Intravesical Doxorubicin Following Resection of Primary Non-muscle-invasive Bladder Cancer - Expert Commentary
The investigators identified NMIBC patients between 2002 and 2018 at a single center in Japan. The cohort of SID and the cohort of TURBT alone were matched one-to-one using propensity scores. The authors evaluated the time to recurrence as well as time to progression. The investigators used univariate and multivariate competing-risk regression models to define the relationship between adding SID and clinical outcomes.
After matching, a total of 364 patients, including 182 receiving SID and 182 receiving TURBT alone, were analyzed. After propensity score matching, there were no statistically significant differences in the baseline characteristics between the SID and TURBT-only cohorts. The investigators found a lower cumulative incidence of recurrence in the SID cohort (P=0 .028; Gray test). Furthermore, the time to recurrence was significantly longer in patients who received post-operative SID (subdistribution hazard ratio, 0.68; 95% confidence interval, 0.49-0.95; P = 0.024). On the other hand, there was no statistically significant difference in the time to progression to muscle-invasive disease (subdistribution hazard ratio, 0.61; 95% confidence interval, 0.11-3.49; P = .58) but this analysis was limited by the small number of patients who progressed on both arms.
This analysis demonstrates the efficacy of a single perioperative installation of intravesical doxorubicin in preventing NMIBC recurrences. The study did not report data on the tolerability of this regimen. The authors highlight that the cost of doxorubicin is low. They suggest that a prospective randomized head-to-head comparison of the effectiveness of different intravesical chemotherapy drugs is needed. Several newer intravesical agents are currently being tested in BCG-refractory NMIBC patients. Likely, the agents that prove effective and safe will then be tested as perioperative treatments to reduce recurrence.
Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine, New York City, New York
Reference:
1. Fukuokaya, Wataru, Takahiro Kimura, Jun Miki, Shoji Kimura, Hisaki Watanabe, Fan Bo, Daigo Okada et al. "Effectiveness of Intravesical Doxorubicin Immediately Following Resection of Primary Non–muscle-invasive Bladder Cancer: A Propensity Score-matched Analysis." Clinical Genitourinary Cancer (2019).
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