Prostate-specific antigen doubling time as a predictor of Gleason grade in prostate cancer

ABSTRACT

Our aim was to evaluate the value of serum prostate-specific antigen doubling time [PSADT] to differentiate patients with high-grade prostate cancer who require more aggressive therapy from those with low-grade cancer. Of 460 patients with extended 12-core transrectal ultrasonography-guided biopsy of the prostate, 59 with confirmed prostate cancer were selected. They had not received any previous treatment for prostate cancer and had at least 2 consecutive serum PSA tests with a rising trend. The PSADT was calculated in patients with 2 serum PSA levels measured with an interval more than 3 months. Of 59 patients with prostate cancer, 35 [59.3%] had low-grade and 24 [40.7%] had high-grade tumors. There was no difference in age between the two groups. The median PSADT in patients with high-grade tumors were 12.70 months [range, 0.7 to 44.8 months] and 25.00 months [range, 1.65 to 41.2 months; P=.001]. A total of 21 patients with high-grade tumors [87.5%] had a PSADT less than 12 months, while only 9 of those with low-grade tumors [25.7%] had a PSADT less than 12 months. A PSADT with low-grade tumors [25.7%] had a PSADT less than 12 months. A PSADT cutoff of 12 months provided a sensitivity of 74% and a specificity of 87% for differentiation of high-grade from low-grade cancers. We concluded that men with a short PSADT [<12 months] were at a higher risk of harboring a high-grade prostate cancer. Our data suggests PSADT can identify patients with high-grade tumors who require more aggressive therapy