Fluctuation in prostate cancer gene 3 (PCA3) score in men undergoing first or repeat prostate biopsies.
OBJECTIVE
To evaluate the variability in prostate cancer gene 3 (PCA3) score over time in men with elevated serum prostate-specific antigen (PSA) levels who are undergoing first or repeat prostate biopsy.


METHODS
A total of 360 men from two Italian institutions who had undergone at least two PCA3 assessments were selected. Of these, 97.5% were scheduled for first or repeat prostate biopsy because of elevated PSA level and/or positive digital rectal examination (DRE). We compared the PCA3 scores in men with a negative biopsy (normal parenchyma, benign prostatic hyperplasia [BPH], chronic prostatitis, high-grade prostate intraepithelial neoplasia [HG-PIN]) with those in men with a positive biopsy. We evaluated PCA3 repeated measures biological variability and its possible association with basic patient characteristics (age, family history of prostate cancer, DRE, prostate volume, BPH, prostatitis and HG-PIN). Three different thresholds were used to evaluate the possible changes in risk class: the standard threshold (a PCA3 score of 35), a US Food and Drug Administation-approved PCA3 threshold of 25 and a threshold selected based on our previous research which was a PCA3 score of 50.


RESULTS
The PCA3 scores varied significantly (P < 0.001) when comparing men with a negative biopsy with those with a positive biopsy (median [range] PCA3 score: 25 [2-276] vs 43 [7-331]). There was no significant difference in PCA3 scores in men with chronic prostatitis and HG-PIN compared with other men with negative biopsies. The median (range) time between the two PCA3 assessments was 16.2 (3-53.7) months. No association was found between PCA3 repeated measures modifications and age, family history of prostate cancer, DRE, BPH, prostatitis, HG-PIN and use of 5-α-reductase inhibitors. The variability of PCA3 scores on repeated measures confirmed the risk class for about 80% of patients; of the remaining 20% of patients, the risk class was upgraded in two thirds and downgraded in one third.


CONCLUSIONS
PCA3 score can be considered a stable marker over time in most cases but there is a group of men among whom there is clinically notable risk class change. Further investigation is required to determine the genesis of this phenomenon.
Department of Urology, San Luigi Gonzaga Hospital, Orbassano, Italy.
Stefano
S
De Luca
Department of Nuclear Medicine, San Giovanni Battista Hospital, Torino, Italy.|University of Torino, Torino, Italy.
Roberto
R
Passera
Department of Pathology, San Luigi Gonzaga Hospital, Orbassano, Italy.
Susanna
S
Cappia
Department of Pathology, San Luigi Gonzaga Hospital, Orbassano, Italy.
Enrico
E
Bollito
Department of Urology, Gradenigo Hospital, Torino, Italy.
Donato Franco
DF
Randone
Department of Laboratory Medicine, Gradenigo Hospital, Torino, Italy.
Angela
A
Milillo
Department of Pathology, San Luigi Gonzaga Hospital, Orbassano, Italy.|University of Torino, Torino, Italy.
Mauro
M
Papotti
Department of Urology, San Luigi Gonzaga Hospital, Orbassano, Italy.|University of Torino, Torino, Italy.
Francesco
F
Porpiglia
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000235:genetics*; D002908:Chronic Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000235:genetics; D011470:Prostatic Hyperplasia / Q000235:genetics / Q000473:pathology; D019048:Prostatic Intraepithelial Neoplasia / Q000235:genetics* / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology*; D011472:Prostatitis / Q000235:genetics / Q000473:pathology; D012334:RNA, Neoplasm / Q000032:analysis*; D018570:Risk Assessment
D000951:Antigens, Neoplasm; D012334:RNA, Neoplasm; C479341:prostate cancer antigen 3, human; D017430:Prostate-Specific Antigen
high-grade prostate intraepithelial neoplasia; prostate cancer; prostate cancer antigen 3 gene; prostate specific antigen; prostatitis