By Dr Greggory Pinto
Prostate specific antigen (PSA) is a type of protein released by the prostate gland. Screening for possible prostate cancer involves taking a PSA blood test, which is recommended annually starting at the age of 40 years old.
Men with strong risk factors for developing prostate cancer should start annual prostate cancer screening at the age of 35 years old. High risk factors for developing prostate cancer include a first degree relative being diagnosed with prostate cancer before the age of 50 years old or a genetic predisposition such as being BRCA (breast cancer gene) mutation positive. Men and women can have a BRCA mutation and it puts these individuals at greater risk of developing several cancers, including breast and pancreatic cancer and for men. There is also an associated greater risk for being afflicted with prostate cancer.
You have gone for your annual physical and your physician has informed you that your PSA blood test is abnormal. What is the next step?
Firstly, keep calm.
The PSA blood test is an important screening tool for prostate cancer but it is not a very specific indicator of prostate cancer. There are many conditions other than prostate cancer that can lead to an elevated PSA value. However, a PSA value of greater than 100 ng/ml has a very high likelihood of indicating prostate cancer.
Repeat the PSA value immediately if the PSA value is significantly elevated or repeat more than one month later if the value is marginally elevated. Your urologist will assess whether you have an infection of your prostate, prostatitis or clinically significant incomplete bladder emptying that could have contributed to an elevated PSA value. Medications would be prescribed if necessary for treating prostate gland infections or to assist in fully emptying the bladder. Ejaculation within three days of taking a PSA blood test could also lead to elevation of PSA values.
Repeating the value right away, only rules out the very unlikely and almost never seen scenario of lab error. Repeating the PSA value assessment four to six weeks later allows for resolution of possible natural fluctuations in PSA and allows for the treatment of possible infection of the prostate or confirmed significant incomplete emptying of the bladder. It is, however, possible to have confirmed infection of the prostate and incomplete bladder emptying and still have prostate cancer.
If the first PSA value was between 4 to 10 ng/ml then your urologist will request the free PSA value along with your repeat PSA assessment. The lower the free PSA value, the greater the statistical probability that there is prostate cancer present.
It is fundamentally important to review the history of PSA values and not just consider a PSA number in isolation. A PSA might be in the age specific normal range but there may be a large increase in the value from one year to the next; which indicates a high PSA velocity. Approximately 15 percent of men diagnosed with prostate cancer have a PSA value in a normal range.
The repeat PSA value is still elevated. What’s next?
If the clinical exam reveals a malignant feeling prostate and the PSA value is strongly supportive of advanced prostate cancer then your urologist might opt for immediate ultrasound guided prostate biopsies. The biopsy of the prostate can be done under local anesthesia, conscious sedation or general anesthesia.
Most urologists would strongly recommend imaging of the prostate in the form of a 3T MRI or a PSA PET/CAT scan. These forms of state of the art imaging will reveal any areas within the prostate that are suspicious for prostate cancer, as well as provide a scoring system indicating the statistical probability of any prostate lesions being prostate cancer.
Your urologist will then use this information to determine whether a prostate biopsy is warranted. The advanced imaging of the prostate allows this information to be used to allow for image directed, more accurate prostate biopsies if that is indicated.
Prostate cancer diagnosis requires a prostate biopsy with a pathology confirmed tissue diagnosis.
There are several biomarker tests available that can be also be requested for prostate cancer screening.
IsoPSA blood test
A relatively new blood test IsoPSA has been found to be more accurate in predicting prostate cancer than the standard PSA blood test. The IsoPSA is effective at diagnosing prostate cancer and discriminating between high grade and low-grade prostate cancer.
A highly specific and sensitive biomarker blood test must be both tissue specific and cancer specific; both these requirements are fulfilled by the IsoPSA blood test. PSA is only tissue specific and it can be elevated for conditions other than prostate cancer.
PSA density is more accurate than routine PSA alone for predicting prostate cancer, if the PSA value is elevated above 4 ng/ml and less than 20 ng/ml.
PSA density is calculated by dividing the total PSA by the prostate volume. PSA values are influenced by the volume of the prostate.
Noncancerous prostate cells contribute to PSA values; thus a patient with a very large noncancerous prostate can have an elevated PSA value without prostate cancer being present. PSA density removes the influence of a large prostate on the PSA value.
4K score is a blood test that combines four prostate specific biomarkers with clinical information such as age; to predict the likelihood of clinically significant prostate cancer being present. The use of MRI prostate and 4K score provides a strong indicator for detecting high risk prostate cancer that requires treatment
There are several other prostate cancer biomarkers available including PCA3, which is a urine test, and Prostate Health Index (PHI) which is a biomarker based mathematical determined test.
African ancestry and advancing age are strong risk factors for prostate cancer.
Bahamians and residents should be diligent in having annual prostate cancer screening every year starting at the age of 40 years old.
Commonly prescribed medications such as Avodart or Finasteride will artificially halve a PSA value if taken for longer than five months. These medications are often prescribed for men with an enlarged obstructive prostate to aid them in reducing their urinary symptoms. Patients taking these medications long term, should double their PSA value to get a accurate value during prostate cancer screening.
Early detection is key for successfully curing prostate cancer.
The 10-year survival for early prostate cancer is 98 percent at ten years.
Prostate cancer is a very curable disease.
• Dr Greggory Pinto is a board certified Bahamian urologist and laparoscopic surgeon. He has trained in Germany, South Africa and France, and is a member of the European Association of Urology. He can be contacted at OakTree Medical Center, #2 Fifth Terrace & Mount Royal Avenue. Telephone: (242) 322-1145 (6) (7); e-mail: firstname.lastname@example.org, or visit the website:www.urologycarebahamas.com.