PCA3 sensitivity and specificity for prostate cancer detection in patients with abnormal PSA and/or suspicious digital rectal examination. First Latin American experience.
BACKGROUND
Prostate Cancer Gene 3 (PCA3) is a recently described and highly specific urinary marker for prostate cancer (CaP). Its introduction in clinical practice to supplement low specificity of prostate specific antigen (PSA) can improve CaP diagnosis and follow-up. However, before its introduction, it is necessary to validate the method of PCA3 detection in distinct geographic populations.


OBJECTIVE
Our aim was to describe for the first time in Latin America, the application of the PROGENSA PCA3 assay for PCA3 detection in urine in Chilean men and its utility for CaP diagnosis in men with an indication of prostate biopsy.


METHODS
Sixty-four Chilean patients (mean age, 64 years) with indication of prostate biopsy because of elevated PSA and/or suspicious digital rectal examination (DRE) were prospectively recruited. PCA3 scores were assessed from urine samples obtained after DRE, before biopsy, and compared with PSA levels and biopsy outcome.


RESULTS
The median PSA value and mean PCA3 score were 5.8 ng/ml and 31.7, respectively. Using a cutoff PCA3 score of 35, the sensitivity and specificity for detecting CaP were 52% and 87%, respectively. The receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.77 for PCA3 and 0.57 for PSA, for the same group of patients. In patients with previous negative biopsy, PCA3 specificity increased by 2.2%.


CONCLUSIONS
This is the first report in Latin America on the use of PCA3 in diagnosing CaP. Our results are comparable to those reported in other populations in the literature, demonstrating the reproducibility of the test. PCA3 score was highly specific and we specially recommend its use in patients with persistent elevated PSA and prior negative biopsies.
Urology Department, Clinica Las Condes, Santiago, Chile. Electronic address: cramos@clc.cl.
Christian G
CG
Ramos
Raul
R
Valdevenito
Ivonne
I
Vergara
Patricio
P
Anabalon
Catherine
C
Sanchez
Juan
J
Fulla
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000235:genetics* / Q000652:urine; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics / Q000652:urine; D001706:Biopsy; D002677:Chile; D051517:Digital Rectal Examination; D015972:Gene Expression Regulation, Neoplastic; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000378:metabolism / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D012372:ROC Curve; D012680:Sensitivity and Specificity
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C479341:prostate cancer antigen 3, human; D017430:Prostate-Specific Antigen