Risks associated with serial biopsies for men on active surveillance protocols

In a paper to be presented at the annual meeting of the American Urological Association,  Ehdaie et al. have shown that, among men with prostate cancer being managed on active surveillance, the number of previous biopsies is associated with significant risk of infectious complications and every previous biopsy increases the risk an infectious complication.

It is well understood that infectious complications subsequent to prostate biopsy can be associated with significant morbidity. We also know that fluoroquinolone-resistant and extended-spectrum, β-lactam-producing sub-species of Escherichia coli have been increasingly recovered from patients with sepsis, and contribute to the rising incidence of sepsis after prostate biopsy. On the other hand, active surveillance is being increasingly recognized, used, and valued as a means to manage men with low-risk prostate cancer.

Ehdaie et al. (see abstract no. 1244 among the abstracts of the AUA annual meeting) conducted a prospective, cohort analysis based on data from 615 consecutive patients who were given a TRUS-guided prostate biopsy at Memorial Sloan-Kettering Cancer Center (MSKCC) in New York between between January 2011 and January 2012. of these 615 patients, 433 (70.4 percent) had previously been diagnosed with prostate cancer and received a 14-core TRUS-guided prostate biopsy as part of an active surveillance regimen or for confirmatory purposes prior to enrollment into the MSKCC active surveillance study. Following the biopsy procedure, all men received a phone call from a nurse within 7 days, and information was collected on potential complications, potential antibiotic received, and urine culture results in patients with infectious complications.

Here are the key study findings:

  • 12/433 patients (2.8 percent) had infectious complications requiring hospitalization after TRUS-guided biopsy.
    • 5 patients had fluoroquinolone-resistant isolates (most Escherichia coli)
    • 2 patients had extended-spectrum, β-lactam-producing isolates.
  • The average (mean) age of men with a prior diagnosis of prostate cancer was 63 years.
  • 268/433 patients (61.9 percent) exhibited prostate cancer on the current biopsy.
  • The average (median) number of previous prostate biopsies was 1 (range, 1 to 12).
  • The number of previous prostate biopsies was significantly associated with an increased risk of infectious complications (p = 0.036).
  • No other risk factor evaluated (including history of benign prostatic hyperplasia, previous infectious complications, and antibiotic regimen) was significantly associated with increased risk for infectious complications.
  • For every previous biopsy, the odds of an infection increase 1.3 times (odds ratio [OR] = 1.34).

The authors note simply that men being managed on active surveillance should be aware of the risks associated with serial repeat prostate biopsies. The ramifications of this finding, however, are serious, and potentially include the following:

  • The use of annual biopsies as a core component of active surveillance protocols comes with significantly increasing risk for infectious complications and should no longer be recommended as routine.
  • The number of repeat biopsies being given to men on active surveillance protocols should be minimized by use of other methods to evaluate patients risk for progressive disease (such as multiparametric MRI studies, as an example).
  • Rectal swabs should probably be used routinely to minimize risk of prostate infection in men undergoing serial biopsies under active surveillance.

It is true that in the above study, only 12/433 patients demonstrated serious infectious complications requiring hospitalization, but this is still 12 patients too many among a cohort of patients who are on active surveillance at least in part to avoid the serious complications and side effects associated with invasive treatment for prostate cancer. We may not be able to eliminate the risk for infectious complications of prostate biopsies entirely, but in men on active surveillance we should seek to reduce this risk to more like 1 percent.

4 Responses

  1. Borrowing a word from the InfoLink management — this comes as utterly no surprise to me. Having seen enough men on AS that had repeat biopsies and repeat infections it seems that a man that had an infection on a previous biopsy is the patient in whom restraint should be considered for a second or subsequent biopsy. Not sure how that will affect the statistical data, but I know a few men that appear to have predisposition to infection that simply will not get another biopsy. If their PSA rises significantly they will move straight to treatment.

    I don’t think that’s unreasonable. But the question as to whether it’s a best practice is unknown. …

  2. Hi Tony,

    Sitemaster recommended I contact you regarding a possible trial of IADT2 vs. IADT3. Would you mind looking at my response of 5/1 8:28 pm to the thread “New meta-analysis endorses IADT …”?

  3. Why is it that MRIs don’t take over in active surveillance? Surely once you know you have some amount of prostate cancer, you don’t want to disturb the prostate anymore. If the issue is cost, shouldn’t that be accepted as part of the price of active surveillance and aren’t the costs associated with successive biopsies (including hospital treatment of infections) pretty substantial?

  4. Dear Chris:

    Actually the defining factors in the use of MRIs as a means to monitor patients on active surveillance are almost certainly (a) the relatively small number of MRI machines that can provide this typoe of high quality MRI scan (most of which are at major research centers) and even most importantly (b) the very small number of trained uro-radiologists who have experience in reading these scans. Being able to read scans like this is not simple. The cancer isn’t “obvious” to the untrained eye, and even an experienced uro-radiologist who was used to looking at older types of MRI needs time to learn to read the newer multiparametric MRI scans that we probably need to monitor men on active surveillance. Changes like this take time for the simple reason that more people need to learn new/different skills and we have to be able to make the technology more widely available.

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