Prediagnostic prostate-specific antigen velocity and probability of detecting high-grade prostate cancer.

OBJECTIVES: Men with high-grade prostate cancer experience a survival benefit when androgen suppression therapy is combined with radiotherapy (RT) compared with RT alone. We evaluated whether an association exists between the pretreatment prostate-specific antigen (PSA) velocity and high-grade prostate cancer at diagnosis, controlling for known predictors of high-grade disease.

METHODS: The study cohort consisted of 358 men with Stage T1c-T4 prostate cancer treated with external beam RT from 1989 to 2002. Univariate and multivariate logistic regression analyses were used to assess whether an association exists between the pretreatment PSA velocity, PSA level, age, clinical T stage, and Gleason score 4+3 or greater compared with Gleason score 3+4 or less prostate cancer.

RESULTS: Of the 358 men, 73 had a Gleason score of 4+3 or greater. The median PSA velocity was 2.71 ng/mL/yr (interquartile range 1.09 to 12.6) for men with a Gleason score of 4+3 or greater and 1.24 ng/mL/yr (interquartile range 0.71 to 3.37) for men with a Gleason score of 3+4 or less. All clinical covariates were significantly associated (P < or = 0.05) with a Gleason score of 4+3 or greater on univariate analysis. On multivariate analysis, the PSA velocity (odds ratio 1.06, 95% confidence interval 1.02 to 1.10, P = 0.004), age (odds ratio 1.07, 95% confidence interval 1.02 to 1.13, P = 0.008), and clinical T stage (odds ratio 2.17, 95% confidence interval 1.21 to 3.92, P = 0.01) were significantly associated with the detection of Gleason score 4+3 or greater prostate cancer.

CONCLUSIONS: The prediagnostic PSA velocity, patient age, and clinical T stage were significantly associated with high-grade prostate cancer at diagnosis. Because a biopsy Gleason score of 4+3 or greater is associated with a prostatectomy Gleason score of 7 or greater in the vast majority of cases, these parameters can identify men at high risk of harboring occult high-grade prostate cancer, permitting improved selection of RT fields and the use of androgen suppression therapy.