Estimations of the S phase fraction in situ in transitional cell carcinoma of the renal pelvis and ureter with bromodeoxyuridine labelling.

Abstract

This report concerns the estimation of the S phase fraction (SPF) in situ and its value in predicting the malignant potential of transitional cell carcinoma of the renal pelvis and ureter. Eighteen patients with transitional cell carcinoma of the renal pelvis and ureter were given a 0.5 h intravenous infusion of the thymidine analogue bromodeoxyuridine (BrdU) (500 mg) at the time of surgery to label tumour cells in the DNA synthesis phase. The tumour specimens were stained by an indirect immunoperoxidase method using anti-BrdU monoclonal antibody as the first antibody. The BrdU labelling index, S phase fraction, was determined by counting the number of bromodeoxy-uridine labelled cells in the tissue sections. All grade 1 tumours had an S phase fraction lower than 10%. The average S phase fraction for non-invasive tumour (12 cases) and invasive tumour (6 cases) were 9.7 and 20.9%, respectively. Two patients with rapid spread of ureteric tumour showed an S phase fraction of 18.4 and 22.3%. The results obtained with the S phase fraction were comparable with histological tumour grade and invasive potential. The higher S phase fraction may indicate greater biological malignancy. We believe that determination of the S phase fraction of transitional cell carcinoma of the renal pelvis and ureter offers a new objective and quantitative assay of the biological potential of individual tumours and might have practical value in their management.