Does prostate-specific antigen nadir predict longer-term outcomes of prostate cancer after neoadjuvant and adjuvant androgen deprivation therapy in conjunction with brachytherapy? - Abstract

PURPOSE: To evaluate whether nadir prostate-specific antigen (nPSA), time to nPSA (TnPSA), and nPSA 3-years post-treatment are prognostic for prostate cancer (PC) in patients treated with temporary brachytherapy plus external beam radiation therapy (EBRT) and hormonal manipulation.

METHODS AND MATERIALS: We retrospectively analyzed our database of 253 patients with Stage T1-T3 N0M0 PC who underwent brachytherapy with temporary brachytherapy plus EBRT. All patients received neoadjuvant androgen deprivation for a median of 6 months. Treatment consisted of three pulses of pseudo pulsed-dose-rate brachytherapy to a median dose of 18Gy with 50.4Gy in 28 fractions of EBRT. Treatment took place between December 1999 and March 2006.

RESULTS: At a median of 6-years followup, nPSA value was a predictor of biochemical control. Rising nPSA categories of < 0.01, 0.01-< 0.05, 0.05-≤ 0.1, 0.1-≤ 1.0, or >1.0ng/mL correlated with a deteriorating 5-year biochemical control (nBED) by the Phoenix definition of 100%, 90.0%, 82.5%, 64.3%, and 10%, respectively. A highly statistically significant relationship between nPSA value and subsequent clinical failure is also demonstrated. The relationship between TnPSA and nBED was strongly significant (p< 0.0001), with a significantly longer nPSA for patients who had Phoenix nBED. A PSA of < 1.5ng/mL achieved 3-year post radiation therapy was prognostic for biochemical and clinical disease control (p< 0.0001).

CONCLUSION: The nPSA, TnPSA, and reaching a PSA cutoff level of < 1.5ng/mL at 3 years post-treatment can provide useful prognostic information on long-term biochemical and clinical control of PC in patients treated with pseudo PDR, EBRT, and hormone manipulation.

Written by:
Morris LM, Izard MA, Wan WY.   Are you the author?
Crown Princess Mary Cancer Centre, Westmead Hospital, Sydney, Australia; Department of Radiotherapy, Mater Hospital, North Sydney, New South Wales, Australia; Department of Biostatistics, University of Sydney, New South Wales, Australia.

Reference: Brachytherapy. 2014 Dec 5. pii: S1538-4721(14)00682-5.
doi: 10.1016/j.brachy.2014.11.002

PubMed Abstract
PMID: 25487524 Prostate Cancer Section