PCA3 Gene In Prostate Cancer Diagnosis

The PCA3 gene, discovered in 1999, is being studied as a new biomarker to be used in the workup of potential prostate cancer.

To date, PSA or Prostate Specific Antigen, is being used as a screening marker for potential prostate cancer.

The problem with the PSA test is that it produces many false positive results. This leads to many unnecessary tests and biopsies.

Currently, a dilemma exists if a PSA is high and subsequent prostate biopsies are negative which happens often since approximately 60% of prostate biopsies following an elevated PSA turn out to be negative. Often, further biopsies are recommended.

The PCA 3 Gene can be detected and measured in urine samples of patients being worked up for prostate neoplasm. The gene is overexpressed by a factor of 60-100 in 90% of prostate tumors.

The PCA 3 gene appears to have more specificity than PSA since PSA can be overexpressed and therefore be high in non-cancerous prostate conditions. It also appears that the PCA3 Gene has more positive and negative predictive value.

In studies so far, it appears that PCA3 is a better predictor of prostate cancer following an initial negative biopsy as compared to PSA.

The PCA3 molecular marker also appears to be able to stratify patients by tumor volume and Gleason score.

Further studies are being done to define the role of the PCA3 Gene.