Right Hemicolectomy is not Routinely Indicated in Pseudomyxoma Peritonei

Abstract

Pseudomyxoma peritonei (PMP) is primarily the result of a ruptured mucinous appendix neoplasm (MAN). Often MAN is lumped with but biologically distinct from intestinal appendiceal adenocarcinoma. Nodal and systemic dissemination are rare with the peritoneal cavity being the primary site of recurrence. Routine performance of right hemicolectomy (RHC) for PMP/MAN has been extensively debated without consensus. Our objective was to ascertain whether RHC has a survival advantage over appendectomy. We hypothesize if RHC is mandatory, then increased tumor recurrence and mortality should be observed in appendectomy only. Retrospective chart review was carried out in patients with tumors that met the Ronnett classification for PMP/MAN. Demographics, tumor grade, extent, recurrence, and progression were recorded. We report the rate of nodal involvement/recurrence in patients treated with RHC versus appendectomy as well as the rate of systemic and peritoneal recurrence and survival. Multivariate logistic regression was done to identify factors that impact survival. Of 120 patients, 48 had appendectomy and 72 had RHC. Seven per cent of patients undergoing RHC had positive lymph nodes and no nodal failures (0%) in patients undergoing appendectomy. Appendectomy versus RHC recurrence rates (21 vs. 28%, P = 0.12) and death resulting from disease (8 vs. 22%, P = 0.27) were similar. Logistic regression revealed that the type of surgery had no impact on recurrence and mortality, only optimal resection score and performance status. There was no difference in tumor recurrence or survival based on treatment by appendectomy or RHC. Performance status and complete cytoreduction are the only factors associated with survival. Lymph node involvement is rare and selective RHC is safe in PMP/MAN.