Rising PSA with a negative biopsy.

Abstract

The use of prostate-specific antigen (PSA) as a diagnostic and screening tool has led to a significant rise in the numbers of patients undergoing prostate biopsy. However, the specificity of the PSA test is low, and the majority of patients in the diagnostically uncertain serum PSA range of 4-10 ng/ml will be negative for prostate cancer on biopsy. In addition, current biopsy techniques are sub-optimal. Improvements in technique are needed to increase the tumour detection rate and reduce the number of repeat biopsies. Several biopsy techniques have now been described that sample the prostate gland more effectively, by taking extra core samples in addition to the established sextant biopsy core samples. Sampling of peripheral areas of the gland results in significantly improved tumour detection rates while morbidity to the patient is not increased. The presence of prostatic intraepithelial neoplasia (PIN) is evidence that cancer is present, or is likely to appear, in the prostate, but has not been sampled in the biopsy. In the event of a rising PSA and negative biopsy, serum free/total PSA (% free PSA) measurement can be beneficial in discriminating between cancer and other possible causes of raised PSA, such as benign prostatic hyperplasia. PIN in association with reduced % free PSA is a valuable indicator in the decision to carry out a repeat biopsy.