Association between platelet-to-lymphocyte ratio and high risk for prostate cancer among middle-aged and older US men

Prostate cancer (PCa) is one of the most common malignancies among men worldwide, and growing evidence implicates inflammation as a key contributor to its initiation and progression. Among various inflammatory markers, the platelet-to-lymphocyte ratio (PLR) has gained attention due to its simplicity, non-invasiveness, and clinical relevance. This study aims to evaluate the association between PLR levels and PCa risk in middle-aged and older U.S. men using nationally representative data. This study conducted a cross-sectional evaluation using data derived from the National Health and Nutrition Examination Survey (NHANES) spanning 2001 to 2010, aiming to investigate a possible link between the PLR and PCa risk. The PLR was determined by dividing the platelet count by the lymphocyte count. Individuals were classified as high risk for PCa if total PSA (tPSA) exceeded 10 ng/mL, or ranged from 4 to 10 ng/mL with a free-to-total PSA (f/t PSA) ratio ≤ 25%. Others were categorized as low risk. To evaluate the association between PLR and PCa risk, multivariate logistic regression and restricted cubic spline models were employed. Stratified subgroup analyses were conducted to explore potential effect modification across different populations, while supplementary sensitivity analyses were performed to confirm the stability and reliability of the results. Among the 6,285 participants, 437 (4.86%) were classified as the high risk for PCa. After controlling for potential confounding variables, each 10-unit increase in PLR corresponded to a 3% elevation in high risk for PCa (OR 1.03, 95% CI 1.02-1.05). Individuals in the top quartile of PLR had a 74% greater high risk of PCa than those in the bottom quartile (OR 1.74, 95% CI 1.24-2.45). A restricted cubic spline model demonstrated a significant linear relationship between PLR and high risk for PCa. Additional sensitivity analyses reinforced the stability of these observed associations. Stratified analyses demonstrated that the link between PLR and PCa risk persisted consistently across diverse demographic and clinical categories, such as age, marital status, body mass index, smoking behavior, alcohol consumption, hypertension, and diabetes status. Within the U.S. middle-aged and elderly population, PLR exhibits a significant linear association with high risk for PCa. These findings suggest that PLR may serve as an epidemiological reference indicator for identifying individuals with potentially elevated PCa risk.