Presentation Authors: Hirotaka Horiguchi*, Shingo Hatakeyama, Hayato Yamamoto, Atsushi Imai, Takahiro Yoneyama, Yasuhiro Hashimoto, Hirosaki, Japan, Takuya Koie, Gifu, Japan, Chikara Ohyama, Hirosaki, Japan
Introduction: A platinum-based neoadjuvant chemotherapy (NAC) is being established as standard therapy for muscle invasive bladder cancer (MIBC). However, the prediction of pT0 disease after NAC and optimal candidate selection for bladder preservation therapy remain challenging. We retrospectively examined whether clinical parameters could predict pT0 on radical cystectomy (RC).
Methods: Between March 2005 and June 2018, we performed platinum-based neoadjuvant chemotherapy followed by radical cystectomy in 254 patients with T2-4NxM0 MIBC. After diagnostic transurethral resection of bladder tumor (TURBT), all participants received two courses of gemcitabine plus cisplatin (GCis) or gemcitabine plus carboplatin (GCb) based on cisplatin eligibility. Quantitative radiologic response was defined by RECIST ver. 1.1 using contrast enhanced computed tomography (CT). RC and bilateral pelvic lymphadenectomy were performed approximately within 90 days after initial diagnosis of MIBC. Multivariate logistic regression analysis was applied to develop the nomogram for pT0 prediction.
Results: Median age and follow-up periods were 68 years and 50 months, respectively. Number of patients with GCis and GCb were 57 (22%) and 197 (78%), respectively. Of 254, 24 (9.5%), 89 (35%), 69 (27), and 7 (2.7%) patients achieved radiologic complete response (CR), partial response (PR), stable disease (SD), and progression disease (PD), respectively. In addition, 65 (26%) patients who underwent complete TURBT (cTURBT) remain undetectable tumor after NAC. We considered 89 patients with CR + cTURBT (CR group) were potential candidate for bladder preservation therapy. After RC, 65 (26%) patients achieved pT0. The pT0 rate in CR, PR, SD and PD groups were 51%, 52%, 17%, 7.2%, and 0%, respectively. Multivariate logistic regression analysis showed that male, orthotopic ileal neobladder reconstruction, CR group were significant factor for pT0. The nomogram for predicting pT0 probability showed significant association with actual pT0 rate (c-index = 0.812).
Conclusions: Although CR group significantly contributed to pT0 rate, residual tumor remains in half of patients with CR after NAC. Careful selection for bladder preservation therapy is necessary to avoid under treatment and/or overtreatment in patients with CR after NAC.