A year after draft guidelines on PSA screening were published by the USPSTF, diagnoses of new low-risk prostate cancers had fallen by 37.9%.
In October 2011, the US Preventive Services Task Force (USPSTF) decided that the harms of regular prostate-specific antigen (PSA) screening outweighed the benefits, which led them to recommend against regular screening for prostate cancer.
A combination of radiation therapy, surgery and complications associated with treatment for the condition were felt to be having too great a negative impact on the quality of life of many of those being treated.
A team from the Department of Urologic Surgery at Vanderbilt University Medical Center in Nashville, TN, wanted to know what impact the new guidelines have had.
"We know there is decreased utilization of PSA testing in some institutions and health systems, but has the number of incident cases per month changed substantially since the draft guideline was issued?," says lead investigator Dr. Daniel A. Barocas.
The study - published in The Journal of Urology - looked at screening practices among urologists and primary care providers and the incidence of prostate cancer to identify any changes in the number and distribution of new prostate cancer diagnoses in the US.
- Prostate cancer is the second leading cause of cancer deaths in men the US, after skin cancer
- Prostate cancer declined by about 40% since the advent of PSA screening in the late 1980s, of which 40-70% is attributable to screening
- There will be approximately 27,540 deaths from prostate cancer in the US in 2015.
Cancers diagnosed in the National Cancer Database between January 2010 and December 2012 were studied to assess monthly trends in new prostate cancer diagnoses both before and after the USPSTF guidelines were issued. They compared these trends with those of colon cancer.
In the month after the USPSTF draft guidelines were issued, across all subgroups of age, comorbidity, race, income, and insurance, the number of overall prostate cancer diagnoses fell by more than 12%, and diagnoses continued to fall for a further 11 months.
The number of low-, intermediate- and high-risk prostate cancers all reduced in the first 12 months after the recommendations changed, while the number of new diagnoses of nonlocalized disease remained stable.
In comparison, the number of colon cancers remained stable.
The study revealed that 12 months after the draft guidelines were issued, diagnoses of new low-risk cancers reduced by 37.9% and continued to fall faster than other disease risk grades.
However, the study also identified a drop of 28.1% in diagnoses of intermediate-risk disease, as well as a 23.1% reduction in high-risk prostate cancer 1 year after the draft guidelines were published.
The benefits identified as a result of the new guidelines were a reduction in overdiagnosis and overtreatment of low-risk disease and disease found in elderly men, while the harms were missed opportunities to diagnose cases in men who may benefit from the treatment.
Higher-risk cancers risk being missed, study says
While on the one hand, the USPSTF guidelines had the intended effect of reducing regular screening, and may, therefore, have gotten it right for low-risk cancer in relation to overdiagnosis and overtreatment, the study suggests there is a danger that the reduction in the diagnosis of intermediate- and high-risk cancer could lead to higher-risk cancers being missed.
Dr. Barocas says:
"Future research should focus on prostate cancer screening paradigms that both minimize harms and maximize the potential benefits of screening, as well as accounting for individual patient risk factors and preferences."
Earlier this month, Medical News Today reported that men with unaggressive prostate tumors were unlikely to develop or to die from prostate cancer.
Written by Jonathan Vernon