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Monitoring, not treatment, better for low-risk prostate cancer – US study

While the diagnosis of low-risk prostate cancer used to lead directly to aggressive treatment, increasing numbers of men are opting for active surveillance, with experts saying too many older men are being screened, and rarely benefit from treatment.

This more conservative approach means periodic prostate-specific antigen (PSA) assessments and biopsies, often with MRIs and other tests, to watch for signs that the cancer may be progressing.

As recently as 2010, about 90% of men with low-risk prostate cancer underwent immediate surgery to remove the prostate gland (a prostatectomy) or received radiation treatment, sometimes with hormone therapy.

But between 2014 and 2021, the proportion of men at low risk of the cancer who chose active surveillance rose to nearly 60% from about 27%, according to a study using data from the American Urological Association’s national registry.

“Definitely progress but it’s still not where we need to be,” said Dr Matthew Cooperberg, a urologic oncologist at the University of California, San Francisco, and lead author of the study, published in JAMA Network Open.

Changing medical practice often takes a frustratingly long time. In the study, 40% of men with low-risk prostate cancer still had invasive treatment. And approaches vary enormously between urology practices, reports The New York Times.

The proportion of men under active surveillance “ranges from 0% to 100%, depending on which urologist you happen to see”, Cooperberg said. “Which is ridiculous.”

The results of a large British study, recently published in the New England Journal of Medicine, provide additional support for surveillance. Researchers followed more than 1 600 men with localised prostate cancer who, from 1999 to 2009, received active monitoring, a prostatectomy or radiation with hormone therapy.

Over a long follow-up averaging 15 years, fewer than 3% of the men, whose average age at diagnosis was 62, had died of prostate cancer. The differences between the three treatment groups were not statistically significant.

Although the cancer in the surveillance group was more likely to metastasise, it didn’t lead to higher mortality.

“The benefit of treatment in this population is just not apparent,” said Dr Oliver Sartor, an oncologist at the Mayo Clinic who specialises in prostate cancer, in an accompanying editorial.

“It doesn’t help people live longer,” he said of the treatment, probably because of what is known as competing mortality, the likelihood of dying from something else first.

Men whose PSA readings and other test results indicate higher-risk tumours, or who have family histories of prostate cancer deaths, fall into a different category, experts cautioned.

“The point of screening is to find the aggressive tumours – a small minority, but they kill more men than any other cancer except lung cancer,” Cooperberg said.

But most prostate cancer grows so slowly, if it grows at all, that other illnesses are likely to prove lethal first, especially among older men. During the British study, one in five men died from other causes, predominantly cardiovascular or respiratory diseases and other cancers.

That’s why guidelines from the US Preventive Services Task Force and the American College of Physicians recommend against routine prostate cancer screening for men over 69 or 70, or for men who have less than a 10- to 15-year life expectancy. (Men ages 55 to 69 are advised to discuss the harms and benefits with health care providers before deciding to be screened.)

Study details

Time trends and variation in the use of active surveillance for management of low-risk prostate cancer in the US

Matthew Cooperberg, William Meeks, Raymond Fang, Franklin Gaylis, William Catalona, and Danil Makarov.

Published in JAMA Network Open on 2 March 2023

Key Points
Question What are the recent trends and ongoing variation in the use of active surveillance for patients diagnosed with low-risk prostate cancer, as determined using the large, national American Urological Association Quality Registry?

Findings In a cohort study of more than 20 000 men treated at nearly 350 urology practices across the US, with data drawn directly from electronic health record systems, rates of active surveillance increased sharply from 26.5% in 2014 to 59.6% in 2021. However, the use of surveillance varied widely across practices and individual urology practitioners.

Meaning These findings suggest that active surveillance rates are rising nationally but are still suboptimal, and local variation is high; improving these practice patterns is essential to improve our national prostate cancer outcomes.

Abstract

Importance
Active surveillance (AS) is endorsed by clinical guidelines as the preferred management strategy for low-risk prostate cancer, but its use in contemporary clinical practice remains incompletely defined.

Objective
To characterise trends over time and practice- and practitioner-level variation in the use of AS in a large, national disease registry.

Design, Setting, and Participants
This retrospective analysis of a prospective cohort study included men with low-risk prostate cancer, defined as prostate-specific antigen (PSA) less than 10 ng/mL, Gleason grade group 1, and clinical stage T1c or T2a, newly diagnosed between January 1, 2014, and June 1, 2021. Patients were identified in the American Urological Association (AUA) Quality (AQUA) Registry, a large quality reporting registry including data from 1945 urology practitioners at 349 practices across 48 US states and territories, comprising more than 8.5 million unique patients. Data are collected automatically from electronic health record systems at participating practices.

Exposures
Exposures of interest included patient age, race, and PSA level, as well as urology practice and individual urology practitioners.

Main Outcomes and Measures
The outcome of interest was the use of AS as primary treatment. Treatment was determined through analysis of electronic health record structured and unstructured clinical data and determination of surveillance based on follow-up testing with at least 1 PSA level remaining greater than 1.0 ng/mL.

Results
A total of 20 809 patients in AQUA were diagnosed with low-risk prostate cancer and had known primary treatment. The median age was 65 (IQR, 59-70) years; 31 (0.1%) were American Indian or Alaska Native; 148 (0.7%) were Asian or Pacific Islander; 1855 (8.9%) were Black; 8351 (40.1%) were White; 169 (0.8%) were of other race or ethnicity; and 10 255 (49.3%) were missing information on race or ethnicity. Rates of AS increased sharply and consistently from 26.5% in 2014 to 59.6% in 2021. However, use of AS varied from 4.0% to 78.0% at the urology practice level and from 0% to 100% at the practitioner level. On multivariable analysis, year of diagnosis was the variable most strongly associated with AS; age, race, and PSA value at diagnosis were all also associated with odds of surveillance.

Conclusions and Relevance
This cohort study of AS rates in the AQUA Registry found that national, community-based rates of AS have increased but remain suboptimal, and wide variation persists across practices and practitioners. Continued progress on this critical quality indicator is essential to minimise overtreatment of low-risk prostate cancer and by extension to improve the benefit-to-harm ratio of national prostate cancer early detection efforts.

 

JAMA Network Open article – Time trends and variation in the use of active surveillance for management of low-risk prostate cancer in the US (Creative Commons Licence)

 

The New York Times article – Too Many Older Men Are Still Screened for Prostate Cancer (Restricted access)

 

See more from MedicalBrief archives:

 

Prostate cancer patients can delay treatment without increased death risk – long-term study

 

Drug delaying prostate cancer by more than a year gets approval in UK

 

New prostate cancer blood test has 94% accuracy – UK study

 

 

 

 

 

 

 

 

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