The use of the most advanced technologies for treating prostate cancer, such as intensity-modulated radiotherapy and robotic prostatectomy, is common and increasing among the very men least likely to benefit from treatment, according to a report published June 26 in JAMA.
In a retrospective cohort study involving nearly 56,000 men newly diagnosed with prostate cancer during a recent 5-year period, advanced treatment technologies steadily supplanted more conservative approaches in older men who had low-risk disease, a high risk of dying from some other cause, or both, said Dr. Bruce L. Jacobs of the University of Michigan, Ann Arbor, and his associates (JAMA 2013;309:2587-95).
Paradoxically, this increase occurred against a backdrop of "increasing awareness about the indolent nature of some prostate cancers and of growing dialogue about limiting treatment in these patients," the researchers noted.
"Our findings suggest that, even during this period of enhanced stewardship, incentives favoring the diffusion of these technologies outweighed those related to implementing a more conservative management strategy," they said.
Dr. Jacobs and his colleagues examined this issue using data from the Surveillance, Epidemiology, and End Results (SEER) Medicare database after noting the rapid growth in the use of advanced treatment technologies, as well as the aggressive direct-to-consumer marketing and other "incentives" propelling that growth. They identified men aged 66 years and older whose prostate cancer was diagnosed during a 5-year period and who were followed for 1-6 years afterward.
The study population comprised 23,633 men who underwent intensity-modulated radiotherapy (IMRT) and 5,881 who had robotic prostatectomy, who were compared with 3,926 men who underwent traditional external-beam radiation therapy, 6,123 who had open radical prostatectomy, and 16,384 who opted for watchful waiting (observation).
The investigators estimated the study subjects’ probability of dying within 10 years based on age, race, comorbidity, socioeconomic class, type of residence (urban or rural), and the region of the country in which they lived.
As expected, the use of the advanced technologies increased over time in the entire study population. But it also increased among the men who "stood to gain the least in terms of survival."
During the 5-year study period, the use of both IMRT and robotic prostatectomy increased from 32% to 44% of men who had low-risk disease based on the clinical stage of their tumor, Gleason score, and prostate-specific antigen (PSA) level. The use of both also increased from 36% to 57% of men who were at high risk of dying from another cause. And it rose from 25% to 34% of men who had both low-risk disease and a high risk of noncancer mortality.
At the same time, the use of more conservative approaches declined to a similar degree in these low-risk patients.
In a further analysis of the data, the use of advanced treatment technologies in men who were the most unlikely to die of prostate cancer increased from 13% at the start of the 5-year period to 24% at the end, a relative increase of 85%, Dr. Jacobs and his associates said.
These trends are particularly concerning because both IMRT and robotic prostatectomy are considerably more expensive than the less aggressive approaches they are displacing, the researchers added.
Some clinicians and patients may believe that the more advanced technologies yield better outcomes, but "comparative studies have shown that the advantages of these newer treatments are marginal at best," Dr. Jacobs and his colleagues said.
"More diligence is needed to reduce the potentially unnecessary treatment of men with a low risk of dying from prostate cancer," they said.
The study was supported by the American Cancer Society, the National Institutes of Health, Blue Cross Blue Shield of Michigan, and the National Cancer Institute. Dr. Jacobs reported no financial conflicts of interest, and two of his associates reported ties to ArborMetrix and HistoSonics.