Robert W. Veltri, PhD

The promise of using reverse transcriptase–polymerase chain reaction (RT-PCR) technology for the detection of circulating prostate cancer cells in peripheral blood, although technically feasible at the molecular level, has proven clinically impractical for routine implementation in patient management. Reverse transcriptase–polymerase chain reaction has been successfully applied to detect and quantify (relatively speaking) genes that are differentially expressed in cells and tissues obtained from patients during various stages of malignant growth. In addition, the method has been applied to the detection of circulating cancer cells in peripheral blood using highly specific primer sets for specific molecular targets. These include epithelial cell cytokeratins for breast cancer, as well as enzymes, such as tyrosinase for melanoma and prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) for prostate cancer, using either nonnested or nested methodologies.