Secondary Cytoreduction and Perioperative Intraperitoneal Chemotherapy After Initial Debulking of Pseudomyxoma Peritonei: A Study of Timing and the Impact of Malignant Dedifferentiation

J Am Coll Surg. 2010 Oct;211(4):526-35. doi: 10.1016/j.jamcollsurg.2010.06.011. Epub 2010 Aug 21.


Background: Cytoreductive surgery and perioperative intraperitoneal chemotherapy (PIC) is recognized as an effective treatment modality for patients with pseudomyxoma peritonei. This study investigates its role as a secondary definitive treatment procedure after earlier primary treatments.

Study design: Patients with pseudomyxoma peritonei undergoing secondary cytoreduction combined with PIC were identified from a prospective database. Retrospective analysis investigated the outcomes, prognostic factors, critical time points, and impact of malignant dedifferentiation. Survival analysis was performed via the Kaplan-Meier method and compared via the log-rank test.

Results: The median time to progression after secondary cytoreduction was 28 months (95% CI 14 to 41 months), median survival was 97 months (95% CI 82 to 113 months), and 10-year survival was 25%. Median overall survival from initial diagnosis was 17 years and 10-year survival rate was 75%. Forty-five patients remained disease free (63%). Requiring an urgent treatment (waiting time < 60 days) after disease progression (p = 0.045) and having moderate or severe symptoms (p = 0.033) were associated with a shorter time to progression. Improved survival was associated with patients who had low-grade tumors (p = 0.029), and those who required less urgent treatment (wait > 30 days) after disease progression (waiting up to 15 days, p = 0.010; waiting up to 30 days, p = 0.005). Malignant dedifferentiation appeared to affect survival from initial diagnosis (p = 0.062) and after secondary cytoreduction (p = 0.006).

Conclusions: Secondary cytoreduction with PIC achieves long-term survival. Tumors that undergo malignant dedifferentiation appear to adversely affect survival, and this may support the rationale for early definitive treatment with cytoreduction and PIC.

MeSH terms

  • Adult
  • Antineoplastic Agents / administration & dosage*
  • Cell Differentiation
  • Cell Transformation, Neoplastic
  • Disease Progression
  • Female
  • Fluorouracil / administration & dosage
  • Humans
  • Infusions, Parenteral
  • Male
  • Middle Aged
  • Mitomycin / administration & dosage
  • Peritoneal Neoplasms / drug therapy*
  • Peritoneal Neoplasms / surgery*
  • Prognosis
  • Pseudomyxoma Peritonei / drug therapy*
  • Pseudomyxoma Peritonei / surgery*
  • Retrospective Studies
  • Survival Analysis
  • Time Factors
  • Treatment Outcome


  • Antineoplastic Agents
  • Mitomycin
  • Fluorouracil