A Multicenter Randomized Trial to Evaluate Hematologic Toxicities after Hyperthermic Intraperitoneal Chemotherapy with Oxaliplatin or Mitomycin in Patients with Appendiceal Tumors.

BACKGROUND: Appendiceal cancer is a rare disease that has proven difficult to study in prospective trials. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is an established therapy for peritoneal dissemination from appendiceal cancer. The optimal chemotherapeutic agent to use in the HIPEC is not clear. Mitomycin has long been used, however, our previous phase I experience and European retrospective studies suggest oxaliplatin as an alternative. Therefore, we initiated a multicenter randomized trial to compare mitomycin with oxaliplatin HIPEC for appendiceal cancer.

STUDY DESIGN: Patients with mucinous appendiceal neoplasms with evidence of peritoneal dissemination underwent cytoreductive surgery and HIPEC using a closed technique for 120 minutes. Patients were randomized intraoperatively to HIPEC using mitomycin (40 mg) or oxaliplatin (200 mg/M2 ). Follow-up included daily blood counts and toxicity assessments.

RESULTS: One hundred and twenty-one analytic patients were accrued to the trial during 6 years at 3 sites. The patients were 57% female, with a mean age of 55.3 years (range 22 to 82 years). The disease was low grade in 77% and high grade in 23%. There were no significant differences in hemoglobin or platelet counts. The WBC was significantly lower in the mitomycin group between postoperative days 5 and 10. Overall and disease-free survival rates at 3 years were similar at 83.7% and 66.8% for mitomycin and 86.9% and 64.8% for oxaliplatin.

CONCLUSIONS: This represents the first completed prospective randomized trial for cancer of the appendix, and shows that multicenter trials for this disease are feasible. Both mitomycin and oxaliplatin are associated with minor hematologic toxicity. However, mitomycin has slightly higher hematologic toxicity and lower quality of life than oxaliplatin in HIPEC. Consequently, oxaliplatin might be preferred in patients with leukopenia and mitomycin preferred in patients with thrombocytopenia due to earlier chemotherapy.