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Prostate Biopsy: A Risk-Benefit Analysis
Prostate Biopsy: A Risk-Benefit Analysis THE ideal diagnostic test would be noninvasive with no associated morbidity and 100% sensitivity for the disease of interest.1 Prostate cancer (CaP) diagnostic tests meet none of these criteria. Prostate biopsy is invasive, has potential associated risks and only samples a limited portion of the prostate, and current imaging modalities are not sufficiently reliable for CaP detection or localization.1 Nevertheless, transrectal prostate biopsy with about 12 cores remains the current standard for CaP detection at many institutions. According to Urologic Diseases in America Project data 282,640 prostate biopsies were performed in Medicare beneficiaries in 2001,2 corresponding to an annual rate of 1,601/100,000 men enrolled in Medicare. Although it is generally considered a benign procedure, serious complications may occur and may in fact be increasing in frequency.3 In this issue of The Journal Nam et al (page 963) used administrative data from Ontario, Canada to examine hospital admissions within 30 days of prostate biopsy. During the study interval of 1996 to 2005 the odds of hospital admission within 30 days increased 3.7-fold and infection was the most responsible diagnosis in 72% of admissions. Overall the study shows that the rate of infection and obstruction related diagnoses after prostate biopsy increased with time but the rate of bleeding related complications remained stable. The use of coding records precluded examination of important covariates such as medication history (recent antimicrobials or antiplatelet drugs), biopsy prophylaxis type (antimicrobial agent or enemas), the number of cores sampled and urine culture results. Thus, it was not possible to elucidate the underlying explanation of these findings (increasing bacterial resistance, an increasing number of biopsy cores sampled etc). Another study limitation is the lack of a control group to examine the baseline hospitalization rate in a similar population that did not undergo prostate biopsy. Finally, it is unknown whether these results are generalizable to other geographic areas and populations with potentially different bacterial resistance patterns. Nevertheless, these provocative results suggest that the risks of prostate biopsy may be greater than in 0022-5347/10/1833-0852/0 THE JOURNAL OF UROLOGY® © 2010 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
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the past. What is the clinical take-home message? Although prostate biopsy is generally safe, men should be counseled about the potential for serious complications. The American Urological Association best practice policy statement recommends uniform antimicrobial prophylaxis in all patients undergoing transrectal prostate biopsy with fluoroquinolones as the agent of choice.4 Alternative antimicrobial choices are clindamycin or an aminoglycoside with metronidazole and the recommended duration of therapy is 24 hours or less. Current clinical practice is largely based on a series of randomized trials of prostate biopsy prophylaxis done in the 1990s. For example, Kapoor et al enrolled 437 men from 1992 to 1993 in a multicenter double-blind, placebo controlled trial of a single dose of 500 mg ciprofloxacin vs placebo before transrectal prostate biopsy.5 On intent to treat analysis ciprofloxacin was associated with a significantly lower proportion of post-biopsy bacteriuria than placebo. Moreover, they estimated an annual $68,195 cost savings using ciprofloxacin prophylaxis, primarily due to fewer hospitalizations for febrile urinary tract infection. Other studies similarly show that antimicrobial prophylaxis including fluoroquinolones decreased the risk of infectious complications from prostate biopsy.6 Since the time of these studies, the number of cores sampled on prostate biopsy has dramatically increased, as has Escherichia coli resistance to standard antimicrobial therapy. For example, in a population based study of E. coli bloodstream isolates in Olmsted County, Minnesota from 1998 to 2007 there was a significant linear increase in E. coli resistance to fluoroquinolones.7 These results highlight the need for ongoing studies to reevaluate the optimal antimicrobial prophylaxis regimen for prostate biopsy, considering local resistance patterns. These issues are also particularly germane in the setting of repeat biopsy. In a Medicare population 38% of men without CaP on initial biopsy underwent repeat biopsy within 5 years.8 Clearly careful patient selection is also essential to decrease the potential harm associated with prostate biopsy. For example, Walter et al reported that 36% of men 85 Vol. 183, 852-853, March 2010 Printed in U.S.A. DOI:10.1016/j.juro.2009.12.063
PROSTATE BIOPSY RISK-BENEFIT ANALYSIS
years old or older in the worst health underwent prostate specific antigen testing in 2003.9 Prostate specific antigen based screening was recently reported to decrease CaP specific mortality.10 Because the followup test (ie prostate biopsy) for a positive screening result is not always benign, more careful patient selection may help maximize the benefits of screening while minimizing unnecessary risk in those unlikely to benefit. Repeat biopsy is done not only for CaP detection but also in men with documented CaP as part of an active surveillance or focal therapy protocol. Although data are controversial, some series suggest an increased risk of infectious complications in the setting of repeat biopsy.3 Thus, more study is also warranted to determine the optimal antimicrobial prophylaxis in the repeat biopsy setting.
853
Finally, the search for new CaP biomarkers continues. Future identification of highly sensitive and specific serum or urinary markers, or substantial improvements in imaging may enhance screening specificity, decrease the number of unnecessary biopsies or possibly someday replace prostate biopsy altogether. In the meantime the study by Nam et al should serve as a wake-up call. As urologists, we should reexamine our practices to determine whether the rate of complications from prostate biopsy is increasing and search for measures to decrease these risks. Stacy Loeb Department of Urology The Johns Hopkins Medical Institutions Baltimore, Maryland
REFERENCES 1. Chang P and Friedland GW: The role of imaging in screening for prostate cancer. A decision analysis perspective. Invest Radiol 1990; 25: 591. 2. Litwin MS and Saigal CS: Prostate cancer. In: Urologic Disease in America. National Institutes of Health Publication 07-5512. United States Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. Washington D. C.: United States Government Publishing Office 2007; p 76. 3. Ozden E, Bostanci Y, Yakupoglu KY et al: Incidence of acute prostatitis caused by extendedspectrum beta-lactamase-producing Escherichia coli after transrectal prostate biopsy. Urology 2009; 74: 119.
4. Wolf JS Jr, Bennett CJ, Dmochowski RR et al: Best practice policy statement on urologic surgery antimicrobial prophylaxis. J Urol 2008; 179: 1379. 5. Kapoor DA, Klimberg IW, Malek GH et al: Singledose oral ciprofloxacin versus placebo for prophylaxis during transrectal prostate biopsy. Urology 2998: 52: 552. 6. Aron M, Rajeev TP and Gupta NP: Antibiotic prophylaxis for transrectal needle biopsy of the prostate: a randomized controlled study. BJU Int 2000; 85: 682. 7. Al-Hasan MN, Lahr BD, Eckel-Passow JE et al: Antimicrobial resistance trends of Escherichia coli bloodstream isolates: a population-based
study, 1998 –2007. J Antimicrob Chemother 2009; 64: 169. 8. Welch HG, Fisher ES, Gottlieb DJ et al: Detection of prostate cancer via biopsy in the MedicareSEER population during the PSA era. J Natl Cancer Inst 2007; 99: 1395. 9. Walter LC, Bertenthal D, Lindquist K et al: PSA screening among elderly men with limited life expectancies. JAMA 2006; 296: 2336. 10. Schroder FH, Hugosson J, Roobol MJ et al: Screening and prostate-cancer mortality in a randomized European study. N Engl J Med 2009; 360: 1320.
852
www.jurology.com
AND
RESEARCH, INC.
the past. What is the clinical take-home message? Although prostate biopsy is generally safe, men should be counseled about the potential for serious complications. The American Urological Association best practice policy statement recommends uniform antimicrobial prophylaxis in all patients undergoing transrectal prostate biopsy with fluoroquinolones as the agent of choice.4 Alternative antimicrobial choices are clindamycin or an aminoglycoside with metronidazole and the recommended duration of therapy is 24 hours or less. Current clinical practice is largely based on a series of randomized trials of prostate biopsy prophylaxis done in the 1990s. For example, Kapoor et al enrolled 437 men from 1992 to 1993 in a multicenter double-blind, placebo controlled trial of a single dose of 500 mg ciprofloxacin vs placebo before transrectal prostate biopsy.5 On intent to treat analysis ciprofloxacin was associated with a significantly lower proportion of post-biopsy bacteriuria than placebo. Moreover, they estimated an annual $68,195 cost savings using ciprofloxacin prophylaxis, primarily due to fewer hospitalizations for febrile urinary tract infection. Other studies similarly show that antimicrobial prophylaxis including fluoroquinolones decreased the risk of infectious complications from prostate biopsy.6 Since the time of these studies, the number of cores sampled on prostate biopsy has dramatically increased, as has Escherichia coli resistance to standard antimicrobial therapy. For example, in a population based study of E. coli bloodstream isolates in Olmsted County, Minnesota from 1998 to 2007 there was a significant linear increase in E. coli resistance to fluoroquinolones.7 These results highlight the need for ongoing studies to reevaluate the optimal antimicrobial prophylaxis regimen for prostate biopsy, considering local resistance patterns. These issues are also particularly germane in the setting of repeat biopsy. In a Medicare population 38% of men without CaP on initial biopsy underwent repeat biopsy within 5 years.8 Clearly careful patient selection is also essential to decrease the potential harm associated with prostate biopsy. For example, Walter et al reported that 36% of men 85 Vol. 183, 852-853, March 2010 Printed in U.S.A. DOI:10.1016/j.juro.2009.12.063
PROSTATE BIOPSY RISK-BENEFIT ANALYSIS
years old or older in the worst health underwent prostate specific antigen testing in 2003.9 Prostate specific antigen based screening was recently reported to decrease CaP specific mortality.10 Because the followup test (ie prostate biopsy) for a positive screening result is not always benign, more careful patient selection may help maximize the benefits of screening while minimizing unnecessary risk in those unlikely to benefit. Repeat biopsy is done not only for CaP detection but also in men with documented CaP as part of an active surveillance or focal therapy protocol. Although data are controversial, some series suggest an increased risk of infectious complications in the setting of repeat biopsy.3 Thus, more study is also warranted to determine the optimal antimicrobial prophylaxis in the repeat biopsy setting.
853
Finally, the search for new CaP biomarkers continues. Future identification of highly sensitive and specific serum or urinary markers, or substantial improvements in imaging may enhance screening specificity, decrease the number of unnecessary biopsies or possibly someday replace prostate biopsy altogether. In the meantime the study by Nam et al should serve as a wake-up call. As urologists, we should reexamine our practices to determine whether the rate of complications from prostate biopsy is increasing and search for measures to decrease these risks. Stacy Loeb Department of Urology The Johns Hopkins Medical Institutions Baltimore, Maryland
REFERENCES 1. Chang P and Friedland GW: The role of imaging in screening for prostate cancer. A decision analysis perspective. Invest Radiol 1990; 25: 591. 2. Litwin MS and Saigal CS: Prostate cancer. In: Urologic Disease in America. National Institutes of Health Publication 07-5512. United States Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. Washington D. C.: United States Government Publishing Office 2007; p 76. 3. Ozden E, Bostanci Y, Yakupoglu KY et al: Incidence of acute prostatitis caused by extendedspectrum beta-lactamase-producing Escherichia coli after transrectal prostate biopsy. Urology 2009; 74: 119.
4. Wolf JS Jr, Bennett CJ, Dmochowski RR et al: Best practice policy statement on urologic surgery antimicrobial prophylaxis. J Urol 2008; 179: 1379. 5. Kapoor DA, Klimberg IW, Malek GH et al: Singledose oral ciprofloxacin versus placebo for prophylaxis during transrectal prostate biopsy. Urology 2998: 52: 552. 6. Aron M, Rajeev TP and Gupta NP: Antibiotic prophylaxis for transrectal needle biopsy of the prostate: a randomized controlled study. BJU Int 2000; 85: 682. 7. Al-Hasan MN, Lahr BD, Eckel-Passow JE et al: Antimicrobial resistance trends of Escherichia coli bloodstream isolates: a population-based
study, 1998 –2007. J Antimicrob Chemother 2009; 64: 169. 8. Welch HG, Fisher ES, Gottlieb DJ et al: Detection of prostate cancer via biopsy in the MedicareSEER population during the PSA era. J Natl Cancer Inst 2007; 99: 1395. 9. Walter LC, Bertenthal D, Lindquist K et al: PSA screening among elderly men with limited life expectancies. JAMA 2006; 296: 2336. 10. Schroder FH, Hugosson J, Roobol MJ et al: Screening and prostate-cancer mortality in a randomized European study. N Engl J Med 2009; 360: 1320.