Patients newly diagnosed with prostate cancer who have a prostate specific antigen levels of 4.0 ng/mL or below tend to receive aggressive therapy despite having a low risk of disease, according to a retrospective study of 123,934 men in the July 26 issue of the Archives of Internal Medicine.
In a multivariate analysis correcting for age, race, and year of diagnosis, men with screen-detected prostate cancer and prostate specific antigen (PSA) values of 4.0 ng/mL or below were 49% more likely to undergo radical prostatectomy and 39% more likely to undergo radiation therapy than were men with non–screen detected prostate cancer, according to Yu-Hsuan Shao, Ph.D., of the Cancer Institute of New Jersey, New Brunswick, and her colleagues.
Although 54% of men diagnosed with prostate cancer with low PSA levels harbor low-risk disease, 77% of them underwent radical prostatectomy or radiotherapy. Men with low PSA levels and screen-detected prostate cancer were 33% less likely to have high-grade disease than were men with non–screen detected prostate cancer, the investigators said.
“The finding that men in low-risk groups were treated intensively raises the concern of overtreatment, especially among older patients,” the authors wrote.
Investigators used the Surveillance, Epidemiology, and End Results (SEER) database, covering approximately 26% of the U.S. population, to identify men newly diagnosed with prostate cancer between 2004 and 2006. They excluded men under the age of 24 years, those with missing PSA values, or those with missing Gleason scores and clinical stage.
The men in the study were divided into four groups based on PSA values. A total of 14% of the men had PSA values of 4.0 ng/mL or less, 57.6% had values between 4.1-10.0 ng/mL, 15.9% had values between 10.1-20.0 ng/mL, and 12.5% had values above 20 ng/mL (Arch. Int. Med. 2010;170:1256-61).
Of the men with the lowest PSA values, 44% underwent radical prostatectomy, 33% underwent radiation therapy, and 23% were treated with conservative management. In contrast, of the men with the highest PSA levels, 12.5% underwent radical prostatectomy, 31.5% underwent radiation therapy, and 56% were treated with conservative management.
One of the study’s authors acknowledged receiving clinical research funding from the Ohl Foundation, the New Jersey Commission on Cancer Research, and the Agency for Healthcare Research and Quality. Another author acknowledged receiving clinical research funding from Sanofi-Aventis and consultation fees from Blue Cross/Blue Shield. The study was supported by the National Cancer Institute, the Cancer Institute of New Jersey, and the Robert Wood Johnson Foundation.