January 10, 2017
By Marilynn Larkin
NEW YORK (Reuters Health) - The incidence of metastatic prostate cancer in men over age 75 has been rising since 2011, suggesting a link between the increase and the U.S. Preventive Services Task Force (USPSTF) recommendation against prostate-specific antigen (PSA) testing in this population, researchers suggest.
Since the introduction of PSA testing in the early 1990s, there has been a 50% decline in prostate cancer-specific mortality and more than a 70% decline in the incidence of men diagnosed with metastatic disease, Dr. Jim Hu of Weill Cornell Medicine in New York City and colleagues note in JAMA Oncology, online December 29.
Prostate-Specific Antigen Prostate Cancer Screening: Answers to the Critical Questions
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Nonetheless, in 2008, the USPSTF recommended against PSA testing in men over age 75, and in 2012, it extended that recommendation to healthy men of all ages.
To assess the effect of these recommendations, Dr. Hu and colleagues analyzed data from the SEER database on 1.1 million men age 40 or older diagnosed with prostate cancer from 2004 to 2013. They looked at the variation over time in prostate cancer presentation at diagnosis in men 75 and older and those younger than 75, and tied the findings to the release of the 2008 and 2012 PSA screening recommendations.
In men younger than 75, the proportion presenting with distant metastases rose from 2.7% to 4.0% during the study period, and the proportion presenting with intermediate- and high-grade prostate cancer rose from 46.3% to 56.4%.
Similarly, in men 75 or older, there was an increase in the proportion of distant metastases from 6.6% to 12.0%, and in intermediate- and high-grade prostate cancer from 58.1% to 72%.
Between 2010 and 2013, the median PSA at diagnosis increased from 6.0 to 6.4 ng/mL among men younger than 75, and from 9.0 to 9.7 ng/mL among men 75 and older.
Subsequent analyses revealed the incidence of distant metastases at diagnosis in men 75 or older decreased from 2004 to 2011 and increased afterward, whereas no change was seen in men younger than 75.
Dr. Hu told Reuters Health the results are "concerning in light of recent criticisms and guidelines against PSA testing. In 2008, the USPSTF recommended against PSA testing in (men 75 or older), and in our study, we see the incidence of metastasis at diagnosis rising in 2012 and 2013."
"This is significant because there is no cure for men with metastatic prostate cancer," he said by email. "The traditional argument against PSA screening is that it leads to over-diagnosis and over-treatment of prostate cancer. However, we currently do not have a better test for diagnosing prostate cancer before it has spread beyond the prostate."
"Remarkably, when Ben Stiller shared his personal use of PSA testing in his mid-to-late 40s and how this led to the detection of intermediate-risk prostate cancer that led him to surgery and cure, others criticized him for sharing his story," Dr. Hu continued.
"Although PSA is not a perfect test, I believe like any test, the most important take away is what course and decision results from (it)," he observed.
"However, questions remain regarding when to start using PSA testing, how frequently to undergo screening and ultimately when to stop," he noted. "These are individualized decisions that men must come to grips with, in contrast to the wide-sweeping, broad unconditional recommendation against PSA screening."
"The recommendations by the USPSTF were made with a flawed understanding of the randomized trial, PLCO, which had significant limitations that did not come to light when it was published in 2009 (bit.ly/2jcfgrH) showing that use of PSA testing did not reduce deaths from prostate cancers in the U.S.," Dr. Hu added. "In contrast, a large European study found the opposite, that PSA screening was associated with a lower risk of dying from prostate cancer."
Dr. Timothy Wilson, director of the Urologic Oncology Research Program and chair of urology at the John Wayne Cancer Institute at Providence Saint John's Health Center in Santa Monica, California, told Reuters Health, "Without screening, we will see more men diagnosed with higher risk and more advanced disease. This will likely translate into an increase in the death rate from prostate cancer."
"This increased diagnosis in more advanced disease will result in more pain and suffering and side effects from advanced and metastatic cancer," he said by email. "This will also increase the cost to the health care system."
"The answer is better screening not only using PSA, but additional advanced testing like the 4k test, which helps distinguish which men truly need a biopsy," he concluded. "Once men have a biopsy, then we use additional testing, like genetic testing and MRI to guide us as to the best treatment for that individual."
A USPSTF spokesperson told Reuters Health by email, "The Task Force is aware of this study and is considering it along with the other newly available evidence as they work on their latest recommendation around prostate cancer screening."
JAMA Oncol 2016.
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