2207: Pretreatment PSA Velocity as a Predictor of Disease Outcome Following Radical Radiation Therapy

Abstract

BackgroundPSA velocity (PSAV) greater than 2.0 ng/mL/year has been identified as a predictor of disease-specific survival (DSS) and overall survival (OS) after radiotherapy for prostate adenocarcinoma (D’Amico et al, JAMA 2005; 294:440).Purpose/Objective(s)To assess if pretreatment PSAV is associated with biochemical disease-free survival (bDFS), DSS, or OS in men undergoing radical radiation therapy for prostate cancer in British Columbia.Materials/Methods473 patients with localized prostate cancer treated with radiation therapy between 1993 and 2001 formed the study cohort. No men received neoadjuvant or adjuvant hormones. PSAV was calculated using two or more PSA levels in the year prior to treatment. Kaplan-Meier survival analysis and Cox regression multivariate analysis were used to evaluate if PSAV was associated with disease endpoints.ResultsMen with a PSAV greater than 2.0 ng/mL/year had a shorter bDFS compared to men with a PSAV of 2.0 ng/mL/year or less (median bDFS 68 months vs. 97 months; Log-rank p = 0.0003). With inclusion of Gleason score, tumor stage, and pre-treatment PSA on multivariate analysis, PSAV greater than 2.0 ng/mL/year was no longer a significant predictor of bDFS (p=0.09). There was no difference between the two groups in DSS or OS (Log-rank p=0.55 and p=0.97 respectively).ConclusionsA pretreatment PSAV greater than 2.0 ng/mL/year is associated with reduced bDFS. However, PSAV is not an independent predictor of bDFS once other pretreatment risk factors are taken into account. PSAV does not predict DSS or OS. PSAV may be a surrogate marker of aggressive disease but does not provide independent prognostic information in this cohort. BackgroundPSA velocity (PSAV) greater than 2.0 ng/mL/year has been identified as a predictor of disease-specific survival (DSS) and overall survival (OS) after radiotherapy for prostate adenocarcinoma (D’Amico et al, JAMA 2005; 294:440). PSA velocity (PSAV) greater than 2.0 ng/mL/year has been identified as a predictor of disease-specific survival (DSS) and overall survival (OS) after radiotherapy for prostate adenocarcinoma (D’Amico et al, JAMA 2005; 294:440). Purpose/Objective(s)To assess if pretreatment PSAV is associated with biochemical disease-free survival (bDFS), DSS, or OS in men undergoing radical radiation therapy for prostate cancer in British Columbia. To assess if pretreatment PSAV is associated with biochemical disease-free survival (bDFS), DSS, or OS in men undergoing radical radiation therapy for prostate cancer in British Columbia. Materials/Methods473 patients with localized prostate cancer treated with radiation therapy between 1993 and 2001 formed the study cohort. No men received neoadjuvant or adjuvant hormones. PSAV was calculated using two or more PSA levels in the year prior to treatment. Kaplan-Meier survival analysis and Cox regression multivariate analysis were used to evaluate if PSAV was associated with disease endpoints. 473 patients with localized prostate cancer treated with radiation therapy between 1993 and 2001 formed the study cohort. No men received neoadjuvant or adjuvant hormones. PSAV was calculated using two or more PSA levels in the year prior to treatment. Kaplan-Meier survival analysis and Cox regression multivariate analysis were used to evaluate if PSAV was associated with disease endpoints. ResultsMen with a PSAV greater than 2.0 ng/mL/year had a shorter bDFS compared to men with a PSAV of 2.0 ng/mL/year or less (median bDFS 68 months vs. 97 months; Log-rank p = 0.0003). With inclusion of Gleason score, tumor stage, and pre-treatment PSA on multivariate analysis, PSAV greater than 2.0 ng/mL/year was no longer a significant predictor of bDFS (p=0.09). There was no difference between the two groups in DSS or OS (Log-rank p=0.55 and p=0.97 respectively). Men with a PSAV greater than 2.0 ng/mL/year had a shorter bDFS compared to men with a PSAV of 2.0 ng/mL/year or less (median bDFS 68 months vs. 97 months; Log-rank p = 0.0003). With inclusion of Gleason score, tumor stage, and pre-treatment PSA on multivariate analysis, PSAV greater than 2.0 ng/mL/year was no longer a significant predictor of bDFS (p=0.09). There was no difference between the two groups in DSS or OS (Log-rank p=0.55 and p=0.97 respectively). ConclusionsA pretreatment PSAV greater than 2.0 ng/mL/year is associated with reduced bDFS. However, PSAV is not an independent predictor of bDFS once other pretreatment risk factors are taken into account. PSAV does not predict DSS or OS. PSAV may be a surrogate marker of aggressive disease but does not provide independent prognostic information in this cohort. A pretreatment PSAV greater than 2.0 ng/mL/year is associated with reduced bDFS. However, PSAV is not an independent predictor of bDFS once other pretreatment risk factors are taken into account. PSAV does not predict DSS or OS. PSAV may be a surrogate marker of aggressive disease but does not provide independent prognostic information in this cohort.