Active low risk surveillance Prostate cancer, which implies the immediate abandonment of a treatment, has been multiplied by three since such a "conservative" management had been recommended by an important directive in the United States 5 years ago.
Specifically, the practice of active surveillance or watchful waiting (AS / WW) increased from 14.5% in 2010 to 42% in 2015, when it became the approach the more common for the management of low-risk prostate cancer.
The new figures were published online Feb. 11 in JAMA.
The increase in AS / WW over time is "encouraging," said lead author Brandon A. Mahal, MD, a radiation oncologist at the Dana-Farber Cancer Institute in Boston, This "suggests that clinicians better adhere to current guidelines and recommendations," which will reduce over-treatment rates, he told Medscape Medical News.
However, another expert was surprised that the figures reported are so low.
"Despite these positive trends, it is disturbing to note that in 2015, only 42% of low-risk patients were treated conservatively," said Stacy Loeb, MD, urologist at NYU Langone Health in New York, in an email to Medscape Medical News.
Loeb and his colleagues recently reported Much higher rates: 72% of men under age 65 and 79% of men aged 65 and over with low-risk prostate cancer observed in the US Department of Veterans Affairs health system been carefully managed in 2015.
How could two American studies lead to such different results?
Data sources – and what they reflect in terms of treatment parameters – could be the explanation, Mahal and Loeb said.
The new findings are derived from the Active Surveillance Database / Monitored Prostate Watch on Surveillance, Epidemiology and End-of-Life Outcomes (SEER). These patients have been supported in various settings. On the other hand, the Loeb VA study only concerns one health system.
Mahal also pointed out that the VA study included a proxy for AS / WW via administrative codes, but not a validated AS / WW variable, embedded in the custom SEER database.
Loeb nevertheless stressed that the recently reported AS / WW rate was still low, considering what could be achieved.
Other results reinforce his argument. For example, data from the Swedish National Registry of Prostate Cancer shown in 2014, 74% of men with low-risk prostate cancer had been cared for with active surveillance.
Another emerging trend
Mahal and his colleagues, most of whom are also radiation oncologists from Boston institutions, also point to another trend that has emerged from 2010 to 2015 in the United States: for patients with cancer high-risk prostate, management plans have shifted to increased use prostatectomy and far from the use of radiotherapy.
This change "does not coincide with any new Level 1 evidence or any change in direction," they point out.
The surgery rate increased by 5% for high-risk prostate cancer, while the radiation therapy rate decreased by 5%.
This "downstream effect" of the AS / WW on surgery, performed by urologists, and radiation therapy, performed by radiation oncologists, requires further investigation, said the authors.
"This conclusion is provocative and could be a central topic of discussion," Mahal said in a press release.
"Further studies will be needed to determine if this trend is continuing and what forces may be behind this trend," he added.
In summary, the authors ask: what is happening in the full prostate cancer treatment landscape now that AS / WW is taking root?
Details of the study
For their study, the researchers analyzed initial management trends in patients with low-risk, intermediate or high-risk prostate cancer in the SEER Custom Database during the period of time. 5 year study.
They found that out of a total of 164,760 men, 20,879 (12.7%) had been treated by AS / WW, 68,350 (41.5%) had undergone radiotherapy and 75,531 (45.8%) had undergone a radical prostatectomy.
As expected, the use of surgery and radiation therapy during the study period decreased in men with low-risk prostate cancer (n = 50,302).
As noted above, among men with low-risk disease, the use of AS / WW almost tripled from 14.5% to 42.1% between 2010 and 2015 (p <0.001 for the trend), while radical prostatectomy decreased from 47.4% to 31.3%. % (P <0.001 for trend) and radiotherapy decreased from 38.0% to 26.6% (p <0.001 for trend).
Similar patterns of AS / WW increase and decrease in the other two treatments in men with intermediate-risk disease.
However, as noted, something unexpected was discovered in men with high-risk prostate cancer (n = 32,622).
The researchers report that the use of AS / WW has remained stable (1.9% to 2.2%) from 2010 to 2015 (p = 0.08 for the trend), while treatment with Radical prostatectomy increased from 38.0% to 42.8% (P <0.001 for the trend). and the use of radiotherapy decreased from 60.1% to 55.0% (p <0.001 for the trend).
The authors conclude their letter noting that the study only covered initial management plans. "The way trends will translate into clinical outcomes is unknown," they conclude.
The study was funded by several sources, including the Wood Family Foundation, the Baker family, the Freedman family, Fitz's Cancer Warriors and David and Cynthia Chapin. Many of the authors of the study have financial ties to industry, including companies offering prostate cancer products.
JAMA. Posted online February 11, 2019.
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