Results of treatment of 385 patients with peritoneal surface spread of appendiceal malignancy

In the past, peritoneal carcinomatosis, regardless of primary tumor type, has always been a lethal condition. Recently, special treatments using cytoreductive surgery with peritonectomy procedures combined with perioperative intraperitoneal chemotherapy have resulted in long-term survival. Appendiceal malignancy with a low incidence of liver and lymph node metastases may be especially appropriate for these aggressive local regional treatments.

All patients treated with surgery before January 1999 are included. Patients left with gross residual disease after surgery were not given intraperitoneal chemotherapy, but were later treated with intravenous chemotherapy. The intraperitoneal chemotherapy was given in the perioperative period, starting with mitomycin C at 12.5 mg/m2 for males and 10 mg/m2 for females. For patients whose pathology showed adenomucinosis, intraperitoneal chemotherapy was limited to treatment in the operating theater with heated mitomycin C. Patients with mucinous adenocarcinoma or pseudomyxoma/adenocarcinoma hybrid had, in addition to mitomycin C, five consecutive days of intraperitoneal 5-fluorouracil at 650 mg/m2 instilled in 1-1.5 liters of 1.5% dextrose peritoneal dialysis solution. A complete cytoreduction was defined as tumor nodules <2.5 mm in diameter remaining after surgery. The histopathology categorized the patients as having adenomucinosis, adenomucinosis/carcinomatosis hybrid, or mucinous carcinomatosis. A previous surgical score was used to estimate the extent of previous surgical procedures.

The morbidity of treated patients was 27% and the mortality was 2.7%. In a multivariate analysis, prognostic factors for survival included the completeness of cytoreduction (P < .0001), the histopathological character of the appendix malignancy (P < .0001), and the extent of previous surgical interventions (P = .001). Patients with a complete cytoreduction and adenomucinosis by pathology had a 5-year survival of 86%; with hybrid pathology, survival at 5 years was 50%. Incomplete cytoreduction had a 5-year survival of 20% and 0% at 10 years.

Cytoreductive surgery and perioperative intraperitoneal chemotherapy can be used to salvage selected patients with peritoneal surface spread of appendiceal primary tumors. Similar strategies for other patients with peritoneal surface malignancy such as peritoneal carcinomatosis from colon or gastric cancer, peritoneal sarcomatosis, or peritoneal mesothelioma should be pursued.