PD36-07 DEFINING OPTIMAL CANDIDATES FOR BLADDER-SPARING TREATMENT IN MUSCLE-INVASIVE BLADDER CANCER: ANALYSIS USING PATHOLOGICAL REFERENCE STANDARDS AFTER CHEMORADIATION

Abstract

You have accessJournal of UrologyCME1 Apr 2023PD36-07 DEFINING OPTIMAL CANDIDATES FOR BLADDER-SPARING TREATMENT IN MUSCLE-INVASIVE BLADDER CANCER: ANALYSIS USING PATHOLOGICAL REFERENCE STANDARDS AFTER CHEMORADIATION Hajime Tanaka, Wei Chen, Kasumi Yoshitomi, Takahiko Soma, Masaki Kobayashi, Motohiro Fujiwara, Yuki Nakamura, Bo Fan, Yudai Ishikawa, Shohei Fukuda, Yuma Waseda, Kazuma Toda, Soichiro Yoshida, Minato Yokoyama, Ryoichi Yoshimura, and Yasuhisa Fujii Hajime TanakaHajime Tanaka More articles by this author , Wei ChenWei Chen More articles by this author , Kasumi YoshitomiKasumi Yoshitomi More articles by this author , Takahiko SomaTakahiko Soma More articles by this author , Masaki KobayashiMasaki Kobayashi More articles by this author , Motohiro FujiwaraMotohiro Fujiwara More articles by this author , Yuki NakamuraYuki Nakamura More articles by this author , Bo FanBo Fan More articles by this author , Yudai IshikawaYudai Ishikawa More articles by this author , Shohei FukudaShohei Fukuda More articles by this author , Yuma WasedaYuma Waseda More articles by this author , Kazuma TodaKazuma Toda More articles by this author , Soichiro YoshidaSoichiro Yoshida More articles by this author , Minato YokoyamaMinato Yokoyama More articles by this author , Ryoichi YoshimuraRyoichi Yoshimura More articles by this author , and Yasuhisa FujiiYasuhisa Fujii More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003334.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Bladder-sparing treatment based on chemoradiotherapy (CRT) has taken a large interest as an alternative to radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC). However, major concerns include MIBC recurrence even after achieving clinical complete response (CR) to CRT, which may be derived from microscopic cancer remnant in the preserved bladder. We have conducted a bladder-sparing protocol that incorporates induction CRT and subsequent partial cystectomy (PC). In addition, CRT was administered as an induction therapy before RC for MIBC patients who had no indication for bladder preservation. In this study, we analyzed these patient series and investigated clinical determinants of CRT response using the pathological reference standards to define optimal candidates for bladder preservation. METHODS: We analyzed 285 patients with cT2-4N0M0 bladder cancer who underwent CRT (40 Gy to the true pelvis with concurrent cisplatin) followed by PC/RC (approval # M2019-192). CRT response was assessed using the cystectomy specimens. Risk factors related to the CRT response were identified using multivariable logistic regression model, and the accuracy of the multivariable model was assessed using the area under the curve (AUC) in the receiver operating characteristic curve (ROC) analysis. RESULTS: Clinical T stage was T2/3/4 in 169 (59%)/105 (37%)/11 (3.9%) patients, respectively. The median tumor size was 3.0 cm and 108 patients (38%) had multiple tumors. Hydronephrosis was observed in 69 patients (24%). Overall, 54 (19%), 34 (12%), and 60 (21%) patients had bladder neck involvement (BNI), concomitant carcinoma in situ, and variant histology in the transurethral resection before CRT. The cystectomy specimens revealed ypT0, defined as pathological CR (pCR), in 178 patients (63%). In the multivariable logistic regression analysis, cT3-4 (Odds ratio=0.53 [95% confidence interval: 0.30-0.92]), tumor size>3.0 cm (0.45 [0.26-0.80]), multiplicity (0.34 [0.19-0.59]), and BNI (0.40 [0.20-0.80]) were independently associated with pCR. The final model including the four factors yielded the AUC of 0.75. In the cohort, 85 (30%), 83 (29%), and 117 (41%) patients had 0, 1, and 2 or more risk factors, respectively; pCR rates after CRT in the respective groups were 87%, 65%, and 43% (p<0.001). CONCLUSIONS: Our analysis identified independent risk factors related to CRT response using the pathological reference standards, which may help decide the indication of bladder preservation in MIBC patients. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e982 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hajime Tanaka More articles by this author Wei Chen More articles by this author Kasumi Yoshitomi More articles by this author Takahiko Soma More articles by this author Masaki Kobayashi More articles by this author Motohiro Fujiwara More articles by this author Yuki Nakamura More articles by this author Bo Fan More articles by this author Yudai Ishikawa More articles by this author Shohei Fukuda More articles by this author Yuma Waseda More articles by this author Kazuma Toda More articles by this author Soichiro Yoshida More articles by this author Minato Yokoyama More articles by this author Ryoichi Yoshimura More articles by this author Yasuhisa Fujii More articles by this author Expand All Advertisement PDF downloadLoading ...