The role of Ki-67 in predicting biological behavior of goblet cell carcinoid tumor in appendix

BACKGROUND: The aim of this study was to examine the role of Ki-67, a cellular proliferation marker, in the prognosis of goblet cell appendiceal carcinoid tumor. METHODS: Twelve goblet cell appendiceal carcinoid tumors were stained with MIB-1, a monoclonal antibody of Ki-67, to assess their cell proliferation and correlations with clinical and histologic parameters. RESULTS: Among 12 patients studied, the mean MIB-1 index was 24%, with tumors ranging from .5 to 5.0 cm in size. No correlation was observed between tumor size and MIB-1 index. Two patients had metastatic disease on presentation (MIB-1 index 10% and 60%). All patients received surgical intervention according to extent of tumor invasion regardless of their MIB-1 index values. Median follow-up was 54 months, with a 75% follow-up rate and 1 death from metastasis. The overall survival rate was 76%, with a disease-specific survival rate of 87%. CONCLUSIONS: Ki-67 had no prognostic significance for goblet cell carcinoid tumors and should not be used solely to determine treatment and surgical approach.