COMPARING PROSTATE SPECIFIC ANTIGEN OUTCOMES AFTER DIFFERENT TYPES OF RADIOTHERAPY MANAGEMENT OF CLINICALLY LOCALIZED PROSTATE CANCER HIGHLIGHTS THE IMPORTANCE OF CONTROLLING FOR ESTABLISHED PROGNOSTIC FACTORS
作者:ANTHONY V. D’AMICO、DELRAY SCHULTZ、LINDSEY SCHNEIDER、MARK HURWITZ、PHILIP W. KANTOFF、JEROME P. RICHIE
DOI:10.1016/s0022-5347(05)67546-5
日期:2000.6
Purpose: We evaluated the impact that the composition of prognostic factors in a patient cohort may have on prostate specific antigen (PSA) outcome following external beam radiation therapy for clinically localized prostate cancer.Materials and Methods: The distribution of PSA, biopsy Gleason score and American joint Committee on Cancer (AJCC) T stage in men with prostate cancer treated with interstitial plus external beam radiation therapy was used to select a matched cohort who underwent 3-dimensional (D) conformal external beam radiation therapy. We compared PSA outcomes after 3-D conformal external beam radiation therapy in the overall and matched cohorts of 766 and 570 patients, respectively.Results: Men treated with interstitial plus external beam radiation therapy had a significantly lower rate of PSA greater than 10 to 20 (p = 0.02) and greater than 20 ng./ml. (p <0.0001), biopsy Gleason score 7 (p = 0.02) and 8 to 10 (p <0.0001), and AJCC stage T2c disease (p <0.0001). Likewise, these men also had a significantly higher rate of PSA greater than 4 to 10 ng./ml. (p <0.0001), biopsy Gleason score 5 to 6 (p = 0.0001) and AJCC stage T1 disease (p <0.0001) than those who underwent 3-D conformal external beam radiation therapy. The 5-year estimate of PSA failure-free survival after 3-D conformal external beam radiation therapy was 45% versus 67% (p = 0.0007) for all 766 consecutively treated patients and the matched cohort of 570, respectively.Conclusions: The composition of prognostic factors in a patient cohort may impact PSA outcome. Therefore, controlling for established prognostic factors is essential when comparing PSA outcome after different forms of radiotherapy for adenocarcinoma of the prostate.