Purpose: The feasibility of harvesting intact, circulating prostate cancer cells from the blood of men with advanced prostate cancer has previously been demonstrated. We studied the influence of sextant prostate needle biopsy and radical prostatectomy on harvesting intact circulating prostate cancer cells.
Materials and methods: Via standard venipuncture 20 c.c. blood were obtained preoperatively, and 30 minutes and 3 days postoperatively from 23 men with clinically localized prostate cancer undergoing surgery. Similarly, blood was obtained before and after routine prostate biopsy from 13 men for an elevated prostate specific antigen level and/or abnormal digital rectal examination. The blood cells were removed via density centrifugation and magnetic cell sorting. The remaining prostate epithelial cells were characterized by indirect fluorescent immunocytochemical staining and fluorescent in situ hybridization using deoxyribonucleic acid probes.
Results: Sextant biopsy of the prostate induced circulating cells in 3 of 13 men (23%), only 1 of whom demonstrated cells with aneuploidy (Gleason score 3+4 = 7). Circulating cells were detected preoperatively, 30 minutes or 3 days postoperatively in 35% of radical prostatectomy cases. Of the patients 13% had detectable circulating cells 30 minutes postoperatively only and 9% had cells harvested on postoperative day 3. Persistence of circulating prostate cancer cells was noted in 13% of men on postoperative day 3. Serum prostate specific antigen level and pathological stage did not appear to be related to harvested cell number.
Conclusions: Prostate cancer cells can be harvested from men with clinically localized disease undergoing sextant needle biopsy or radical prostatectomy. Routine prostate biopsy and surgery may influence the number of measurable circulating cells in the short term but the clinical significance and long-term prevalence of detectable circulating cells are unknown. Further studies are needed to evaluate the clinical usefulness of this assay for detecting, staging and monitoring prostate cancer.