Is bladder biopsy necessary at three or six months post BCG therapy?

The standard of practice set by the SWOG investigation of BCG therapy for superficial bladder cancer has been to evaluate response at 3 months with cystoscopy and bladder biopsy. This study is to determine if all patients require a biopsy post therapy at 3 or 6 months. We reviewed the charts of 43 patients who had received a 6-weekly course of BCG (Connaught strain) for high grade or recurrent Ta, T1, or Tis transitional cell carcinoma of the bladder. The patients with Ta recurrent, T1 or Tis disease received maintenance therapy. All patients were followed through 6 months. At 3 months, 32/43 patients had negative cystoscopies. All 32 patients had corresponding negative biopsies. Eight patients had visible papillary tumors, while three patients had erythematous lesions, which were biopsy negative. At 6 months, eight different patients had visible lesions on cystoscopy that were biopsy proven superficial bladder cancer. The positive predictive value at 3 and 6 months post BCG therapy was 72.6% and 100%, respectively. The false positive rate was 7% at the 3-month checkpoint. Bladder biopsy is not necessary at the 3 or 6 month period following BCG therapy in the face of negative cystoscopic findings.