A question raising concerns among urologists worldwide is why the infection rate following prostate biopsies is on the rise. Like with many cancers, a biopsy is typically performed in order to confirm and more accurately diagnose the cancer. Over 1 million men in the US alone will undergo a prostate biopsy. Studies have been done to determine which procedures lead to specific infections and how they can be reduced or eliminated.
What is a TRUS?
Transrectal ultrasound-guided (TRUS) biopsy is the most common method used to extract tissue for histological pathology analysis.1 TRUS is performed using an ultrasound probe and biopsy needle to extract 12 core tissue samples from the prostate taken through the rectal wall. Generally done on an outpatient basis, the TRUS has been considered safe. But in recent years, infection rate and complications following a TRUS has been increasing.
After a TRUS it is common to have some bleeding or discomfort, even pain.2 More serious complications can be simple urinary tract infections, fevers, infections that reach the heart and nervous system up to full sepsis (severe complications from infection). TRUS results on average suggest that one quarter of those who undergo it will receive a diagnosis of prostate cancer, one third will experience post biopsy symptoms or complications and 4% will require hospitalization within 30 days. These collective results have been on the rise in recent years.
Risk factors for infection
Studies are investigating whether risk factors for infection were due to the specific TRUS procedure or whether comorbid conditions, like diabetes or a history of urinary tract infections (UTIs), had an impact. In different countries, varied preventive measures are currently employed to reduce post-biopsy infection rate. Some physicians prescribe oral antibiotic medications, fluoroquinolone or cephalosporin, the day before a TRUS. This practice is because the most common organism found with infections was e. coli. Yet in recent years, studies revealed that bacterial strains were resistant to the standard medications, signifying increased antibiotic resistance.3 Infectious disease experts have been reviewing alternative approaches that might prevent post-biopsy infections.
To reduce the risk of death and infection from diagnosing prostate cancer, the American Urological Association (AUA) guidelines have been revised. Routine screening is now recommended for men ages 55 to 69. The PSA screening can identify prostate cancer, yet the risk of complications from a biopsy, combined with higher detection and overtreatment of indolent (not active) disease can result in worse medical problems.
Biopsy is still an appropriate diagnostic tool for younger patients and those with severe localized disease. Experts in the US and abroad agree that for routine cases there should be an evaluation of individual patient risks. Consideration should be given to the risks of biopsy, the possibility of death from prostate cancer or effects of its treatment.2
Alternative approach to biopsies
Another approach to prostate biopsy is also being performed in Australia. The transperineal approach goes into the prostate through the perineum (the skin behind the testicles) rather than the rectum. This reduces exposure to antibiotic resistant bacteria that can colonize in the fecal area. In Australia this method has resulted in a decreased post biopsy infection rate. Study results from Spain, Sweden and the United States all agree that new approaches and better preventions are needed to promote the health of men who may have prostate cancer. Some use longer durations of antibiotics, some cleansing enemas (not demonstrated to be effective), and work is being done on the use of topical bactericidal gels during the biopsy procedure to create barriers to harmful bacteria.
For those men who will require surgical or radiation treatment because they have a PSA level above 100 or prostate cancer that has been detected by examination or scan, biopsies should not be needed. According to Swedish researchers, even with improved techniques and infection reducing protocols, reducing the number of unnecessary biopsies will in and of itself improve infection rates, reduce complications, and eliminate unnecessary treatments for indolent conditions.
Anderson E, Leahy O, et al. Risk factors for infection following prostate biopsy - a case control study. BMC Infect Dis. 2015;15:580. Published online December 23, 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4690315/. Accessed online June 6, 2018
Chamberland RR. Cutting to the Core of the Issue: Emerging Strategies To Reduce Prostate Biopsy-Related Infections. J Clin Microbiol. 2016;54(10):2431-5. Published October, 2016. http://jcm.asm.org/content/54/10/2431.full. Accessed online June 5, 2018
Harrison, P. Severe Infections After Prostate Biopsy on the Rise. Published August 26, 2014. https://www.medscape.com/viewarticle/830452. Accessed online June 6, 2018.