Questions and Answers
Would the PCA3 test be a good option for men with a high prostate specific antigen (PSA) level and an enlarged prostate who have had a colostomy, i.e. in whom a prostate biopsy by means of a rectal approach can not be performed?
Firstly, it must be said that prostate biopsies can be safely performed by a transperineal approach, exactly as brachytherapy (seeds implant) is performed [1]. Before deciding on whether to perform a transperineal biopsy, a dynamic contrast magnetic resonance imaging (MRI) can be performed to assess if there are suspicious lesions.
The Prostate CAncer gene 3 (PCA3) test can provide additional information about the probability of prostate cancer. However, the standard collection procedure, i.e. a 3-stroke digital rectal examination (DRE) before the collection of first catch urine, can not be performed. Not performing a DRE will not impact the accuracy of the test if a result is obtained. However, it does increase the chance of an in-valid result, meaning that no PCA3 Score can be determined. It is generally believed that omitting the DRE increases the chance of an invalid result from 1-2% to approximately 30%.
1. Merrick GS et al. Prostate cancer distribution in patients diagnosed by transperineal template-guided saturation biopsy. Eur Urol 2007;52(3):715-23.