Ki67 Antigen as a Predictive Factor for Prognosis of Sinonasal Mucosal Melanoma

Abstract

OBJECTIVES: Sinonasal mucosal melanoma is a rare and aggressive disease. The aim of this study was to analyze the clinical features of patients with sinonasal mucosal melanoma and to determine the role of Ki67 antigen as a predictor of prognosis in sinonasal mucosal melanoma.METHODS: This was a retrospective case-series study at a single institution, an academic tertiary referral center. From 1995 to 2007, 27 patients with sinonasal mucosal melanoma were reviewed retrospectively, and the expression of Ki67 antigen was assessed by immunohistochemistry.RESULTS: The overall 5-yr survival rate was 33.9%. No significant differences were observed in 5-yr survival according to age, sex, stage, or the presence of melanin. The rates of local failure, regional failure, and distant failure were 37.0%, 14.8%, and 11.1%, respectively. Patients with spindle or mixed cell types had better prognoses than those with other cell types. At a cut-off value of 35%, patients with lower Ki67 scores showed better survival than those with higher Ki67 scores.CONCLUSION: The presence of spindle or mixed cell types may indicate a better prognosis than other cell types. Ki67 immunostaining may be a useful predictor of prognosis in patients with mucosal malignant melanoma of the sinonasal tract.