Tumour growth rates in squamous carcinoma of the head and neck measured by in vivo bromodeoxyuridine incorporation and flow cytometry

Abstract

The cell kinetics of 82 squamous cell carcinomas of the head and neck were studied by in vivo administration of the thymidine analogue, bromodeoxyuridine (BrdUrd). Ploidy, BrdUrd labelling index (LI), duration of S-phase (Ts), potential doubling time (Tpot) and S-phase fraction (SPF) were measured by flow cytometry on 50 m paraffin embedded sections. The range of values obtained compared well with other in vivo cell kinetic studies of head and neck cancer. Aneuploid tumours had a significantly higher BrdUrd labelling index and SPF, and a short Tpot than diploid tumours. To validate the use of 50 µm sections for measuring cell kinetic parameters by flow cytometry a comparison of values obtained by 50 pm sections and small blocks of tissue was made. No significant difference was found between the two methods. Reproducibility of values between two consecutive thick sections was also good. We conclude that reproducible cell kinetic measurements can be made in tumour samples using 50 pm sections of BrdUrd labelled tissue.developed the technique to calculate the potential doubling time of tumours from a single biopsy taken a number of hours after BrdUrd administration thus obviating the need for multiple biopsies.Here we present preliminary data on the labelling index, duration of S-phase and potential doubling times of 82 squamous cell tumours from the head and neck which form part of a prospective study to determine whether cell kinetic data, in particular the potential doubling time, have any predictive value regarding prognosis and response to treatment. © 1992 Macmillan Press Ltd.