Thymidine kinase: the future in breast cancer prognosis

The ability to precisely describe tumour aggressiveness in human breast cancer is inadequate. Current prognostic indicators, although useful, cannot accurately predict tumour behavior. As a result, multivariate analyses are required to obtain any significant value from a wide rangeastic indicators. Prognostic indications are generally determined from the primary tumour, but real prognostic value is dependent upon the activity of potentially metastatic lesions. We present in this paper evidence for the use of thymidine kinase, an enzyme indicative of cellular proliferation, as a tumour marker with individual prognostic value. It has been previously established that thymidine kinase levels in both tumours and sera of patients with breast cancer have been shown in clinical studies to be positively correlated with tumour stage. The monitoring of serial serum samples has also proven to be of prognostic value in predicting response to therapy. Measurements of thymidine kinase levels in primary tumours have demonstrated utility as a predictor of tumour recurrence. We propose that the development of a more accurate method of measuring thymidine kinase activity may aid significantly in the management of breast cancer, while eliminating the current detection problems of radio-labeling assay systems. This can be done by the inclusion of an immunologically based detection system.