Response to second-line hormonal manipulation monitored by serum PSA in stage D2 prostate carcinoma

Changes in prostate-specific antigen (PSA) have been demonstrated to accurately assess response to initial hormone deprivation in metastatic prostate cancer patients. The role of PSA in monitoring response to second-line hormonal treatment has not been documented. In a group of 20 patients with an initial response to androgen deprivation and subsequent relapse, we monitored PSA levels before and after second-line therapy. Ten patients had a clinical response. Four had a more than 90 percent decrease in serum PSA compared with the level at initial progression. This clinical response was maintained for a mean of eighteen months. Six patients had a PSA decrease less than 90 percent; their clinical response was of a mean 5.5 months. Ten patients had no change or increase in PSA. Seven had no clinical response, and 3 responded for an average of four months. Although production of PSA might be under endocrine control, changes in PSA are useful for monitoring response to second-line hormonal therapy.