The in vivo proliferation kinetics of human solid tumours

Abstract

The study of tissue and tumour cell kinetics is one approach to better understanding of human tumour biology and to the formulation of better treatment strategies. Past efforts to measure in vivo the duration of cell cycle phases has been severely handicapped by the need to use radioisotopes and to take sequential biopsies. The drug 5-bromo-2-deoxyuridine (BRdU) is a safe, ethical alternative to tritiated thymidine for in vivo labelling of DNA during the S phase of the cell cycle. The label can be detected by conventional histochemistry, and by multiparameter flow cytometry. The latter provides measurements of ploidy, phase related DNA labelling, and the duration of the S phase and of the potential doubling time (Tpot) of the tumour or tissue. These parameters have not been characterised in many types of tumour, nor have their relationships to prognosis or to treatment strategies been explored.