title: Incidence, characteristics, treatment strategies, and oncologic outcomes of synchronous bilateral upper tract urothelial carcinoma in the Chinese population.
abstract: OBJECTIVE
  To investigate the incidence and treatment strategies for bilateral upper tract urothelial carcinoma (UTUC) and to compare the characteristic and oncologic outcomes of bilateral UTUC with those of unilateral tumors.
  
  
  METHODS
  The study included 892 consecutive patients with UTUC. Bilateral UTUC was defined as synchronous bilateral carcinoma on preoperative imaging before confirmation by pathology or positive urine cytology result plus direct visualization. Radical nephroureterectomy (RNU) or nephron-sparing surgery (NSS) or both were carried out.
  
  
  RESULTS
  A total of 39 patients (4.37%) suffered from bilateral disease. Discordant histological grade of bilateral tumor was found in 39.3% cases. Bilateral tumors were associated with female sex (P<0.001), preoperative renal insufficiency (P<0.001), previous or concomitant bladder tumors (P = 0.013), lower tumor stages (P = 0.020), papillary architecture (P = 0.001), and smaller-sized tumors (P = 0.020). Patients with worse renal function (P<0.001) or large-sized tumors (P = 0.039) tended to be treated with bilateral RNU. Most patients (67.6%) were treated with unilateral RNU plus unilateral NSS, with NSS being performed on tumors that only extended to the ureter (P = 0.003) and had a smaller size (P = 0.005). The median follow-up duration was 56 months. The 5-year cancer-specific survival and bladder recurrence-free survival rates were 81.2% and 64.5%, respectively, similar to those of unilateral tumors. Male sex (hazard ratio = 11.535) and higher tumor stage (hazard ratio = 3.386) were independent worse prognostic factors.
  
  
  CONCLUSIONS
  The prevalence of bilateral UTUC is rare. Female patients, patients with renal insufficiency, and those with bladder tumor tended to suffer from bilateral disease and were less likely to present with worse pathological outcomes in the Chinese population. The tumor characteristics and renal function were informative in treatment selection. The oncologic outcomes were similar to those in unilateral UTUC, and male sex and a higher tumor stage were poor prognostic factors for these patients.
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Fang
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Gengyan
authors.initials: G
authors.lastname: Xiong
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China. Electronic address: pineneedle@sina.com.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China; Department of Urology, Suining Central Hospital, Suining, Sichuan, China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China; Department of Urology, Tangdu Hospital, Fourth Military Medical University, Xi׳an, Shaanxi, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yao
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Kan
authors.initials: K
authors.lastname: Gong
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: He
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Zhisong
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China. Electronic address: zhouliqunmail@sina.com.
authors.forename: Liqun
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Centre, Beijing, China.
authors.forename: Yinglu
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015994:Incidence; D007680:Kidney Neoplasms / Q000453:epidemiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016896:Treatment Outcome; D014516:Ureteral Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery / Q000628:therapy; D014571:Urologic Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery / Q000628:therapy*
keywords: Bilateral; Chronic kidney disease (CKD); Nephron-sparing surgery (NSS); Radical nephroureterectomy (RNU); Sex; Upper tract urothelial carcinoma (UTUC)