1. Dose escalation for prostate cancer radiotherapy: predictors of long-term biochemical tumor control and distant metastases-free survival outcomes.
- Author
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Zelefsky MJ, Pei X, Chou JF, Schechter M, Kollmeier M, Cox B, Yamada Y, Fidaleo A, Sperling D, Happersett L, and Zhang Z
- Subjects
- Aged, Androgen Antagonists therapeutic use, Antineoplastic Agents, Hormonal therapeutic use, Chemotherapy, Adjuvant, Disease-Free Survival, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Neoadjuvant Therapy, Neoplasm Staging, New York City, Nomograms, Proportional Hazards Models, Prostate-Specific Antigen blood, Prostatic Neoplasms immunology, Prostatic Neoplasms mortality, Prostatic Neoplasms secondary, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Prostatic Neoplasms radiotherapy, Radiotherapy Dosage, Radiotherapy, Conformal adverse effects, Radiotherapy, Conformal mortality, Radiotherapy, Intensity-Modulated adverse effects, Radiotherapy, Intensity-Modulated mortality
- Abstract
Background: Higher radiation dose levels have been shown to be associated with improved tumor-control outcomes in localized prostate cancer (PCa) patients., Objective: Identify predictors of biochemical tumor control and distant metastases-free survival (DMFS) outcomes for patients with clinically localized PCa treated with conformal external-beam radiotherapy (RT) as well as present an updated nomogram predicting long-term biochemical tumor control after RT., Design, Setting, and Participants: This retrospective analysis comprised 2551 patients with clinical stages T1-T3 PCa. Median follow-up was 8 yr, extending >20 yr., Intervention: Prescription doses ranged from 64.8 to 86.4 Gy. A total of 1249 patients (49%) were treated with neoadjuvant and concurrent androgen-deprivation therapy (ADT); median duration of ADT was 6 mo., Measurements: A proportional hazards regression model predicting the probability of biochemical relapse and distant metastases after RT included pretreatment prostate-specific antigen (PSA) level, clinical stage, biopsy Gleason sum, ADT use, and radiation dose. A nomogram predicting the probability of biochemical relapse after RT was developed., Results and Limitations: Radiation dose was one of the important predictors of long-term biochemical tumor control. Dose levels < 70.2 Gy and 70.2-79.2 Gy were associated with 2.3- and 1.3-fold increased risks of PSA relapse compared with higher doses. Improved PSA relapse-free survival (PSA-RFS) outcomes with higher doses were observed for all risk groups. Use of ADT, especially for intermediate- and high-risk patients, was associated with significantly improved biochemical tumor-control outcomes. A nomogram predicting PSA-RFS was generated and was associated with a concordance index of 0.67. T stage, Gleason score, pretreatment PSA, ADT use, and higher radiation doses were also noted to be significant predictors of improved DMFS outcomes., Conclusions: Higher radiation dose levels were consistently associated with improved biochemical control outcomes and reduction in distant metastases. The use of short-course ADT in conjunction with RT improved long-term PSA-RFS and DMFS in intermediate- and high-risk patients; however, an overall survival advantage was not observed., (Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.)
- Published
- 2011
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