Faculty Collaboration Database

Importance of Local Control in Early-Stage Prostate Cancer: Outcomes of Patients With Positive Post-Radiation Therapy Biopsy Results Treated in RTOG 9408. Int J Radiat Oncol Biol Phys 2015 Jul 15;92(4):863-73

Date

06/25/2015

Pubmed ID

26104939

Pubmed Central ID

PMC4480595

DOI

10.1016/j.ijrobp.2015.03.017

Scopus ID

2-s2.0-84931419214 (requires institutional sign-in at Scopus site)   27 Citations

Abstract

PURPOSE: The purpose of this study was to assess the association between positive post-radiation therapy (RT) biopsy results and subsequent clinical outcomes in males with localized prostate cancer.

METHODS AND MATERIALS: Radiation Therapy Oncology Group study 94-08 analyzed 1979 males with prostate cancer, stage T1b-T2b and prostate-specific antigen concentrations of ≤ 20 ng/dL, to investigate whether 4 months of total androgen suppression (TAS) added to RT improved survival compared to RT alone. Patients randomized to receive TAS received flutamide with luteinizing hormone releasing hormone (LHRH) agonist. According to protocol, patients without evidence of clinical recurrence or initiation of additional endocrine therapy underwent repeat prostate biopsy 2 years after RT completion. Statistical analysis was performed to evaluate the impact of positive post-RT biopsy results on clinical outcomes.

RESULTS: A total of 831 patients underwent post-RT biopsy, 398 were treated with RT alone and 433 with RT plus TAS. Patients with positive post-RT biopsy results had higher rates of biochemical failure (hazard ratio [HR] = 1.7; 95% confidence interval [CI] = 1.3-2.1) and distant metastasis (HR = 2.4; 95% CI = 1.3-4.4) and inferior disease-specific survival (HR = 3.8; 95% CI = 1.9-7.5). Positive biopsy results remained predictive of such outcomes after correction for potential confounders such as Gleason score, tumor stage, and TAS administration. Prior TAS therapy did not prevent elevated risk of adverse outcome in the setting of post-RT positive biopsy results. Patients with Gleason score ≥ 7 with a positive biopsy result additionally had inferior overall survival compared to those with a negative biopsy result (HR = 1.56; 95% CI = 1.04-2.35).

CONCLUSIONS: Positive post-RT biopsy is associated with increased rates of distant metastases and inferior disease-specific survival in patients treated with definitive RT and was associated with inferior overall survival in patients with high-grade tumors.

Author List

Krauss DJ, Hu C, Bahary JP, Souhami L, Gore EM, Chafe SM, Leibenhaut MH, Narayan S, Torres-Roca J, Michalski J, Zeitzer KL, Donavanik V, Sandler H, McGowan DG, Jones CU, Shipley WU

Author

Elizabeth M. Gore MD Professor in the Radiation Oncology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adenocarcinoma
Aged
Aged, 80 and over
Androgen Antagonists
Biopsy
Combined Modality Therapy
Disease-Free Survival
Flutamide
Gonadotropin-Releasing Hormone
Humans
Male
Middle Aged
Neoplasm Grading
Neoplasm Recurrence, Local
Neoplasm Staging
Prostate
Prostate-Specific Antigen
Prostatic Neoplasms
Treatment Outcome