Clinical Relevance of Proliferation Rates in Renal Cell Carcinoma

Abstract

Flemming (1882) and Waldeyer (1888) were the first to describe the histomorphological conception of cell division, mitosis and cell proliferation in human malignancies [5]. In different malignant tumors, pathologists found a correlation between mitosis rate determined in histological specimens and the clinical course of patients with malignancies. Mitosis, however, plays only a small part in the active cell cycle and is therefore only an indirect parameter of the proliferative pattern of the tissue. A long time passed before direct detection of tumor-specific proliferation rates (PRs) was possible. Through autoradiographic studies using the thymidine incorporation assay direct measurement of the portion of DNA synthesizing cells became available. In 1979, H.M. Rabes and his coworkers presented a clinical report of PR in renal cell carcinoma (RCC) using this technique [10]. They found a correlation between PR and recurrence rate in a series of ten patients. The main disadvantages of the thymidine incorporation technique are (a) extracorporal organ perfusion (ex vivo) after tumor nephrectomy and (b) radioactivity; therefore, it is not a practicable technique for routine diagnosis.