AMELOBLASTOMA RECURRENCE: PROGNOSIS STUDY
Ameloblastoma. Recurrence. Risk factors. Immunohistochemistry. DNA damage. DNA Mismatch Repair.
Ameloblastoma is an odontogenic neoplasm, locally aggressive and infiltrative with high rates of postoperative recurrence. The molecular mechanisms involved in the etiopathogenesis of this tumor are unsolved, and although changes in the DNA base-pairing error repair system, known as the mismatch system (MMR) favor the development of different human neoplasms, their importance in the development of ameloblastoma still remains poorly understood. Therefore, this study aims to identify the prognostic factors associated with ameloblastoma recurrence, as well as to investigate the role of the immunoexpression of hMLH1, hMSH2 and Ki-67 proteins in the recurrence of this odontogenic tumor.This is a descriptive, cross-sectional and retrospective study, which in a later stage will be characterized by the observation, analysis, recording and quantification of hMSH2, hMLH1 and Ki-67 proteins, through immunohistochemistry, in ameloblastomas. The sample will be intentional and non-probabilistic, consisting of 22 cases of recurrent ameloblastomas and 22 cases of non-recurring ameloblastomas. The immunohistochemical analysis will be performed quantitatively, considering the cellular (nuclear) location of the proteins studied. Descriptive statistics will be used to characterize the sample. The normality and homoscedasticity of the sample will be performed using kurtosis and the Shapiro-Wilk test. The chi-square test and Fisher's exact test will be used to assess the associations of variables with recurrence. The McNemar test for paired data will be used to compare variables between primary and recurrent ameloblastoma lesions. To compare the immunoexpression of hMSH2, hMLH1 and Ki67 between relapsing and non-recurring ameloblastomas, unpaired Student's t test and Mann-Whitney test will be used. Recurrence-free survival will be analyzed by the Kaplan-Meier method and the survival functions will be compared according to the variables by the log-rank test. The significance level of 5% will be considered for all statistical tests (p<0.05). The development of this research aims to contribute to the understanding of the biological behavior of this odontogenic neoplasm, as well as a better understanding of the role of MMR proteins in the recurrence of ameloblastomas.