Severe Infections After Prostate Biopsy on the Rise

Pam Harrison

August 26, 2014

Rates of severe infection after transrectal ultrasound-guided (TRUS) prostate biopsy that require hospitalization are on the rise, a population-based Swedish study shows.

"Over 100,000 biopsies are done in Europe and the United States each year, so small increases in the risk of complications affect many individuals," said investigator Karl-Johan Lundström, MD, a consultant urologist at Umeå University in Östersund, Sweden.

"It's therefore of paramount importance to monitor men carefully for complications to ascertain whether the incidence of these complications is increasing and, if it is, to identify specific risk factors that might explain it," he told Medscape Medical News.

The results were published online May 6 in the Journal of Urology.

The investigators estimated the frequency and severity of infectious complications in a cohort of 51,321 men who underwent ultrasound-guided prostate biopsy from 2006 to 2011. In Sweden, a single dose of an antibiotic administered before the procedure is the most common form of prophylaxis, Dr. Lundström reported.

The team found that 3210 men (6%) received a prescription for a urinary tract antibiotic in the month after the biopsy, and 54% had the prescription filled in the week after the procedure.

In addition, 587 men (1%) were hospitalized for an infectious complication; 74% of these hospitalizations occurred in the week after the procedure.

Men who reported a urinary tract infection (UTI) in the 6 months preceding the biopsy were more likely to develop a UTI after the procedure (odds ratio [OR], 1.59). In addition, men with diabetes were more likely to develop a UTI after undergoing prostate biopsy (OR, 1.32), as were men with a high Charlson Comorbidity Index score (OR, 1.25).

Prescriptions for antibiotics after prostate biopsy dropped by about 20% from 2006 to 2011 (OR, 0.79). During this period, the Swedish government began to encourage antimicrobial stewardship initiatives and promote the appropriate use of antibiotics, which probably led to the decrease, Dr. Lundström told Medscape Medical News.

However, the risk for hospitalization after prostate biopsy was twice as high in 2011 as it was in 2006 (OR, 2.14). The investigators believe this increase is a reflection of the increasing resistance of Enterobacteriaceae species, a common cause of UTI in Sweden and elsewhere.

Men with a high comorbidity score were at highest risk for infection requiring hospitalization (OR, 1.54). Hospitalized men were more likely to die from infection than those who were not hospitalized (OR, 12.6).

Still, only 34 patients in the cohort (0.07%) died of a UTI or sepsis. And there was no significant increase in the 90-day mortality rate between patients who developed an infection after prostate biopsy and those who did not.

Biopsy Still Appropriate

In general, biopsy should only be done in patients whose survival or morbidity can be improved with a diagnosis of prostate cancer, Dr. Lundström told Medscape Medical News. "Treatment of localized prostate cancer is most beneficial for younger patients," he said. "I would suggest that all patients with an estimated survival of more than 10 years should have a biopsy if prostate cancer is suspected, as well as those with locally advanced disease."

Men with a prostate-specific antigen level above 100 ng/mL and palpable prostate cancer plus visible bone metastases on a bone scan would not benefit from prostate biopsy, said Dr. Lundström. "A negative biopsy wouldn't change the treatment of these patients, and a biopsy would only impose an unnecessary risk," he explained.

The benefits of biopsy are also "debatable" in patients with significant comorbidity who have a high competing risk for death from causes other than prostate cancer and who are already at high risk for postprocedure infectious complications, he noted.

A systemic review of complications of prostate biopsy also demonstrated that infection is becoming more common after prostate biopsy (Eur Urol. 2013;64:876-892). The review authors suggest that the increase in infection is largely the result of increased antibiotic resistance in the community.

Transperineal a Better Approach

To minimize the risk for sepsis, many practitioners now use a transperineal approach rather than the transrectal route to prostate biopsy, explained Declan Murphy, MD, from the Peter MacCallum Cancer Centre at the University of Melbourne in Australia.

"The findings in this study are consistent with data from elsewhere that demonstrate increasing rates of infection and sepsis following TRUS biopsy of the prostate," Dr. Murphy told Medscape Medical News. "It is likely that antibiotic resistance is contributing to this, with up to 20% of patients having ciprofloxacin-resistant organisms in the rectum at the time of biopsy, according to a Canadian study," he reported.

An "obvious way" to address these concerns is to avoid inoculating the prostate by not passing a needle through the rectum in the first place, he said. "The use of a transperineal approach in centers in Australia and the United Kingdom has all but eliminated prostate biopsy sepsis, and has also demonstrated better diagnostic ability," Dr. Murphy said, adding that he himself has not done what he refers to as a "transfecal" biopsy of the prostate in more than 10 years.

The fact that infectious complications after TRUS prostate biopsy appear to be increasing (at least serious infections) likely reflects the high prevalence of antibiotic-resistant strains of Enterobacteriaceae in Sweden and elsewhere, said Josep Maria Gil-Vernet, MD, from the Department of Urology at the Clinic Hospital of Barcelona in Spain.

"I think it is time to raise new strategies for prophylaxis of UTIs after TRUS prostate biopsy," Dr. Gil-Vernet stated.

In a previous study, he and his colleagues found that, of 530 men who were administered 10% povidone-iodine 30 g intrarectally before undergoing TRUS biopsy, only 1 developed an Escherichia coli acute bacterial epididymitis after the procedure (Arch Esp Urol. 2012;65:463-466). Each patient also received prophylactic ciprofloxacin 1 g/day for 3 days, starting the day before the biopsy, as well as cleansing enemas.

On the basis of their study, Dr. Gil-Vernet noted that he and his colleagues now use the same gel to coat the anorectal mucosa, along with prophylactic ciprofloxacin.

"Unlike that which occurs with antibiotics, the bactericidal efficacy of iodine has not diminished over time and, until now, no microbial strains resistant to povidone-iodine have been detected," he explained. "With this simple, easy-to-use, low-cost technique, we've had a 0.25% incidence of UTIs [to date], and only 1 patient requiring hospitalization. We think that the developing and future use of topical bactericidal gels could represent the beginning of a new age in the prevention of infectious complications after TRUS prostate biopsy."

Dr. Lundström, Dr. Murphy, and Dr. Gil-Vernet have disclosed no relevant financial relationships.

J Urol. Published online May 6, 2014. Abstract

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