Prostate Cancer Screening
The prostate releases the prostate-specific antigen, or PSA. Small amounts of PSA ordinarily circulate in the bloodstream and can be measured by a PSA test to monitor the health of the prostate. A PSA test is a simple blood test and can be done at any blood testing laboratory or by your doctor.
PSA Test: What is Normal?1
PSA tests produce results measured by nanograms of PSA per milliliter of blood (ng/ml).
Most physicians consider a PSA level of 4 ng/ml or higher an indicator that further diagnostics should be performed – a score of 4 ng/ml or above typically means there is a 25% chance that a patient is being diagnosed with prostate cancer. Scores of 10 ng/ml or above typically mean there is a 50% chance of being diagnosed with prostate cancer.
Some doctors will lower the cutoff for further diagnosis to 2.5 or 3 ng/ml, however, doctors largely agree that a score lower than 2.5 ng/ml does not need further examination.
It is important to note that PSA levels can rise naturally with age, and that a number of benign (not cancerous) conditions can also affect PSA levels, such as prostatitis (inflammation of the prostate), benign prostatic hyperplasia (BPH, enlarged prostate), urinary tract infection (UTI), or even injury to the prostate. Other factors such as sexual activity right before testing can impact the PSA levels as well, so it is essential to consult a doctor regarding the meaning and next steps of your PSA testing results.
Doctors will frequently ask patients to repeat a PSA test if the first test result was high, to exclude external factors that may be impacting the PSA results.
The HALO Dx Approach – PSA Density
PSA testing is typically the first step in screening for prostate cancer, however the PSA screening by itself does not indicate if cancer is present.
To increase the efficacy of PSA interpretation, at HALO Dx we use PSA Density instead. PSA levels are higher in men with larger prostate glands. The PSA density (PSAD) adjusts for that. The doctor measures the volume (size) of the prostate gland with an ultrasound and divides the PSA number by the prostate volume.
Interview with Dick Ablin, the discoverer of PSA, lead by HALO Dx’ Bernadette Greenwood:
Where Can I Get PSA Testing?
Consult with your general practitioner or urologist about receiving a PSA test in their offices. PSA tests are typically covered by Medicare once a year for men 50 years and older, and there is no co-pay or deductible needed. However, additional PSA test costs may need to be covered by the patient. Many states now have laws which require private health insurers to cover the costs for PSA testing.
Companies such as ImAware also offer take-home PSA testing kits and telemedicine appointments to discuss PSA results with a physician.
Improved Screening with mpMRI
We use multiparametric magnetic resonance imaging (mpMRI)—combined with PSA testing—for to help improve the accuracy of prostate cancer screening.
The American Urologic Association (AUA) now recommends mpMRI along with a PSA test prior to any biopsy. mpMRI can not only detect prostate cancer more accurately than other tests, it can differentiate between aggressive and slow growing cancers. This can help you avoid an unnecessary biopsy.
If a biopsy is needed, mpMRI can be used to more precisely guide the biopsy, ensuring that sampling is not “blind”—randomly taken from across the gland—which may completely miss the disease.
mpMRI: A Clinically Proven Innovation
Multiparametric magnetic resonance imaging (mpMRI) is a powerful tool used to identify areas of the prostate that might be suspicious for clinically significant cancer. mpMRI is based on well-established MRI scanning technology and provides a detailed image of the prostate.
mpMRI provides a more holistic view of the prostate compared with more traditional approaches. While only a biopsy can diagnose cancer, mpMRI can assist with the characterization of areas within the gland that may warrant biopsy. Given the utility of mpMRI, the AUA recommends mpMRI for men with high PSA and BEFORE biopsy in their most recent policy statement.
mpMRI uses three different types of images to see inside the prostate gland. The first are T1- and T2-weighted imaging which show the anatomy of the gland. Second is diffusion- weighted imaging (DWI) which identifies areas where motion of water molecules is restricted due to cancer tissue, and the third is dynamic contrast enhanced imaging (DCE) which uses gadolinium-based contrast to find areas where new blood vessels are growing (cancer cells make their own blood vessels to supply themselves with oxygen and nutrients). All of these images are sent to a computer workstation to aid the radiologist in interpreting the images with the goal of finding tumor-suspicious regions. This is called Computer Aided Detection (CAD).