Chance of a positive biopsy
Biopsy yes or no?
Risk indicator 3 allows a more precise prediction of a positive biopsy than indicator 2 because it includes the results of the rectal examination, the ultrasonography (hypoechogenic lesions yes or no?), and of the volume of the prostate determined at ultrasonography. Each of these parameters has independent value in predicting biopsy outcome (Roobol et al, Prostate 2006).
Risk indicator 4 is based on 10890 men who were previously screened, had a serum PSA < 4.0 ng/ml and were not biopsied. Of these men 1921 were biopsied 4 years later for PSA progression to ≥ 3.0 ng/ml, 430 cancers were found (PPV 22.4%).
Risk indicator 5 is based on 989 men who were previously screened, were biopsied and had no cancer. These men were again biopsied 4 years later with PSA values ≥ 3.0 ng/ml, 120 cancers were found (PPV 12.1%).
Both, a negative previous screen and, more importantly, a prior negative biopsy significantly decrease the risk of a later positive biopsy.
The disclaimer, which is part of the risk indicator 1 and 2, obviously also is applicable to the risk indicator 3-6. As a professional you have the freedom to discuss the results of risk indicator 3 with your patient and to assist in the decision whether to do a biopsy or not. Please note that a large prostate volume is an important negative predictor of prostate cancer.
