The relative density of tumor cells that are dependent on adrenal androgen after gonadal androgen withdrawal may be greater in patients with localized cancer and deferred flutamide treatment may enhance cancer control in those with localized disease.
To identify prostate specific antigen (PSA) functions of prognostic significance in regard to treatment with androgen deprivation for prostate cancer we analyzed the pretreatment PSA, PSA half-life, PSA nadirs, times to PSA elevation and PSA doubling times in 245 patients with localized and 78 with metastatic disease who were treated with this modality. There was a direct correlation between the pretreatment PSA and the time to PSA elevation in patients with localized cancer (p = 0.000003) but no significant correlation in those with metastatic cancer. The PSA half-life was highly variable and did not correlate with other PSA functions of prognostic significance. Incremental increases in the PSA nadir correlated with the time to PSA elevation in patients with localized and metastatic cancer (p < 0.000001 and p = 0.00009, respectively), and with other parameters of prognostic significance. The median PSA doubling time in 26 patients with localized cancer in whom distant metastases did not develop (7.5 months) was significantly longer than that in 7 in whom new metastases developed (2.5 months) and in 43 with preexisting metastatic cancer (2.5 months) (p < 0.05 and p < 0.0001, respectively). In the 7 patients with localized cancer in whom metastases developed the median of the ratios of the PSA when the metastases were manifest and the pretreatment PSA was 0.14, and in 24 patients with preexisting metastatic cancer the median of the ratios of the antemortem PSA and the pretreatment PSA was 1.2. These data show that PSA synthesis by prostate cancer is reduced after androgen deprivation but that the PSA nadir and PSA doubling time following treatment provide important prognostic information.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.