[Expression of CD117, MITF and NAT10 and their prognostic values in sinonasal mucosal melanoma]

Objective: To investigate the correlation between the expression of CD117, MITF, NAT10 and clinical parameters in sinonasal mucosal melanoma (SNMM). Methods: Formalin-fixed paraffin-embedded tumor specimens of 80 cases of SNMM at the Eye, Ear, Nose and Throat Hospital, Fudan University, from December 1999 to November 2013 were analyzed for CD117, MITF and NAT10 expression by immunohistochemistry. Results: There were 40 men and 40 women. The median age was 61 years, age 26 to 85 years. There was no correlation of the expression of CD117, MITF and NAT10 with the patients' age, gender, tumor site, stage, therapy method and brain metastases (P>0.05). The expression of MITF and NAT10 was associated with lymph node metastasis and the tumors were more likely to metastasize when MITF and NAT10 were positive. However, expression of CD117 had no correlation with lymph node metastasis. Log-rank test revealed that the expression of CD117 was correlated with both three-year and five survival rate (P=0.012, P=0.023; respectively) and patients with tumor having low expression of CD117 had the worse outcome. COX test revealed that low CD117 expression, advanced age and lymph node metastasis were independent risk factors (P<0.05). No significant association was found between the expression of CD117, MITF and NAT10 with disease free survival (P>0.05). Conclusions: Patients with SNMM expressing low level of CD117 have decreased survival rate. Tumors with high level of MITF and NAT10 expression are more likely to metastasize. The expression level of CD117 can be used as an important indicator for the patient survival, and the expression of MITF and NAT10 can be used as a predictor of tumor metastasis.