Biochemical Response to Androgen Deprivation Therapy Before External Beam Radiation Therapy Predicts Long-Term Prostate Cancer Survival Outcomes
Menée sur 1 045 patients atteints d'un cancer localisé de la prostate et devant recevoir une radiothérapie externe combinée à un traitement anti-androgénique (durée médiane de suivi : 8,5 ans), cette étude montre une association entre la réponse biochimique à un traitement anti-androgénique néoadjuvant et la survie à long terme des patients
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. 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. 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. 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.
International journal of radiation oncology, biology, physics , résumé, 2012