'Historic Reversal': No Immediate Tx for Low-Risk Prostate Cancer

Pam Harrison

May 17, 2018

Record numbers of men with low-risk prostate cancer are opting for conservative management in the form of watchful waiting or active surveillance rather than undergoing immediate treatment, a Veterans Affairs (VA) analysis indicates.

With watchful waiting, men defer treatment until symptoms worsen, whereas active surveillance relies on regular follow-up visits to monitor patients for any signs of disease progression. 

"Low-risk prostate cancer has a favorable prognosis without treatment," said lead author,  Stacy Loeb, MD, Perlmutter Cancer Center at NYU Langone Health and the Manhattan Veterans Affairs (VA) Medical Center in New York City. "[And g]uidelines recommend conservative management or deferring upfront treatment as the preferred approach."

The VA analysis found a sharp increase in this practice over the last decade.

It found that 2005, 27% of men younger than age 65 years and 35% of men age 65 years or older were managed conservatively.

Ten years later, in 2015, that number had increased to 72% of men younger than age 65 years and 79% of men age 65 years or older (P < .0001 for both endpoints).

This marks a historic reversal, at least at the VA, in the decades-long overtreatment of men with prostate cancers least likely to cause harm. Dr Stacy Loeb

"This marks a historic reversal, at least at the VA, in the decades-long overtreatment of men with prostate cancers least likely to cause harm, and brings their care more in line with the latest best practice guidelines," Loeb said in a statement.

The findings appear in research letter published online May 15 in JAMA.

Central Data Warehouse

Data from the VA central data warehouse were analyzed for men diagnosed with low-risk prostate cancer between 2005 and 2015.

Low-risk prostate cancer was defined as a prostate-specific antigen (PSA) of less than 10 ng/mL, a Gleason score of 6 or less, and stage cT1/T2 disease.

"Among 125,083 veterans with low-risk prostate cancer, mean age was 64 years…and mean PSA was 5.4 ng/mL," the investigators note.
When all the veterans treated over the 10 years were considered, almost half of the cohort, at 48%, was managed conservatively, 30% of men underwent watchful waiting, and 18% of men received active surveillance.

"On multivariable analysis, more recent years were associated with greater odds of conservative management, as were increasing age, black race, unmarried status, higher PSA, [and] increasing comorbidity," the study authors note.

Where the men were treated also influenced whether they were managed conservatively. For example, approximately 39% of men treated in the South were managed conservatively vs about 24% of men managed in the West.

About 21% of men in the Midwest were also managed conservatively while men treated in the Northeast were the least likely to undergo conservative management, at about 14% of that particular subgroup, researchers also noted.

Loeb suggested that the successful uptake of conservative management in the VA system is due to several factors, one of which might be that the VA is publicly funded with salaried physicians so there is little financial incentive to overtreat patients.

Reflect National Practices

Approached by Medscape Medical News to comment on the study, Marc Garnick, MD, Gorman Brothers professor of medicine, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts, said that the change in management of low-risk prostate cancer reported at the VA has also been seen nationally. He does not think that being a salaried physician, such as those in a VA setting, has much influence on increased uptake of conservative management for low-risk prostate cancer for men in the United States.

"I think results simply reflect national practices," Garnick noted.

National practices in turn reflect what is now recommended in the most recent guidelines, Garnick added. For example, the US Preventive Services Task Force (USPSTF) now recommends that men age 55 to 69 years make an informed individual decision to undergo prostate cancer screening after they discuss the potential benefits and harms of screening with their physician.

The most recent USPSTF guidelines on prostate cancer screening still do not recommend PSA screening for men 70 years of age and older.

As Garnick noted, previous guidelines from the USPSTF issued in 2012 basically said the harms of screening outweigh the benefits.

"The harms were by treating people who probably didn't even need to be diagnosed," Garnick noted.

"So I think over the past 5 years, our ability to identify patients with diagnosed prostate cancer who do not necessarily need to be treated based on either clinical characteristics or on genomic characteristic has decreased the harm component," he added.

"And those are simply the national trends — patients with Gleason 3+3 cancer basically are going onto active surveillance more than anything else," Garnick reaffirmed.

Loeb reported consulting for Lilly, MDx Health, GenomeDx, and General Electric and receiving personal fees from Astellas, Sanofi, Minomic, and Boehringer Ingelheim. Garnick is editor-in-chief of Harvard Medical School's Annual Report on Prostate Diseases and its website.

JAMA. Published online May 15, 2018. Abstract

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