Appendiceal tumors with glandular and neuroendocrine features exhibiting peritoneal metastases - Critical evaluation of outcome following cytoreductive surgery with perioperative chemotherapy.

BACKGROUND: A rare appendiceal malignancy is characterized by both glandular and neuroendocrine histology. It often presents with dissemination of the perforated tumor to peritoneal surfaces. Current treatments involve systemic chemotherapy, cytoreductive surgery and perioperative intraperitoneal chemotherapy.

METHODS: The impact of clinical, histological and treatment-related characteristics on survival were evaluated and subjected to univariate statistical analyses. All patients had stage IV disease and were treated by a uniform treatment strategy. Survival was determined from onset of disease until death or most recent follow-up.

RESULTS: There were 47 patients available for study of whom 17 were male. Median age was 48 with a range of 27-65. None or a single symptom vs. 2 or more symptoms had a significant effect on survival. Median survival of the entire cohort was 45 months and 34.88% and 8.72% of patients survived 5 and 10 years, respectively. The use of neoadjuvant chemotherapy showed no impact on survival. Patients with a peritoneal cancer index (PCI) of 0-20 as compared to PCI > 20 survived longer (p = 0.012). The survival of patients able to have a complete resection as compared to an incomplete resection of disease was significant (p = 0.0087). The type of perioperative chemotherapy did not alter survival.

CONCLUSIONS: These data show that patients with a lesser extent of disease with a complete cytoreduction had an improved prognosis. No benefit from systemic or perioperative regional chemotherapy was apparent. With long-term follow-up, patients with the combined glandular and neuroendocrine histology exhibiting peritoneal metastases have a guarded prognosis.