Long-term Outcome of Small, Incidentally Detected Rectal Neuroendocrine Tumors Removed by Simple Excisional Biopsy Compared With the Advanced Endoscopic Resection During Screening Colonoscopy.

BACKGROUND: Incidental, small rectal neuroendocrine tumors during colonoscopy screening are sometimes removed using biopsy forceps. Few studies have examined the clinical course of rectal neuroendocrine tumors removed by simple excisional biopsy.

OBJECTIVE: We investigated the long-term outcome of rectal neuroendocrine tumors removed by simple excisional biopsy compared with standard endoscopic resection.

DESIGN: This was a cohort study.

SETTINGS: This study was performed at a healthcare center in Korea.

PATIENTS: We enrolled patients with rectal neuroendocrine tumors detected during a screening colonoscopy between 2003 and 2015.

MAIN OUTCOME MEASURES: The clinical characteristics and long-term outcomes (overall survival and disease-free survival) of small neuroendocrine tumors <10 mm were compared between the simple excisional biopsy group and advanced endoscopic resection group.

RESULTS: In total, 166 patients were diagnosed with rectal neuroendocrine tumors (≤5 mm, n = 100; 6-9 mm, n = 50; 10-19 mm, n = 15; ≥20 mm, n = 1). Among the 150 patients with neuroendocrine tumors <10 mm, follow-up endoscopy was performed on 99 (59.6%). All of the tumors were confined to the mucosa or submucosa. Thirty-one and 68 patients were included in the simple excisional biopsy and advanced endoscopic resection groups. The overall follow-up duration was 6.5 years (range, 1.0-12.8 y). Neither overall nor disease-related death occurred. Two patients exhibited local recurrence (6.5%, at 8 and 11 y) in the simple excisional biopsy group and 1 patient (1.5%, at 7 y) in the advanced endoscopic resection group, resulting in no significant difference (p = 0.37). All of the recurrences were diagnosed >5 years from initial diagnosis and successfully treated endoscopically.

LIMITATIONS: More long-term data should be warranted.

CONCLUSIONS: The long-term outcome of small rectal neuroendocrine tumors <10 mm removed by simple excisional biopsy was excellent. Neither overall survival nor disease-free survival significantly differed between the simple excisional biopsy group and the advanced endoscopic resection group. Thus, simple excisional biopsy and long-term follow-up can be cautiously applied for small rectal neuroendocrine tumors in clinical practice. See Video Abstract at https://links.lww.com/DCR/A406.