This morning The New York Times published an article announcing the results of the United States Preventive Services Task Force (USPSTF) regarding prostate cancer screenings. The USPSTF is a Department of Health panel charged with the task of assembling evidence-based guidelines for health screening. The article highlights the growing fear that routine PSA screening is resulting in unnecessary anxiety and stress, without impacting overall survival.
The Times references two large population based randomized controlled trials, citing their conflicting results as support for these new recommendations. The American paper failed to find a significant difference in mortality between the screening and control groups. However, this trial ended prematurely and the follow up period was not adequate to show mortality difference for a disease with a long natural history such as prostate cancer. Furthermore, the majority of the control group was also screened with PSA during the study period, possibly obscuring any benefits from screening. The major European study demonstrated a 20% reduction in prostate cancer related death. As a multi-country trial, however, each country was responsible for establishing the individual screening parameters for the study, introducing possible unintended variability into the results. Furthermore, the men in this trial were older-ranging from 50-74 years of age, with the focus on men being between 55 and 69 years old.
Another large randomized controlled trial not mentioned by the times article, “Mortality Results from the Goteborg Randomized Population-Based Prostate-Cancer Screening Trial,” showed that prostate cancer mortality was reduced by half over the 14 year study period. This paper benefited from having adequate follow up time in order to appreciate the effect that PSA has on prostate cancer specific mortality. Additionally, this cohort was younger andthus more likely to benefit from early screening. Patients diagnosed by PSA in this study had lower incidence of advanced disease compared to their non-screened counterparts.
As alluded to by The Times, PSA screening is not a perfect test, it is not capable of determining which cancers will progress and which are clinically insignificant. This brings to light the importance of not just looking at a single result, but rather, the individual patient. We need to look at the PSA trend and velocity, take into account their co-morbid conditions and overall life expectancy and most importantly understand the patient’s treatment goals.
A report from the US Preventative Services Task Force today suggests current PSA tests aren’t reliable, and there’s no sure way to tell in advance who needs aggressive therapy. The government doctors also say there is potential harm from prostate cancer treatments, like impotence, infections, even death caused by biopsies and radiation. Treatments used frequently after PSA tests.
Dr. Javid Javidam, a urological oncologist with Mercy San Juan, says he is astounded by the task force’s recommendation that men shy away from routine testing. Primarily, he says, because PSA testing is one of the few means of detecting prostrate cancer.
Dr David Samadi, Vice Chairman of the Urology Department at Mount Sinai Medical Center in New York City insists the recommendation is “irresponsible.”
The American Cancer Society for some time has recommended men consider the pros and cons of PSA screening before deciding on their own.News