Pseudomyxoma peritonei: a French multicentric study of 301 patients treated with cytoreductive surgery and intraperitoneal chemotherapy.

OBJECTIVE: To analyze a large series of patients with pseudomyxoma peritonei (PMP) treated with cytoreductive surgery associated with perioperative intraperitoneal chemotherapy (PIC) in 18 French-speaking centers.

PATIENTS AND METHODS: From March 1993 to December 2007, 301 patients with diffuse PMP were treated by cytoreductive surgery with PIC. Complete cytoreductive surgery was achieved in 219 patients (73%), and hyperthermic intraperitoneal chemotherapy (HIPEC) was performed in 255 (85%), mainly during the latter period of the study.

RESULTS: Postoperative mortality and morbidity were 4.4% and 40%, respectively. The mean follow-up was 88 months. The 5-year overall and disease-free survival rates were 73% and 56%, respectively. The multivariate analysis identified 5 prognostic factors: the extent of peritoneal seeding (p=0.004), the center (p=0.0004), the pathologic grade (p=0.03), gender (p=0.02), and the use of HIPEC (p=0.04). When only the 206 patients with complete cytoreductive surgery were considered, the extent of peritoneal seeding was the only significant prognostic factor (p=0.004).

CONCLUSION: This large multicentric retrospective study confirms that cytoreductive surgery combined with PIC (with the use of hyperthermia) should be considered as the gold standard treatment of PMP and should be performed in specialized centers. It underlines the prognostic impact of the extent of peritoneal seeding, especially in patients treated by complete cytoreductive surgery. This prognostic impact appears to be greater than that of the pathologic grade.