In vitro estimation of cell kinetic parameters in human urinary bladder cancers

The DNA synthetic time (T4) and the labeling index (LI) or urinary bladder carcinomas from 10 patients were measured by using the 3H-thymidine labeling technique in vitro under hyperbaric oxygen, and the potential doubling time (Tpot) was determined. The LI and Tpot were enormously variable depending on the histologic type, and ranged from 3.7 to 18.0% and from 48 to 136 hr, respectively. In contrast, Ts values fell in a rather narrow range. On comparing these results with the histologic patterns it was found that papillary carcinoma had longer Tpot than nonpapillary carcinoma and histologic grades were not well correlated with the LI's However, patients with higher LI and/or shorter Tpot showed poor prognosis. The practical significance of these kinetic parameters is discussed