Frequency of positive biopsies after visual disappearance of superficial bladder cancer marker lesions.

INTRODUCTION AND OBJECTIVES

In phase II trials in superficial bladder cancer, marker lesions have been used to test the ablative activity of intravesical chemo- or immunotherapy. These studies provide important knowledge about drug activity and toxicity without exposing hundreds of patients in phase III trials to drugs which ultimately may not be successful in preventing tumour recurrence or progression. After treatment a deep biopsy was necessary at the site of the marker lesion even in the absence of any visual tumour. The question is if this biopsy, in the absence of any visual tumour, should be done.

MATERIAL AND METHODS

The ablative effect of MMC, epirubicin, and quarter dose BCG instillations was evaluated in three different studies on a papillary marker lesion. Patients with multiple, primary or recurrent superficial bladder tumours were included. All visible Ta-T1 lesions were resected except for one marker lesion not exceeding 1 cm. TIS was excluded. In the last study, patients with T1 G3 tumours or multiple tumours >10 were also excluded. If the marker lesion disappeared completely, a deep biopsy was performed at the scar in order to prove histological disappearance of the tumour.

RESULTS

185 patients were evaluated. No visual tumours were seen in 110 patients and a TUR was performed in 101 of them. It revealed only 3 Ta lesions. In the 9 others no biopsy was performed but follow-up cystoscopy revealed no lesions.

CONCLUSIONS

In the absence of any visual tumors, TUR and deep biopsy at the site of the scar of the marker lesion only rarely revealed (3 out of 110) the histological presence of a tumour. Therefore, this biopsy can be omitted in new marker lesion protocols in patient with Ta-T1, G1 G2 papillary superficial bladder tumours at intermediate risk for recurrence and low risk for progression.