Long-term survival following treatment of pseudomyxoma peritonei - An analysis of surgical therapy

Background Data: Pseudomyxoma peritonei (PMP) is a clinical syndrome with a poorly defined natural history. Relative contributions of tumor biology, patient selection, and the extent of treatment on ultimate outcome are not well characterized. Methods: Patients treated at the Memorial Sloan-Kettering Cancer Center between 1980 and 2002 with a diagnosis of PMP were identified. Patient characteristics, pathologic features, and details of treatment were analyzed retrospectively. Results: The 97 patients included in this study underwent a mean 2.2 +/- 0.1 operations (range, 1-6). Although complete cytoreduction was achieved in 55% (53/97), disease recurred in 91% (48/53) of patients. The median disease-free interval after complete cytoreduction was 24 months. The median overall survival was 9.8 years and was independently associated with low-grade pathologic subtype (P < 0.001) and the ability to achieve complete cytoreduction (P < 0.001). Ten-year survival was attained in 21% (20/97) of the patients, of which 90% (18/20) had low-grade pathologic features. At the time of death or completion of follow-up, only 12% (12/97) of the patients were disease free. Conclusions: Outcome in patients with PMP is strongly associated with tumor biology. Although improved survival is associated with low-grade pathology and tumors amenable to complete cytoreduction, recurrence of PMP is common. Treatment may be beneficial, particularly in controlling symptoms, but absolute cure, defined as a prolonged disease-free state, is uncommon.