Use of radical prostatectomy (RP) for localized prostate cancer (PCa) increased significantly from 2004 to 2011, whereas the use of radiotherapy decreased during that period, according to study findings presented at the 56th annual meeting of the American Society for Radiation Oncology in San Francisco.
Using the National Cancer Data Base, Phillip J. Gray, MD, of Massachusetts General Hospital in Boston, and colleagues identified 823,977 patients diagnosed with PCa from 2004 to 2011. Of these, 38.5%, 42.7%, and 18.9% had low-, intermediate-, and high-risk disease, respectively, according to National Comprehensive Cancer Network guidelines.
In low-risk patients, active surveillance rates increased from 12.4% to 18.5% from 2004 to 2011 and the RP rates rose from 40.3% to 54.4%. During the same period, brachytherapy rates decreased from 24.4% to 11.4% and the rates of external beam radiotherapy (EBRT) alone decreased from 18.2% to 13.4%.
Among patients with intermediate-risk disease, active surveillance rates increased from 6.1% to 7.3% and RP rates increased from 48.1% to 58.5%, whereas brachytherapy rates dropped from 12.1% to 6.4%. Rates of combined therapy with EBRT and androgen deprivation therapy (ADT) declined from 14.7% to 8.7%.
In the high-risk group, active surveillance rates and EBRT monotherapy rates remained stable over the study period (about 8% and 10%, respectively), whereas radical surgery rates rose from 30.6% to 41.3%, the researchers reported. The rates of combined EBRT plus ADT declined from 30.4% to 28.0% and brachytherapy rates fell from 8.7% to 4.1%. Rates of primary ADT dropped from 7.2% to 5.8%.
On multivariable analysis, the researchers found that black men were 48% less likely than whites to undergo RP versus radiotherapy. Individuals without insurance and those covered by Medicaid were 34% and 50% less likely, respectively, than those with private insurance to have RP rather than radiotherapy. Patients living in low-income areas also were less likely to undergo RP versus radiotherapy.
“I think one of the most surprising trends that we didn’t expect to find was that, over the study period, the use of RP for patients went up by double digits across all risk groups,” Dr. Gray told Renal & Urology News. “This was particularly striking for low-risk patients. While active surveillance increased slightly for patients with low-risk disease, the absolute number of patients on active surveillance was low, and, during this time, rates of surgery were increasing. This suggests that it is primarily the patients that would typically be treated with radiotherapy who are being placed on surveillance, not the patients who are primarily discussing active surveillance versus RP with their urologist.”
The trend for increased use of surgery in high-risk disease is concerning, Dr. Gray added. “Many patients with high-risk disease who are undergoing surgery have indications for post-operative radiotherapy and perhaps hormonal therapy, and are therefore potentially being subjected to multiple treatments that can additively affect quality of life.”
As for why black patients are less likely than whites to undergo RP, the reasons are unclear. “One hypothesis is that the majority of RPs are occurring at large academic centers,” Dr. Gray said.
“There are ample data to suggest that racial minorities lack access to high-quality medical care. Additionally, minorities who live in rural areas may not have the resources that would allow them to travel to a center which could offer RP. Other socioeconomic factors may also be at play given the correlation between higher income and the receipt of RP.”