Real-World Outcomes of EBRT Treatment for Patients With Localized Prostate Cancer
A recent study investigated real-world outcomes for patients with high-risk localized prostate cancer (HRLPC) and low/intermediate-risk LPC (LIRLPC) who were treated with external beam radiation therapy (EBRT) in the US. Lawrence Karsh, MD, the Urology Center of Colorado, Denver, CO, and colleagues presented their findings in an abstract at the 2023 ASCO GU Cancers Symposium.
EBRT is a standard treatment for LPC and can be curative in some patients. However, there is limited real-world evidence available on the long-term clinical outcomes for these patients, particularly those with HRLPC.
Using Surveillance, Epidemiology, and End Results–Medicare linked registry claims data from 2012 to 2019, the authors conducted a retrospective study of patients with LPC aged ≥65 who were treated with EBRT as their initial definitive therapy. Of the 11,127 patients with LPC who were treated with EBRT within 6 months, approximately 40% (n = 4,414) were patients with HRLPC and approximately 60% (n = 6,713) were patients with LIRLPC. In addition, androgen deprivation therapy (ADT) was used with EBRT in 78% of patients with HRLPC and in 34% of patients with LIRLPC. The demographic and clinical characteristics for both patient groups were similar: the mean age at EBRT initiation was >70 years, 86% of the patients were white, and the mean follow-up time was >40 months.
The authors used the Kaplan-Meier (KM) and Cox proportional hazards (PH) models to compare the clinical outcomes of interest, which included overall survival, metastasis-free survival, and time to initiation of advanced PC treatment. According to the KM analysis, the median (IQR) duration of ADT therapy was 9.9 months for patients with HRLPC and 7.2 months for patients with LIRLPC.
The results showed that across the board, a higher proportion of patients with HRLPC experienced the measured clinical outcomes vs patients with LIRLPC (earliest of metastasis or death, 23.5% vs 12.1%; death, 13.7% vs 7.6%; advanced PC treatment, 6.8% vs 2.7%); medians were not reached. In addition, the Cox PH survival analyses indicated a higher risk for these outcomes in patients with HRLPC vs patients with LIRLPC.
The results from the study suggest that there is a “substantial additional disease burden in patients with HRLPC” and underscores the need for “additional strategies and treatments to improve clinical outcomes in patients with HRLPC,” concluded Dr Karsh and colleagues.
Reference
Karsh LI, Du S, He J, Waters D, Muser E, Shore ND. Real-world clinical outcomes of patients with localized prostate cancer (LPC) treated with external beam radiation therapy (EBRT). Presented at: the 2023 ASCO GU Cancers Symposium; February 16-18, 2023; San Francisco, CA, and virtual; Abstract 330.
