As the AS strategy gains a foothold among urologists both here in the US and around the world, a study presented at the 110th Annual Scientific Meeting of the American Urological Association suggests that among men in the US, very few are following the stringent protocol for AS that is recommended by major academic institutions.
Stacy Loeb, MD
As the active surveillance (AS) strategy gains a foothold among urologists, a study1 presented at the 110th Annual Scientific Meeting of the American Urological Association suggests that among men in the United States very few are following the stringent protocol for AS that is recommended by major academic institutions.
At Johns Hopkins University, the AS program recommends prostate-specific antigen (PSA) tests every 3 months and annual biopsies.2 Other programs use different protocols for follow-up during AS. For example, in the PRIAS program,3 a large international trial that is registered with the Dutch Trial Register (ID NTR1718), biopsies are conducted at year 1, 3, and 7 after initial diagnosis with PSA testing conducted every 3 months for the first 2 years and then every 6 months thereafter. “So there’s quite a bit of heterogeneity in the testing when AS is used,” said Stacy Loeb, MD, lead researcher.
“As more men choose AS, more attention must be paid to determine the optimal protocol to use,” continued Loeb, an assistant professor of urology at New York University School of Medicine and the NYU Langone Medical Center. “Ultimately, we want to ensure that men have sufficient follow-up.”
Loeb and her colleagues identified 4185 patients undergoing AS (among the 5192 men diagnosed with prostate cancer) from the Surveillance, Epidemiology and End Results Program (SEER) Medicare database. The database links the cancer registries of SEER and the Medicare claims for covered healthcare services from the time of a person’s Medicare eligibility until death. The researchers followed the men from 2001-2009.
“The difficulty with SEER is that it doesn’t tell you who is on AS or who is just on watchful waiting. So we selected men who had a biopsy within 2 years after their initial diagnosis to try to distinguish AS,” said Loeb.
The number and type of tests that men generally receive during each year of AS was calculated. The primary dependent variable of interest was the number of prostate biopsies. Secondary dependent variables included the number of PSA tests and imaging studies including transrectal ultrasonography (TRUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). The independent variables of interest were year of diagnosis, patient age, race, and tumor characteristics.
The men were a median age of 73, 10.7% were African American, and 73.7% had a Charlson Comorbidity Index score of 0. The D’Amico risk category was low in 51.8%, intermediate in 36.6%, and high in 11.7%.
“We found that 22.6% of men got a PSA test within 3 months of their diagnosis, which is pretty early. From 4 to 12 months after diagnosis, 89% of men received a PSA test. After that, about 84% to 94% got a PSA test every year,” said Loeb.
The use of imaging tests after initial diagnosis demonstrates a similar pattern over time. “Quite a few men received imaging tests during the first 1 to 2 years of AS, but it declined after that. And of the 109 who were still being followed at 10 years, only 16.5% got an imaging study.”
Prostate biopsy, a known source of patient noncompliance, varied by institution. “Johns Hopkins had the highest rate of compliance with prostate biopsy–they have 89% compliance with all biopsies in their program. In some community settings, like the VA population, biopsy is only 53%. Biopsy use is pretty low over time. Beyond the first 2 years of AS, less than 13% of men got a biopsy, and by year 10, only 1%.”
The researchers then conducted a subset analysis that included all the men who had exactly 5 years of follow-up in order to calculate the total number of tests during a 5-year period.
For PSA tests, 95% of men had a PSA every year during the 5-year period. When the researchers looked at PSA tests administered every 6 months during the time period, they found only 59% had undergone testing. “And only 10% had a PSA every 3 months for 5 years, which is the Johns Hopkins protocol for AS,” said Loeb.
For imaging tests, 96% had undergone 1 imaging study within 5 years, but only 39% had an imaging study every year. Prostate biopsy frequency exhibited a similar pattern, with 34% of men undergoing more than 2 biopsies after diagnosis in the 5-year timeframe, but only 2% undergoing more than 5 biopsies after diagnosis in the timeframe.
If the PRIAS and Johns Hopkins criteria are applied to the data, then only 11% of men followed the PRIAS protocol, which means 2 or more biopsies and 14 or more PSA tests during the 5-year time frame. For the Johns Hopkins protocol, which would be 4 or more biopsies and 20 or more PSA tests during a 5-year time period, only 0.6% would be in compliance.
“Active surveillance should be encouraged for men with low-risk prostate cancer that can delay or avoid the need for treatment,” said Loeb. “However, the surveillance is meant to be an active process so men on AS should continue to follow up with their doctor regularly.”