Analyses of the Effects of Intravesical Bacillus Calmette-Guerin (Tokyo 172 Strain) Therapy for Superficial Bladder Cancer

In this paper, we summarize the results of a multicentric controlled study of induction treatment with intravesical BCG in patients with superficial bladder cancer (Ta, T1) or CIS. The BCG Tokyo 172 strain (Japan BCG K. K.) was given for 8 weeks, as a rule, in a dose of either 80mg or 120mg in 40ml of saline instilled into the bladder.Sixty-six (90.5%) of the 73 patients registered in the study were evaluable for response. High response rates were obtained in the patients with Ta or T1 tumors, irrespective of the treatment dose; 65.4% CR, 27.3% PR and 7.3% NC for all. The number of CIS patients is too small to draw any conclusions, but 54.5% CR, 36.4% PR and 9.1% NC were obtained.Several factors were evaluated in relation to the tumor ablative effects. The CR rate was significantly higher for tumors less than 1cm in size compared with tumors 1-3 or larger in size, although the response rates, including CR and PR, were very similar irrespective of the size. Other factors did not contribute to provoke a significant difference.Japanese elder people show a high positive rate of PPD reaction. Thus, in our study, 78% of the patients showed positive PPD reactin. In this situation, no significant relation between PPD reaction and BCG efficacy was obtained. In addition, OKT8, OKT7, OKT4, OKT4/OKT8 ratio, Leu7, ADCC activity and NK activity did not show any correlation with tumor ablative effect of BCG.It should be remarked that 3 out of 4 NC patients with Ta or T1 tumor were female and they experienced minor bladder irritative symptoms.The one year disease free survival rate was 80.6% for 42 patients showing CR.Three patients could not tolerate BCG instillation more than 3 times because of adverse effects. Thus, it is concluded that BCG Tokyo 172 strain is effective both for tumor ablation and prophylaxis.