Tuesday, 25 October 2016
Gleason 6? Should I wait before having radical treatment?
What does it mean to have a Gleason score of 6 (or 7 or 8-10) ?
The use of active surveillance for the management of nonaggressive prostate cancer has soared to record highs in Sweden in recent years, providing a "benchmark" for the rest of the world, according to the authors of a new study.
From 2009 to 2014, the proportion of Swedish men with very-low-risk cancer choosing active surveillance increased from 57% to 91% and, among those with low-risk cancer, it rose from 40% to 74%, report the investigators, led by Stacy Loeb, MD, MSc, from New York University in New York City. The authors used data from a nationwide prostate cancer registry.
Low-risk prostate cancer and its prolonged natural history can be safely managed with active surveillance and the deferred, as-needed use of curative treatment, such as prostatectomy and radiation therapy, explain Dr Loeb and her coauthors, who include academics from three different Swedish universities.
Notably, in Sweden, medical records distinguish between active surveillance, which includes blood testing, biopsy, and imaging, and watchful waiting, which is a passive approach that waits to see whether clinical symptoms develop before medical intervention.
The new Swedish active surveillance data, which are an update from an earlier report that extended only to 2011, are the "highest rates yet reported" and "should serve as a benchmark to compare the use of active surveillance for favorable-risk disease around the world," write the authors.
Currently, the United States does not measure up very well, suggest the authors. Most low-risk disease is treated immediately, they observe.
"We hope that our data from Sweden will showcase that…the use of this management option is growing around the world and will encourage US men who are diagnosed with low-risk prostate cancer to ask their doctor about it," Dr Loeb told Medscape Medical News.
Dr Loeb has been an ongoing supporter of the use of active surveillance. At a press conference at the 2014 annual meeting of the American Urological Association (AUA), she declared the "era of active surveillance" had arrived. This meeting featured multiple studies indicating large upticks in its use.
The new study from Dr Loeb and colleagues is published online today in JAMA Oncology.
The high rate of active surveillance in Sweden "is likely a goal to which we should aspire on both sides of the Atlantic," says Matthew R. Cooperberg, MD, MPH, from University of California San Francisco in an accompanying editorial.
Dr Cooperberg also says that active surveillance rates "are still too low" in the United States.
Still, progress is being made, he suggests.
Dr Cooperberg says that data from some prospective, community-based registries have shown use of active surveillance "skyrocketing" to 40% to 50% for low-risk disease in the current decade, up from historical rates of about 10% (JAMA. 2015;314:80-82).
He also highlights guidance newly endorsed by the American Society of Clinical Oncology that surveillance is "not merely an option" for men with low-risk disease but rather is the "preferred alternative" for any clinically localized, Gleason 3 + 3 cancer.
But Dr Cooperberg makes no mention of guidance from the most influential organization in the United States with regard to prostate cancer: the AUA.
The AUA has not updated its guidelines for the management of localized prostate cancer, which include active surveillance recommendations, since 2007.
With regard to Sweden, the study authors describe some "potential facilitating factors" for the "rapid uptake" of active surveillance.
For example, in 2007 national guidelines were issued that recommended active surveillance for men with low-risk prostate cancer and a life expectancy of 10 to 20 years. Then, in 2014, the life expectancy limit was abandoned, and active surveillance was recommended for all men with very-low-risk prostate cancer.
The study authors also believe it is important that Sweden's National Prostate Cancer Register provides "real-time feedback" to practices on their adherence to these national guidelines and also in annual reports publicly available online.
Furthermore, the Swedish healthcare system "is dominated by equal access, tax-funded care without financial incentives for clinicians to recommend curative treatment," the authors observe.
Overall, 32,518 men with a median age of 67 years were diagnosed with favorable-risk prostate cancer during the study period.
These included 4693 men with very-low-risk disease (clinical stage, T1c; Gleason score 6 or less; prostate-specific antigen [PSA], <10 ng/mL; PSA density <0.15 ng/mL/cm3; and <8-mm total cancer length in 4 positive biopsy cores).
A total of 15,403 men with low-risk disease (including all men in the very-low-risk group) (T1 to T2; Gleason score, 6 or less; and PSA <10 ng/mL), and 17,115 men had intermediate-risk disease (T1 to T2; Gleason score, 7; and/or PSA, 10 to 20 ng/mL).
Use of active surveillance for intermediate-risk disease was much lower — only 19% of cases in 2014.
In a press statement, Dr Loeb said that more US men opting for active surveillance "could go a long way toward reducing the harms of screening by minimizing overtreatment of non-aggressive prostate cancer."
Dr Cooperberg agrees.
In his editorial, he writes: "A default assumption that most low-risk prostate cancers do not need immediate treatment would completely shift the balance of benefits and harms for prostate cancer early detection efforts, and it will prove invaluable in reframing the ongoing national debate regarding optimal screening policy."
Nick Mulcahy: October 20, 2016