Title: Trends in neoadjuvant chemotherapy use and oncological outcomes for muscle-invasive bladder cancer in Japan: a multicenter study
Abstract: // Go Anan 1, 2 , Shingo Hatakeyama 1 , Naoki Fujita 1 , Hiromichi Iwamura 2 , Toshikazu Tanaka 1 , Hayato Yamamoto 1 , Yuki Tobisawa 1 , Tohru Yoneyama 3 , Takahiro Yoneyama 1 , Yasuhiro Hashimoto 3 , Takuya Koie 1 , Hiroyuki Ito 4 , Kazuaki Yoshikawa 5 , Toshiaki Kawaguchi 6 , Makoto Sato 2 and Chikara Ohyama 1, 3 1 Department of Urology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan 2 Department of Urology, Tohoku Medical and Pharmaceutical University, Sendai, Japan 3 Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan 4 Department of Urology, Aomori Rosai Hospital, Hachinohe, Japan 5 Department of Urology, Mutsu General Hospital, Mutsu, Japan 6 Department of Urology, Aomori Prefectural Central Hospital, Aomori, Japan Correspondence to: Shingo Hatakeyama, email: [email protected] Keywords: bladder cancer, carboplatin, cisplatin, neoadjuvant chemotherapy, trends in use Received: July 27, 2017 Accepted: August 27, 2017 Published: September 18, 2017 ABSTRACT Objective: Despite benefits of neoadjuvant chemotherapy (NAC), the adoption of guideline recommendations for NAC use in patients with muscle-invasive bladder cancer (MIBC) has been slow. We aimed to evaluate temporal trends in NAC use and oncological outcomes in a representative cohort of patients with MIBC. Methods: We included 532 patients from 4 hospitals who underwent radical cystectomy (RC) for ≥ cT2 MIBC in 1996–2017. We retrospectively evaluated temporal changes in NAC use and progression-free and overall survival. Candidates for NAC were administered with either cisplatin- or carboplatin-based regimens. The impact of NAC on oncological outcomes was examined using multivariate Cox regression analysis with inverse probability of treatment weighting (IPTW) models. Results: Of 532 patients, 336 underwent NAC followed by RC (NAC group) and 196 underwent RC alone (Ctrl group). NAC use significantly increased from 10% (1996–2004) to 83% (2005–2016). The number of patients administered with cisplatin- and carboplatin-based regimens was 43 and 280, respectively. Oncological outcomes in the NAC group were significantly improved compared to those in the Ctrl group. Multivariable analysis with IPTW models revealed that NAC significantly improved oncological outcomes in patients with MIBC. A nomogram for 5-year overall survival predicted 16% improvement in patients undergoing NAC. Conclusions: NAC use for MIBC increased after 2005. Platinum-based NAC for MIBC potentially improves oncological outcomes.