Ces Urol 2014, 18(3):216-224 | DOI: 10.48095/cccu2014029

Age specific PSA and PSA velocity - comparison on the basis of prostate biopsies

Jiří Janů, Tomáš Lakomý, Jaroslav Tůma

Urologické oddělení Nemocnice Nové Město na Moravě

Aim:
To compare predictive value of age specific PSA (VSPSA) and PSA velocity (PSAV).

Methods:
Histology findings of benign prostatic hyper-plasia and prostate cancer were divided into groups according to number of biopsies performed. The data was evaluated separately for every order of biopsy in relation to age specific PSA and PSA velocity.
1. Models of age specific PSA (ng/ml):
MODEL A: 40-49 years: 2.5; 50-59 years:3.5; 60-69 years: 4.5; 70-79 years: 6.5
MODEL B: 40-49 years: 2.5; 50-59 years: 3.5; 60+years: 4
MODEL C: cut off value 3.5
MODEL D: cut off value 2.5
2. PSA velocity (ng/ml/year): Using the method mentioned above, we compared PSAV 0.75, PSAV 0.5 and PSAV 0,35 at groups of patients (pts.) with 2 and 3 biopsies.

Results:
1. Age specific PSA
Percentage of true positives increases from A (36.6%) to D (44.2%). False negatives decrease from A (8.5%) to D (0.8%). Percentage of true negatives decreases from A (14.4%) to D (3.4). False positives increase from A (40.5%) to D (51.6%). There is a high similarity between B and C (percentage deviation for true positives 0.6%, for false negative 7.3%, for true negative 11.4% and false positive 1.6%).
2. PSA velocity PSAV
0.75 has a low number of true positive results: 16.7-29.6%. False negative results were obtained in 16.7% pts. with 2 biopsies and in 11.1% pts. with 3 biopsies. PSAV 0.35 is more accurate in true positives (by 25%) and in false negatives (by 25% in pts. with 2 biopsies, by 66.7% in pts. with 3 biopsies) when compared with PSAV 0.75.
Sensitivity and specificity of ASPSA and PSAV react as expected.

Conclusion:
With respect to age specific PSA, no greater differences were found between models B and C. Use of model D led to reduction in the number of false negative results but increase number false positive results. PSAV identified lower number of true positive results. Lowering the threshold PSAV to 0.35 resulted in identification of higher number of true positives, however at the same time it was associated with more false positive results.

Keywords: PSA, age specific PSA, PSA velocity, prostate biopsv, prostate cancer

Received: April 3, 2014; Accepted: July 7, 2014; Published: June 1, 2014