e u r o p e a n u r o l o g y 5 4 ( 2 0 0 8 ) 2 3 1 – 2 3 6 233

[4] Peytremann-Bridevaux I, Faeh D, Santos-Eggimann B.

Prevalence of overweight and obesity in rural and

urban settings of 10 European countries. Prev Med

2007;44:442–6.

[5] Buschemeyer III WC, Freedland JS. Obesity and prostate

cancer: epidemiology and clinical implications. Eur Urol

2007;52:331–43.

Judd W. Moul

Division of Urologic Surgery and the Duke Prostate Center,

Duke University Medical Center,

Durham, North Carolina 27710, USA

DOI:10.1016/j.eururo.2008.03.062

Re: Needle Biopsies on Autopsy Prostates: Sensi-tivity of Cancer Detection Based on True Preva-lenceHaas GP, Delongchamps NB, Jones RF, et al

J. Natl. Cancer Inst 2007;99:1484–9.

Expert’s summary:This study was designed to assess the diagnosticaccuracy of current prostate biopsy protocols. Eigh-teen-core needle biopsies were performed onautopsy prostates from 164 US men (median age64 yr) who had no history of prostate cancer. Sixcores were taken from each of the following regions:the midperipheral zone, the lateral peripheral zone,and the central zone. Using 4-mm whole-mountsections, cancer was found in 47 (29%) cases, ofwhich 27 met the Stamey criteria for insignificantdisease (< 0.5 ml tumour volume and Gleason score� 6). Pathological stage mix was 62% T2a/b, 12% T2c,and 13% T3. Median tumour volume was 0.29 ml(IQR 0.07–0.88 ml). Central zone biopsies did notdetect cancer in any case that was not also detectedfrom the peripheral zone biopsies.

Expert’s comments:The ideal biopsy strategy would detect all significantprostate cancers, and no insignificant cancers.Although this is not possible, this is the ideal forwhich we should aim. This unique study confirmsthe importance of laterally directed peripheral zonebiopsies, but cautions against the trend towardstaking ever-increasing numbers of cores. The morecores taken, the greater the chance of detecting aclinically insignificant cancer. A 6-core protocoldetected 11% of all ‘‘insignificant’’ cancers, whereasa 12-core protocol detected 33%.

The study also calls into question the Stameycriteria for ‘‘clinically insignificant’’ disease, origin-ally based on a study of 55 prostate cancers in

139 cystoprostatectomy specimens [1]. Given alifetime prostate cancer risk, in the absence ofprostate-specific antigen (PSA) testing of 8%, theauthors argued that only 11 (8% of 139) of the cancersdetected were destined to be significant. The largest11 tumours ranged in volume from 0.5–6.1 ml,leading to the conclusion that tumours smallerthan 0.5 ml were insignificant. In the current study,20 of the 47 cases did not meet the criteria forinsignificant disease, whereas in reality, they wereall clinically insignificant because they were notdiagnosed within the patients’ lifetime. This illus-trates that, strictly speaking, it is not possible todefine clinically insignificant disease in terms ofhistopathological features alone. There remains aneed for long-term, prospective studies of untreatedprostate cancer to better understand the naturalhistory of the disease, rather than relying onrelatively arbitrary histopathological definitions ofclinical significance. As this study shows, manycancers that do not meet histopathological criteriafor insignificant disease will in fact turn out not to besignificant.

Conflicts of interest: The author has nothing to disclose.

Reference

[1] Stamey TA, Freiha FS, McNeal JE, et al. Localized prostate

cancer. Relationship of tumour volume to clinical signifi-

cance for treatment of prostate cancer. Cancer

1993;71(Suppl 3):933–8.

Chris Parker

Institute of Cancer Research and Royal Marsden Hospital,

Sutton, United Kingdom

Tel. +44 020 8661 3425.

E-mail address: chris.parker@icr.ac.uk

DOI: 10.1016/j.eururo.2008.03.063