title: Outcomes following radical cystectomy for micropapillary bladder cancer versus pure urothelial carcinoma: a matched cohort analysis.
abstract: OBJECTIVE
  Micropapillary (MP) bladder cancer is a rare variant of urothelial carcinoma (UC) which has been associated with an aggressive natural history. We sought to report the outcomes of patients with MP bladder cancer treated with radical cystectomy (RC) and compare survival to patients with pure UC of the bladder.
  
  
  METHODS
  We identified 73 patients with MP bladder cancer and 748 patients with pure UC who underwent RC at our institution with median postoperative follow-up of 9.6 years. MP patients were stage-matched 1:2 to patients with pure UC. Survival was estimated using the Kaplan-Meier method and compared with the log-rank test.
  
  
  RESULTS
  MP cancers were associated with a high rate of adverse pathologic features, as 48/73 patients (66 %) had pT3/4 tumors and 37 (50 %) had pN+ disease. Ten-year cancer-specific survival in MP patients was 31 %, compared with 53 % in the overall cohort with pure UC (p = 0.001). When patients with MP bladder cancer were then stage-matched to those with pure UC, no significant differences between the groups were noted with regard to 10-year local recurrence-free survival (62 vs. 69 %; p = 0.87), distant metastasis-free survival (44 vs. 56 %; p = 0.54), or cancer-specific survival (31 vs. 40 %; p = 0.41).
  
  
  CONCLUSIONS
  MP cancers are associated with a higher rate of locally advanced disease. However, when matched to patients with pure UC, patients with MP tumors did not have increased local/distant recurrence or adverse cancer-specific survival following RC.
authors.affiliation: Department of Urology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. wang.jeffrey@mayo.edu
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Wang
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boorjian
authors.forename: John C
authors.initials: JC
authors.lastname: Cheville
authors.forename: Simon P
authors.initials: SP
authors.lastname: Kim
authors.forename: Robert F
authors.initials: RF
authors.lastname: Tarrell
authors.forename: Prabin
authors.initials: P
authors.lastname: Thapa
authors.forename: Igor
authors.initials: I
authors.lastname: Frank
mesh_terms: D000368:Aged; D002291:Carcinoma, Papillary / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D002295:Carcinoma, Transitional Cell / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D016022:Case-Control Studies; D015653:Cystectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D019459:Urothelium / Q000473:pathology