Active surveillance strategy for low-grade appendiceal mucinous neoplasm (LAMN): 5-year results
Abstract
Objectives Low-grade appendiceal mucinous neoplasms (LAMNs) are rare tumors with potential progression to pseudomyxoma peritonei (PMP). The optimal management of patients without macroscopic peritoneal disease remains debated. We previously reported 3-year outcomes of an active surveillance (AS) strategy. This study evaluates the 5-year results of the same cohort. Methods This prospective observational study was conducted at a tertiary referral center. Patients with histologically confirmed LAMN, normal postoperative MRI and tumor markers, and limited or no extra-appendiceal mucin were enrolled in an AS protocol. Surveillance included clinical examination, serum tumor markers, and abdominopelvic MRI at 6 months and annually thereafter. Disease progression was defined as histologically proven PMP. Results Among the 30 patients initially included, 25 completed a mean 5-year follow-up and 5 were excluded after exceeding 75 years of age. No new PMP cases occurred among patients disease-free at 3 years. All four patients previously suspected of radiologic progression underwent cytoreduction and HIPEC; only two (8 %) had histologically confirmed low-grade PMP and achieved remission after complete cytoreduction. Two cases were false-positive imaging findings. Conclusions After 5 years, active surveillance remains a safe and effective long-term strategy for selected patients with LAMN, supporting conservative MRI-based follow-up and avoiding unnecessary aggressive surgery.
Related
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BibTeX
@article{mouawad2026active,
title = {{Active surveillance strategy for low-grade appendiceal mucinous neoplasm (LAMN): 5-year results}},
author = {Christian Mouawad and Armelle Bardier and Olivier Lucidarme and Solène Doat and Dahbia Djelil and Jade Fawaz and Marc Pocard},
journal = {Pleura and peritoneum},
year = {2026},
month = sep,
doi = {10.1515/pp-2025-0043},
url = {https://u-picardie.hal.science/hal-05749112v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Active surveillance strategy for low-grade appendiceal mucinous neoplasm (LAMN): 5-year results
AU - Christian Mouawad
AU - Armelle Bardier
AU - Olivier Lucidarme
AU - Solène Doat
AU - Dahbia Djelil
AU - Jade Fawaz
AU - Marc Pocard
PY - 2026
DA - 2026/09/14
JO - Pleura and peritoneum
DO - 10.1515/pp-2025-0043
UR - https://u-picardie.hal.science/hal-05749112v1
AB - Objectives Low-grade appendiceal mucinous neoplasms (LAMNs) are rare tumors with potential progression to pseudomyxoma peritonei (PMP). The optimal management of patients without macroscopic peritoneal disease remains debated. We previously reported 3-year outcomes of an active surveillance (AS) strategy. This study evaluates the 5-year results of the same cohort. Methods This prospective observational study was conducted at a tertiary referral center. Patients with histologically confirmed LAMN, normal postoperative MRI and tumor markers, and limited or no extra-appendiceal mucin were enrolled in an AS protocol. Surveillance included clinical examination, serum tumor markers, and abdominopelvic MRI at 6 months and annually thereafter. Disease progression was defined as histologically proven PMP. Results Among the 30 patients initially included, 25 completed a mean 5-year follow-up and 5 were excluded after exceeding 75 years of age. No new PMP cases occurred among patients disease-free at 3 years. All four patients previously suspected of radiologic progression underwent cytoreduction and HIPEC; only two (8 %) had histologically confirmed low-grade PMP and achieved remission after complete cytoreduction. Two cases were false-positive imaging findings. Conclusions After 5 years, active surveillance remains a safe and effective long-term strategy for selected patients with LAMN, supporting conservative MRI-based follow-up and avoiding unnecessary aggressive surgery.
SN - 2364-7671
SN - 2364-768X
ER -