Pseudomyxoma peritonei. Long-term patient survival with an aggressive regional approach.

Abstract

The aims of this study were to analyze the natural history of patients with pseudomyxoma peritonei (PMP), evaluate clinical and pathologic variables as prognostic indicators, and review the authors' experience with different treatments. PMP is an unusual form of intra-abdominal neoplasm that presents with large amounts of extracellular mucin. Diffuse peritoneal spread occurs in most patients with PMP, and distant metastasis is infrequent. Debulking surgery, radiation therapy (radioisotope and external beam), and chemotherapy (both intraperitoneal and systemic) have all been advocated for optional patient management, but the variability of patients studied, the small patient numbers, and the prolonged course of this disease make the evaluation of results difficult. Fifty-six patients were treated for PMP at the Mayo Clinic between 1957 and 1983. The data were collected retrospectively. Univariate (log-rank test) and multivariate (Cox regression model) analyses were performed for disease recurrence and patient survival. Most patients with PMP had carcinomas of the appendix (52%) or ovary (34%). All gross tumor could be removed only in the 34% of patients with limited disease. Although tumor progression occurred in 76% of patients, the 1-, 5-, and 10-year survival rates were 98%, 53%, and 32%, respectively. Adverse predictors of patient survival included weight loss (p = 0.001), abdominal distention (p = 0.004), use of systemic chemotherapy (p = 0.005), diffuse disease (p = 0.038), and invasion of other organs (p = 0.04). Intraperitoneal chemotherapy (p = 0.009) and radioisotopes (p = 0.0043) both were effective in prolonging the recurrence time of symptomatic PMP. Although PMP is an indolent disease, aggressive surgical debulking followed by intraperitoneal radioisotopes and/or chemotherapy should be considered because of the diffuse peritoneal involvement.