Transrectal ultrasound-guided biopsy causes hematogenous dissemination of prostate cells as determined by RT-PCR.
OBJECTIVE
To determine if transrectal ultrasound-guided (TRUS) prostate biopsy causes dissemination of prostate cells into the circulation as assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) targeted against prostate-specific antigen (PSA) mRNA.


METHODS
RT-PCR PSA analysis was performed before and after prostatic invasive manipulations in 50 men. The cases consisted of 47 patients with TRUS and 3 with transurethral resection of the prostate (TURP). Peripheral venous blood (8 mL) was drawn before and within 60 minutes after the procedure. Total RNA was extracted from fractionated blood, and RNA/cDNA quality was assured and normalized with beta-actin RT-PCR analysis. The PSA primers hybridize exons 3 and 5, yielding a 254-basepair PCR product. The assay detects one LNCaP cell in a background of 100 million lymphoid cells and a single copy of PSA cDNA on an ethidium bromide gel.


RESULTS
Among the 47 TRUS cases, 43 specimens were evaluable. Forty-two cases were negative before biopsy; among these patients, 4 cases (9.5%) converted to a positive RT-PCR PSA result. Both benign and malignant TRUS biopsies were capable of producing a positive RT-PCR PSA signal implicating iatrogenic dissemination of cells. All three TURP cases converted from a negative to a highly intense positive signal.


CONCLUSIONS
We conclude that a positive RT-PCR PSA signal may result from release of prostate cells into the peripheral circulation after a TRUS biopsy and TURP. TURP causes greater dissemination than TRUS. Based on these preliminary data, we recommend that future molecular staging studies should be based on blood specimens drawn before performance of TRUS biopsy. This may be an important mechanism of prostate cancer dissemination meriting further investigations.
Moreno
J G
JG
Department of Urology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
O'Hara
S M
SM
Long
J P
JP
Veltri
R W
RW
Ning
X
X
Alexander
A A
AA
Gomella
L G
LG
D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood* / Q000235:genetics; D011470:Prostatic Hyperplasia / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D012194:RNA-Directed DNA Polymerase; D012007:Rectum; D012680:Sensitivity and Specificity; D014463:Ultrasonography
D012333:RNA, Messenger; D012194:RNA-Directed DNA Polymerase; D017430:Prostate-Specific Antigen