Evaluation of the platelet-to-lymphocyte ratio as a prognostic indicator in a European cohort of patients with prostate cancer treated with radiotherapy.

OBJECTIVES: 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 AND MATERIALS: 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.