In-office laser coagulation of Ta bladder tumor compared to TUR-BT: 12 months follow-up randomized clinical trial

PURPOSE: Ta low grade bladder tumors, accounting for 45% of new bladder cancer cases, have considerable risk of recurrence but low risk of progression. Traditionally, treatment is burdensome and costly. Office-based laser coagulation of Ta low-grade bladder tumors is efficient, tolerable, and safe; however long-term outcomes need to be determined. Primary objective of this study is to determine whether in-office laser coagulation of recurrent Ta low grade bladder tumor is non-inferior to standard TUR-BT regarding 12-months recurrence-free survival (RFS).

MATERIALS AND METHODS: Prospective, randomized, non-inferiority clinical trial, performed in a hospital setting in Denmark between 2016-2022. 300 consecutive patients with recurrent Ta low grade bladder tumor participated. Laser (photo) coagulation of the bladder tumor (PC-BT) was performed with a 980 nm laser under local anesthesia in an office setting and compared to gold standard TUR-BT under general anesthesia. Primary outcome, 12-months RFS, was analyzed with non-inferiority criterion of 15% absolute difference. Secondary outcomes included long term RFS and stage progression.

RESULTS: RFS at 12 months was 43.5% after PC-BT and 43.0% after TUR-BT; difference of -0.5% compared to PC-BT (one-sided 95% CI upper bound 12%), meeting non-inferiority requirement. During extended follow-up (median 47.9 months) RFS was not significantly different between groups (p=0.25) and only one case of stage progression was observed in each group.

CONCLUSIONS: Office-based laser photo coagulation of bladder tumor is non-inferior to TUR-BT regarding 12-months RFS and is a safe, efficient treatment for recurrent Ta low-grade bladder tumors.