Prostate Cancer Screening

Digital Rectal Exam (DRE)

For this test, the doctor inserts a gloved and lubricated finger into the rectum.

This allows the doctor to feel the back portion of the prostate gland for size, and any irregular or firm areas.

It is not accurate at detecting prostate cancer that is situated deep within the gland or is very small.

Prostate Specific Antigen (PSA)

PSA is a protein produced by both normal and cancerous cells in the prostate.

Growth of prostate cancer cells as well as other conditions such as benign enlargement of the prostate (BPH) or inflammation/infection (prostatitis) can cause an elevation of the PSA level in the blood.

The normal range of PSA is generally considered to be between zero and four nanograms of PSA per milliliter (ng/mL) of blood.

If the results of the PSA blood test are above the normal range, or the level has increased rapidly from the last test, the doctor may recommend further testing and possibly a biopsy.

It should be noted that men can be diagnosed with prostate cancer even with a PSA in the normal range. In one large study, about 15 percent of men diagnosed with prostate cancer did indeed have a PSA in the normal range.

Percent-Free PSA

The percent-free PSA is a blood test that compares the amount of PSA bound to proteins in the blood to the amount of PSA that circulates by itself (unbound).

When the percent-free PSA is found to be less than 25 percent, prostate cancer is more likely to be present.

The lower the percentage, the more likely prostate cancer is present. This test can be useful when the standard PSA test is at or just over the high end of the normal range.


PCA3Plus® is a urine test that detects a specific gene called PCA3, which is highly expressed in prostate cancer cells.

For this test, the doctor will perform a digital rectal exam and massage the prostate to induce the shedding of prostate cells into the urine.

A urine sample is then collected and sent to a laboratory to obtain a PCA3 score.

The higher the score, the more likely a biopsy will be positive for prostate cancer. This test is available in the United States, but it is not yet FDA approved.

Transrectal Ultrasound

Transrectal ultrasound (TRUS) is a specific ultrasound test that uses a probe inserted into the rectum to visualize the prostate gland.

It can be used to measure the size of the gland, detect anatomic variations and sometimes detect abnormal tissue.

Needle biopsies of the prostate are usually done under TRUS guidance. A urologist usually performs these procedures in the office by placing the patient on his side and inserting the ultrasound probe into the rectum.

Needles are pushed alongside the ultrasound probe through the rectal wall and into the prostate to sample the tissue. Usually 10-12 biopsies are taken covering the entire gland.

A newer technique called transperineal saturation biopsy is also done under TRUS guidance.

This procedure is usually done under anesthesia, and needles are placed through the skin between the rectum and scrotum (perineum) and into the prostate gland.

Up to 24 or more biopsies can be obtained using this technique.

Areas that are difficult to access using the transrectal approach can be reached using the transperineal technique.

Transperineal saturation biopsy is often done if a prior transrectal biopsy is negative, but other tests, such as PSA, indicate a high likelihood of cancer.

Prostate Biopsy 

Based on the screening test results, a biopsy may be recommended and performed as described using transrectal ultrasound guidance.

A pathologist will then examine the tissue samples under a microscope to determine whether or not the prostate contains cancerous tissue.

The biopsy can also give important indications as to how extensive the cancer is within the prostate by number of cores that are positive for cancer.