Clinical Outcomes of Patients with Rectal Neuroendocrine Tumors smaller than 10 mm after Endoscopic Resection

Aims Rectal neuroendocrine tumors (r-NETs) are the second most common neuroendocrine tumors in the gastrointestinal tract, with increasing incidence due to improved colonoscopy and cancer screening. These small, low-grade lesions are often discovered incidentally and generally have a favorable prognosis, although up to 20% may be misdiagnosed during endoscopy, risking inadequate treatment. Prognosis is influenced by factors such as tumor size, grading, staging, and lymphovascular invasion, leading to guidelines recommending endoscopic resection for small, low-grade lesions.The study aims to evaluate the clinical outcomes of patients with r-NETs≤10 mm after endoscopic resection [1] [2].

Methods A retrospective single-center study was carried out including patients with rectal neuroendocrine tumors measuring≤10 mm following endoscopic resection. The main endpoint of the study was progression-free survival. Statistical analyses were conducted using MedCalc software, with a p-value of less than 0.05 deemed statistically significant.

Results Out of the 81 patients initially assessed, 68 (83.9%) were included in the study after excluding 13 for various reasons. The final cohort consisted of 40 males (58.8%) and 28 females (41.2%), with a median age of 53 years and a median tumor size of 5 mm (range: 1–10 mm). Among the tumors, 92.6% were classified as G1, while 7.4% were classified as G2. Endoscopic resections were deemed inadequate (using biopsy forceps or cold/hot snare) in 42 cases (61.8%), while advanced techniques (such as EMR, ESD, or TAMIS/TEMS) were applied in 26 cases (38.2%). Positive resection margins were found in 47% of cases, and lymphovascular invasion was present in 1.4%. Tumor recurrence occurred in 3 patients (3.4%) after a median follow-up of 22 months (range: 2–104 months). The median progression-free survival was recorded at 33.5 months, and the median overall survival was 35.5 months (range: 1–170 months). Only two deaths were reported, neither related to the tumor. An attempt to identify predictive factors for disease progression through univariate analysis did not yield significant results.

Conclusions Overall, r-NETs measuring≤10 mm typically demonstrate non-aggressive behavior; however, more extensive prospective studies are necessary to gain a thorough understanding of these rare and heterogeneous tumors.

 

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Conflicts of Interest

Authors do not have any conflict of interest to disclose.

• References

• 1 Fine C, Roquin G, Terrebonne E, Lecomte T, Coriat R, Do Cao C, de Mestier L, Coffin E, Cadiot G, Nicolli P, Lepiliez V, Hautefeuille V, Ramos J, Girot P, Dominguez S, Céphise FV, Forestier J, Hervieu V, Pioche M, Walter T.. Endoscopic management of 345 small rectal neuroendocrine tumours: A national study from the French group of endocrine tumours (GTE). United European Gastroenterol J 2019; 7 (8): 1102-1112
• 2 Rinke A, Ambrosini V, Dromain C, Garcia-Carbonero R, Haji A, Koumarianou A, van Dijkum EN, O'Toole D, Rindi G, Scoazec JY, Ramage J.. European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for colorectal neuroendocrine tumours. J Neuroendocrinol 2023; 35 (6): e13309

Publikationsverlauf

Artikel online veröffentlicht:
27. März 2025