The impact of a delay in initiating radiation therapy on prostate‐specific antigen outcome for patients with clinically localized prostate carcinoma

• Published in: Cancer Vol. 103; no. 10; pp. 2053 - 2059
• Main Authors: Nguyen, Paul L., Whittington, Richard, Koo, Sophia, Schultz, Delray, Cote, Kerri B., Loffredo, Marian, McMahon, Elizabeth, Renshaw, Andrew A., Tomaszewski, John E., D'Amico, Anthony V.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.05.2005; Wiley-Liss
• Subjects: Adenocarcinoma - diagnostic imaging; Adenocarcinoma - pathology; Aged; Biological and medical sciences; Biopsy; Cohort Studies; delay; Disease-Free Survival; Follow-Up Studies; Forecasting; Humans; Male; Medical sciences; Neoplasm Recurrence, Local - pathology; Nephrology. Urinary tract diseases; Prostate - radiation effects; prostate carcinoma; Prostate-Specific Antigen - blood; prostate‐specific antigen outcome; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - pathology; radiation therapy; Radionuclide Imaging; Radiotherapy Dosage; Radiotherapy, Conformal; Risk Factors; Seminal Vesicles - radiation effects; Time Factors; Treatment Outcome; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland; Human; Prostate carcinoma; Urinary system disease; Prognosis; Prostate disease; Patient; Tumoral marker; Malignant tumor; Radiotherapy; prostate-specific antigen outcome; Prostate specific antigen; Cancerology; Treatment; delay; radiation therapy; Male genital diseases; Localized
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/cncr.21050

BACKGROUND 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. METHODS 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. RESULTS 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. CONCLUSIONS Treatment delay adversely affected PSA outcome for high‐risk patients but not for low‐risk patients following RT. Cancer 2005. © 2005 American Cancer Society. A delay in initiating radiation therapy appears to adversely affect prostate‐specific antigen outcome for patients with high‐risk, clinically localized, prostate carcinoma. This effect was not seen in low‐risk patients.