title: Evaluation of the platelet-to-lymphocyte ratio as a prognostic indicator in a European cohort of patients with prostate cancer treated with radiotherapy.
abstract: OBJECTIVE
  Recent evidence suggests that the presence of a systemic inflammatory response plays an important role in the progression of several solid tumors. The platelet-to-lymphocyte ratio (PLR) has been proposed as an easily assessable marker of systemic inflammation and has been shown to represent a prognostic marker in different cancer entities. To evaluate the prognostic value of the PLR in prostate cancer, we performed the present study.
  
  
  METHODS
  Data from 374 consecutive patients with prostate cancer, treated with 3D conformal radiotherapy from 1999 to 2007, were analyzed. Distant metastases-free survival (MFS), cancer-specific survival (CSS), overall survival (OS), biochemical disease-free survival, and time to salvage systemic therapy were assessed using the Kaplan-Meier method. Cox proportional hazards analysis was performed to calculate hazard ratio (HR) and 95% CI. Multivariate Cox regression analysis was performed to adjust for other covariates.
  
  
  RESULTS
  Using receiver operating characteristics analysis, the optimal cutoff level for the PLR was 190. Kaplan-Meier analyses revealed that PLR≥190 was a prognostic factor for decreased MFS (P = 0.004), CSS (P = 0.004), and OS (P = 0.024) whereas a significant association of an elevated PLR with biochemical disease-free survival (P = 0.740) and time to salvage systemic therapy (P = 0.063) was not detected. In multivariate analysis, an increased PLR remained a significant prognostic factor for poor MFS (HR = 2.24, 95% CI: 1.06-4.76, P = 0.036), CSS (HR = 3.99, 95% CI: 1.19-13.4, P = 0.025), and OS (HR = 1.87, 95% CI: 1.02-3.42, P = 0.044).
  
  
  CONCLUSIONS
  Our findings indicate that the PLR may predict prognosis in patients with prostate cancer and may contribute to future individual risk assessment in them.
authors.affiliation: Department of Therapeutic Radiology and Oncology, Comprehensive Cancer Center, Medical University of Graz, Austria. Electronic address: tanja.langsenlehner@medunigraz.at.
authors.forename: Tanja
authors.initials: T
authors.lastname: Langsenlehner
authors.affiliation: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, TX.
authors.forename: Martin
authors.initials: M
authors.lastname: Pichler
authors.affiliation: Department of Therapeutic Radiology and Oncology, Comprehensive Cancer Center, Medical University of Graz, Austria.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Thurner
authors.affiliation: Department of Therapeutic Radiology and Oncology, Comprehensive Cancer Center, Medical University of Graz, Austria.
authors.forename: Sabine
authors.initials: S
authors.lastname: Krenn-Pilko
authors.affiliation: Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Stojakovic
authors.affiliation: Department of Medicine, Comprehensive Cancer Center, Medical University of Graz, Austria.
authors.forename: Armin
authors.initials: A
authors.lastname: Gerger
authors.affiliation: Division of Internal Medicine, Outpatient Department Graz, Austria.
authors.forename: Uwe
authors.initials: U
authors.lastname: Langsenlehner
mesh_terms: D000368:Aged; D001792:Blood Platelets / Q000378:metabolism*; D015331:Cohort Studies; D018450:Disease Progression; D005060:Europe; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*
keywords: Inflammation; Platelet-to-lymphocyte ratio (PLR); Prognosis; Prostate cancer