Analysis of circulating tumor cells in prostate cancer patients at psa recurrence and review of the literature

Background: Circulating tumor cells have been described in prostate cancer patients at diagnosis and in the metastatic phase but little is known on their role at biochemical PSA recurrence. Patients and Methods: Patients radically cured with either prostatectomy or radiotherapy were sequentially included at PSA recurrence. The presence of CTCs was evaluated by the CellSearch system. Results: Twenty-nine patients were accrued at PSA recurrence. Median PSA at recurrence was 7.2 ng/ml (range=3.86-51.0 ng/ml). The median time to PSA progression was 4.66 years (range=0.1-16 years). CTCs were detected in one patient (3%) with low numbers (1 CTC/7.5 ml). Conclusion: In patients radically cured for prostate cancer at biochemical recurrence, CTCs are detected at very low levels in a minority of patients. Further studies are required to investigate alternative methods of CTC detection and the possible role of the bone marrow pre-metastatic niche at biochemical recurrence.