Tool to estimate risk of prostate cancer better than using PSA and DRE alone

A nomogram identifies age, free: total PSA ratio, prostate specific antigen (PSA) and digital rectal examination (DRE) were the most important factors to include when assessing risk of prostate cancer in a screening program. In Canada and the US approximately 75% of men at least 50 years of age have regular PSA screening for prostate cancer. Evidence suggests that abnormal PSA levels are not reliable to distinguish benign from malignant disease, and cancer may be present in those with a normal PSA. This cross-sectional study aimed to develop a simple non invasive tool that could be used at the time of first PSA and DRE to estimate the individual’s risk of having prostate cancer. It included 3,108 men who had 6-15 ultrasound guided needle core biopsies, and included 408 men with normal PSA levels who agreed to have a biopsy. A nomogram was constructed including age, family history of prostate cancer, ethnicity, urinary symptoms, PSA, free:total PSA ratio, and DRE. Multivariate analysis showed that all risk factors were important predictors for prostate cancer. A total of 42.0% were found to have prostate cancer, including 24.3% of those who had a normal PSA of < 4.0 ng/mL. The nomogram was validated by comparing predicted and actual probabilities for prostate cancer overall as well as aggressive prostate cancer. The area under the curve (AUC) for the nomogram in predicting any cancer, which included age, ethnicity, FHPC, urinary symptoms, free:total PSA ratio, PSA, and DRE, was 0.74 (95% CI, 0.71 to 0.81) and 0.77 (95% CI, 0.74 to 0.81) for high-grade cancer. This was compared with values for conventional screening using PSA and DRE only, which were 0.62 (95% CI, 0.58 to 0.66) and 0.69 (95% CI, 0.65 to 0.73) respectively. Free: total PSA was the most important predictor for patients with PSA of 4 ng/ml and above, and age, DRE, PSA and the free:total PDSA ratio was most important for predicting high grade cancer. The authors concluded that these factors should always be considered in any screening program. Reference...