PD15-04 THE ASSOCIATION BETWEEN FAMILY HISTORY AND PROSTATE-SPECIFIC ANTIGEN FROM A LARGE GROUP OF 45-YEAR OLD MEN EMBARKING ON PROSTATE CANCER SCREENING: RESULTS FROM THE PROBASE TRIAL

INTRODUCTION AND OBJECTIVES: A family history of prostate cancer gives sufficient reason to initiate prostate-specific antigen (PSA) screening as early as 45 years of age according to the European and US guidelines. However, little is known about the association between family history (FH) and PSA among men of very young age. This study aimed to quantify this relationship in a large cohort of over 5.000 45-year old men enrolled in a German prostate cancer screening Trial. METHODS: PROBASE is a German prostate cancer screening study enrolling men of age 45. Men are randomized to have either an immediate PSA at time of enrollment or one 5 years later at age 50. This study investigates results from participants who received a PSA measurement immediately on entry at age 45 until September 2015. Men were categorized into the group with first-degree FH of prostate cancer (father and/or brother) and no first-degree FH. The chi-square test was used to evaluate the association between first-degree FH of prostate cancer and whether the PSA was less than 1.5 ng/ml, between 1.5 and 3.0 ng/ml, or over 3.0 ng/ml. The non-parametric Wilcoxon test was used to determine differences in median PSA. Normal linear regression was used to evaluate whether the effect of other cancers in the family or a malignancy other than prostate cancer in the participant additionally influenced PSA. PSA was log-transformed to improve the goodnessof-fit. RESULTS: Among 5.818 participants, 11.1% had at least 1 first-degree relative diagnosed with prostate cancer, 56.1% had a FH of other cancer and 3.0% had a malignancy other than prostate cancer. Among those with no first-degree FH, 88.5% had PSA 0.05). CONCLUSIONS: This largest study to date of 45-year old men demonstrated higher PSA levels among men with a family history, supporting current European and American recommendations for earlier screening among these men.