Prostate needle biopsies containing prostatic intraepithelial neoplasia or atypical foci suspicious for carcinoma: implications for patient care

[Trends in prostate biopsy interpretation]

Driven by the pressure of increasing use of PSA screening, cancer diagnosis based on histopathology has been constantly improved. When appropriate quality standards for obtaining a biopsy specimen and for tissue preparation are upheld, even the smallest tumour foci can be identified with certainty. Efforts to standardize the Gleason grading should also help to render assessments of tumour biology more precise. In addition, subtle diagnosis of precancerous or cancer-associated lesions will permit more exact prognoses of existing cancer risk to be made. There are still weak points: reliable recognition of clinically insignificant carcinomas and the danger of overtreatment. Further research activity on this topic is needed.

GOLPH2 protein expression as a novel tissue biomarker for prostate cancer: implications for tissue-based diagnostics

GOLPH2 is coding the 73-kDa type II Golgi membrane antigen GOLPH2/GP73. Upregulation of GOLPH2 mRNA has been recently reported in expression array analyses of prostate cancer. As GOLPH2 protein expression in prostate tissues is currently unknown, this study aimed at a comprehensive analysis of GOLPH2 protein in benign and malignant prostate lesions. Immunohistochemically detected GOLPH2 protein expression was compared with the basal cell marker p63 and the prostate cancer marker alpha-methylacyl-CoA racemase (AMACR) in 614 radical prostatectomy specimens. GOLPH2 exhibited a perinuclear Golgi-type staining pattern and was preferentially seen in prostatic gland epithelia. Using a semiquantitative staining intensity score, GOLPH2 expression was significantly higher in prostate cancer glands compared with normal glands (P<0.001). GOLPH2 protein was upregulated in 567 of 614 tumours (92.3%) and AMACR in 583 of 614 tumours (95%) (correlation coefficient 0.113, P = 0.005). Importantly, GOLPH2 immunohistochemistry exhibited a lower level of intratumoral heterogeneity (25 vs 45%). Further, GOLPH2 upregulation was detected in 26 of 31 (84%) AMACR-negative prostate cancer cases. These data clearly suggest GOLPH2 as an additional ancillary positive marker for tissue-based diagnosis of prostate cancer.

False positive labeling of prostate cancer with high molecular weight cytokeratin: p63 a more specific immunomarker for basal cells

Occasional nonspecific staining of prostate cancer cells with high molecular weight cytokeratin (HMWCK) can lead to false-negative diagnoses. We compared p63 and HMWCK immunostaining to check their specificity for basal cell identification. Out of 6887 prostate cancer cases sent in consultation to one of the authors over 1.5 years, we identified 22 (0.3%) cases with HMWCK labeling of cancer cells, including 20 needle biopsies and 2 transurethral resections of prostate (TURP). Cases were sent in consultation because of the confusing immunostaining pattern, where prostate cancer cells labeled with HMWCK at the outside institutions. In 6 cases, p63 immunostains were also received from the outside institution, whereas in the remaining 16 cases p63 immunohistochemistry was performed at our institution. In 14 cases, we used either an extra destained hematoxylin and eosin slide or a negative control slide for immunohistochemistry with antibodies to p63, and in the 2 remaining cases submitted unstained slides were used. The Gleason scores were 3+3=6 in 20 cases and 4+4=8 in 2 cases. The size of the tumor on needle biopsy ranged from 0.5 to 6.0 mm (mean 1 mm) and on the 2 TURP cases consisted of 44 and 68 cancer glands, respectively. The number of tumor cells positive for HMWCK in each of the needle biopsy cases ranged from 3 to 48 (mean 13 cells), whereas on the 2 TURP cases 26 and 10 cells were labeled with HMWCK. Corresponding stains for p63 on the same cases were negative in 18 cases. In 3 of 4 cases, p63 labeled 1, 1, and 2 tumor cells, respectively. The fourth case had 5 positive cells on p63 staining with 4 positive for HMWCK. To assess whether overstaining was a factor, we evaluated the intensity of HMWCK staining in the basal cells of the benign glands, which was moderate in 6 and strong in 16 cases. The cytoplasm of benign secretory cells showed focal weak (n=3), diffuse weak (n=1), and focal moderate (n=2) staining for HMWCK. HMWCK labeling of prostate cancer cells is uncommon and does not seem to be solely attributable to overstaining. p63 is a more specific marker for basal cells than HMWCK, with less labeling of tumor cells. Recognition of this phenomenon and performing stains for p63 when it occurs can help prevent underdiagnosing prostatic carcinoma.

[Clinical features and histopathology of prostate cancer diagnosed from the third biopsy]

OBJECTIVE

To study of histological and clinical features of prostate cancer diagnosed after three or more prostate biopsies in order to assess its clinical relevance and to discard the overdiagnosis of prostate cancer.

MATERIAL AND METHODS

We reviewed the clinical records of 61 patients who underwent three or more prostate biopsies between January 2000 and December 2006. The analyzed variables were: age, PSA level, free/total PSA ratio, PSA density, digital rectal examination, prostate volume, sonographic findings and previous malignant lesion strongly associated to the presence of tumor on previous biopsy. We studied the pathology of the tumors diagnosed from the third biopsy, therapeutical approach and its evolution with a minimum follow-up of 3 months.

RESULTS

Fifteen out of 61 patients with more than three biopsies had prostate cancer (24,59%) in the third biopsy, 5 out of 14 patients with 4 biopsies (35,71%) and 1 of the 2 cases (50%) who underwent a fifth biopsy. According to the results of biopsy, 6 patients met the criteria of clinically insignificant cancer (28,57%). Curative treatment was performed in all patients: brachytherapy in 5, external beam radiotherapy in 6 and radical prostatectomy in 10. Clinically significant tumors were found in all cases: 2 pT2b tumors and 7 pT2c tumors with negative surgical margins and with an excellent control of the cancer after a minimum follow up of 13 months, and one pT4 tumor with bladder neck infiltration.

CONCLUSION

In our practice, overall detection rate of the third, fourth and fifth biopsy is 34,42% corresponding with tumors that could benefit from curative treatment.

Precursor lesions to prostatic adenocarcinoma

High-grade prostatic intraepithelial neoplasia (PIN) is the one well-documented precursor to adenocarcinoma of the prostate. This review article defines both low- and high-grade PIN. Unusual variants of high-grade PIN are illustrated. Benign lesions that may be confused with high-grade PIN, including central zone histology, clear cell cribriform hyperplasia, and basal cell hyperplasia are described and illustrated. High-grade PIN is also differentiated from invasive acinar (usual) and ductal adenocarcinoma. The incidence of high-grade PIN, its relationship to carcinoma (including molecular findings), and risk of cancer on rebiopsy are covered in detail. Finally, intraductal carcinoma of the prostate, a controversial entity, is discussed and differentiated from high-grade PIN.

Prostatic Adenocarcinoma, Prostatic Intraepithelial Neoplasia, and Intraductal Carcinoma

Prostate carcinoma (PCa) exhibits a wide range of architectural and cytological features. Gleason grading remains as one of the most powerful histological prognostic parameters. However, it has evolved considerably. High-grade prostatic intraepithelial neoplasia (high-grade PIN) is accepted as a precursor lesion to PCa. Its detection in prostate biopsy is also considered as a risk factor for detecting cancer in subsequent biopsies. Such risk, however, has significantly decreased in recent studies. Intraductal carcinoma of the prostate (IDC-P) represents the intraductal spread of invasive cancer and constitutes a poor histologic parameter. This article reviews the key histological features of PCa, high-grade PIN and IDC-P, as well as the Gleason grading system that was most recently updated in 2005.

Precursor Lesions of Prostate Cancer

Several morphological lesions have been proposed that may act as potential precursor lesions of prostate cancer. These are the morphologically distinct entities of focal atrophy or post-atrophic hyperplasia (PAH), atypical adenomatous hyperplasia (AAH) or adenosis, and prostatic intraepithelial neoplasia (PIN). The diagnostic criteria of low-and high-grade PIN (LGPIN and HGPIN, respectively) and of lesions suspicious for cancer (LSC) have been established. In the present review, we present the current knowledge about the precursor lesions of prostate cancer. We focus on the epidemiology, pathogenesis, clinical markers, and differential diagnosis of PIN. The similarities between HGPIN and prostate cancer are also discussed. Furthermore, potential markers and management strategies (that is, repeat biopsy, chemoprevention, radical prostatectomy, radiotherapy) are outlined along with updated recommendations.

[Clinical significance of prostatic intraepithelial neoplasm and atypical small acinar proliferation: relationship with prostate cancer]

INTRODUCTION

Prostatic intraepithelial neoplasia (PIN) and atypical small acinar proliferation (ASAP) in the setting of prostatic needle biopsies are considered premalignant although questions still remain.

OBJECTIVES

In this paper, we have studied the clinical relevance of these histologic findings.

MATERIAL AND METHODS

We collected 138 subjects (108 PIN, 30 ASAP); in 67% we performed a second biopsy and the rate of cancer in this late biopsy were 19% and 27% respectively. We cannot identify any clinical factor to predict the finding of cancer in the re-biopsy (PSA, age, digital rectal examination, prostatic volume).

RESULTS

In the follow-up, we observed higher rates of cancer for the ASAP; the finding of ASAP was the single clinical or histopathological factor that was an independent predictor of cancer.

CONCLUSIONS

We observed that the finding of ASAP was an indication for re-biopsy because of the higher rates of cancer; on the contrary, the paper of PIN in the prostatic needle biopsy still requires further investigation.

Characterization of TMPRSS2-ERG fusion high-grade prostatic intraepithelial neoplasia and potential clinical implications

PURPOSE

More than 1,300,000 prostate needle biopsies are done annually in the United States with up to 16% incidence of isolated high-grade prostatic intraepithelial neoplasia (HGPIN). HGPIN has low predictive value for identifying prostate cancer on subsequent needle biopsies in prostate-specific antigen-screened populations. In contemporary series, prostate cancer is detected in approximately 20% of repeat biopsies following a diagnosis of HGPIN. Further, discrete histologic subtypes of HGPIN with clinical implication in management have not been characterized. The TMPRSS2-ERG gene fusion that has recently been described in prostate cancer has also been shown to occur in a subset of HGPIN. This may have significant clinical implications given that TMPRSS2-ERG fusion prostate cancer is associated with a more aggressive clinical course.

EXPERIMENTAL DESIGN

In this study, we assessed a series of HGPIN lesions and paired prostate cancer for the presence of TMPRSS2-ERG gene fusion.

RESULTS

Fusion-positive HGPIN was observed in 16% of the 143 number of lesions, and in all instances, the matching cancer shared the same fusion pattern. Sixty percent of TMPRSS2-ERG fusion prostate cancer had fusion-negative HGPIN.

CONCLUSIONS

Given the more aggressive nature of TMPRSS2-ERG prostate cancer, the findings of this study raise the possibility that gene fusion-positive HGPIN lesions are harbingers of more aggressive disease. To date, pathologic, molecular, and clinical variables do not help stratify which men with HGPIN are at increased risk for a cancer diagnosis. Our results suggest that the detection of isolated TMPRSS2-ERG fusion HGPIN would improve the positive predictive value of finding TMPRSS2-ERG fusion prostate cancer in subsequent biopsies.

Use of tissue ink to maintain identification of individual cores on needle biopsies of the prostate

BACKGROUND

There is an increasing necessity to extract the maximum amount of information, beyond even a cancer diagnosis, from prostate biopsies. Thus, maintaining site-specific information regarding individual biopsy cores might be critical.

AIM

To evaluate the applicability of employing tissue ink to maintain the identity of individual prostatic biopsy cores.

METHOD

In this ongoing study, 12 core prostate biopsy specimens are sent to the laboratory in individual pots labelled according to anatomical site. The specimens are placed in two separate multi-compartment cassettes. They are inked with different colours to identify the site of origin from each lobe. The cassettes are then processed with a single paraffin block for each side; the six cores from each side can be mounted on a single slide.

RESULTS

The different colours used adhere well to the biopsy cores, thus maintaining the identity of each core. Six cores from each side are embedded in a single paraffin block and examined on a single slide, making it cost-effective, while maintaining high quality, accurate histopathological information.

CONCLUSION

Differential inking of prostate biopsy cores is an easily applicable method that is cost-effective and provides tumour location information. Prostate biopsy data archived to maintain individual core information might be used to determine applicability of such information to predict extra-capsular extension by correlating with imaging and radical prostatectomy findings, and for treatment planning.

Risk of prostate cancer after diagnosis of atypical glands suspicious for carcinoma on saturation and traditional biopsies

PURPOSE

Prostatic glandular atypia is present in approximately 5% of traditional template biopsy specimens. Prior reports suggest this finding carries a 40% risk of prostate cancer on subsequent biopsy. We determined the risk of malignancy in patients with atypia diagnosed on saturation biopsy.

MATERIALS AND METHODS

We identified 57 patients with a diagnosis of atypia who underwent repeat biopsy between January 2001 and August 2007. Charts were reviewed for clinical and pathological information.

RESULTS

Median patient age was 62 years (range 46 to 79). Of the 57 patients 19 (33%) had atypia diagnosed on saturation biopsy (20 cores or greater) (group 1), whereas 38 (67%) had atypia diagnosed with a more traditional biopsy technique (12 cores or fewer) (group 2). All patients subsequently underwent saturation repeat biopsy a median of 5 months after the original biopsy. Eight group 1 patients (42%) were found to have cancer on rebiopsy compared to 15 (39.5%) in group 2 (p = 1.00). Whereas only 1 of the 8 patients (12.5%) with cancer in group 1 had a Gleason score of 7 or greater, this was found in 5 of the 15 (33%) in group 2 (p = 0.37). Interestingly patients with cancer were less likely to have inflammation on initial biopsy (p = 0.05).

CONCLUSIONS

The finding of atypia on prostate biopsy is associated with a high likelihood of underlying malignancy regardless of the number of cores taken on initial biopsy. Inflammation in the initial biopsy may create a false-positive finding of atypia.

A novel nomogram to predict the probability of prostate cancer on repeat biopsy

PURPOSE

We developed a predictive model that incorporates clinical data and prostate specific antigen kinetic from general practice to detect prostate cancer in patients with a previously negative prostate biopsy.

MATERIALS AND METHODS

From January 2001 to January 2007 data on 419 men who underwent repeat prostate biopsy with 12 or more cores were used to develop the nomogram. From February 2007 to June 2007 data on 63 men with the same criteria were used to validate the nomogram. The factors that we evaluated for the risk of a positive repeat prostate biopsy were patient age, digital rectal examination findings, total prostate specific antigen, the free-to-total prostate specific antigen ratio, prostate specific antigen density and slope, and previous high grade prostatic intraepithelial neoplasia.

RESULTS

On multivariate logistic regression all factors except age and prostate specific antigen showed significant ability to predict the outcome of 12-core repeat prostate biopsy. In the validation group the AUC of the predicted results from the model was 0.856 (95% CI 0.744-0.931), better than that of prostate specific antigen, the free-to-total prostate specific antigen ratio, and prostate specific antigen density and slope (p <0.05).

CONCLUSIONS

We successfully developed an accurate model to predict the outcome of repeat prostate biopsy. Adding the free-to-total prostate specific antigen ratio, digital rectal examination, prostate specific antigen and slope, and history of high grade prostatic intraepithelial neoplasia sharply improves the accuracy of our model.

Discovery and validation of urinary biomarkers for prostate cancer

Only 30% of patients with elevated serum prostate specific antigen (PSA) levels who undergo prostate biopsy are diagnosed with prostate cancer (PCa). Novel methods are needed to reduce the number of unnecessary biopsies. We report on the identification and validation of a panel of 12 novel biomarkers for prostate cancer (PCaP), using CE coupled MS. The biomarkers could be defined by comparing first void urine of 51 men with PCa and 35 with negative prostate biopsy. In contrast, midstream urine samples did not allow the identification of discriminatory molecules, suggesting that prostatic fluids may be the source of the defined biomarkers. Consequently, first void urine samples were tested for sufficient amounts of prostatic fluid, using a prostatic fluid indicative panel ("informative" polypeptide panel; IPP). A combination of IPP and PCaP to predict positive prostate biopsy was evaluated in a blinded prospective study. Two hundred thirteen of 264 samples matched the IPP criterion. PCa was detected with 89% sensitivity, 51% specificity. Including age and percent free PSA to the proteomic signatures resulted in 91% sensitivity, 69% specificity.

Prognostic significance of alpha-methylacyl-coA racemase among men with high grade prostatic intraepithelial neoplasia in prostate biopsies

PURPOSE

Serum prostate specific antigen screening has increased the number of prostate biopsies performed increasing the number of patients with high grade prostatic intraepithelial neoplasia. The criteria for re-biopsy are not standardized but may be refined by the identification of novel biomarkers demonstrating prognostic significance. Alpha-methylacyl-CoA racemase is a robust marker of prostate cancer and is expressed in a subset of high grade prostatic intraepithelial neoplasia. This study evaluates the prognostic significance of alpha-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia glands in prostate biopsies.

MATERIALS AND METHODS

Immunohistochemical staining with alpha-methylacyl-coA racemase and p63 was examined in a selected group of 62 patients with a diagnosis of high grade prostatic intraepithelial neoplasia on initial prostate biopsy, of which on repeat biopsy 32 had no carcinoma and 30 had prostate cancer. There was no significant difference in age, number of cores sampled or prostate specific antigen history between the 2 outcome groups (ANOVA p >0.9). High grade prostatic intraepithelial neoplasia glands in each case were evaluated for alpha-methylacyl-coA racemase and p63.

RESULTS

Reactivity for alpha-methylacyl-coA racemase was found in 27 of the 62 cases examined. Fisher's exact analysis revealed that patients with at least 1 alpha-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia gland were 5.2 times more likely to have a subsequent diagnosis of prostate cancer on repeat biopsy than those without any alpha-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia glands (p = 0.0044). No correlation was found between alpha-methylacyl-coA racemase positivity and any other clinical variable.

CONCLUSIONS

This is the first study to our knowledge to illustrate that alpha-methylacyl-coA racemase reactivity in high grade prostatic intraepithelial neoplasia may be useful to refine re-biopsy criteria and assist in clinical management decisions.

Initial extended transrectal prostate biopsy--are more prostate cancers detected with 18 cores than with 12 cores?

PURPOSE

We retrospectively investigated the detection rates of prostate cancer, high grade prostatic intraepithelial neoplasia and atypical glands suggestive of carcinoma by initial 18 and 12-core prostate biopsy.

MATERIALS AND METHODS

A total of 3,460 consecutive patients with prostate specific antigen between 2.5 and 15 ng/ml underwent 12 (1,684) or 18 (1,776) core prostate biopsy under local anesthesia at 2 departments that adopted the same indications for performing biopsy. Biopsies were evenly distributed throughout the prostate in 6 sectors. In the 12-core prostate biopsy group 2 samples were obtained from each sector and in the 18-core prostate biopsy group 1 additional core was taken from each sector.

RESULTS

The cancer detection rate in patients who underwent 18-core prostate biopsy was not different from the rate in those who underwent 12-core prostate biopsy (39.9% and 38.4%, p = 0.37), nor did the detection of atypical glands suggestive of carcinoma differ significantly between the 2 groups (2.9% and 3.3%, respectively, p = 0.33). However, 18-core prostate biopsy detected a significantly higher percent of cases of high grade prostatic intraepithelial neoplasia (20.0% vs 12.9%, p = 0.001). The cancer detection rate was higher with 18 than with 12-core prostate biopsy in patients with a prostate volume of 55 cc or greater (31.5% vs 24.8%, p = 0.01) but not in those with a prostate volume of less than 55 cc (54.3% and 53.0%, respectively, p = 0.7). Moreover, we determined that patients with positive digital rectal examination findings do not need 18-core prostate biopsy as opposed to 12-core prostate biopsy.

CONCLUSIONS

Compared with 12-core prostate biopsy, 18-core prostate biopsy detects significantly more cases of high grade prostatic intraepithelial neoplasia. However, 18-core prostate biopsy detects a significantly higher number of cancer only in patients with a prostate volume of 55 cc or greater.

Positive predictive value of high-grade prostatic intraepithelial neoplasia in initial core needle biopsies of prostate adenocarcinoma--a study with complete sampling of hemi-prostates with corresponding negative biopsy findings

OBJECTIVES

High-grade prostatic intraepithelial neoplasia (HGPIN) is a putative premalignant lesion of prostate adenocarcinoma (PCa). The significance of isolated HGPIN in initial biopsy cores as a marker of PCa in repeat biopsies has been extensively investigated, but little is known of the true occurrence of PCa in this setting, because repeat biopsies can miss the focus of cancer. In this study, a hemi-prostate model was used to define the true positive predictive value of HGPIN in core biopsies in predicting PCa.

METHODS

From 132 consecutive resected prostate specimens, 70 hemi-prostates with all corresponding biopsy cores negative for PCa were thoroughly examined.

RESULTS

Of the 70 hemi-prostates, 38 had PCa (including 8 with clinically significant PCa), and 11 had HGPIN. In the group of 38 hemi-prostate with PCa, 7 were associated with HGPIN-positive biopsies. No statistically significant difference was found between the hemi-prostates with or without PCa, regarding the presence, microscopic pattern, or multiple core involvement of HGPIN in the biopsies. The positive predictive value of HGPIN in predicting for clinically significant PCa was 27%, the negative predictive value was 87%, the sensitivity was 38%, and the specificity was 91% (P = 0.04, statistically significant). In addition, the positive predictive value of multiple cores with HGPIN in predicting for clinically significant PCa was 75% (negative predictive value 92%).

CONCLUSIONS

The results of the present study have failed to support HGPIN as a statistically significant predictor for the occurrence of PCa. More importantly, however, HGPIN and multiple core involvement did seem to be a useful marker for clinically significant PCa.

4E-binding protein 1: a key molecular "funnel factor" in human cancer with clinical implications

In an attempt to identify molecules that clearly reflect the oncogenic role of cell signaling pathways in human tumors, we propose a concept we term "funnel factor", a factor where several oncogenic signals converge and drive the proliferative signal downstream. In studies done in various tumor types, the expression of key cell signaling factors, including Her1 and Her2 growth factor receptors, as well as the RAS-RAF-mitogen-activated protein kinase and the phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin pathways was correlated with the associated clinicopathologic characteristics of these tumors. The downstream factors p70, S6, 4E-binding protein 1 (4E-BP1), and eukaryotic translation initiation factor 4E, which play a critical role in the control of protein synthesis, survival, and cell growth, were also analyzed. We found that phosphorylated 4E-BP1 (p-4E-BP1) expression in breast, ovary, and prostate tumors is associated with malignant progression and an adverse prognosis regardless of the upstream oncogenic alterations. Thus, p-4E-BP1 seems to act as a funnel factor for an essential oncogenic capability of tumor cells, self-sufficiency in growth signals, and could be a highly relevant molecular marker of malignant potential. Further investigation into this concept may identify additional funnel factors in the oncogenic pathways and provide potential therapeutic targets.

Contemporary clinical management of isolated high-grade prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (HGPIN) is a premalignant lesion associated with increased risk of coexistent cancer or delayed progression to carcinoma. Extended biopsy schemes have improved the ability to rule out concurrent cancers, increased the detection of isolated HGPIN and removed the routine necessity for immediate repeat biopsy. As the natural history of HGPIN is poorly defined, and no non-invasive marker allows monitoring of progression to cancer, routine delayed interval biopsy should be considered in all patients. In this article, we present an overview of the existing literature on HGPIN and a proposed strategy for clinical management.

Prostate adenocarcinoma detected after high-grade prostatic intraepithelial neoplasia or atypical small acinar proliferation

OBJECTIVE

To review specific histological variables in patients with prostate cancer who previously had diagnoses of high-grade prostatic intraepithelial neoplasia (HGPIN) and/or atypical small acinar proliferation (ASAP), compared with those who had no such diagnoses.

PATIENTS AND METHODS

The histological characteristics of prostate cancers which were detected after a previous diagnosis of HGPIN and/or ASAP during 1998-2005 were investigated and correlated with the biopsies from patients with prostate cancer but with no such previous diagnoses.

RESULTS

HGPIN was followed by prostate cancer on repeat biopsy in 16.8% of patients, and ASAP in 26.7%. The mean age of patients with HGPIN or ASAP was higher than in those with no such diagnoses (P < 0.001). Similarly, patients with these previous diagnoses had a lower Gleason score (P = 0.017 and <0.001, respectively) and lower tumour volume variables (fewer tumour foci, P = 0.033 and 0.041, respectively) and shorter cancer (P = 0.048 and 0.030) in core biopsies than those without.

CONCLUSIONS

Patients with prostate cancer who had previous biopsies with HGPIN or ASAP were older and has lower grade- and volume-cancers than those who had not.

Clinicopathologic Features of Prostate Adenocarcinoma Incidentally Discovered at the Time of Radical Cystectomy: An Evidence-Based Analysis

OBJECTIVES

To review all relevant features of incidentally discovered prostate cancer (PCa) in patients undergoing radical cystectomy for bladder cancer: incidence, pathologic characteristics, clinical significance, and implications for its management.

METHODS

A structured literature review through a MEDLINE search was performed.

RESULTS

The frequency of incidentally discovered PCa in cystoprostatectomy specimens is extremely variable because of several factors, particularly the pathology sampling. The relationship among clinically, incidentally, and autopsy-detected cancer is uncertain. The definition of clinically significant cancer varies among published reports and remains inadequate for clinical application. High-grade prostatic intraepithelial neoplasia is a marker for concurrent PCa and the risk depends more on the volume than on its absolute presence. Outcome of patients with unsuspected PCa after cystoprostatectomy relies mostly on the bladder tumor.

CONCLUSIONS

Incidental PCa in patients with bladder cancer is highly variable and with an unclear clinical significance. For those who are candidates for prostate-sparing surgery, it seems reasonable to include a routine prostate biopsy in the standard preoperative work-up irrespective of prostate-specific antigen values. In the absence of sufficient data to make firm recommendations, when PCa is incidentally discovered, PCa surveillance should be part of the follow-up scheme after radical cystectomy.

Recommendations for the reporting of prostate carcinoma

It has been evident for decades that pathology reports are very variable even within a single institution. Standardization of reporting is the optimal way to insure that information necessary for patient management, prognostic and predictive factor assessment, grading, staging, analysis of outcomes, and tumor registries are included in pathology reports. The ADASP has chosen a pathologist expert in each field to assemble a group from within the pathology community (with clinician input if desired) to write specific cancer protocols. These were then approved by the ADASP council and subsequently by the membership. The American College of Surgery Commission on Cancer (COC) accredits cancer centers in the United States. Recently, the COC decided to require elements, deemed as essential by the CAP, to be described in all pathology reports in their accredited cancer centers as of January 2004. Importantly, they do not require that the specific College of Pathologists (CAP) protocols or synoptic reports be used. ADASP has updated all of its protocols to comply with the COC requirements in the form of uniform checklists. The checklists use the staging criteria cited in the American Joint Committee on Cancer 2002 staging manual (sixth edition) but include a variety of other references listed in each of the checklists. Moreover, the checklists are formatted for ease of use. They may be used as templates for uniform reporting and are designed to be compatible with voice-activated transcription. The different elements in these revised ADASP diagnostic checklists have been divided into Required and Optional. The term Required in this context only signifies compliance with the COC guidelines. ADASP realizes that specimens and practices vary, and it will not be possible to report these elements in every case. However, ADASP hopes that pathologists will find these checklists useful in daily clinical practice while facilitating compliance with the new COC requirements.

Significance of Minute Focus of Adenocarcinoma on Prostate Needle Biopsy

OBJECTIVES

To assess the radical prostatectomy findings in patients with a minute focus of adenocarcinoma on prostate needle biopsy in current practice in Australia.

METHODS

A total of 58 patients with a 0.5-mm focus or less of Gleason score 6 adenocarcinoma on needle biopsy who had been treated by radical prostatectomy were selected. At each biopsy, 6 to 20 cores (mean 11, median 13) were taken. Significant tumors were those with a Gleason score of 6 or more and tumor volume of 0.5 cm3 or larger.

RESULTS

The 58 patients (mean age 50 years, median 58, range 44 to 69) had a mean prostate-specific antigen (PSA) level of 6.9 ng/mL (range 0.7 to 16, median 6). Of the 58 men, 48 (82.75%) had pathologically significant tumor, with 8 (13.8%) showing extraprostatic extension. No statistically significant association was found between significant carcinoma and age, mean PSA level, PSA density greater than 0.15, prior negative biopsy, coexistent atypical glands, or the number of tissue cores per biopsy. A prostate weight greater than 40 g correlated significantly with insignificant cancer on both univariate (P = 0.03) and multivariate (P = 0.02) analyses. In 14 (29.2%) of 48 patients with significant tumor, the largest cancer focus in the radical prostatectomy was anterior, lateral, or anterolateral. In patients without atypical glands, 37 (78.72%) of 47 had significant carcinoma, a risk not significantly lower than that of the entire group.

CONCLUSIONS

The results of our study have shown that in populations without PSA screening, a minute focus of prostate cancer on needle biopsy, even with extended biopsy cores, does not mean insignificant carcinoma in most cases. Patients with larger glands had a greater chance of insignificant cancer.

A proposal on the identification, histologic reporting, and implications of intraductal prostatic carcinoma

CONTEXT

Prostatic adenocarcinoma growing within acinar-ductal spaces (intraductal carcinoma) in contrast to high-grade prostatic intraepithelial neoplasia (HG-PIN) impacts negatively on patient outcome. There is currently no generally accepted definition of this lesion nor is it classified in the current prostate cancer grading system (Gleason).

OBJECTIVE

To define intraductal carcinoma of the prostate (IDC-P) with major and minor diagnostic criteria that clearly separate it from HG-PIN. The implications of such a lesion are discussed with proposals to incorporate this entity into the Gleason grading system.

DATA SOURCES

We reviewed all published data referring to intraductal spread of prostate carcinoma. Articles discussing endometrial, endometrioid, and ductal carcinoma are included.

CONCLUSIONS

Intraductal carcinoma of the prostate as defined by major criteria that include enlarged gland structures, neoplastic cells spanning the gland lumen, central comedonecrosis, and further supported by minor diagnostic criteria including molecular biological markers, separate this entity from HG-PIN. Despite its perimeter basal cells, IDC-P should be interpreted as biologically equivalent to Gleason pattern 4 or 5 adenocarcinoma. Several hypotheses are proposed as to the evolution of IDC-P, which is almost always a late event in prostate carcinoma progression. Diagnosis of IDC-P on needle biopsy should prompt therapeutic intervention rather than surveillance or repeat biopsy, as is the case for HG-PIN.

Gene methylation and early detection of genitourinary cancer: the road ahead

DNA methylation is a common mechanism of inactivation of tumour-suppressor and other cancer genes in neoplastic cells. The advantages of gene methylation as a target for the detection and diagnosis of cancer in biopsy specimens and non-invasive body fluids such as urine or blood has led to many studies of application in genitourinary cancer. Here, we consider the background, promise and status, challenges and future directions of gene methylation and its clinical utility for the early detection of genitourinary cancer. The challenges of, and strategies for, advancing gene-methylation-based detection are relevant to all types of cancer.

Mechanisms of Disease: high-grade prostatic intraepithelial neoplasia and other proposed preneoplastic lesions in the prostate

High-grade prostatic intraepithelial neoplasia (HGPIN) is the most likely precursor of prostatic adenocarcinoma according to virtually all available evidence. This lesion is characterized by cellular proliferations within pre-existing ducts and acini, with nuclear and nucleolar enlargements similar to those seen in prostate cancer, although unlike cancer HGPIN retains a basal-cell layer. The recognition of HGPIN is clinically important because of the strong association between this disease and prostatic carcinoma. The predictive value for cancer of an initial diagnosis of HGPIN on needle biopsy has substantially declined, with values falling from 36% to 21%. A major factor contributing to this decline is related to increased use of needle biopsy core sampling, which has provided the means for many cancers associated with HGPIN to be detected on initial biopsy; repeat biopsy, even with good sampling, does not detect many additional cancers. Other possible findings in the prostate might indicate premalignant disease (low-grade prostatic intraepithelial neoplasia, atrophy, malignancy-associated changes, and atypical adenomatous hyperplasia or adenosis), but the data for these premalignant diseases are much less convincing than those for HGPIN.

Prospective diagnostic efficiency of biopsy washing DNA GSTP1 island hypermethylation for detection of adenocarcinoma of the prostate

BACKGROUND

The prospective diagnostic efficiency of quantitative glutathione S transferase (GSTP1) promoter hypermethylation analysis in biopsy washing samples has not been determined so far.

METHODS

Biopsies were obtained prospectively from 86 patients suspicious for prostate cancer (CaP). After isolation of DNA from biopsy washings and bisulfite conversion methylated and unmethylated GSTP1 sequences were specifically quantitated by real-time fluorescence PCR. Relative degrees of methylation were compared to results of histopathological examination.

RESULTS

Increased relative methylation was found for the CaP group (mean 28.1%) compared to biopsies without histological evidence for malignancy (5.2%; P < 0.001). A sensitivity and specificity of 92% and 86% and positive and negative predictive values of 82% and 94% were obtained. Receiver operating characteristic (ROC) analysis demonstrated a value of 0.90 (95% CI 0.82-0.98) for the area under curve (AUC).

CONCLUSIONS

Biopsy washing DNA GSTP1 hypermethylation analysis demonstrates a high diagnostic efficacy which is comparable to the retrospective analysis of biopsy tissue specimens. Moreover it is compatible with routine biopsy examination thus permitting further prospective evaluation in CaP diagnosis.

Finasteride decreases the risk of prostatic intraepithelial neoplasia

PURPOSE

High grade prostatic intraepithelial neoplasia is likely a premalignant lesion of the prostate. Decreasing the frequency of high grade PIN may decrease the risk of prostate cancer. In the Prostate Cancer Prevention Trial we evaluated the impact of finasteride on the risk of a needle biopsy diagnosis of high grade prostatic intraepithelial neoplasia.

MATERIALS AND METHODS

The Prostate Cancer Prevention Trial was a randomized, placebo controlled clinical trial that enrolled 18,882 men without evidence of prostate cancer, prostate specific antigen less than 3.0 ng/ml and normal digital rectal examination, and randomized them to 5 mg finasteride daily or placebo. Subjects were followed for 7 years with biopsy recommended for prostate specific antigen greater than 4.0 ng/ml, adjusted in the finasteride group to achieve an equal number of biopsy recommendations or for abnormal digital rectal examination. All cancer-free subjects were recommended to undergo biopsy after 7 years on study. We evaluated the diagnosis of high grade prostatic intraepithelial neoplasia with or without concomitant prostate cancer in these 2 study groups.

RESULTS

The number of men evaluable for high grade prostatic intraepithelial neoplasia was 4,568 in the finasteride group and 4,886 in the placebo group. High grade prostatic intraepithelial neoplasia alone was diagnosed in 276 men (6.0%) in the finasteride group vs 347 (7.1%) in the placebo group (RR 0.85, 95% CI 0.73-0.99, p=0.04). High grade prostatic intraepithelial neoplasia accompanied by prostate cancer was diagnosed in 144 men (3.2%) in the finasteride group vs 223 (4.6%) in the placebo group (RR 0.69, 95% CI 0.56-0.85, p=0.0004). Finasteride significantly decreased the overall risk of high grade prostatic intraepithelial neoplasia (alone and with cancer) from 570 cases (11.7%) in the placebo group to 420 (9.2%) in the finasteride group (HR 0.79, 95% CI 0.70-0.89, p<0.001).

CONCLUSIONS

Finasteride significantly decreased the risk of high grade PIN. This observation may explain how finasteride decreased prostate cancer in the Prostate Cancer Prevention Trial, supporting the notion that high grade prostatic intraepithelial neoplasia is a premalignant lesion of the prostate, and it provides new information relevant to the consideration of finasteride for prostate cancer prevention.

Early Prostate Cancer Antigen Expression in Predicting Presence of Prostate Cancer in Men With Histologically Negative Biopsies

PURPOSE

Early prostate cancer antigen is a nuclear matrix protein that was recently shown to be expressed in prostate adenocarcinoma and adjacent benign tissue. Previous studies have demonstrated early prostate cancer antigen expression in benign prostate tissue up to 5 years before a diagnosis of prostate carcinoma, suggesting that early prostate cancer antigen could be used as a potential predictive marker.

MATERIALS AND METHODS

We evaluated early prostate cancer antigen expression by immunohistochemistry using a polyclonal antibody (Onconome Inc., Seattle, Washington) on benign biopsies from 98 patients. Biopsies were obtained from 4 groups that included 39 patients with first time negative biopsy (group 1), 24 patients with persistently negative biopsies (group 2), 8 patients with initially negative biopsies who were subsequently diagnosed with prostate carcinoma (group 3) and negative biopsies obtained from 27 cases where other concurrent biopsies contained prostate carcinoma (group 4). Early prostate cancer antigen staining was assessed by 2 of the authors who were blind to the group of the examined sections. Staining intensity (range 0 to 3) and extent (range 1 to 3) scores were assigned. The presence of intensity 3 staining in any of the blocks of a biopsy specimen was considered as positive for early prostate cancer antigen for the primary outcome in the statistical analysis. In addition, as secondary outcomes we evaluated the data using the proportion of blocks with intensity 3 early prostate cancer antigen staining, the mean of the product of staining intensity and staining extent of all blocks within a biopsy, and the mean of the product of intensity 3 staining and extent.

RESULTS

Primary outcome analysis revealed the proportion of early prostate cancer antigen positivity to be highest in group 3 (6 of 8, 75%) and lowest in group 2 (7 of 24, 29%, p=0.04 for differences among groups). A relatively higher than expected proportion of early prostate cancer antigen positivity was present in group 1 (23 of 39, 59%). Early prostate cancer antigen was negative in 41% of group 4 who were known to harbor prostate carcinoma. The proportion of early prostate cancer antigen positivity was statistically significantly lower in group 2 than in each of the other groups when compared pairwise. A lower proportion of early prostate cancer antigen positivity was encountered in older archival tissue blocks (p<0.0001) pointing to a potential confounding factor. Corrected for block age, group 3 was the only group to remain statistically significantly different in early prostate cancer antigen positivity compared to the reference group 2. Similar findings were obtained when adjustments for patient age were made and when analysis was based on secondary outcome measurements.

CONCLUSIONS

Our study showed a higher proportion of early prostate cancer antigen expression in initial negative prostate biopsy of patients who were diagnosed with prostate carcinoma on subsequent followup biopsies. We found a relatively high proportion of early prostate cancer antigen positivity (59%) in the group with first time negative biopsies and a potential 41% rate of false-negative early prostate cancer antigen staining in benign biopsies from cases with documented prostate carcinoma on concurrent cores. The lower early prostate cancer antigen positivity in cases with older blocks raises the question of a confounding effect of block age. Additional studies on the antigenic properties of early prostate cancer antigen in archival material are required to further delineate the usefulness of early prostate cancer antigen immunostaining on biopsy material.

The incidence of high-grade prostatic intraepithelial neoplasia and atypical glands suspicious for carcinoma on first-time saturation needle biopsy, and the subsequent risk of cancer

OBJECTIVE

To investigate the detection rate and extent of high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical glands (AG) suspicious for prostate cancer, and the cancer risk in subsequent biopsies, diagnosed by a first 24-core saturation biopsy, as although the optimum extent of biopsy is controversial there is a trend to increase the number of cores taken, and apart from detecting prostate cancer, identifying HGPIN and AG is associated with a greater risk of finding cancer in subsequent biopsies, thus warranting a closer follow-up.

PATIENTS AND METHODS

The study included 100 men with consecutive first-time saturation biopsies; the indications for biopsy were an abnormal digital rectal examination and/or a serum prostate-specific antigen (PSA) level of >2.5 ng/mL. Each biopsy specimen was reviewed retrospectively by two pathologists to confirm the histological diagnosis. The number and percentage of cores positive for HGPIN, bilateral involvement and multifocality (HGPIN involving two or more cores) were recorded in each case. The presence of AG and cancer was also recorded. An extended (10-12 cores) repeat biopsy was available in 23 patients.

RESULTS

The median (range) age and PSA level of the patients was 63 (41-80) years and 4.9 (1.5-67.0) ng/mL, respectively. Of the 100 patients, 34% had normal findings (benign prostatic tissue, BPT), 39% had cancer, 26% had HGPIN and cancer, 22% had HGPIN alone, and 5% had AG. Repeat biopsies were available in nine of the 22 (41%) patients with HGPIN, four of five with AG, and 10 of the 34 (29%) with BPT. The median (range) interval between the first and second biopsy was 13 (4-36) months. Prostate cancer was detected at the second biopsy in a third of patients with isolated HGPIN on the first biopsy, and one of the four with AG. None of the patients with BPT had cancer on re-biopsy. The cancer detection rate was significantly greater in patients with multifocal than in those with unifocal HGPIN (80% vs none, P = 0.010). The median number of cores and percentage of tissue involved by HGPIN was 3.5 (2-5) and 1.0 (0.5-1.2)%, respectively, in patients with cancer detected in repeat biopsies, compared to 1.0 (1-3) and 0.2 (0.2-0.6)% in patients without cancer on repeat biopsy (P = 0.023 and 0.015, respectively).

CONCLUSION

Identifying multifocal HGPIN on first saturation biopsy is associated with an overall cancer detection rate of 80% on repeat 10-12-core biopsy. Although there were few patients, the detection of multifocal HGPIN warrants additional searches for concurrent invasive carcinoma by repeated biopsy.

Prostate volume modifies the association between obesity and prostate cancer or high-grade prostatic intraepithelial neoplasia

The relationship between obesity and prostate cancer remains unclear. We investigated the effect of prostate volume on the obesity and prostate cancer association. With a multi-centered, rapid-recruitment protocol, weight and body size measurements were collected prior to diagnosis, and medical charts were reviewed for pathology results (n = 420 controls, 119 high-grade prostatic intraepithelial neoplasia (PIN) cases, and 286 cancer cases (41% Gleason > 6). In multivariable logistic regression models adjusting for age, PSA levels and history, DRE results, and number of cores at biopsy, the association between BMI and cancer was restricted to men with a smaller prostate volume (volume < 40 cm(3): OR(BMI > or = 30) = 2.17 (1.09, 4.32), p (trend) = 0.02; volume > or = 40 cm(3): OR(BMI > or = 30) = 0.77 (0.34, 1.77), p (trend) = 0.17; p (interaction) = 0.03). Similarly, the WHR and PIN association was significantly modified by prostate volume (volume < 40 cm(3): OR((WHR: Tertile 3 vs. T1)) = 3.76 (1.54, 9.21) (p (trend) < 0.01); volume > or = 40 m(3): OR((WHR: T3 vs. T1)) = 0.63 (0.32, 1.23) (p (trend) = 0.17); p (interaction) < 0.01). In conclusion, prostate volume acts as a modifier, and BMI and WHR are significantly associated with prostate cancer or PIN, respectively, in the absence of biopsy sampling error derived from obesity-related prostate enlargement.

Diagnosis of adenocarcinoma in prostate needle biopsy tissue

Prostate cancer is a major public health problem throughout the developed world. For patients with clinically localised prostate cancer, the diagnosis is typically established by histopathological examination of prostate needle biopsy samples. Major and minor criteria are used to establish the diagnosis, based on the microscopic appearance of slides stained using haematoxylin and eosin. Major criteria include an infiltrative glandular growth pattern, an absence of basal cells and nuclear atypia in the form of nucleomegaly and nucleolomegaly. In difficult cases, basal cell absence may be confirmed by immunohistochemical stains for high-molecular-weight cytokeratins (marked with antibody 34betaE12) or p63, which are basal cell markers. Minor criteria include intraluminal wispy blue mucin, pink amorphous secretions, mitotic figures, intraluminal crystalloids, adjacent high-grade prostatic intraepithelial neoplasia, amphophilic cytoplasm and nuclear hyperchromasia. Another useful diagnostic marker detectable by immunohistochemistry is alpha-methylacyl coenzyme A racemase (AMACR), an enzyme selectively expressed in neoplastic glandular epithelium. Cocktails of antibodies directed against basal cell markers and AMACR are particularly useful in evaluating small foci of atypical glands, and in substantiating a diagnosis of a minimal adenocarcinoma. Reporting of adenocarcinoma in needle biopsy specimens should always include the Gleason grade and measures of tumour extent in the needle core tissue. Measures of tumour extent are (1) number of cores positive for cancer in the number of cores examined, (2) percentage of needle core tissue affected by carcinoma and (3) linear millimetres of carcinoma present.

My approach to intraductal lesions of the prostate gland

The morphologically heterogeneous (intra)ductal lesions of the prostate frequently present a diagnostic challenge, particularly when found within prostate needle biopsies. By current convention, all high-grade intra-acinar and intraductal neoplastic lesions of prostatic origin fall under the diagnostic umbrella term: prostatic intraepithelial neoplasm (PIN). Although a long-standing contentious issue, some lesions currently adhering to the diagnostic criteria of PIN may actually represent the intraductal spread of (generally high grade) invasive cancer. Illustrating this fact, the well-described ductal subtype of prostatic adenocarcinoma is frequently associated with conventional-type acinar adenocarcinoma, and has a tendency to propagate within adjacent intact prostatic ducts. Clearly, the misdiagnosis of lesions representing invasive disease as preinvasive has the potential for unfavourable clinical sequelae. As yet, however, many of these lesions have escaped the establishment of reliable morphologic criteria or immunohistochemical differentiation for diagnosis. By defining stringent architectural and cytonuclear features specific for each of these lesions, it may be feasible to separate potentially sinister lesions from the subset of traditional (preinvasive) PIN lesions with limited clinical urgency. This review discusses the (intra)ductal lesions of the prostate, along with their differential diagnoses. Given the current state of knowledge, a pragmatic approach to their effective reporting is outlined, taking into consideration the clinical implications, as well as current guidelines for treatment and follow-up.

Intraductal carcinoma of the prostate on needle biopsy: Histologic features and clinical significance

Intraductal carcinoma of the prostate (IDC-P) has been described in radical prostatectomies. However, there is limited information as to its histologic features and clinical significance when seen on prostate biopsy. A total of 27 cases of prostate biopsies with only IDC-P (ie no infiltrating cancer anywhere on the biopsy) were studied from the consult files of one of the authors. IDC-P was defined as malignant epithelial cells filling large acini and prostatic ducts, with preservation of basal cells forming either: (1) solid or dense cribriform patterns or; (2) loose cribriform or micropapillary patterns with either marked nuclear atypia (nuclear size 6 x normal or larger) or comedonecrosis. The numbers of cores involved by IDC-P in the biopsies ranged from 1 to 7, with >1 core involved in 17 cases. The architectural patterns of IDC-P were solid (12), dense cribriform (19), loose cribriform (17), and micropapillary (5). More than one pattern was present in 24 of 27 cases. The cytological features frequently observed in IDC-P were marked pleomorphism (18), non-focal comedonecrosis (22), and mitoses (20). Basal cells were observed on regular hematoxylin and eosin stained slides in 14 cases; in all the cases, basal cells were confirmed by immunohistochemical stains for high molecular weight cytokeratin (n=25) and/or p63 (n = 4). After the diagnosis of IDC-P on prostate biopsies, patients were treated by radical prostatectomy (6), radiation (7), hormone (5), combined radiation and hormone (1), or watchful waiting (2). The follow-up information was not available for six patients. The follow-up times ranged up to 4 years with an average of 2.1 years. In all six radical prostatectomy specimens, high-grade infiltrating carcinoma with Gleason score 8 or 9 was present with five cases also revealing prominent IDC-P. Non-focal extraprostatic extension of carcinoma was observed in five of the six prostatectomy cases with two cases also demonstrating vascular invasion. Three of 16 patients who did not receive radical prostatectomy developed bone metastases. Our study indicates that IDC-P on prostate biopsies is frequently associated with high-grade cancer and poor prognostic parameters at radical prostatectomy as well as potentially advanced disease following other therapies. These findings support prior studies that IDC-P represents an advanced stage of tumor progression with intraductal spread of tumor. Consideration should be given to treat patients with IDC-P on biopsy aggressively even in the absence of documented infiltrating cancer.

Is high-grade prostatic intraepithelial neoplasia on needle biopsy different in an Asian population: a clinicopathologic study performed in Singapore

OBJECTIVES

To evaluate the incidence, pathologic findings, and follow-up of high-grade prostatic intraepithelial neoplasia (HGPIN) in a series of prostate core biopsies from Singaporean men.

METHODS

We studied isolated HGPIN diagnosed on prostate core biopsies and the incidence of cancer discovered in men who had undergone repeat biopsies from 1999 to 2003 at the Department of Pathology, Singapore General Hospital.

RESULTS

Of 1219 men undergoing prostate needle biopsy, 56 (4.6%) had isolated HGPIN. Most cases affected a single prostate core (44 cases, 78.6%). Twenty-nine men (51.8%) underwent repeat biopsies. Cancer was discovered in 7 (24.1%) of the 29 men within two repeat biopsies.

CONCLUSIONS

The incidence of isolated HGPIN on prostate needle core biopsies in Asian men, as well as the likelihood of subsequent cancer detection, are comparable to the rates reported for Western populations. The relatively low yield of cancer detection on repeat biopsy supports the need to re-evaluate recommendations for rebiopsy strategies.

Should finasteride be used to prevent prostate cancer?

Prostate cancer is an important public health problem. Chemoprevention offers an attractive solution because it may lead to decreased disease-specific mortality. Furthermore, because many men are treated radically for prostate cancers that pose little or no threat to life, chemoprevention may also provide an excellent strategy for diminishing treatment-related costs and adverse effects such as erectile and urinary dysfunction. The Prostate Cancer Prevention Trial was a 7-year randomized study of finasteride versus placebo among men aged older than 55 years. All men were intended to have a prostate biopsy at study conclusion. At trial's end, there was a 25% reduction in period prevalence in all prostate cancers (24.4% for placebo vs 18.4% for finasteride). This represents a 6% absolute risk reduction. A larger number of higher-grade cancers were noted among men randomized to finasteride, which post hoc analyses and studies suggest are almost certainly related to previously unrecognized biases in trial design. There continues to be great debate as to the clinical significance of the cancers prevented. It is our opinion that among men who warrant 5-alpha reductase inhibitors (5ARIs) as part of their benign prostatic hyperplasia regimen, cancer prevention should be recognized as an additional benefit of treatment. Furthermore, men with high risk of clinically significant prostate cancer, such as significant family history, abnormal prostate biopsy histologies, and African descent, should be made aware of these findings. Men with significant anxiety or concern about prostate cancer should also be made aware of the risks and benefits of this therapy. Additional trials of antiestrogens, micronutrients, and other 5ARIs, which will mature over the next 2 to 5 years, will better define the role of 5ARIs in prostate cancer chemoprevention.