Abstract: To explore the effect of low dose bacillus CalmetteGuerin(BCG) intravesical instillation in preventing superficial bladder transitional cell carcinoma(BTCC) recurrence and complications. Methods150 patients with superficial BTCC who underwent transurethral resection of a bladder tumor or partial cystectomy were randomly divided into 3 groups: group 1 (50 cases) received a standard dose (120mg) BCG treatment, group 2 (50 cases) received half a standard dose (60mg) BCG, and group 3 received a low dose (40mg) BCG. Each patient was given a regular instillation schedule: different doses of BCG plus 50?mL NS were instilled into bladders once a week, and after 6 weeks, the treatment was performed once a month. Urine cytology and cystoscopy were used to monitor the recurrence at 3month intervals and the side effects of the BCG treatment were surveyed. ResultsAt a median followup of 20 months (ranging from 12 to 30), the rates of tumor recurrence in groups 1, 2 and 3 were 15.2％, 14.3％ and 18.0％. There was a no significant difference between group 1 and 2 (χ²_2vs1＝0.02, P＞0.05) or between group 1 and group 3 (χ²_3vs1＝0.13， P＞0.05). The rates of complications in groups 1, 2 and 3 were 22％, 10％ and 6％. There was a significant difference between group 3 and 1(χ²＝4.07，P＜0.05). ConclusionsCompared with standard dose intravesical BCG treatment, low dose BCG is similar in preventing superficial BTCC recurrence but is good in decreasing the complications.

Key words: Bacillus CalmetteGuerin, Bladder neoplasms, Carcinoma, Prophylaxis