Men with lymph node-positive prostate cancer (PCa) have better outcomes from external beam radiation therapy (EBRT) if they receive it at facilities with a high radiation case volume, according to a new study.
Patients treated at centers with a high vs low average cumulative facility volume (ACFV) of prostate radiation cases had a significantly longer median overall survival (111.1 vs 92.3 months). In addition, treatment at a low-volume center was significantly associated with a 22% increased risk for death compared with treatment at a high-volume center, after adjusting for multiple potential confounders.
“Node-positive prostate cancer is a complex disease entity with the potential for long-term disease control with aggressive management, and these findings suggest that treatment at a high-volume radiation center is associated with improved long-term oncologic outcomes,” a team led by Benjamin W. Fischer-Valuck, MD, of the Winship Cancer Institute at Emory University in Atlanta, Georgia, and colleagues concluded in a paper published in JAMA Network Open.
Using the National Cancer Database (NCDB), the investigators studied 1899 patients receiving curative-intent EBRT and concurrent androgen deprivation therapy for node-positive PCa from January 2004 to December 2016. Of these, 1491 (78.5%) were White and 1145 (60.3%) received treatment at nonacademic centers. Patients had a median age of 66 years. Of the 1899 patients, 1114 (58.7%) and 785 (41.3%) were treated at low- and high-volume centers, respectively. The median follow-up duration was 102.8 months.
Noting that a facility’s radiation patient volume can vary from year to year, Dr Fischer-Valuck’s team defined cumulative facility volume as the total number of prostate radiation cases at an individual patient’s treatment facility from 2004 until the year of that patient’s diagnosis. “This cumulative facility volume, specific to each patient, was then divided by the total number of years that the facility reported to the NCDB until that patient’s year of diagnosis,” they wrote, adding that this was subsequently defined as the ACFV for that individual patient.
The optimal cutoff point that maximized the separation between high and low ACFV was 66.4 patients treated per year, they reported.
With regard to study limitations, the authors noted that the NCDB is a hospital-based cancer registry that captures only patients diagnosed or treated at Commission on Cancer-accredited facilities. “These results may not represent the entire cancer population in the United States; however, given that the NCDB includes approximately 70% of all newly diagnosed cancer cases each year, we believe that this analysis is a notable reflection of outcomes between other high-volume and low-volume facilities in the United States that may not be captured in the registry.”
Patel SA, Goyal S, Liu Y, et al. Analysis of radiation facility volume and survival in men with lymph node-positive prostate cancer treated with radiation and androgen deprivation therapy. Published online December 1, 2020. JAMA Netw Open. 2020;(12):e2025143. doi:10.1001/jamanetworkopen.2020.25143