Undergoing more frequent prostate-specific antigen (PSA) screening after radical prostatectomy or primary radiation for localized prostate cancer was not associated with improved overall survival (OS), regardless of disease risk, according to results of the AFT-30 study (abstract 6503) presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting, held June 1–5 in Chicago.
“Based on our study results, PSA testing every 3 to 6 months may represent overutilization of care,” said Ronald Chen, MD, of the University of North Carolina at Chapel Hill. “This study provides empiric data to inform future guidelines and clinical practice.”
The ideal PSA screening frequency for patients who have completed treatment for localized prostate cancer is unknown. Current guidelines recommend post-treatment PSA surveillance, but the frequency of screening varies from once a year to four times a year. Intense post-treatment surveillance has the potential to cause harm, and it is unknown whether more frequent surveillance improves survival.
With this study, Chen and colleagues wanted to gain more insight into the appropriate frequency of screening, find out if this frequency should vary by aggressiveness of disease or the type of primary treatment received, and determine if more intense surveillance was associated with improved survival.
The study used data from the medical records of 10,476 patients taken from the National Cancer Data Base. All patients had been diagnosed with localized prostate cancer between 2005 and 2010 and undergone radical prostatectomy or radiation therapy. Of these patients, 4,088 had low-risk disease, 3,241 had intermediate-risk disease, and 3,148 had high-risk disease. The median age of patients was 64 years.
In the first year after treatment, the median number of screenings was two for all groups, regardless of risk or treatment. Two years post-treatment, the median number of screens was two, regardless of risk or treatment group. However, by year two the proportion of patients undergoing three or more PSA screens decreased compared with year 1.
OS across all groups was 8 years or longer. There was no significant association between frequency of PSA surveillance and OS in any of the risk or treatment groups.
Commenting on the study, Discussant Cary P. Gross, MD, of Yale School of Medicine, said the results made him reflect on the burden of surveillance on cancer survivors.
“Surveillance exerts a toll,” he said. “On the health system, it can be financial toll. On providers, it can take a toll on our attention and energy, but most importantly [it takes a toll] on patients.”
In future analyses, he said he hoped Chen and colleagues might look at how PSA screening frequency affected other outcomes, such as cost and patient anxiety.