Consensus Guideline for the Management of Peritoneal Metastases from Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NEN) with peritoneal metastases (PM) represent a complex clinical challenge due to low incidence and heterogeneous phenotypes. This manuscript describes the results of a national consensus aimed at addressing clinical management of patients with NEN-PM.

An update of the 2018 Chicago consensus guidelines was conducted using a modified Delphi technique, encompassing two rounds of voting. The levels of agreement for various pathway blocks were assessed. Key systemic therapy concepts were summarized by content experts. Supporting evidence was evaluated via a rapid literature review.

Overall, the level of evidence for the management of PM in this disease was universally low. In total, 107 participants responded in the first round, with 88/107 (82%) participating in the second round. Strong consensus (> 90%) was achieved in 5/7 (71%) and 7/7 (100%) blocks in rounds I and II respectively. A multidisciplinary approach including psychosocial and wellness assessments received a strong positive recommendation. Management of NENs with PM was organized according to disease grade and symptom profiles. In grade 1 and 2 well-differentiated NENs, cytoreductive surgery (CRS) received strong support (>95%) following the management of functional syndromes (if present). For grade 3 well-differentiated NENs, systemic therapy is the primary recommendation, with surgical resection considered in select cases.

Given limited evidence, the consensus-driven clinical pathway offers vital clinical guidance for the management on NENs with PM. The need for high-quality evidence remains critical to the field.