Dose-Escalated EBRT Yields Survival Benefit in Intermediate- and High-Risk but Not Low-Risk Nonmetastatic Prostate Cancer
In a retrospective study reported in JAMA Oncology, Kalbasi et al found that dose-escalated external-beam radiation therapy was associated with improved overall survival among men with intermediate- and high-risk, but not low-risk, nonmetastatic prostate cancer.
Study Details
The study involved National Cancer Database data from men with low-risk (n = 12,229), intermediate-risk (n = 16,714), or high-risk (n = 13,538) prostate cancer diagnosed between 2004 and 2006. Patients were characterized as receiving standard-dose (68.4 Gy to < 75.6 Gy) or dose-escalated (≥ 75.6 Gy to 90 Gy) external-beam radiation therapy. Overall survival was compared using Cox proportional hazard models with an inverse probability weighted propensity score approach.
Overall Survival
Dose-escalated external-beam radiation therapy was associated with improved survival in the intermediate-risk (adjusted hazard ratio [HR] = 0.84, P < .001) and high-risk groups (HR = 0.82, P < .001) but not in the low-risk group (HR = 0.98, P = .54). For each increase of approximately 2 Gy in dose, risk of death was reduced by 7.8% (P < .001) in intermediate-risk patients and 6.3% (P < .001) in high-risk patients.
Adjusted 7-year overall survival for dose-escalated vs standard-dose groups were 86% vs 86% in low-risk patients, 82% vs 78% in intermediate-risk patients, and 74% vs 69% in high-risk patients.
The investigators concluded: “Dose-escalated [external-beam radiation therapy] is associated with improved overall survival in men with intermediate- and high-risk prostate cancer but not low-risk prostate cancer. These results add to the evidence questioning aggressive local treatment strategies in men with low-risk prostate cancer but supporting such treatment in men with greater disease severity.”
Anusha Kalbasi, MD, of the Hospital of the University of Pennsylvania, is the corresponding author for the JAMA Oncology article.
The study was supported by the National Cancer Institute and the David and Leslie Clarke Fund.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
