A new study suggests that older patients who survived prostate cancer with a low risk of recurrence could benefit from fewer prostate cancer antigen (PSA) tests, as they are more likely to experience the harmful effects of PSA monitoring that could outweigh the advantages.
The study, “Individualizing PSA Monitoring Among Older Prostate Cancer Survivors,” was published in the Journal of General Internal Medicine.
In the follow-up to prostatectomy or radiation therapy to cure prostate cancer, men are monitored for disease recurrence with blood tests that measure PSA levels.
Recurrence is generally considered at PSA levels equal to or higher than 0.2 ng/mL after a radical prostatectomy, or an increase over baseline by 2.0 ng/mL when radiation therapy was used.
Although PSA monitoring might be beneficial for early detection of disease relapses and warrant early interventions, in some older patients the dangers of PSA monitoring might surpass the benefits.
Older men who have survived cancer with low risk of recurrence are the least likely to experience disease relapse during their lifetime. In such cases, exposing men to frequent PSA tests might lead to unnecessary invasive diagnostics or treatments and pose more harm than good, researchers said.
Investigators at the University of California, San Francisco examined how common in clinical practice it is to prescribe fewer PSA tests to patients with limited life expectancy and who have had low-risk prostate cancer.
The team examined data from the U.S. Veterans Affairs Cancer Registry and Medicare from 13,397 men ages 65 or older who have been treated for prostate cancer with radiation or radical prostatectomy.
All participants survived without a recurrence for at least one year after treatment and were followed for the next four years.
Men with limited life expectancy — ages 85 and older or ages 65 and older with a high comorbidity index — who were treated for low-risk cancer received more PSA tests than those with low-risk cancer and a favorable expectancy — ages 65-74 without no comorbidity index (1.9 tests per year versus 1.8 tests per year, respectively).
And they received only slightly fewer PSA tests than men with a favorable life expectancy and treated for high-risk cancer (1.9 tests per year versus two tests per year, respectively).
The number of PSA tests only decreased significantly with the years a man had survived without prostate cancer. While in the first year men had 2.3 PSA tests per year, this decreased to two in year two, 1.8 in year three, and 1.6 in year four.
The team concluded that PSA test frequencies are similar across patients and cancer risk characteristics, indicating little individualization of PSA monitoring.
According to Louise Walter, MD, senior author of the study, the research suggests for the first time that clinicians need guidelines considering life expectancy, risk of recurrence, and the values and preferences of cancer survivors to determine when to use PSA tests.
Walter is the chief of the UCSF Division of Geriatrics and a geriatrician at San Francisco VA Health Care System.