Management of pseudomyxoma peritonei by cytoreduction+HIPEC (hyperthermic intraperitoneal chemotherapy): results analysis of a twelve-year experience.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare peritoneal carcinomatosis, characterized by a slowly progressive disease process with a large amount of mucus containing occasional epithelial cells. PMP is histologically classified into disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA) and an intermediate or discordant feature group (ID). Recent studies have shown that most cases of PMP originate from ruptured appendiceal tumors with progressive dissemination in the peritoneal cavity of mucin-producing epithelial cells. Encouraging results in the treatment of PMP have been reported by surgical cytoreduction of the primitive cancer, peritonectomy (stripping of implants on the peritoneal surface) and intraperitoneal hyperthermic chemoperfusion (HIPEC). In recent trials, this combined approach has been proposed as the standard treatment for PMP. PATIENTS AND METHODS: In this study, the results of twelve years single-institution experience on 60 consecutive patients affected by PMP, treated by cytoreductive surgery and the original semi-closed HIPEC technique are reported with special reference to overall survival (OS) and progression-free survival (PFS).
RESULTS: The postoperative morbidity rate was 45% (27 patients); surgical morbidity was observed in 19 patients and medical complications in 9 cases. No postoperative deaths were observed. The survival data, 53 patients were analized (the last 7 were considered only for the complications rate, postoperative mortality and cancer features, not for OS or PFS because they were too recent for evaluation). At the final follow-up of the 53 patients, five and ten years OS were respectively 94% and 84.6% . DFS was 80% and 70% at five and ten years respectively. The follow-up data indicated that the survival probability may be good in patients with hystological type appendicular adenoma optimally cytoreduced (CCR-0). Interestingly if preoperative chemotherapy was performed represented a negative prognostic factor with statistically significant impact both on OS and DFS.
CONCLUSION: As in other similar studies, cytoreductive surgery plus HIPEC, even when combined with an aggressive surgical procedure, is associated with an acceptable risk of postoperative complications and mortality. This combined treatment results in DFS and OS rates that are not described in the literature for surgery associated with systemic chemotherapy and, in our opinion, may be considered the gold standard treatment for this rare tumor.