One-shot intravesical instillation of the mucous adhesive anticancer agent hydroxypropylcellulose-doxorubicin for the treatment of superficial bladder carcinoma is sufficient to determine antitumor effects.

A 20 mg/20 ml dose of the membrane adhesive anticancer preparation, hydroxypropylcellulose-doxorubicin (HPC-doxorubicin), was instilled into urinary bladders through a catheter for the treatment of superficial bladder carcinomas (Ta-T1). After 14-30 days, the effects of the drug on tumors was examined by cystoscopy, and the residual tumor tissue where reduction in size was observed was resected by transurethral resection (TUR). Therapeutic effects were as follows: a complete response (CR) was found in 6 cases (37.5%), a reduction in size of more than 50% (partial response = PR) in 4 cases (25%), and a less than 25% reduction (no change = NC) in 6 cases (37.5%). In no case was progression of the disease noted. In CR cases, cold cup punch biopsy revealed no tumor cells remaining at the site where the tumor was present before the instillation. Side effects such as bladder irritation were found in 4 cases, but they were only temporary in nature. The one-dose HPC-doxorubicin approach developed by ourselves allowed detection of antitumor effects between 14 and 30 days after the instillation and therefore determination of sensitivities at an earlier stage than with instillation of the conventional water-soluble type of doxorubicin hydrochloride.