Impact of maintenance therapy using a half dose of the bacillus Calmette\u2013Gu\xe9rin Tokyo strain on recurrence of intermediate and high-risk nonmuscle invasive bladder cancer: a retrospective single-center study

Dai Koguchi,Shigetaka Moroo,Masatsugu Iwamura,Masaomi Ikeda,Kazumasa Matsumoto,Momoko Kobayashi,Takahiro Hirayama,Hiroki Katsumata

doi:10.1186/s12894-020-00766-4

Abstract

BackgroundData are scarce regarding intravesical maintenance therapy (MT) with the low-dose bacillus Calmette–Guérin (BCG) Tokyo strain. We investigated the efficacy and safety of MT with a half dose of the Tokyo strain for patients following transurethral resection of nonmuscle invasive bladder cancer (NMIBC).MethodsThis study retrospectively reviewed clinical data on 78 patients diagnosed with intermediate or high-risk NMIBC followed by either MT (n = 38) or IT alone (n = 40) between January 2012 and March 2018. Statistical analysis was performed to compare recurrence-free survival (RFS) and adverse effects between the two groups. BCG was instilled once weekly for 6 weeks as IT, then once weekly in 2-week for a total of 20 instillations over 3 years.ResultsKaplan–Meier analyses showed that patients undergoing MT had significantly better RFS than did those undergoing IT alone (hazard ratio (HR):0.32, 95% confidence interval (CI):0.12–0.89, P = 0.02). The 3-year RFS was 65.0% in the IT group and 89.5% in the MT group. Multivariate analysis showed that MT was associated with a reduced risk of recurrence (HR: 0.32, 95% CI:0.11–0.93, P = 0.03). One MT patient (2.6%) exhibited progression.ConclusionsThe BCG Tokyo strain showed acceptable efficacy and safety in patients undergoing MT; thus, it is a potential treatment for preventing bladder cancer recurrence.

Highlights

Data are scarce regarding intravesical maintenance therapy (MT) with the low-dose bacillus Calmette–Guérin (BCG) Tokyo strain
Data are limited regarding the efficacy of MT using the Tokyo strain for low-dose BCG (LD-BCG), especially with a less intensive regimen than that used in the Southwest Oncology Group (SWOG) [10, 15]
A phase II study performed by the Kanagawa Urological Research Group (KURG) showed the potential efficacy of MT with full-dose BCG (FD-BCG) based on a 2-week cycle regimen over 3 years after 6 weeks of Induction therapy (IT) in patients with intermediate and high-risk nonmuscle invasive bladder cancer (NMIBC) [16]

Summary

Introduction

Data are scarce regarding intravesical maintenance therapy (MT) with the low-dose bacillus Calmette–Guérin (BCG) Tokyo strain. A meta-analysis of MT set as 1-yeare period showed, in comparison with 81 mg the Connaught strain, a significantly better expected overall survival in patients receiving 27 mg with lower probability of AEs [11]. Such low-dose MT appears promising for treating NMIBC, global BCG shortages due to the sudden cessation of Connaught BCG may limit the MT prevalence. A phase II study performed by the Kanagawa Urological Research Group (KURG) showed the potential efficacy of MT with FD-BCG based on a 2-week cycle regimen over 3 years after 6 weeks of IT in patients with intermediate and high-risk NMIBC [16].

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