PROSTATE-SPECIFIC ANTIGEN REGRESSION AND PROGRESSION AFTER ANDROGEN DEPRIVATION FOR LOCALIZED AND METASTATIC PROSTATE-CANCER

To identify prostate specific antigen (PSA) functions of prognostic si gnificance in regard to treatment with androgen deprivation for prosta te cancer we analyzed the pretreatment PSA, PSA half-life, PSA nadirs, times to PSA elevation and PSA doubling times in 245 patients with lo calized and 78 with metastatic disease who were treated with this moda lity. There was a direct correlation between the pretreatment PSA and the time to PSA elevation in patients with localized cancer(p = 0.0000 03) but no significant correlation in those with metastatic cancer. Th e PSA half-life was highly variable and did not correlate with other P SA functions of prognostic significance. Incremental increases in the PSA nadir correlated with the time to PSA elevation in patients with l ocalized and metastatic cancer (p < 0.000001 and p = 0.00009, respecti vely), and with other parameters of prognostic significance. The media n PSA doubling time in 26 patients with localized cancer in whom dista nt metastases did not develop (7.5 months) was significantly longer th an that in 7 in whom new metastases developed (2.5 months) and in 43 w ith preexisting metastatic cancer (2.5 months) (p < 0.05 and p < 0.000 1, respectively). In the 7 patients with localized cancer in whom meta stases developed the median of the ratios of the PSA when the metastas es were manifest and the pretreatment PSA was 0.14, and in 24 patients with preexisting metastatic cancer the median of the ratios of the an temortem PSA and the pretreatment PSA was 1.2. These data show that PS A synthesis by prostate cancer is reduced after androgen deprivation b ut that the PSA nadir and PSA doubling time following treatment provid e important prognostic information.