Cytokeratin 19 expression by reverse transcriptase-polymerase chain reaction in the peripheral blood of prostate cancer patients

Aims and background: Sensitive reverse transcriptase-polymerase chain reaction-based techniques for detection of epithelial antigen expression, such as cytokeratin 19, in the peripheral blood mononuclear fraction of prostate cancer patients may allow the detection of tumor progression at A molecular level. Methods: We studied cytokeratin 19 expression by reverse transcriptase-polymerase chain reaction in peripheral blood mononuclear cell samples of 10 control men and serially in 44 patients with prostate cancer every three months for 18 months. Results: None of the 10 normal control men expressed cytokeratin 19 in their peripheral blood mononuclear fraction. In the patients, cytokeratin 19 positivity at entry was not associated with age, Gleason score, clinical stage, prostate-specific antigen or alkaline phosphatase. Interestingly, having at least one positive cytokeratin 19 result during follow-up correlated significantly with time to prostate-specific antigen progression (P = 0.049), especially in the subgroup of metastatic patients (P = 0.032). Conclusions: We conclude that cytokeratin 19 expression by reverse transcriptase-polymerase chain reaction in the peripheral blood mononuclear cell fraction of prostate cancer patients correlates with time to prostate-specific antigen progression. Further studies are needed to confirm these findings.