title: The association of platelet count with clinicopathological significance and prognosis in renal cell carcinoma: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Elevated platelet count (PC), a measure of systemic inflammatory response, is inconsistently reported to be associated with poor prognosis in patients with renal cell carcinoma (RCC). We conducted a systematic review and meta-analysis to clarify the significance of PC in RCC prognosis.
  
  
  METHODS
  PubMed, Embase, and Web of Science databases were searched to identify eligible studies to evaluate the associations of PC with patient survival and clinicopathological features of RCC.
  
  
  RESULTS
  We analyzed 25 studies including 11,458 patients in the meta-analysis and categorized the included articles into three groups based on RCC stage. An elevated PC level was associated with poor overall survival (OS, hazard ratio [HR] 2.24, 95% confidence interval [CI] 1.87-2.67, P<0.001) and cancer-specific survival (CSS, HR 2.59, 95% CI 1.92-3.48, P<0.001) when all stages were examined together; with poor CSS (HR 5.09, 95% CI 2.41-10.73, P<0.001) and recurrence-free survival (HR 6.68, 95% CI 3.35-13.34, P<0.001) for localized RCC; with poor OS (HR 2.00, 95% CI 1.75-2.28, P<0.001) for metastatic RCC; and with poor OS (HR 2.05, 95% CI 1.04-4.03, P = 0.038), CSS (HR 3.38, 95% CI 1.86-6.15, P<0.001), and PFS (HR 2.97, 95% CI 1.47-6.00, P = 0.002) for clear cell RCC. Furthermore, an elevated PC level was significantly associated with TNM stage (OR 3.11, 95% CI 1.59-6.06, P = 0.001), pathological T stage (OR 3.13, 95% CI 2.60-3.77, P<0.001), lymph node metastasis (OR 4.01, 95% CI 2.99-5.37, P<0.001), distant metastasis (OR 3.85, 95% CI 2.46-6.04, P<0.001), Fuhrman grade (OR 3.70, 95% CI 3.00-4.56, P<0.001), tumor size (OR 4.69, 95% CI 2.78-7.91, P<0.001) and Eastern Cooperative Oncology Group score (OR 5.50, 95% CI 3.26-9.28, P<0.001).
  
  
  CONCLUSIONS
  An elevated PC level implied poor prognosis in patients with RCC and could serve as a readily available biomarker for managing this disease.
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Liangyou
authors.initials: L
authors.lastname: Gu
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Hongzhao
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Luyao
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Xintao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital/PLA Medical School, No. 28 Fuxing Road, Beijing 100853, P.R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D002292:Carcinoma, Renal Cell / Q000097:blood / Q000453:epidemiology* / Q000473:pathology; D018572:Disease-Free Survival; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000453:epidemiology* / Q000473:pathology; D009362:Neoplasm Metastasis; D010976:Platelet Count; D011379:Prognosis