Prostate-specific antigen (PSA) screening in older men, including those with serious comorbidity, is common practice in spite of recommendations against PSA screening in that population. The recommendations against PSA screening in men with limited life expectancy were issued by the U.S. Preventive Services Task Force, the American Cancer Society, and the American Urological Association due to the often indolent nature of screen-detected prostate cancer.
In 2012, the US Preventive Services Task Force amended its recommendation against PSA screening in men ≥75 years of age to all age groups; however, Medicare continues to cover PSA screenings. The recommendation against all screening has been met with criticism from those who believe that men should be given the opportunity to make their own informed decisions about the benefits and possible harms of PSA screening.
Noting that there are few clear data available to “quantify the chain of events following screening in clinical practice to better inform decisions,” researchers recently conducted a longitudinal cohort study to assess 5-year outcomes following a PSA screening result >4.0 ng/mL in older men. Study results were reported in JAMA Internal Medicine [2013;173(10):866-873].
The study identified 293,645 men ≥65 years of age who underwent PSA screening in 2003 at 1 of 104 Veterans Affairs healthcare system facilities. Using national Veterans Affairs and Medicare data, the men were followed up for 5 years following the screening.
The primary outcome measures among the men whose index screening was >4.0 ng/mL was the number who underwent prostate biopsy, were diagnosed with prostate cancer, were treated for prostate cancer, and were treated for prostate cancer and were alive at the 5-year follow-up. Complications associated with biopsy and treatment were also assessed.
Mean age of the study cohort was 73 years, 9.6% had a Charlson-Deyo Comorbidity Index of ≥3, 89.6% were white, and 35% had undergone PSA screening in the year prior to their index PSA screening in 2003.
Overall, 8.5% (n=25,208) had an index PSA level >4.0 ng/mL; 2.5% (n=7399) had a level >6.5 ng/mL, and 0.9% (n=2775) had a level >10.0 ng/mL. The percentage of men with an abnormal test result increased with age from 5.9% among men 65 to 69 years of age to 17.3% for men ≥85 years of age (P<.001). African-American men were 1.8 times more likely to have an abnormal result than white men.
During the 5-year follow-up period, 33.0% of the total cohort (n=8313) underwent at least 1 prostate biopsy, and 62.8% of those (n=5220) were diagnosed as having prostate cancer. Of those diagnosed with prostate cancer, 82.1% (n=4284) were treated for the disease.
Although the performance of biopsy decreased with advancing age and worsening comorbidity, the percentage treated for biopsy-detected prostate cancer was >75% even among men ≥85 years of age, those with a Charlson-Deyo Comorbidity Index of ≥3, and those having low-risk cancer.
Of those diagnosed with biopsy-detected prostate cancer, 58.1% were treated with curative intent (radical prostatectomy or radiation therapy), 23.9% were treated with hormone therapy alone, and 17.9% were not treated with either of those modalities. Among the cohort with diagnosed prostate cancer, 5-year survival was 82.1%, a percentage that declined with advancing age and worsening comorbidity.
Among the men who underwent prostate biopsy following abnormal PSA screening, 5.6% had complications within 7 days after biopsy. Among 4284 men treated with radical prostatectomy, radiation therapy, or hormone therapy, 13.6% (n=585) had new incontinence, and 13.7% (n=588) had new erectile dysfunction.
In summary, the researchers stated, “Performance of prostate biopsy is uncommon in older men with abnormal screening PSA levels and decreases with advancing age and worsening comorbidity. However, once cancer is detected on biopsy, most men undergo immediate treatment regardless of advancing age, worsening comorbidity, or low-risk cancer. Understanding downstream outcomes in clinical practice should better inform individualized decisions among older men considering PSA screening.”