Prostate Cancer Screening for the Individual: A Patient-based Approach
Jessica Motl, PA-C, Physician Assistant
Prostate cancer is the most common non-cutaneous malignancy and the second leading cause of cancer-related deaths in men. It was estimated that 217,730 men would be diagnosed with and 32,050 men would die of cancer of the prostate in 2010.1 Overall prevalence in 2008 was more than two million men currently with active disease or cured of disease. Since prostate specific antigen (PSA) was first introduced in 1987, there has been a significant increase in the overall diagnosis of prostate cancer. An estimated 85 percent of these diagnoses represent clinically localized disease (diagnosed from an elevated PSA alone or a prostate nodule without evidence of spread beyond the prostate).
Controversy regarding PSA screening has been long standing. Two large studies2,3 released in 2009 sparked a resurgence of the debate, suggesting prostate cancer is likely overdiagnosed and overtreated in the PSA era. In fact, about 90 percent of men diagnosed with prostate cancer elect some type of intervention such as radical prostatectomy, cryotherapy, high frequency ultrasound ablation, radiation therapy, or androgen deprivation therapy.4
The American Urologic Association (AUA) recommends PSA screening for well-informed men who wish to pursue early diagnosis.5 Prostate cancer screening is to include a PSA and digital rectal exam to screen for those rare, but often more aggressive malignancies which do not result in an elevated PSA. Most recent guidelines recommend a baseline PSA at age 40. Overall, men with a life expectancy of less than 10 years are discouraged from prostate cancer screening. Other important factors to consider are family history (positive family history in a first degree relative) and race (African American men are at increased risk of prostate cancer).
An age-adjusted PSA is a valuable reference range to allow for early, baseline PSA screening as an overall assessment of risk of prostate cancer at a relatively young age. PSA for men ages 40-49 should be less than 1.5; ages 50-59 less than 2.5; ages 60-69 less than 4.5; and ages 70-79 less than 7.5. These reference ranges better account for higher PSA due to higher prostate volume in an aging population.
The United States Preventative Services Task Force does not recommend prostate cancer screening for men older than age 75, which is roughly based on life expectancy for the average 75-year-old man. However, elderly patients who are deemed to be in excellent health, have no-comorbid conditions, and have a family history of longevity may still benefit from screening as the incidence of high risk prostate cancer does increase with age.
Prostate cancer is not the sole cause of PSA elevation. The three most common diseases of the prostate (prostate cancer, benign prostatic hyperplasia, prostatitis) can all cause PSA elevation. Additionally, recent infection or traumas (including catheterization) of the urinary tract are possible causes. These factors need to be considered by practitioners prior to obtaining a PSA.
The overall goal of screening is to decrease morbidity and mortality of disease. The art of medicine as it applies to prostate cancer entails recommending active treatment to patients at risk of morbidity or mortality of disease, and surveillance for those who are not. Patients diagnosed with low risk prostate cancer are generally good candidates for active surveillance. Active surveillance involves a protocol of regular PSA tests, annual digital rectal exams, and repeated prostate biopsies to ensure no or little progression of disease over time. Increased consideration for active surveillance has the potential to avoid the perceived over-treatment of prostate cancer, resulting in less treatment side effects and better quality of life for patients.
The Prostate, Lung, Colorectal, and ovarian (PLCO) Cancer Screening Trial
European Randomized Study of Screening for Prostate Cancer (ERSPC)
Cooperberg, M.R., Broering, J.M., Kontoff, P.W., et al: Contemporary Trends in Low Risk Prostate Cancer: Risk Assessment and Treatment. Sixth Cambridge Conference on innovations and Challenges in Prostate Cancer, J Urol,178:S14, 2007
AUA Best Practice Guidelines