In the U.S., prostate cancer is the most commonly diagnosed non–skin cancer and the second leading cause of cancer death behind lung cancer. One in nine men will be diagnosed with the disease in his lifetime and one in 41 men will die from prostate cancer.
In spite of this, the practice of screening men for prostate cancer is controversial, and opinions vary on whether it actually delivers benefits.
Part of the problem is this: not all prostate cancers are the same. Some may grow slowly and never represent a threat to a man’s life while others may be lethal. In the case of aggressive cancers, men may not have symptoms initially. As the cancer grows and spreads, it may lead to problems including trouble urinating, kidney obstruction, bone pain, weight loss and, ultimately, death. Relying on a doctor with prostate cancer treatment experience is vital.
The goal of screening is to find the right group of men who will benefit from treatment to prevent such complications while sparing unnecessary testing and treatment for those with either slow-growing cancers or no cancer at all.
The following patient factors are taken into consideration when screening for prostate cancer:
- Risk factors such as race and family history
- Life expectancy (i.e., whether < 10-15 yrs) and
- The patient’s values and preferences with an emphasis on shared decision making
WHO SHOULD GET SCREENED AND WHEN SHOULD THIS BEGIN?
Prior to 2012, an annual PSA blood test and prostate exam were recommended for all men in the U.S. Because of concerns about overdiagnosis and overtreatment, the U.S. Preventive Services Task Force (USPSTF) in 2012 assigned a grade of D (recommending against screening) for men of all ages. This led to a disturbing increase in the number of men being diagnosed with late-stage cancers and, ultimately, to a revision of their statement in 2017. Their new recommendations are now more in line with other organizations such as the American Cancer Society and the American Urologic Association (AUA) and are outlined as follows:
- All U.S. men ages 55-69 should consider PSA screening after discussing the risks and benefits with their doctor. This includes African American men and those with a family history of prostate cancer (both known to be at increased risk).
- Men > 70 years of age (according to the USPSTF) should not undergo screening.
The American Urologic Association (AUA) reviewed these new guidelines and made the following additional points:
- The expert panel noted that the greatest benefit of screening was in the (same) age group of 55-69. For these men, the panel strongly recommended shared decision-making & proceeding based on a man’s values and preferences (weighing the benefits of reducing the rate of metastatic disease and death against the known potential harms of screening and treatment)
- Men with a family history of prostate cancer (particularly a father or brother diagnosed before the age of 65) and African American men are at increased risk of developing prostate cancer and are encouraged to consider screening earlier, beginning at 40-45 years of age.
- With regard to men aged > 70, the expert panel believed that those who are in excellent health may still benefit from prostate cancer screening and should talk to their doctor about whether testing is right for them.
- Finally, to reduce the potential harms of screening, they noted that an interval of 2 years or more may be preferred over annual screening
DEFINING THE BASIC TOOLS FOR SCREENING, THE PSA AND DRE:
Prostate-specific antigen (PSA)—First approved by the FDA in 1994, the PSA is a blood test that measures a protein in the bloodstream produced by cells in the prostate. PSA is “prostate-specific” but not “cancer-specific”.
Causes of an elevated PSA may include:
- An enlarged prostate (known as “BPH” or benign prostatic hyperplasia)
- Prostate infection or inflammation
- Prostate cancer
- Other: Ejaculation within 24 hrs of the blood test and testosterone replacement therapy may also (slightly) increase the PSA, whereas doing a prostate exam before the blood test and/or long-distance bicycle-riding have not been proven to significantly alter the PSA.
What is a normal PSA?
The short answer is a PSA 0-4.0 ng/mL. Some experts use an “age-adjusted” reference range as follows:
PSA cutoff (ng/mL)
Another useful tool is the National Comprehensive Cancer Network (NCCN) clinical practice guidelines as follows:
- Discuss risks & benefits of screening with physician
- Have a baseline PSA and consider a baseline DRE
- If PSA < 1 ng/mL & DRE normal, repeat testing every 2-4 years
- If PSA 1-3 ng/mL and DRE normal, repeat testing every 1-2 years
- If PSA > 3 ng/mL or abnormal DRE, consider additional testing or biopsy
Digital rectal exam (DRE)—In this exam, the doctor will insert their “digit” (a lubricated, gloved finger) into the rectum to feel the surface of your prostate. From this position, the doctor can detect any abnormalities in the shape, size, or texture of the prostate gland. If any abnormalities are found, further testing may be indicated.
RECENT ADVANCEMENTS IN PROSTATE CANCER SCREENING
The AUA expert panel recommended the use of one or more of the following tools to help decide which patients with an elevated PSA might require a prostate biopsy. These tools can help identify men who are more likely to harbor a prostate cancer and which may have a more aggressive, clinically significant type. These include:
Use of better “biomarkers”: These tests outperform PSA alone in determining the need for a biopsy and include blood tests such as the “4K score” (https://4kscore.com/) and “PHI test” (https://www.beckmancoulter.com/products/immunoassay/phi). There are also urine tests available such as the “urine PCA3 test” (https://www.medicalnewstoday.com/articles/319675.php).
PSA “derivatives”: These include the % free to total PSA, PSA velocity (rate of rise/year), PSA density (total PSA/prostate volume), and PSA-based nomograms incorporating age, exam findings, family history, and prostate volume.
Prostate MRI: Prostate MRI’s are now able to accurately identify any area of suspicion inside the gland and have significantly improved the ability (via targeted biopsy) to find a cancer if one is present. In addition, if a prostate MRI shows no abnormal findings, one can be reasonably certain that there is no need for a biopsy or further prostate cancer treatment.
In summary, although it remains controversial whether screening for prostate cancer can actually save lives, most experts agree that stopping PSA screening altogether is not the answer.
With better technology and more focused-screening, urologists can offer a smarter approach that is better able to identify those who are at most risk for an aggressive cancer and, therefore, those who may benefit from early diagnosis and prostate cancer treatment. I hope this blog was helpful. Stay tuned for more regarding prostate cancer treatment options.
If you live in the Houston area and have been diagnosed with an elevated PSA or would like to learn more about prostate cancer treatments and screening, feel free to make an appointment with Dr. Durrani at 281-589-7175 or visit us at www.durranimd.com.