title: Prognostic role of pretreatment platelet/lymphocyte ratio in patients with non-small cell lung cancer.
abstract: BACKGROUND
  It was reported that hematological markers of systemic inflammatory response might be prognostic in various cancer types. We aimed to evaluate the platelet/lymphocyte ratio (PLR) as a prognostic factor and its effect on overall survival in non-small cell lung cancer (NSCLC).
  
  
  METHODS
  Clinicopathological characteristics and basal (pretreatment) PLR of 145 patients with NSCLC were evaluated retrospectively. The preoperative or pretreatment blood count data were obtained from the recorded computerized database. PLR was defined as the absolute platelet count divided by the absolute lymphocyte count.
  
  
  RESULTS
  A total of 145 patients were enrolled. Median age was 57 years(range 26-83). Receiver operating characteristic curves for overall survival prediction were plotted to verify the optimum cut-off point for PLR. The recommended cut-off values for PLR was 198.2 with a sensitivity of 65.0 % and a specificity of 71.4 %. Median overall survival was 34.0 (95 % confidence interval (CI) 14.7-53.3) months in the group with low PLR (< 198.2), while it was 11.0 (95 % CI 5.6-16.3) months in the group with high PLR (≥ 198.2). The difference between the groups was statistically significant (p < 0.0001).
  
  
  CONCLUSIONS
  Our study supports the view that a high basal PLR is a poor prognostic factor in NSCLC. However, the validity of the cut-off values for PLR identified in our study needs further prospective trials.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Duzce University, Duzce, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kos
authors.affiliation: Department of Medical Oncology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Cemil
authors.initials: C
authors.lastname: Hocazade
authors.affiliation: Department of Medical Oncology, Faculty of Medicine, Duzce University, 81000, Duzce, Turkey. tugbasan@yahoo.com.
authors.forename: F Tugba
authors.initials: FT
authors.lastname: Kos
authors.affiliation: Department of Medical Oncology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Dogan
authors.initials: D
authors.lastname: Uncu
authors.affiliation: Department of Internal Medicine, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Esra
authors.initials: E
authors.lastname: Karakas
authors.affiliation: Department of Medical Oncology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Mutlu
authors.initials: M
authors.lastname: Dogan
authors.affiliation: Turkish Drug & Medical Device Institution, Ankara, Turkey.
authors.forename: Hikmet Gulsen
authors.initials: HG
authors.lastname: Uncu
authors.affiliation: Department of Medical Oncology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Nuriye
authors.initials: N
authors.lastname: Yildirim
authors.affiliation: Department of Medical Oncology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Nurullah
authors.initials: N
authors.lastname: Zengin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000401:mortality* / Q000473:pathology*; D018655:Lymphocyte Count / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D010976:Platelet Count / Q000706:statistics & numerical data*; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014421:Turkey / Q000453:epidemiology
chemical_list: D015415:Biomarkers
keywords: Non-small cell lung cancer; Platelet lymphocyte ratio; Prognosis