Ten-Year Outcome of a Randomized Trial: Cytoreduction and HIPEC with Mitomycin C Versus Oxaliplatin for Appendiceal Neoplasm with Peritoneal Dissemination.

BACKGROUND: Appendiceal cancer is a rare disease that has proven difficult to study in prospectively. Our initial report of this trial showed minor hematologic toxicity with both mitomycin C and oxaliplatin and similar 3-year survival. We now report an update of the first prospective randomized trial for appendiceal cancer with 10-year follow up.

PATIENTS AND METHODS: Patients with mucinous appendiceal neoplasms and evidence of peritoneal dissemination were enrolled in the Multicenter Randomized Trial to evaluating HIPEC for 120 min with oxaliplatin (200 mg/M2) or mitomycin C (40 mg). Overall survival and disease-free survival were calculated at 10 years and compared between the groups.

RESULTS: A total of 121 patients were included in the study. The patients were 57% female, with a mean age of 55.3 years (range 22-82 years). The disease was low grade in 71% and high grade in 29%. The average peritoneal cancer index (PCI) score was 18 (SD 10) in the mitomycin C group and 17.9 (SD 9.4) in the oxaliplatin group (p = 0.94). The 10-year survival rate was 56.2% (SE 7.2) with mitomycin C and 47.5% (SE 8.4) with oxaliplatin, p = 0.83. The 10-year progression-free survival rate in the mitomycin C group was 45.2% (SE 8.4) compared with 50.4% (SE 6.7) in the oxaliplatin group, p = 0.95. Median survival was 9.1 years after HIPEC with oxaliplatin, and median not reached for the mitomycin C group (> 5.6 years).

CONCLUSIONS: Oxaliplatin and mitomycin C have similar long-term efficacy for hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with appendiceal neoplasms and peritoneal dissemination. Long-term survival is experienced by most patients after cytoreduction surgery (CRS) and HIPEC for appendiceal neoplasms.