the PROSTATE EXAM or DRE
Bert Vorstman MD, MS, FAAP, FRACS, FACS
The prostate exam, also known as the DRE (digital rectal exam), is considered a normal part of a man’s physical examination. However, aside from this DRE prostate exam being considered “standard” by physicians and, expected by men as part of their testing, the DRE is highly subjective and unreliable. Furthermore, the DRE is highly overutilized in men having their Gleason 3+3=6 “cancer” managed through active surveillance since examining a prostate every 3 to 6 months or, even yearly in the face of stable PSAs, serves no useful purpose and is unsupported by any scientific data.
DRE Indications (urological)
Elevated PSA (prostatic specific antigen)
Anal fissure and pain
Acute inflammation or prostatitis
I ask my patients to assume the position by bending over the exam table, pants down, shoulders down in the customary fashion. Alternatively, the prostate can be examined with the patient lying on his side or, on his back in the lithotomy position. With a gloved hand and well lubricated index finger, jelly is applied to the anus and, with steady pressure the anal canal is then entered to feel sphincter tone before advancing the finger into the rectum and sweeping the rectal walls to check for any rectal lesions. Finally, the prostate is checked.
This exam attempts to estimate very roughly:
> the size of the prostate; the prostate is basically bilobar with a slight midline furrow, about 4 cm by 4 cm, somewhat walnut shaped with the widest part attached to the bladder neck and the narrowest part to the membranous urethra and, with the urinary channel running through the middle of the gland. Generally the size is poorly estimated and, is commonly described as being small, moderate or, large. Some physicians use arbitrary classifications of 1 plus, 2 plus etc, but these are meaningless. Furthermore, findings of prostate asymmetry or, unusual shapes are also within normal limits and, not a specific reason for needle biopsy. In addition, size or weight of the prostate does not correlate with the severity of urinary symptoms. On the other hand, big prostates usually mean “big” PSAs.
> degree of tenderness; to denote existence of possible inflammation.
> texture and consistency. For urologists this is the usual reason for performing a DRE but again, the interpretation of whether or not there is any nodularity or hardness to suspect an underlying prostate cancer is quite unreliable. In fact, only about 50% of socalled hard areas will be found to be cancerous after biopsy and, many of these will be diagnosed as the non healthrisk Gleason 6 “cancer”.
Prostate Massage (medical indications)
> “massage therapy” for nonbacterial chronic prostatitis has not been proven scientifically to be of benefit. In fact, most chronic prostatitis is not because of an underlying chronic bacterial infection but, because of increased pelvic floor muscle activity as a consequence of stress. This muscle overactivity gives rise to feelings of perineal pressure along with mild burning and urinary frequency and, is easily treated with an alpha blocker or, low dose valium.
> prostate massage for expressed prostatic secretions (EPS) and microscopic examination and culture may be useful rarely, prior to treatment of a chronic bacterial prostatitis. The 2 and 4 glass tests are uncommonly employed now.
> prostate massage and urine specimen collection immediately following the massage is commonly undertaken for the PCA3 biomarker prostate cancer prediction test.
Aside from the embarrassment that some may feel about this exam, there may be several other issues.
>fainting or vasovagal anxiety in response to the exam.
>pain because of a rectal fissure or, because of anal stenosis from previous rectal surgery or hemorroidectomy or, because of an overly
>aggressive physician with big fingers
>some may notice seminal fluid expressed from the urethra.
>some may experience shortlived, deepseated perineal discomfort.
>seldom, there can be some urethral bleeding.
>rarely, the examiner may cause an anal tear.
>even more rarely, dilating an anal stenosis may lead to some fecal incontinence.
> infrequently, there may be some anal bleeding.
> very rarely, the exam may cause a disseminated infection.
Accuracy of the DRE
The DRE is about as accurate as a coin toss. It is very subject to observer error (open to interpretation), meaning that if you get 10 docs examining your prostate, you are likely to get 10 different opinions. Even the same urologist examining your prostate a month later is likely to give you a different opinion.
How Often Should You Have Your prostate Examined?
The prostate exam is reasonable for the initial evaluation of urinary symptoms and, or the evaluation of an elevated PSA. Subsequent DREs are of very questionable value especially for those men whose PSAs stay within their normal fluctuating limits. A repeat DRE may be reasonable when there is persistent upward trending of a PSA during follow up. Otherwise, a study from the Netherlands suggested an interval of at least 4 years between DREs was not unreasonable. Generally however, the DRE is an ineffective screening test and, no useful information is garnered from having men return every 3-6 months (or even yearly) and subjecting them to repeated DREs as part of an active surveillance schedule for their non healthrisk Gleason 6 prostate “cancer”. Such a program could be considered abusive.