Faculty Collaboration Database

Prostate-specific antigen response after short-term hormone therapy plus external-beam radiotherapy and outcome in patients treated on Radiation Therapy Oncology Group study 9413. Cancer 2013 Jun 01;119(11):1999-2004

Date

03/19/2013

Pubmed ID

23504930

Pubmed Central ID

PMC3663874

DOI

10.1002/cncr.28019

Scopus ID

2-s2.0-84878016620 (requires institutional sign-in at Scopus site)   17 Citations

Abstract

BACKGROUND: The objective of this study was to assess the impact of a prostate-specific antigen (PSA) complete response (PSA-CR), measured at the end of external-beam radiotherapy and short-term hormone therapy, on treatment outcomes.

METHODS: The phase 3 Radiation Therapy Oncology Group 9413 trial, as part of its original protocol, used the assessment of PSA-CR (ie, PSA ≤0.3 ng/mL) at the end of short-term HT as a secondary endpoint. Short-term HT consisted of futamide plus a lutenizing hormone-releasing hormone agonist for 4 months. The Kaplan-Meier method was used to estimate overall survival (OS) and disease-free survival. Cumulative incidence was used to estimate biochemical failure, distant metastasis, and disease-specific survival. Univariate and multivariate analyses were performed to correlate PSA-CR after short-term hormone therapy with all endpoints, and the following variables were considered for analysis: PSA at baseline, Gleason score, treatment arm, age, and baseline testosterone status. Phoenix consensus definition was used to define PSA failure.

RESULTS: For 1070 evaluable patients, the median PSA at the end of short-term hormone therapy was 0.2 ng/mL. In total, 744 patients (70%) had a PSA-CR. At a median follow-up of 7.2 years, failure to obtain a PSA-CR was associated significantly with worse disease-specific survival (P = .0003; hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.38-2.97), with worse disease-free survival (P = .003; HR, 1.28; 95% CI, 1.09-1.50), and with a higher incidence of distant metastasis (P = .0002; HR, 1.92; 95% CI, 1.37-2.69) and biochemical failure (P < .0001; HR, 1.57; 95% CI, 1.29-1.91). Other factors that were associated with worse disease-specific survival were Gleason scores from 8 to 10 (P = .0002; HR, 3.06; 95% CI, 1.71-5.47) and PSA levels >20 ng/mL (P = .04; HR, 1.55; 95% CI, 1.02-2.30).

CONCLUSIONS: The current results indicated that failure to obtain a PSA-CR (PSA ≤0.3 ng/mL) after short-term hormone therapy and external-beam radiotherapy appears to be an independent predictor of unfavorable outcomes and could help identify patients who may benefit from the addition of long-term androgen ablation.

Author List

Cury FL, Hunt D, Roach M 3rd, Shipley W, Gore E, Hsu IC, Krisch RE, Seider MJ, Sandler H, Lawton C

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

Aged
Aged, 80 and over
Androgen Antagonists
Disease-Free Survival
Gonadotropin-Releasing Hormone
Humans
Male
Middle Aged
Prostate-Specific Antigen
Prostatic Neoplasms
Radiotherapy Dosage
Radiotherapy, Adjuvant
Treatment Outcome