Prostate gland volume is a strong predictor of biopsy results in men 70 years or older with prostate-specific antigen levels of 2.0-10.0 ng/mL.
OBJECTIVE
The incidence of prostate cancer, benign prostatic enlargement and serum level of prostate-specific antigen (PSA) increase with patient age. Intermediate elevation of PSA in elderly populations is apt to be considered insignificant. We evaluated the impact of PSA and prostate volume on the presence of non-palpable prostate cancer in elderly men with an intermediate level of PSA.


METHODS
Clinical records of 154 men 70 years or older, with non-cancerous digital rectal examination findings and with serum PSA levels of 2.0-10.0 ng/mL, who underwent initial 6- to 10-core transrectal prostate biopsy, were reviewed for prostate volume, number of biopsy cores, PSA and associated parameters. Stepwise logistic regression and receiver operating characteristic (ROC) models were used to determine the impacts of the parameters on the biopsy results.


RESULTS
Overall cancer detection rate was 40/154 or 26.0%. Prostate-specific antigen showed no significant association with the presence of prostate cancer (P = 0.59, Mann-Whitney U-test), while prostate volume did (P < 0.0001). On stepwise logistic regression analysis, prostate volume (P = 0.024, 95% CI 1.008-1.116) and biopsy core density (P = 0.017, 95% CI 4.76-7.12 x 10(6)) were independently associated with a cancer diagnosis, whereas PSA density was not an independent factor for a positive biopsy result. The area under the ROC curve for prostate volume was significantly superior to that of PSA (0.802 vs. 0.529; P = 0.012).


CONCLUSIONS
In men 70 years or older with gray zone PSA, prostate cancer patients are equally distributed over any PSA range. Although PSA has less impact on cancer presence than mere prostate volume, prostate cancer would be detected in a substantial proportion of older patients with PSA levels of 2.0-10.0 ng/mL.
Kobayashi
Takashi
T
Department of Urology, Hamamatsu Rosai Hospital, Hamamatsu, Japan. selecao@remus.dti.ne.jp
Mitsumori
Kenji
K
Kawahara
Takashi
T
Nishizawa
Koji
K
Ogura
Keiji
K
Ide
Yoshihiro
Y
D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D006801:Humans; D016015:Logistic Models; D008297:Male; D009929:Organ Size; D011237:Predictive Value of Tests; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D012372:ROC Curve; D014463:Ultrasonography
D017430:Prostate-Specific Antigen