >1 cm remains uncertain. This study aimed to evaluate treatment strategies and outcomes in patients with T1g-NETs>1 cm.

METHODS

We conducted a retrospective multicenter study including 106 adults with T1g-NETs >1 cm. Clinicopathologic and management data were collected. The primary outcome event was a composite unfavorable outcome, defined as recurrence or progression, used to analyze progression-free survival (PFS) as the main time-to-event outcome. Analyses included multinomial logistic regression, Cox models, and Kaplan-Meier curves ( P < 0.05).

RESULTS

Among 106 patients (58.5% female; median age 59), median tumor size was 15 mm. Most tumors were Grade 1 (61.4%) or Grade 2 (37.7%), with median Ki-67 of 2%. Endoscopic resection was performed in 76 patients (71.7%), surgery in 33 (31.1%, including 13 initially treated endoscopically), and 10 (9.4%) were surveilled. Over a median 61-month follow-up, 24 patients (22.6%) recurred, 8 (7.5%) progressed; only 2 deaths (1.9%) were tumor-related. Larger tumors were associated with unfavorable outcome ( P = 0.005), with lesions ≥24 mm predicting shorter PFS (hazard ratio 3.93; P < 0.001). Endoscopic submucosal dissection and modified-endoscopic mucosal resection were associated with a significantly longer PFS ( P = 0.004). R0 resection showed a borderline protective effect. Five-year overall survival approached 95%.

DISCUSSION: T1g-NETs > 1 cm frequently recur and may exhibit aggressive potential, particularly when lesions are larger. When endoscopic resection is feasible, endoscopic submucosal dissection or modified-endoscopic mucosal resection should be preferred to optimize outcomes.