Evaluación del riesgo de cáncer prostático mediante el cociente entre PSA libre y PSA total

DOI: https://doi.org/10.46296/gt.v9i18edespsep.0451 Abstract Prostate cancer is a relevant health problem in adult men, and its assessment requires tools that estimate risk without assigning definitive diagnostic capacity to a single biomarker. This study aimed to assess prostate cancer risk using the free-to-total prostate-specific antigen (PSA) ratio in adult men evaluated at the San Juan Clinical Laboratory in Salcedo. A quantitative, non-experimental, cross-sectional, descriptive study was conducted in 30 participants older than 40 years selected through non-probability purposive sampling. Serum total PSA and free PSA concentrations were measured using automated chemiluminescent immunoassay; the percentage of free PSA was then calculated and used for analytical risk stratification. Mean total PSA was 5.95 ± 2.26 ng/mL, mean free PSA was 1.29 ± 0.50 ng/mL, and mean percentage of free PSA was 21.83 ± 3.45%. A total of 73.3% of participants had total PSA values between 4.0 and 10.0 ng/mL, while 26.7% had a free PSA percentage below 20% and were classified in the higher analytical-risk category. Age showed a positive correlation with total PSA (r = 0.560; p = 0.001) and free PSA (ρ = 0.537; p = 0.002), but not with the percentage of free PSA (r = −0.025; p = 0.894). The free-to-total PSA ratio therefore provides complementary information for risk stratification, particularly when total PSA values are intermediate, but it does not replace clinical assessment or diagnostic confirmation. Keywords: Prostate-specific antigen, free PSA, total PSA, prostate cancer, risk stratification.