PCA3 Materials & News

Presti JC. Rev Urol 2007;9:93-8

• This review discusses the evolution of prostate biopsy techniques from the sextant scheme to an extended scheme.
• Sextant biopsies under-sample most prostates and may miss over 20% of cancers.
• Extended prostate biopsies increase cancer detection rates by more efficiently sampling the prostate; initial biopsies should include at least 12 cores from the peripheral zone with particular attention to sampling the lateral aspect of the prostate.
• Urologists are often troubled by patients with a negative biopsy who continue to have a rising PSA or another indication that raises concern for a missed cancer.
• A repeat biopsy should take additional cores from the anterior apex, or a saturation biopsy should be considered.
• The cancer detection rate with saturation repeat biopsies is about 35%.
• Saturation biopsies are associated with complications such as sepsis, haematuria and urinary retention.
• A recent development in the area of prostate cancer markers that may aid in determining the need for a repeat biopsy is the introduction of a urine test designed to detect messenger RNA of the Prostate CAncer gene 3 (PCA3).
• The PCA3 gene is highly expressed in the majority of prostate cancer cells¹.
• The utility of the PCA3 Assay was assessed in 233 men who had at least one prior negative biopsy².
• An adequate urinary sample was obtained in 97% of patients².
• The PCA3 Assay outperformed PSA in predicting cancer with an area under the receiver operating characteristics curve (AUC) = 0.68 compared with an AUC = 0.52 for PSA².

1) Fradet Y, et al. uPM3, a new molecular urine test for the detection of prostate cancer. Urology 2004;64:311-6
2) Marks LS, et al. PCA3 molecular urine assay for prostate cancer in men undergoing repeat biopsy. Urology 2007;69:532-5

Editorial comment

One of the most difficult issues in the detection of prostate cancer is how to proceed in men with a negative biopsy and a persistent rising PSA level. This paper reviews some important topics relevant to this discussion. First, the quality of the biopsy needs to be evaluated. A negative biopsy consisting of 6 cores can not reliably rule-out cancer. To be sufficiently informative a biopsy of 12 cores needs to be performed (to be adapted depending on the prostate size). It is important to document the exact location of the biopsy sample in order for the "laterality" of the core to be examined. It is important that the lateral zone is examined.

If the first biopsy was done according to standard procedures, a repeat saturation biopsy (24 cores) will only increase the frequency of side effects. In addition, the probability of a positive repeat saturation biopsy is low. Furthermore, there are indications that cancer detected in repeat saturation biopsies are very often insignificant cancers (Stav K, et al. Urology 2008;71:399-403).

In contrast, there is compelling evidence that the PCA3 test is an appropriate approach to help in the decision whether or not to perform a repeat biopsy.

More information: Article in Reviews in Urology