EVALUATION OF CELLULAR-IMMUNITY FOLLOWING BACILLUS-CALMETTE-GUERIN THERAPY IN PATIENTS WITH SUPERFICIAL BLADDER-CANCER

Despite its marked effectiveness in the prevention of tumor recurrence s, a great deal of information on the mode of action of Bacillus Calme tte-Guerin (BCG) as an antitumor therapy modality is still lacking. In this prospective study, by performing lymphocyte subset analysis and quantitative assessment of delayed hypersensitivity skin reactions bef ore transurethral resection of the detected tumor and 3-6 months after intravesical BCC administration in 23 patients with superficial bladd er carcinoma, we tried to demonstrate the immunostimulatory effect of BCG therapy. We had 4 recurrences at 6 months' follow-up. Evaluation o f lymphocyte subset analysis readings in our group revealed a statisti cally significant difference (p < 0.05) in CD4+/CD8+ ratio between bas eline values and that obtained following BCG administration at 3 and 6 months. However, there was no statistically significant increase of t his value in 4 patients who had tumor recurrences. Evaluation of delay ed hypersensitivity skin test score results revealed a statistically s ignificant increase in the whole group at 3 months of follow-up (p < 0 .05) but the same evaluation at 6 months of follow-up showed no statis tically significant difference with respect to this evaluation. Again, no statistically significant difference was found in 4 patients who h ad tumor recurrences. These results support the idea that BCG-associat ed antitumor activity is an immune-mediated reaction and the assessmen t of T-lymphocyte subsets together with quantitative avaluation of del ayed hypersensitivity skin reactions would give us a definite idea abo ut the immunotherapeutic effects of BCG in such patients.