Prostate Biopsy at UCSF: Benefits Outweigh the Risks

A recent article from the NY Times highlighted the risks of prostate cancer biopsies. While, like every procedure, there is the rare potential for complications, the editorial did not point out the benefits of the potentially life saving medical imaging exam. UCSF strives to mitigate risk, and through state of the art imaging research has developed a specialized exam to reduce the number of required biopsies for patients.

Prostate cancer remains the most common cancer diagnosis in males next to skin cancer, with up to 1 in 6 men diagnosed with prostate cancer in their lifetimes. Patients are screened by blood testing for prostate specific antigen, or PSA.  PSA levels are elevated in prostate cancer, as well as in other benign condition such as prostate inflammation or trauma.  Patients with persistently elevated PSA typically undergo diagnosis for prostate cancer through a procedure called a transrectal ultrasound-, or TRUS-guided biopsy of the prostate.

Over 1 million TRUS biopsies are performed each year.  The outpatient TRUS biopsy procedure is usually performed by a urologist with the patient lying on his side.  The urologist gives the patient 3 to 4 injections of an anesthetic directly into the rectum and adjacent to the prostate for pain management during the procedure.  The urologist then uses a biopsy needle to systematically pierce through the rectum and prostate to obtain 10-12 tissue samples of prostate tissue to be further evaluated by a pathologist. The ultrasound machine is used to find the prostate and guide the needle into the prostate, however it does not see the actual cancer focus in up to 40% of cases.  This often leads to cancer not being found in the biopsy samples, or underestimation of cancer volume and aggressiveness in the biopsied sample.  Often, repeat biopsies may need to be obtained at a later time.

Complications of the procedure are rare and include bleeding, inability to urinate, and infection. Of the rare complications, infection is the most common occurring in 2 to 4 patients for every 100 patients biopsied.  Recent studies indicate that infections associated with TRUS biopsies have actually increased over recent years because of increasing resistance of organisms to certain antibiotics.  At UCSF, we employ precautions to minimize the risk of infection.  All patients are placed on antibiotics for three days starting the day before the biopsy.  All patients also undergo a cleansing enema to remove any stool from the rectum prior to the procedure.  Although we employ these precautions, it is important to tell your urologist if you have had any prior serious infections in the past.

The Department of Radiology at UCSF also employs a new procedure using magnetic resonance imaging or MRI-guided biopsies.  In select patients, we are able to see the cancer on a specialized MRI exam.  We can then precisely place a needle into the center of the cancer focus within the prostate using MR imaging.  The advantage to this approach is that far fewer biopsies samples are taken (on average of 2 versus 12), theoretically further decreasing the risk of infection.  Additionally, there is the theoretical benefit of less repeat biopsies.  This procedure however may not be for everyone and should be discussed with one of our urologists and radiologists.

For more information on prostate cancer screening at UCSF, please see here.