Thymidine kinase 1 expression in atypical ductal hyperplasia significantly differs from usual ductal hyperplasia and ductal carcinoma in situ: A useful tool in tumor therapy management

Abstract

Thymidine kinase 1 (TK1) is an enzyme involved in the synthesis of DNA precursors. In studies using immunohistochemistry, it was reported to be a more useful proliferation marker than Ki-67 and PCNA in breast, lung and colorectal carcinoma. In this study, we extend the work of prior breast carcinoma studies by investigating the expression of TK1 in 132 patients with usual ductal hyperplasia (UDH), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). TK1 and Ki-67 expression were determined with monoclonal antibodies using the SP technique. The expression of TK1 was found to be significantly increased in the breast ductal carcinomas in the following manner: UDH