title: Lymphovascular invasion as a prognostic factor in the upper urinary tract urothelial carcinoma: a systematic review and meta-analysis.
abstract: BACKGROUND
  The objective of the present study was to conduct a systematic review and meta-analysis of the published literature investigating lymphovascular invasion (LVI) and its effects on upper urinary tract urothelial carcinoma (UTUC) prognosis.
  
  
  METHODS
  To identify relevant studies, PubMed, Cochrane Library, OVID and SCOPUS database were searched from the inception until June 2012.
  
  
  RESULTS
  A total of 17 trials met the eligibility criteria for the meta-analysis. The total number of patients included was 4896, ranging from 60 to 2492 per study. None of the 17 included studies was based on the data of prospective analysis of survival. In 13 of 17 studies, patients had received adjuvant chemotherapy. Despite our attempts to limit the between-study heterogeneity through a strict inclusion criteria, there was a between-study heterogeneity in the effect of LVI on all of the meta-analyses, with a p value of <0.05 and I(2) generally greater than 50%. Thus, the hazard ratio (HR) was calculated using the random-effect model. The pooled HRs were statistically significant for disease-free survival (pooled HR, 1.91; 95% confidence interval [CI], 1.40-2.41), cancer-specific survival (CSS) (pooled HR, 1.72; 95% CI, 1.28-2.71) and overall survival (pooled HR, 4.05; 95% CI, -0.44-8.53). There was no clear evidence of funnel plot asymmetry, and thus, no evidence of publication bias was found.
  
  
  CONCLUSIONS
  Our meta-analysis showed that LVI is predictive of mortality in UTUC. However, these findings should be interpreted with caution due to the heterogeneity in the series. These results need to be further confirmed by an adequately designed prospective study to provide a better conclusion on the relationship between LVI and the outcome of patients with UTUC.
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Ja Hyeon
authors.initials: JH
authors.lastname: Ku
authors.forename: Seok-Soo
authors.initials: SS
authors.lastname: Byun
authors.forename: Hyeon
authors.initials: H
authors.lastname: Jeong
authors.forename: Cheol
authors.initials: C
authors.lastname: Kwak
authors.forename: Hyeon Hoe
authors.initials: HH
authors.lastname: Kim
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee
mesh_terms: D002295:Carcinoma, Transitional Cell / Q000188:drug therapy / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D006801:Humans; D042601:Lymphatic Vessels / Q000473:pathology*; D009361:Neoplasm Invasiveness; D011379:Prognosis; D014516:Ureteral Neoplasms / Q000188:drug therapy / Q000473:pathology*
keywords: Lymphovascular invasion; Meta-analysis; Prognosis; Renal pelvis; Upper urinary tract; Ureter; Urothelial carcinoma