In 2012, the United States Preventive Services Task Force (USPSTF) recommended against routine prostate-specific antigen (PSA)-based screening for prostate cancer. The potential harms outweigh the potential benefits, they said.
Last week, the Task Force — an independent panel of experts that evaluates the latest scientific evidence regarding preventive tests and screening and then makes recommendations based on that evidence — finalized an update to those recommendations. They now say that men aged 55 to 69 should make up their own mind about whether they want to undergo regular PSA screening — after discussing all the pros and cons with their doctor.
For men aged 70 and older, however, the previous recommendation stands. They should not be routinely screened, according to the Task Force, because the potential benefits for men in that age group do not outweigh the potential harms.
Prostate cancer is the second-most common type of cancer (after skin cancer) among men in the United States. An estimated 165,000 American men will be diagnosed with the disease in 2018. Most will be over the age of 65.
Prostate cancers tend to grow slowly, and most men who are diagnosed with the disease do not die from it. More than 3.1 million men are currently living with prostate cancer in the United States.
Still, the disease can be deadly, and an estimated 29,000 men will lose their lives to prostate cancer in the U.S. this year.
What changed during the past five years to make the USPSTF update their prostate screening recommendations?
One factor was “the influence of longer-term follow up of men in the European Randomized Study of Screening for Prostate Cancer (ERSPC),” writes Dr. Richard Hoffman, a professor of internal medicine and epidemiology at the University of Iowa, for the Minnesota-based website HealthNewsReview.org. “Data published in recent years showed increasing benefits for screening over time in preventing prostate cancer deaths and metastatic spread.”
“Not only did the Task Force factor in the increasingly positive ERPSC results, but it also discounted the negative results of the large American trial, the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO),” Hoffman adds. “Previously, the Task Force equally weighted results from both studies, but the PLCO is now widely recognized as a flawed evaluation of screening. The study was supposed to compare the effects of annual PSA testing vs. no testing on prostate cancer mortality. However, it was later shown that over 80% of the men in the control arm received PSA testing either during or before the study. This helped bias the study towards finding no benefit for screening.”
Another important factor behind the updated USPSTF recommendations, Hoffman points out, is the recognition “that the harms of screening related to overdiagnosis and overtreatment were being partly mitigated by the increased uptake of active surveillance — a monitoring strategy for men with a low-risk prostate cancer that defers active treatment (surgery or radiation) in the absence of cancer progression.”
In other words, doctors are now recommending “watchful waiting” for many of their patients with early-stage, low-grade prostate cancer.
“Active surveillance is primarily described as sparing patients from the harms caused by surgery or radiation,” Hoffman adds. “However, the evidence offers an even more compelling rationale for this strategy. The Prostate Testing for Cancer and Treatment (ProtecT) trial, conducted in the United Kingdom, recently showed that men with early-stage prostate cancers who were randomly assigned to surgery, radiation therapy, or active monitoring had the same low risk of dying from prostate cancer after 10 years of follow up. Active surveillance thus prevents treatment harms without increasing the risk of dying from prostate cancer.”
An emphasis on shared decision-making
In its updated recommendations, the USPSTF stresses the importance of shared decision-making between patients and physicians.
But the assumption that patients will make wise decisions by just talking with their physician is “overly simplistic,” as Hoffman explains:
Studies have consistently shown that clinicians lack the time and often the expertise to conduct shared decision making visits. When screening is discussed, providers often fail to present both the pros and cons of screening or elicit patient preferences. Men are often poorly informed about the screening decision, markedly overestimating the risks of developing cancer and dying from it. They also tend to overestimate the benefits of screening.
An important missing ingredient from [the Task Force’s updated recommendations] is the use of decision aids. These are educational tools that can consistently provide patients with comprehensive and objective information about prostate cancer, the pros and cons of screening, and help patients clarify their values and prepare to discuss screening with clinicians. These tools are readily available, and patients should be encouraged to take responsibility for these decisions, coming into a visit informed about the disease and their options.
“This preparation can lead to much more efficient and productive discussions,” Hoffman emphasizes. “Most people wouldn’t buy a car or a flat-screen TV without first doing some homework, and it should be the same for making cancer screening decisions — which have much higher stakes.”