Non-maintenance intravesical Bacillus Calmette-Guérin induction therapy with eight doses in patients with high- or highest-risk non-muscle invasive bladder cancer: a retrospective non-randomized comparative study.

To explore possible solutions to overcome chronic Bacillus Calmette-Guérin (BCG) shortage affecting seriously the management of non-muscle invasive bladder cancer (NMIBC) in Europe and throughout the world, we investigated whether non-maintenance eight-dose induction BCG (iBCG) was comparable to six-dose iBCG plus maintenance BCG (mBCG).

This observational study evaluated 2669 patients with high- or highest-risk NMIBC who treated with iBCG with or without mBCG during 2000-2019. The patients were classified into five groups according to treatment pattern: 874 (33%) received non-maintenance six-dose iBCG (Group A), 405 (15%) received six-dose iBCG plus mBCG (Group B), 1189 (44%) received non-maintenance seven-/eight-dose iBCG (Group C), 60 (2.2%) received seven-/eight-dose iBCG plus mBCG, and 141 (5.3%) received only ≤5-dose iBCG. Recurrence-free survival (RFS), progression-free survival, and cancer-specific survival were estimated and compared using Kaplan-Meier analysis and the log-rank test, respectively. Propensity score-based one-to-one matching was performed using a multivariable logistic regression model based on covariates to obtain balanced groups. To eliminate possible immortal bias, 6-, 12-, 18-, and 24-month conditional landmark analyses of RFS were performed.

RFS comparison confirmed that mBCG yielded significant benefit following six-dose iBCG (Group B) in recurrence risk reduction compared to iBCG alone (groups A and C) before (P < 0.001 and P = 0.0016, respectively) and after propensity score matching (P = 0.001 and P = 0.0074, respectively). Propensity score-matched sequential landmark analyses revealed no significant differences between groups B and C at 12, 18, and 24 months, whereas landmark analyses at 6 and 12 months showed a benefit of mBCG following six-dose iBCG compared to non-maintenance six-dose iBCG (P = 0.0055 and P = 0.032, respectively). There were no significant differences in the risks of progression and cancer-specific death in all comparisons of the matched cohorts.

Although non-maintenance eight-dose iBCG was inferior to six-dose iBCG plus mBCG, the former might be an alternative remedy in the BCG shortage era. To overcome this challenge, further investigation is warranted to confirm the real clinical value of non-maintenance eight-dose iBCG.

BMC cancer. 2021 Mar 11*** epublish ***

Makito Miyake, Kota Iida, Nobutaka Nishimura, Tatsuki Miyamoto, Kiyohide Fujimoto, Ryotaro Tomida, Kazumasa Matsumoto, Kazuyuki Numakura, Junichi Inokuchi, Shuichi Morizane, Takahiro Yoneyama, Yoshiaki Matsumura, Takashige Abe, Masaharu Inoue, Takeshi Yamada, Naoki Terada, Shuya Hirao, Motohide Uemura, Yuto Matsushita, Rikiya Taoka, Takashi Kobayashi, Takahiro Kojima, Yoshiyuki Matsui, Hiroshi Kitamura, Hiroyuki Nishiyama, Japanese Urological Oncology Group

Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. ., Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan., Department of Urology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Ehime, Japan., Department of Urology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan., Department of Urology, Akita University Graduate School of Medicine, Akita, Japan., Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan., Division of Urology, Department of Surgery, Faculty of Medicine, Tottori University, Tottori, Japan., Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan., Department of Urology, Nara Prefecture General Medical Center, Nara, Japan., Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan., Department of Urology, National Cancer Center Hospital East, Chiba, Japan., Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan., Department of Urology, Miyazaki University, Miyazaki, Japan., Department of Urology, Hirao Hospital, Kashihara, Nara, Japan., Department of Urology, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan., Department of Urology, Hamamatsu University School of Medicine, Shizuoka, Japan., Department of Urology, Faculty of Medicine, Kagawa University, Takamatsu, Kagawa, Japan., Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan., Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan., Department of Urology, National Cancer Center Hospital, Tokyo, Japan., Department of Urology, Faculty of Medicine, University of Toyama, Toyama, Japan.