PURPOSE: To determine whether the response to neoadjuvant androgen deprivation therapy (ADT) defined by a decline in prostate-specific antigen (PSA) to nadir values is associated with improved survival outcomes after external beam radiation therapy (EBRT) for prostate cancer.
METHODS AND MATERIALS: One thousand forty-five patients with localized prostate cancer were treated with definitive EBRT in conjunction with neoadjuvant and concurrent ADT. A 6-month course of ADT was used (3 months during the neoadjuvant phase and 2 to 3 months concurrently with EBRT). The median EBRT prescription dose was 81 Gy using a conformal-based technique. The median follow-up time was 8.5 years.
RESULTS: The 10-year PSA relapse-free survival outcome among patients with pre-radiation therapy PSA nadirs of ≤ 0.3 ng/mL was 74.3%, compared with 57.7% for patients with higher PSA nadir values (P< .001). The 10-year distant metastases-free survival outcome among patients with pre-radiation therapy PSA nadirs of ≤ 0.3 ng/mL was 86.1%, compared with 78.6% for patients with higher PSA nadir values (P=.004). In a competing-risk analysis, prostate cancer-related deaths were also significantly reduced among patients with pre-radiation therapy PSA nadirs of < 0.3 ng/mL compared with higher values (7.8% compared with 13.7%; P=.009). Multivariable analysis demonstrated that the pre-EBRT PSA nadir value was a significant predictor of long-term biochemical tumor control, distant metastases-free survival, and cause-specific survival outcomes.
CONCLUSIONS: Pre-radiation therapy nadir PSA values of ≤ 0.3 ng/mL after neoadjuvant ADT were associated with improved long-term biochemical tumor control, reduction in distant metastases, and prostate cancer-related death. Patients with higher nadir values may require alternative adjuvant therapies to improve outcomes.
Written by:
Zelefsky MJ, Gomez DR, Polkinghorn WR, Pei X, Kollmeier M. Are you the author?
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
Reference: Int J Radiat Oncol Biol Phys. 2013 Mar 21. pii: S0360-3016(13)00165-X.
doi: 10.1016/j.ijrobp.2013.02.004
PubMed Abstract
PMID: 23523323
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