Postneoadjuvant hormone PSA levels and prognosis in locally advanced prostate cancer

To determine whether the response to hormonal therapy before radiation predicts the rate of biochemical relapse in patients with locally advanced prostate cancer.

Between October 1991 and December 1997, 105 patients with locally advanced adenocarcinoma of the prostate received radiotherapy in two dose-escalation studies. Sixty-seven patients received neoadjuvant hormonal therapy. The mean and median duration of hormonal therapy before radiotherapy was 4 months each. All treatments were designed using three-dimensional conformal therapy. The total dose to the gross tumor volume ranged from 73 to 87 Gy in 2 Gy per fraction photon equivalent dose. The median follow-up time was 30 months (range 1 to 66).

The median prostate-specific antigen (PSA) nadir after neoadjuvant hormonal therapy but before radiotherapy was 1.7 ng/mL (range less than 0.05 to 71.2). The median nadir after radiation for patients who did and did not receive neoadjuvant androgen deprivation was 0.25 ng/mL (range less than 0.05 to 6.2) and 1.35 ng/mL (range 0.08 to 10), respectively. Median time to achieve nadir was 6 months (range 1 to 42) with and 12 months (range 1 to 48) without hormonal therapy. There was no significant difference in the rate of biochemical failure for patients with a posthormone (before irradiation) PSA nadir less than 1 ng/mL versus 1 ng/mL or greater (overall P = 0.9). However, there was a significant difference in biochemical no evidence of disease rates between those with a PSA nadir less than 1 ng/mL and those with a PSA nadir of 1 ng/mL or greater after radiation (63% versus 22% at 3 years, overall P <0.001).

Our data showed that the initial response to hormonal therapy before radiation, as indicated by the PSA level, did not impact on the rate of recurrence. However, the time to reach nadir and the absolute nadir level achieved were lower in patients who did receive hormonal therapy.