Effect of distilled water and bacillus Calmette-Guérin on exfoliated bladder tumor cells.

The effect of distilled water on exfoliated tumor cells from transitional bladder carcinoma was compared to the effect of bacillus Calmette-Guérin (BCG; a nonspecific immunotherapeutic agent) dissolved in either saline or distilled water. The experiment was controlled by comparison to the effect of saline on tumor cells under the same conditions. Distilled water proved as effective as BCG in distilled water (p less than 0.001) and much more destructive than BCG in saline within the 2-hour time limit of the experiment (p less than 0.001).