Determinants of Outcome with Reoperative Surgery for Pseudomyxoma Peritonei in 186 Patients.

Objective: To describe the long-term survival and clinical- and treatment-related variables that determine the outcome of repeat cytoreductive surgery (CRS) for mucinous appendiceal neoplasms with peritoneal dissemination.

Summary Background: After patients with peritoneal dissemination of an appendiceal mucinous neoplasm have a CRS, disease progression may require secondary cytoreductive surgery (SCRS) and other treatments performed in a timely manner to prolong survival and help preserve an optimal quality of life.

Methods: The clinical- and treatment-related variables associated with the index CRS and the SCRS were statistically assessed for their impact on survival.

Results: One hundred eighty-six of 687 complete CRS patients (27.1%) had SCRS. The median follow-up was 10 years and the median survival was 12 years. There were 95 males (51%) and the median age was 45.0 years. Survival benefit was associated with the index CRS by use of early postoperative intraperitoneal chemotherapy (EPIC) with 5-fluorouracil [Hazard ratio (HR), 0.4; = 0.0004]. Also, survival of low-grade mucinous appendiceal neoplasms versus mucinous appendiceal adenocarcinoma (HR, 2.8; < 0.0001) was improved. The interval between index CRS and SCRS was significant at ≤12 months versus 12-36 months versus >36 months ( < 0.0001). Change in peritoneal cancer index and disease distribution as focal or diffuse was significant by univariant and multivariant analyses.

Conclusions: If the CRS was complete, the use of EPIC 5-fluorouracil, the interval between the index CRS and the SCRS, the histologic grade of the mucinous neoplasm, and the extent of recurrent disease were prognostic variables that should be used to help select patients for SCRS.