Clinicopathological Features and Outcomes in 132 patients with Perforated High Grade Appendiceal Mucinous Neoplasm Treated with Cytoreductive Surgery and HIPEC ; A Single Institution Experience
Menée à partir de données 2015-2023 portant sur 132 patients présentant des tumeurs mucineuses appendiculaires de haut grade, cette étude analyse les résultats d'un traitement combinant chirurgie de cytoréduction et chimiothérapie hyperthermique intrapéritonéale
Background: Non infiltrative mucinous appendiceal neoplasms are categorized into low grade appendiceal mucinous neoplasms (LAMN) and high grade appendiceal mucinous neoplasms (HAMN). The incidence of lymph node involvement in patients with a HAMN, the need for right hemicolectomy and its impact on prognosis after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has not been widely studied, nor reported.
Methods: This was a single institution retrospective analysis of prospectively collected data of patients who underwent CRS and HIPEC for a HAMN between January 2015 and December 2023. Clinicopathological variables such as Peritoneal Cancer Index (PCI), completeness of cytoreduction (CC), histological subtype, lymph node status and survival were analysed.
Results: Between 2015 and 2023, 1615 patients underwent CRS and HIPEC for perforated appendiceal tumours. HAMNs were histologically confirmed in 132/1615 (8.2%). CRS and HIPEC was performed for a HAMN diagnosed after appendicectomy in 54/132 (40.9%) and 78 presented with the appendix tumour in situ, proceeding straight to surgery. The peritoneal disease in patients with HAMN was high grade mucinous carcinoma peritonei (MCP) in the majority (58.3%), with the remainder having low grade MCP (15.1%), acellular mucin (12.9%) or no peritoneal disease (13.6%). Overall, 96/132 (72.7%) underwent a right hemicolectomy as part of cytoreduction. Eight patients (8/96, 8.3%) had lymph node involvement in the colectomy specimens. The median PCI for those with nodal metastases (N=8) was 29 with high grade MCP in all 8. Overall, 37/132 developed recurrence during the study period. All had peritoneal recurrence and 9/37 also had thoracic disease. In the 54 patients who had a HAMN at previous appendicectomy, 20/54 (37%) had no detectable disease on pre-operative imaging. However, histologically confirmed peritoneal disease was detected in the cytoreductive surgery specimen in 7/20 (35%).
Conclusion: Less than 10% of patients with a perforated HAMN had involved nodes. Positive lymph node status appeared to be associated with high volume and high grade peritoneal disease. Overall, 35% of patients with a HAMN at appendicectomy had histologically proven peritoneal disease despite normal imaging. CRS and HIPEC is advocated for selected patients with a HAMN, predominantly for peritoneal disease cure and control.
European Journal of Surgical Oncology , résumé, 2026