Prognostic Significance of Reck in Ameloblastoma and Ameloblastic Carcinoma

Abstract

Background- Ameloblastoma is a benign aggressive neoplasm of odontogenic epithelium. It has a high rate of recurrence, occasional metastasis and malignant transformation. Reversion-inducing cysteine rich protein with kazal motifs (RECK) gene is a tumour suppressor gene expressed in various normal organs and has been found to be important in suppressing tumour invasion, metastasis and angiogenesis. RECK levels are significantly down regulated in many tumours compared with the adjacent normal tissue and detection of normal or elevated RECK levels in tumour samples has been associated with decreased invasiveness and metastatic potential, with improved prognosis. Poor clinical prognosis in ameloblastoma may be associated with decreased RECK expressions. The aim of this study was to assess the prognostic significance of RECK in ameloblastoma and ameloblastic carcinoma, by determining expression of RECK protein.
Methods- Selected Paraffin blocks of 50 ameloblastoma cases, 8 ameloblastic carcinoma cases and 50 control cases (pyogenic granuloma) were sectioned and stained with commercial antibodies for RECK. Immunohistochemical staining of stromal and tumour cells in individual cases and study controls was assessed at X100 magnification to obtain a quantified combined score for each one. Proportion of cases with positive expression of RECK were compared between ameloblastoma and ameloblastic carcinoma, using chi square statistics. Mean scores for RECK expression in ameloblastoma and ameloblastic carcinoma cases were compared with that of the control group using the ANOVA test.
Results- RECK was positive in a greater proportion of ameloblastoma (96%) than ameloblastic carcinoma (87.5%) than in control cases (80%) (p = 0.049). The mean score of RECK expression in Ameloblastoma was higher than Ameloblastic carcinomas. The mean score of RECK expression was also higher in unicystic ameloblastoma than solid multicystic ameloblastoma.
Conclusion- RECK may be a promising prognostic marker in ameloblastoma and ameloblastic carcinoma.