The role of survivin in thyroid tumors: differences of expression in well-differentiated, non-well-differentiated, and anaplastic thyroid cancers

Background: Survivin is involved in human cancer and is responsible for aggressive biological behavior and poor clinical outcomes in several human malignancies. Thus, we hypothesized that the upregulation of survivin protein expression may be enhanced in parallel with transition toward a poorly differentiated phenotype in human thyroid carcinomas. Methods: The expression of survivin was evaluated, using a standard linked streptavidin-biotin horseradish peroxidase technique technique, in a series of 56 human thyroid carcinomas (42 papillary, 4 poorly differentiated, and 10 anaplastic carcinomas) and thyroid carcinoma cell lines at different degrees of differentiation. Results: The cytoplasmic expression of survivin protein was significantly upregulated in all thyroid tumors. A statistically significant association was found between nuclear survivin expression and anaplastic thyroid cancer (mean±SD: well-differentiated thyroid cancer, 1.22±20.21; non-well-differentiated thyroid cancer, 34.00±25.17; anaplastic thyroid cancer, 56.50±22.10; p30% of nuclear survivin expression. The receiver operating characteristic (ROC) area was 0.92, with a p-value of