ANALYZING OUTCOME-BASED STAGING FOR CLINICALLY LOCALIZED ADENOCARCINOMA OF THE PROSTATE

BAGKGROUND. A clinical staging system based on the prostate-specific a ntigen (PSA) and the calculated prostate carcinoma volume (cVCa) const ruct previously has been proposed. This study was performed to assess whether this proposed clinical staging system was valid in an independ ent surgical and radiation data set in patients with clinically locali zed disease. METHODS. Cox regression multivariable analyses were used to assess the significance of staging systems (1992 American Joint Com mission on Cancer Staging [AJCC] clinical and pathologic stage, versus cVCa-PSA clinical stage) to predict time to posttherapy PSA failure i n 441 and 465 patients managed by surgery and radiation, respectively. Significant staging systems identified using Cox regression were test ed further using established comparative measures to define the most c linically useful system. RESULTS. Both the 1992 AJCC pathologic stage and the cVCa-PSA clinical stage were significant predictors of time to postoperative PSA failure (P = 0.0001), whereas only the cVCa-PSA cli nical stage was a significant predictor of time to postradiation PSA f ailure (P = 0.0001) using a Cox regression multivariable analysis. Fur ther analyses using a pairwise comparison of the 1992 AJCC pathologic stage and cVCa-PSA clinical stage found the cVCa-PSA staging system pr ovided a more clinically useful prediction of time to postoperative PS A failure. Specifically, the cVCa-PSA staging system was able to ident ify surgically managed patients with pathologic AJCC T2 disease who di d poorly (3-year bNED = 22%) while also selecting patients with clinic al ATCC T2b,c disease that was managed by radiation who did well (3-ye ar bNED = 100%). CONCLUSIONS. A clinical staging system based on param eters obtained during the routine evaluation for AJCC clinical T1,2 pr ostate carcinoma provided a clinically useful stratification of both p ostoperative and postradiation PSA failure free survival. Cancer 1998; 83:2172-80. (C) 1998 American Cancer Society.