The impact of a delay in initiating radiation therapy on prostate-specific antigen outcome for patients with clinically localized prostate carcinoma
Version of Record online: 6 APR 2005
Copyright © 2005 American Cancer Society
Volume 103, Issue 10, pages 2053–2059, 15 May 2005
How to Cite
Nguyen, P. L., Whittington, R., Koo, S., Schultz, D., Cote, K. B., Loffredo, M., McMahon, E., Renshaw, A. A., Tomaszewski, J. E. and D'Amico, A. V. (2005), The impact of a delay in initiating radiation therapy on prostate-specific antigen outcome for patients with clinically localized prostate carcinoma. Cancer, 103: 2053–2059. doi: 10.1002/cncr.21050
- Issue online: 28 APR 2005
- Version of Record online: 6 APR 2005
- Manuscript Accepted: 12 JAN 2005
- Manuscript Revised: 3 JAN 2005
- Manuscript Received: 9 SEP 2004
- Clinical Research Fellowship Program at Harvard Medical School offered by the Doris Duke Charitable Foundation
- Harvard PASTEUR Program
- Harvard Office of Enrichment Programs
- prostate carcinoma;
- radiation therapy;
- prostate-specific antigen outcome
To determine whether a delay in initiating external beam radiation therapy (RT) following diagnosis could impact prostate-specific antigen (PSA) outcome for patients with localized prostate cancer, 460 patients, who received 3D conformal RT to a median dose of 70.4 Gy for clinically localized prostate cancer between 1992 and 2001, were studied.
The primary endpoint was PSA failure (American Society for Therapeutic Radiology and Oncology definition). Estimates of PSA control were made using the Kaplan–Meier method. Delay was defined as the time between diagnosis and the start of RT. Risk groups were defined based on known predictors of PSA outcome, namely, baseline PSA level, clinical T-category, Gleason score, and percentage of biopsy cores positive for tumor. Cox multivariate regression analysis was used to determine the ability of treatment delay to predict time to PSA failure after adjusting for the other known predictors.
Treatment delay independently predicted time to PSA failure following diagnosis for high-risk (Adjusted Hazard Ratio = 1.08 per month; P = 0.029) but not low-risk patients (P = 0.31). Patients with high-risk disease (n = 240) had 5-year estimates of PSA failure-free survival of 55% versus 39% (Plog-rank = 0.014) for those with delay < 2.5 months versus ≥ 2.5 months respectively. The median delay was 2.5 months.
Treatment delay adversely affected PSA outcome for high-risk patients but not for low-risk patients following RT. Cancer 2005. © 2005 American Cancer Society.