Prostate-specific antigen in patients with relapsed prostate cancer following endocrine treatment.

We assessed the relationship between changes in PSA and prognosis, as a possible reflection of tumour growth in patients who relapse following primary endocrine therapy. In 8 patients in whom no therapeutic change was attempted after PSA relapse, the PSA level increased exponentially. Their PSA-DT had a close positive relationship to the duration of survival after relapse (r = 0.79, p = 0.02). In 6 patients who received chemotherapy after relapse, PSA-DT between PSA relapse and initiation of chemotherapy also had a relationship to the duration of survival after relapse (r = 0.87, p = 0.05). It appears to be reasonable to conclude from these findings that the PSA-DT value is regarded to be a factor associated with prognosis in cases with an exponential increase in PSA after replase.