Strategies for Preventing Pseudomyxoma Peritonei After Resection of a Mucinous Neoplasm of the Appendix.

Background/aim: Considering the suspected link between mucinous neoplasm (MN) and pseudomyxoma peritonei (PMP), one option could be to propose prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) to selected patients in order to prevent the occurrence of PMP. The aim of this study was to identify risk factors for developing PMP after curative surgery for a MN of the appendix.

Patients And Methods: All consecutive patients referred to our single tertiary care cancer center between September 1992 and March 2014 for MN of the appendix, initially without PMP, were retrospectively studied. Patients who had received prophylactic intraperitoneal treatment were excluded from the analysis.

Results: Twenty-five patients with a median age of 51 (range=25-74) years were identified. At the initial appendectomy, 19 (76%) patients had a perforated MN. Nine of these patients (40%) exhibited disseminated-free acellular intraperitoneal mucin without PMP. Six (24%) patients had an unperforated MN without free intraperitoneal mucin. After a median follow-up of 50 months, 12 (52%) patients had developed PMP after a median time of 61 (range=13-121) months. Complete cytoreductive surgery plus HIPEC was possible in only seven (64%) out of these 12 patients. No factor reached statistical significance in predicting the occurrence of PMP but a trend was found in the case of perforated MN (p=0.068), associated with a 65% recurrence rate, compared to 17% without perforation.

Conclusion: An appendicular MN cannot be considered a benign occurrence because PMP is common after resection and can occur up to 10 years after the initial appendectomy. Patients should be systematically followed up to detect PMP as early as possible. Patients with a perforated MN could be at higher risk of developing PMP.