High Ki-67 Expression Predicts Favorable Survival in Muscle-Invasive Bladder Cancer Patients Treated With Chemoradiation-Based Bladder-Sparing Protocol.
OBJECTIVE
To evaluate associations of Ki-67 expression with oncologic outcomes in muscle-invasive bladder cancer (MIBC) patients treated with chemoradiotherapy (CRT)-based bladder-sparing protocol.


METHODS
Between 1998 and 2011, 190 consecutive MIBC patients were treated with CRT-based bladder-sparing protocol. After transurethral resection of the bladder tumor, the patients underwent induction CRT (40 Gy with concurrent cisplatin) followed by partial cystectomy for bladder preservation or radical cystectomy (RC). Included in this study were 94 patients who were histologically diagnosed with urothelial carcinoma and whose tumor tissues before CRT were available for immunohistochemical evaluation of Ki-67 expression status.


RESULTS
After induction CRT, 16 (17%) and 53 (56%) patients underwent partial cystectomy and RC, respectively, while the remaining 25 (27%) did not undergo cystectomy. Successful bladder preservation was achieved in 34 patients (36%). Higher Ki-67 labeling index (LI) independently predicted CRT response clinically and pathologically. Among the clinicopathologic variables available before CRT and cystectomy, high Ki-67 LI (≥ 20%) was independently associated with better cancer-specific survival (CSS) (5-year CSS rate, 78% vs. 46% for low Ki-67 LI; P = .019). The difference in CSS according to Ki-67 expression status was more remarkable in patients with cT3 disease (5-year CSS rate, 72% vs. 29%; P = .0098).


CONCLUSIONS
High Ki-67 expression predicts favorable CSS in MIBC patients treated with CRT-based bladder-sparing protocol. MIBC patients with high Ki-67 expression status might benefit from CRT-based multimodal approaches in terms of prognosis and quality of life as a result of bladder preservation.
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Kenji
K
Tanabe
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan. Electronic address: s-yoshida.uro@tmd.ac.jp.
Soichiro
S
Yoshida
Department of Urology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan.
Fumitaka
F
Koga
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Masaharu
M
Inoue
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Shuichiro
S
Kobayashi
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Junichiro
J
Ishioka
Department of Pathology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Tomoki
T
Tamura
Department of Pathology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Emiko
E
Sugawara
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Kazutaka
K
Saito
Department of Pathology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Takumi
T
Akashi
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Yasuhisa
Y
Fujii
Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Kazunori
K
Kihara
D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D059248:Chemoradiotherapy / Q000379:methods; D002945:Cisplatin / Q000008:administration & dosage* / Q000627:therapeutic use; D015653:Cystectomy / Q000379:methods*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D059351:Organ Sparing Treatments / Q000379:methods*; D016019:Survival Analysis; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000601:surgery / Q000628:therapy*
D000970:Antineoplastic Agents; D019394:Ki-67 Antigen; D002945:Cisplatin
Chemoradiotherapy; Ki-67 antigen; Organ preservation; Prognosis; Urinary bladder neoplasms