Cytophotometric expression of Caspase-3 in papillary thyroid carcinoma in nodular goiter colloid.

OBJECTIVE To describe quantitative cytophotometric expression of the marker caspase-3 in colloid goiter and in papillary carcinoma of the thyroid, comparing the immunoexpression between them. METHODS An immunohistochemistry study has been made on the protein caspase-3 in 17 of paraffin blocks of papillary carcinoma of the thyroid and 20 cases of colloid goiter, using SAMBA 4000 ® (System of Microscopic Analysis of Automatic Search), aiming analysis of the two variables: marker index and optical density. RESULTS Statistic analysis indicated a significant difference for marker index between colloid goiter and papillary carcinoma, being this difference larger in the carcinoma. Significant difference in optical density hasn't been found. For colloid goiter, the estimated correlation coefficient between the marker index and optical density was 0,72, indicating the rejection of the null hypothesis (p <0,001), affirming that positive and significant association exists between them. For the papillary carcinoma of the thyroid, the same correlation was 0,34 and so, it is not possible to affirm that there's an association between them. CONCLUSION For colloid goiter there is a positive and significant association between the two variables - marker index and optical density -, while for the papillary carcinoma, this is not proved. The quantitative analysis for caspase-3 demonstrates that apoptosis is larger in the papillary carcinoma of the thyroid than in colloid goiter.