Among men with low-grade prostate cancer on prostate biopsy, the 4kscore predicts more aggressive prostate cancer at prostatectomy

INTRODUCTION AND OBJECTIVES: There is increasing evidence that a baseline PSA during mid-life can predict future development of lethal prostate cancer. We determined baseline PSA levels for US men aged 40 to 60 years in a nationally representative cohort and studied the influence of race, BMI, and waist circumference on median PSA levels among men without diagnosed prostate cancer. METHODS: We leveraged data from the National Health and Nutrition Examination Survey (NHANES), a set of studies that gathers lifestyle and nutrition information, and includes in person clinical assessments and biomarker measures. The study was nested among men with PSA measured between 2001-2010. Those with current infection or prostate inflammation, rectal exam in the past week, prostate biopsy or cystoscopy in the past month, or with a history of prostate cancer were excluded from PSA testing. We constructed a multivariable linear regression model to determine associations between age, body mass index (BMI), waist circumference, race, and log-transformed total PSA. RESULTS: There were 3,972 men aged 40 to 60 with PSA measured, of whom 49% were white, 20% black and 19% MexicanAmerican. Median total PSA levels by race, BMI and waist circumference are outlined in the table. In multivariable models, older age was positively associated with PSA levels. Moreover, PSA levels were higher among men of African-American and Mexican-American ancestry, compared to non-Hispanic white ancestry. In contrast, men with higher BMI or greater waist circumference had lower total PSA levels, adjusting for age and race. CONCLUSIONS: This study is among the first to report racial differences in PSA levels among men in midlife, and showing higher levels among African-American, and Mexican-American men. Conversely, BMI and waist circumference were inversely associated with PSA levels, and these associations were independent of race or age.