Cell proliferation of carcinoma in Bilharzial bladder: an autoradiographic study

The rate of cell production in thirty-five cases of carcinoma in Bilharzial bladder was evaluated from the labelling index after in vitro incubation with [3H]TdR. Squamous cell carcinoma was the most frequent histological type in this series and had a median LI of 8.0% which corresponds to a potential doubling time of 5.9 days. In squamous cell tumours the LI increased with the histological grade. Transitional cell tumours had a somewhat greater LI. In all histological types the LI was significantly greater in the deep infiltrating parts of the tumour than in the superficial parts. The discrepancy between the estimated potential doubling time and the growth rate normally attributed to such tumours suggests the existence of an extensive cell loss factor. Areas of focal or diffuse mucosal hyperplasia were associated with increased LI.