Screening for prostate cancer is very important due to the lack of symptoms in the early stages of the disease when it is most treatable. Listed below are the various ways in which doctors can help detect prostate cancer.
The PSA Test is a blood test that detects a protein called the Prostate Specific Antigen (PSA) in the bloodstream. Concentrations of PSA in the bloodstream are typically very small. Detecting higher levels of PSA, usually 3 ng/mL or higher,1 may indicate prostate cancer, but should not be considered the sole possibility; non-cancerous conditions such as prostatitis – an enlarged prostate, exercise and even sex can raise PSA levels.
The PSA test functions as an early detection tool, but more testing is needed before a diagnosis of prostate cancer can be made.
A PSA test can detect prostate cancer before it has fully developed and spread outside of the prostate. Early cancer detection increases the likelihood of successful treatments.2
- A false-positive result on a PSA test suggests that a man might have prostate cancer when he actually doesn’t. A false-positive result can lead to unnecessary follow-up testing that is more invasive, such as biopsies. It can also cause men and their families unnecessary anxiety and distress.
- A false-negative result means that the test shows that the PSA level is normal even though prostate cancer is present. Getting a false-negative result may delay treatment.
- Overdiagnosis can lead to giving treatments that aren’t necessary. Unnecessary follow-up testing and treatment can put men at risk for problems, including erectile dysfunction and loss of bladder control (urinary incontinence).3
The Canadian Urological Association recommends men getting a PSA test in their 40s to establish their baseline as a way to monitor their PSA levels. Men at higher risk for prostate cancer should consult their primary care provider before the age of 40 and over the age of 70 about PSA testing. The decision to cease PSA testing should be based on individual factors discussed with your physician.
Click here for Prostate Cancer Canada’s (PCC) Position and Recommendations on PSA Testing.
High Levels of PSA
If you have a high PSA level, together you and your doctor will decide if you need other tests, procedures, follow-up care or treatment.
Usually the first thing doctors will do to follow up on a high PSA level is another PSA test and a digital rectal exam (DRE) and compare the results to the first test. If the PSA level is still high, your doctor may use one of these follow-up procedures:
- Serial PSA testing, including PSA velocity and PSA doubling time. These tests involve conducting a series of PSA tests over time to compare results and monitor progression.
- Testing for free PSA in blood where free PSA levels are often higher in men with non-cancerous conditions of the prostate and lower in men with prostate cancer
- PSA density of the prostate and PSA density of the transition zone (the part of the prostate that surrounds the urethra) refers to the fact that the larger the prostate, the higher the PSA density in the blood. Therefore, an analysis of these factors can also help to diagnose prostate cancer before moving into more advanced and invasive testing.
- Nomograms look at PSA results and a number of other factors, such as age, ethnicity, family history, urinary symptoms, DRE results and prostate biopsy results and they are used to calculate a man’s risk of developing prostate cancer, determine the need for a biopsy and determine how aggressive the cancer may be.
If your PSA level continues to rise or the doctor feels a lump on the prostate during a DRE, follow-up tests may also include:
- Urine tests, such as a urinalysis
- Transrectal ultrasound (TRUS)
- Bladder exam (called a cystoscopy)
- Prostate biopsy
Digital Rectal Exam (DRE)
A Digital Rectal Exam is performed by introducing a gloved and lubricated finger into the rectum to feel for any anomalies on the prostate; a healthy prostate is soft, smooth, rubbery, and symmetrical, whereas an unhealthy prostate may have lumps, hard areas or other irregular surfaces.
Usually the PSA test is accompanied by a DRE for a more accurate diagnosis.
Transrectal Ultrasound (TRUS)
A Transrectal Ultrasound is a procedure where an ultrasound probe is inserted into the rectum to check the prostate; sound waves are used to create a picture map of the prostate. TRUS is also used to guide a biopsy which removes suspicious tissues from the prostate for further testing.4
This procedure consists of taking small tissue samples of the prostate in order for the pathologist to examine them under a microscope and determine if they are cancerous or not. If cancer is detected, the pathologist will use the same samples to establish the prognosis.
A prostate biopsy is usually performed during TRUS. The images taken with the ultrasound help guide a fine needle to the areas selected for sampling. The spring-loaded needle is attached to the ultrasound probe and enters the prostate through the rectum. Usually between 6 – 12 prostatic tissue samples are obtained and the entire procedure lasts about 10 minutes. A local anesthetic can be used to numb the area and reduce any pain.5