Using colony formation technique and KK-47 cell line established from a human bladder
transitional cell carcinoma, the effect of 6 anticancer drugs,
thio-TEPA,
Bleomycin,
mitomycin C,
carbazilquinone,
Adriamycin and
cis-Platinum, were compared. On the results of tests performed to establish the
drug concentration required to achive a 50% inhibition of cell survival,
carbazilquinone was chosen for the prevention of recurrences of
bladder cancer. The two groups studied consisted of 56 patients (previously untreated groups) who were rendered free of tumours by surgical intervention and of 19 patients (
thio-TEPA failures group) who had experienced a persistent recurrence of tumours after prophylactic
thio-TEPA instillations and were presumed free of the recurrence of tumours after the next surgical intervention. The 2 groups were subjected to prophylactic combined
intravesical instillation therapy with
carbazilquinone and
urokinase. In the previously untreated group, 6 of the 56 patients (10.7%) had a recurrence of tumours, and the recurrence rate after 21 months was 16.7%, using the actuarial method. In the
thio-TEPA failures group, 12 of the 19 patients (63.2%) had a recurrence of tumours, a rate at 21 months of 76.1%. A considerable drop in the recurrence rate was obtained by the combined instillation
therapy in the previously untreated group. The results in the
thio-TEPA failures group suggested the presence of a cross-resistance between both
alkylating agents, and of a persistent susceptibility to multifocal lesions. No bone marrow depression was observed but an episode of
anaphylactic shock attributable to the use of
carbazilquinone occurred in 1 out of a total 75 patients.