# Proposed strategy after complete LAMN (low-grade appendiceal mucinous neoplasm) resection by different RENAPE units: need for a new consensus?

## TL;DR

French experts show differing post-surgery strategies for a rare appendix tumor, highlighting the need for unified guidelines.

## Contribution

Identifies significant variability in postoperative management of LAMNs among French RENAPE centers, suggesting a need for new consensus guidelines.

## Key findings

- 91% of RENAPE centers responded to the survey on postoperative strategies for LAMNs.
- Significant heterogeneity exists in follow-up recommendations, especially for intermediate-risk cases.
- Only 60% of centers recommend early CRS-HIPEC for high-risk scenarios, while others prefer laparoscopic assessment.

## Abstract

To evaluate current postoperative management strategies for incidentally discovered, completely resected low-grade appendiceal mucinous neoplasms (LAMNs) within the French RENAPE network and to assess the need for a new national consensus.

A national survey was conducted among RENAPE expert centers using a structured questionnaire based on standardized postoperative risk scenarios. Survey items addressed surveillance strategies, indications for reoperation, and use of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

Ninety-one percent of centers responded. All reported systematic multidisciplinary discussion, centralized pathology and imaging review, standardized imaging, and tumor marker assessment. Marked heterogeneity was observed. For low-risk patients (R0 resection, no perforation, no extra-appendiceal mucin), 50 % recommended no follow-up and 50 % proposed long-term MRI surveillance. In intermediate-risk cases (limited perforation or adjacent mucin), 80 % favored MRI follow-up, while 20 % recommended diagnostic laparoscopy or prophylactic CRS-HIPEC. In high-risk scenarios with radiologic suspicion of implants, 60% proposed early CRS-HIPEC, whereas others preferred laparoscopic assessment or surveillance.

This survey highlights wide variation in postoperative strategies for LAMNs within RENAPE, especially in intermediate-risk cases. While consensus exists on centralized review and imaging, significant evidence gaps persist regarding prophylactic HIPEC. These findings underscore the need for harmonized, evidence-based protocols and prospective data collection.