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5. Stamey TA, McNeal JE, Yemoto CM, et al. Biological determi-nants of cancer progression in men with prostate cancer. JAMA.1999;281:1395-1400.

6. Quinn DI, Henshall SM, Brenner PC, et al. Prognostic significanceof preoperative factors in localized prostate carcinoma treated withradical prostatectomy: importance of percentage of biopsies thatcontain tumor and the presence of biopsy perineural invasion.Cancer. 2003;97:1884-1893.

7. Pound CR, Partin AW, Eisenberger MA, et al. Natural history ofprogression after PSA elevation following radical prostatectomy.JAMA. 1999;281:1591-1596.

8. Beyer DC, Brachman DG. Failure free survival following brachy-therapy alone for prostate cancer: comparison with external beamradiotherapy. Radiother Oncol. 2000;57:263-267.

9. Brachman DG, Thomas T, Hilbe J, et al. Failure-free survivalfollowing brachytherapy alone or external beam radiation alone forT1-2 prostate tumors in 2222 patients: results for a single practice.Int J Radiat Oncol Biol Phys. 2000;48:111-117.

0. Zelefsky MJ, Wallner KE, Ling CC, et al. Comparison of the 5-yearoutcome and morbidity of three-dimensional conformal radiother-apy versus transperineal permanent iodine-125 implantation forearly stage prostatic cancer. J Clin Oncol. 1999;17:517-522.

DITORIAL COMMENThe quest for a better prediction of the prognosis of the indi-idual patient with prostate has made no quantum leaps duringhe past 10 years. Although the correlation between the tumorolume and outcome was demonstrated quite some time ago,1

ethods for measuring the tumor volume from the biopsyesults have not been consistently established. D’Amico et al.2

ound that the percentage of positive biopsy cores (PPBCs)redicted prostate cancer-specific mortality in patients with lowr favorable intermediate-risk disease who underwent three-imensional conformal radiotherapy. However, Williams etl.,3 in a recent publication, found this parameter to add onlyinimal ability to predict for biochemical failure in a similar

ohort of patients.In the present study, the authors found no correlation be-

ween the PPBCs and biochemical failure in patients whonderwent low-dose-rate brachytherapy or external beam radio-herapy (EBRT). EBRT showed a trend toward more biochem-cal recurrence in patients with a greater PPBCs (25% vs 4% inhe low PPBC group), although no such trend was seen in therachytherapy cohort. However, because of the small number ofatients in the PPBC �50% group, the power of this retrospec-ive study might have been too low to detect a true differencen the EBRT group. Thus, these results are hypothesis generat-ng at best: because low-dose-rate brachytherapy is a form ofose escalation, the results might not have been as sensitivegainst the tumor volume as those of EBRT. This theory haseen confirmed by the findings of Williams et al.3: the influencef PPBCs varied significantly with the radiation dose (P � .02),ith doses �66 Gy and palpable tumors showing the strongest

elationship between the PPBCs and biochemical failure.To further evaluate this issue, a better parameter than the

PBCs should be used. Freedland et al.4 compared the PPBCsith the percentage of total biopsy tissue with cancer and found

he second parameter to be more predictive for advanced patho-ogic features and prostate-specific antigen recurrence after rad-cal prostatectomy. In a recent systematic review on the sub-ect,5 this was confirmed, as was the general predictive power ofhis parameter. However, the marked variability in study design,

onduct, and reporting currently precludes a meta-analysis of t

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he evaluated studies.5 More prospective work is necessary toefinitely establish the information from the biopsies as a solidrognostic parameter for the various local treatments of prostateancer.

urt Miller, M.D., Department of Urology, Charitéindenburgdamm, Berlin, Germany

eferences. Stamey TA, McNeal JE, Yemoto CM, et al. Biological determinants

of cancer progression in men with prostate cancer. JAMA. 1999;281:1395-1400.

. D’Amico AV, Renshaw AA, Cote K, et al. Impact of the percentageof positive prostate cores on prostate cancer-specific mortality forpatients with low or favorable intermediate-risk disease. J Clin Oncol.2004;22:3726-3732.

. Williams SG, Buyyounouski MK, Pickles T, et al. Percentage ofbiopsy cores positive for malignancy and biochemical failure follow-ing prostate cancer radiotherapy in 3,264 men: statistical signifi-cance without predictive performance. Int J Radiat Oncol Biol Phys.2008;70:1169-1175.

. Freedland SJ, Aronson WJ, Csathy GS, et al. Comparison of per-centage of total prostate needle biopsy tissue with cancer to percent-age of cores with cancer for predicting PSA recurrence after radicalprostatectomy: results from the SEARCH database. Urology. 2003;61:742-747.

. Harnden P, Shelley MD, Naylor B, et al. Does the extent of carci-noma in prostatic biopsies predict prostate-specific antigen recur-rence? A systematic review. Eur Urol. 2008;54:728-739.

oi:10.1016/j.urology.2008.10.060ROLOGY 73: 1334, 2009. © 2009 Published by Elsevier

nc.

EPLYn the prostate-specific antigen (PSA) era, much effort has beenade to search for variables defining clinically significant can-

er from indolent disease. This quest for the “Holy Grail” hased to a number of prognostic indicators that serve as guidelinesor clinicians to stratify risk and direct patient care.1

In our study, we did not find any statistically significantorrelation between the percentage of positive biopsy coresPPBCs) and the treatment modality. We acknowledge theain limitations of our report, in particular, the small cohort

ize of patients with a high tumor volume (PPBCs �50%) andhe length of follow-up. This is of particular importance, espe-ially because the patients included were defined as havinglow-risk” disease. We await long-term data allowing for theecruitment of more subjects and longer follow-up. However,e are confident that for the low-risk patient population, thePBCs should not prevent physicians from recommending ex-ernal beam radiotherapy or brachytherapy as treatment op-ions.

We agree that the perfect prognostic indicators for prostateancer have yet to be determined. The PPBCs and the percent-ge of cancer on biopsy are 2 proposed methods of estimatinghe tumor volume. Multiple studies have shown that the PPBCserves as an independent predictor of biochemical recurrencend prostate cancer-specific mortality, regardless of treatmentodality.2–5 The prognostic significance of the percentage of

ancer on biopsy has also been demonstrated.6 In the recenteview by Harnden et al.,7 many of the larger studies showing

he significance of the PPBCs in predicting for biochemical

UROLOGY 73 (6), 2009