Most older men with abnormal prostate-specific antigen (PSA) levels detected on screening do not undergo biopsy, but those who do are often found to have prostate cancer and receive treatment regardless of advancing age, poor health, or the fact that their cancer is low-risk.
These were the findings yielded by a study of 295,645 men aged 65 years and older who underwent PSA screening in the Veterans Affairs (VA) health care system in 2003. Louise C. Walter, MD, of the San Francisco (California) VA Medical Center, and colleagues followed the men for 5 years using VA and Medicare data. In total, 25,208 men (8.5%) had an index PSA level exceeding 4.0 ng/mL.
One-third of the men with a PSA level higher than 4.0 ng/mL (8,313, or 33%) underwent at least one prostate biopsy during the follow-up period, leading to a diagnosis of prostate cancer in 5,220 (62.8%). Most of the men with prostate cancer (4,284, or 82.1%) underwent treatment for the disease.
As Walter’s team reported in JAMA Internal Medicine, performance of prostate biopsy decreased with advancing age and worsening comorbidity, but the percentage of men who received treatment for biopsy-detected prostate cancer exceeded 75% even among men aged 85 years and older, among men with a Charlson-Deyo Comorbidity Index of 3 or higher, and among men with low-risk cancer.
The 5-year survival rate among men with prostate cancer detected through screening was 82.1%, but decreased with advancing age and worsening comorbidity as deaths from causes other than prostate cancer increased. Overall in the first 5 years, 14.4% of deaths were due to causes other than prostate cancer, but that percentage increased to 71.4% among men aged 85 years and older with a comorbidity index of 3 or higher.
“Because PSA screening advances cancer diagnosis 5 to 12 years before clinical diagnosis, screening in subgroups with limited life expectancy risks diagnosing cancer that would never have caused symptoms,” wrote the researchers.
A total of 468 men (5.6%) experienced complications within 7 days after prostate biopsy. Prostate cancer treatment was also associated with complications, with 584 of these patients (13.6%) developing urinary incontinence and 588 (13.7%) developing erectile dysfunction.
Walter and associates concluded that the decision to pursue PSA screening should include personalized discussion regarding when to pursue biopsy and treatment, “because these steps substantially affect downstream outcomes of screening in clinical practice.” They added that these frequencies of downstream outcomes according to age, comorbidity, and other baseline characteristics should better inform clinicians and older men who are considering PSA screening and want to make more individualized decisions.