Education about prostate cancer risk and testing is part of a routine annual exam with a man’s physician. A general practitioner or an urologist can perform a full prostate cancer exam. This includes a PSA blood test and digital rectal exam, also called a DRE.
The PSA (prostate-specific antigen) test is a simple blood test that measures the level of prostate-specific antigen in the blood. The PSA is a protein produced by cells in the prostate. Its primary function is to help keep the semen in a liquid form enabling the sperm to swim. The levels of PSA can rise due to a number reasons including the presence of cancer.
When your prostate is inflamed for any reason, infection, BPH, ejaculation, or even riding a bicycle, can cause a rise in your PSA. It also can rise as cancer develops in the prostate and spreads through the bloodstream to other parts of the body.
The PSA test is also used to track the effects of prostate cancer treatments such as surgery, radiation, hormone therapy, and chemotherapy. A low, dropping or zero PSA is a good sign that these treatments are working for a man with prostate cancer.
In May of 2012, the United States Preventive Services Task Force announced it does not recommend PSA testing for men because it believes there is not a life-saving benefit to the PSA. However, the National Comprehensive Cancer Network and ZERO - The End of Prostate Cancer strongly recommend a man should be fully educated about prostate cancer and the option of early detection. A PSA test score is an important part of making a decision of how best to determine a prostate cancer diagnosis and/or treatment pathway.
It is best to discuss the results of a PSA test with your doctor, urologist, and if necessary an oncologist because every test result must also take age, race, family history, and recent activity into account.
The general guidelines of PSA levels consider:
- 0 to 2.5 ng/mL is considered safe
- 2.6 to 4 ng/mL is safe in most men but talk with your doctor about other risk factors
- 4.0 to 10.0 ng/mL is suspicious and suggest the possibility of prostate cancer
- 10.0 ng/mL and above is dangerous and should be discussed with your doctor immediately
Age-specific PSA reference ranges refer to using different PSA cutoffs for recommending a biopsy. The age ranges are as follows:
- 40-49: 2.5
- 50-59: 3.5
- 60-69: 4.5
- 70 and up: 6.5
Research has shown men generally have a 25 percent chance of having prostate cancer with a PSA over 4.0 and a 50 percent chance of a PSA over 10.0. However, many men have an elevated PSA for many other reasons other than cancer.
Other reasons for an elevated PSA besides cancer:
- Advanced age
- Injury to pelvic region or prostate
- Riding a bicycle
- Sex (within 24 hours)
- Supplements that effect testosterone
- Urinary tract infection
Annual changes in PSA test results is a method doctors use to determine the risk of prostate cancer as PSA can rapidly rise in men who have prostate cancer. It can be especially useful to find prostate cancer in early stages before the cancer has left the capsule of the prostate.
Research shows that an increase of .75 ng/mL over a year is an early indicator of prostate cancer if a man has a total PSA result between 4.0 and 10.0 ng/mL. Further, an increase of 2.0 ng/mL over a year period predicts a higher likelihood of death due to aggressive prostate cancer.
Research is also showing PSA velocity may be able to predict survivability from prostate cancer as men with a PSA increase of .35 ng/ML or less over a year have a 92 percent survival rate compared to PSA increases of more than .35 ng/mL over a year have a 54 percent survival rate.
A High PSA
There are several avenues to consider if a PSA is high and research continues develop more options every day. One should always have a Digital Rectal Exam (DRE), along with the PSA and/or an annual exam as it can detect prostate cancer or prostate problems that a PSA may miss.
A Low PSA
In general, a low PSA is a good result. However, there are several reasons a PSA test level may be artificially low including taking statins to lower cholesterol, anti-inflammatory drugs and obesity (body fat decreases the amount of PSA circulating in the blood stream). Be sure to discuss these with your doctor.
Digital Rectal Exam (DRE)
A DRE is a routine procedure as part of an annual physical exam with a doctor. The physician briefly feels the surface of the prostate for any abnormalities by inserting a gloved and lubricated finger into the rectum for a several seconds.
The DRE is used to help diagnose prostate cancer – even when a PSA test is not high – and for other prostate problems such as benign prostatic hyperplasia or prostatitis.
Science has advanced two genetic tests that can be used after a PSA test to predict aggressive or slow-growing tumors, giving patients and doctors more information to shape treatment regimens or active surveillance plans. Not all prostate cancers are the same and genomic testing of your prostate cancer will give you more options to consider.
Oncotype DX, developed by Genomic Health, evaluates 21 genes in tissue taken during a prostate biopsy to establish a grade and state of the cancer. The test predicts the future recurrence of prostate cancer for patients with localized disease. In order to determine risk level with this test, a man must have a PSA less than 20, a Gleason score of less than 6, and a tumor stage in T1 or T2.
Prolaris, developed by Myriad, measures 46 genes to predict the aggressiveness of the disease. The test can be used to gauge how lethal a tumor may become or can be used after surgery to determine the likelihood of recurrence or metastatic disease.
These tests may prove very useful in avoiding overtreatment or when to act quickly to eradicate aggressive disease. Talk to your doctor if you are a candidate for these tests and find out if your insurance covers them.