STRATEGY FOR REPEAT BIOPSY IN PATIENTS WITH HIGH GRADE PROSTATIC INTRAEPITHELIAL NEOPLASIA

Typing the atypical: Diagnostic issues and predictive markers in suspicious prostate lesions

As much as 5% of prostate biopsies yield findings equivocal for malignancy even for skilled uropathologist; such "grey zone" lesions have been addressed in many ways, although the acronym ASAP (atypical small acinar proliferation) is the most widely used when referring to an atypical focus suspicious, but not diagnostic, for malignancy. Since the introduction of this diagnostic category more than 20 years ago, debate has ensued over its histological characterization and clinical significance. Pathology reporting of ASAP, commonly based on strict morphological criteria and traditional immunohistochemical markers such as basal cell antibodies, has been improved by recent availability of novel immunohistochemical markers such as AMACR and ERG. Further pathological issues, such as the role of pre-analytical variables, number of tissue levels, interobserver variability, and association with prostatic intraepithelial neoplasia also play a role in the optimal assessment of ASAP. Apart from diagnostic issues, a major issue is ASAP predictive value for prostate cancer on repeat biopsy. Therefore, attempts have been made to identify clinical and biological parameters that could predict subsequent diagnosis of malignancy as well as define time and modality of repeat biopsy. Finally, pathological features of cancers detected after a previous ASAP diagnosis are compared with those diagnosed at first prostate biopsy.

Preneoplasia in the prostate gland with emphasis on high grade prostatic intraepithelial neoplasia

There are a variety of morphological patterns and processes that have been implicated in the pathogenesis of prostate cancer. Prostatic intraepithelial neoplasia (PIN), inflammation with or without atrophy, and adenosis (atypical adenomatous hyperplasia) have all been given candidate status as precursor lesions of prostatic adenocarcinoma. Based on decades of research, high grade prostatic intraepithelial neoplasia (HPIN), a proliferative lesion of prostatic secretory cells, has emerged as the most likely morphological pre-invasive lesion involved in the evolution of many but not all prostatic adenocarcinomas. In this manuscript, we briefly discuss other proposed precursors of prostatic adenocarcinoma and then focus on the history, diagnostic criteria and morphology of HPIN. The incidence of HPIN and its relationship to prostate cancer is reviewed. The differential diagnosis of large glandular patterns in the prostate is discussed in depth. Finally, we summarise the recent clinicopathological studies evaluating the clinical significance of HPIN and discuss follow-up strategies in men diagnosed with HPIN.

Diagnosis of isolated high-grade prostatic intra-epithelial neoplasia: proposal of a nomogram for the prediction of cancer detection at saturation re-biopsy

Study Type--Diagnostic (case series). Level of Evidence 4. What's known on the subject? And what does the study add? Multifocality, age, PSA values, and biopsy protocols regarding the predictive value of high grade PIN have been discussed extensively in the literature. Our study developed for the first time a predictive nomogram that could be helpful for patient counselling and to guide the urologist to perform rPBX after an initial diagnosis of isolated HGPIN.

OBJECTIVE

• To evaluate factors that may predict prostate cancer (PCa) detection after the initial diagnosis of high-grade prostatic intra-epithelial neoplasia (HGPIN) on prostate biopsy (PBx) with six to 24 random cores.

PATIENTS AND METHODS

• We retrospectively evaluated 262 patients submitted from 1998 to 2007 to prostate re-biopsy (rPBx) after an initial HGPIN diagnosis in tertiary academic centres. • HGPIN diagnosis was obtained on initial systematic PBx with six to 24 random cores. • All patients were re-biopsied with a 'saturation' rPBx with 20-26 cores, with a median time to rPBx of 12 months. • All slides were reviewed by expert uropathologists.

RESULTS

• Plurifocal HGPIN (pHGPIN) was found in 115 patients and monofocal HGPIN (mHGPIN) was found in 147 patients. • In total, 108 and 154 patients, respectively, were submitted to >12-core initial PBx and ≤12-core initial PBx. • Overall PCa detection at rPBx was 31.7%. PSA level (7.7 vs 6.6 ng/mL; P= 0.031) and age (68 vs 64 years; P= 0.001) were significantly higher in patients with PCa at rPBx. • PCa detection was significantly higher in patients with a ≤12-core initial PBx than in those with a >12-core initial PBx (37.6% vs 23.1%; P= 0.01), as well as in patients with pHGPIN than in those with mHGPIN (40% vs 25.1%; P= 0.013). • At multivariable analysis, PSA level (P= 0.041; hazards ratio, HR, 1.08), age (P < 0.001; HR, 1.09), pHGPIN (P= 0.031; HR, 1.97) and ≤12-core initial PBx (P= 0.012; HR, 1.95) were independent predictors of PCa detection. • A nomogram including these four variables achieved 72% accuracy for predicting PCa detection after an initial HGPIN diagnosis.

CONCLUSIONS

• PCa detection on saturation rPBx after an initial diagnosis of HGPIN is significantly higher in patients with a ≤12-core initial PBx than those with a >12-core initial PBx and in patients with pHGPIN than in those with mHGPIN. • We developed a simple prognostic tool for the prediction of PCa detection in patients with initial HGPIN diagnosis who were undergoing saturation rPBx.

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.

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.

Diagnosis of prostate cancer

The contemporary challenge of prostate cancer diagnosis has been changed in the past decade from the endeavor to increase detection to that of detecting only those tumors that are clinically significant. Better interpretation of the role of prostate-specific antigen (PSA) and its kinetics as a diagnostic tool, the adoption of extended prostate biopsy schemes, and perhaps implementation of new transrectal ultrasound (TRUS) technologies promote the achievement of this clinical mission. This chapter reviews these issues as well as the change in practice of patient preparation for TRUS-biopsy and analgesia during it, the role of repeat and saturation prostate biopsies, and the interpretation of an incidental prostate cancer finding. Currently, the lifetime risk of a diagnosis of prostate cancer for North American men is 16%, compared to the lifetime risk of death from prostate cancer, which is 3% (Carter 2004). The advent of prostate-specific antigen (PSA) screening and transrectal ultrasonography (TRUS) has significantly impacted the detection of prostate cancer over the last 20 years. The mean age at diagnosis has decreased (Hankey et al. 1999; Stamey et al. 2004) and the most common stage at diagnosis is now localized disease (Newcomer et al. 1997; Stamey et al. 2004). The goal of prostate cancer screening is to detect only those men at risk for death from the disease at an early curable phase. The ambiguous natural history of this most common malignancy in men, being latent with questionable life-threatening potential in a large number of cases on the one hand, with only a relatively small number (though not negligible) of highly malignant cases on the other, propels many doubts about whether this is possible. This was famously phrased more than 20 years ago by Whitmore who asked: "Is cure possible for those in whom it is necessary; and is it necessary for those in whom it is possible?" This is probably even more relevant nowadays. During the past decade two factors influenced significantly the increased detection rate of prostate cancer in general and that of clinically insignificant prostate cancers in particular: the widespread use of serum PSA as a screening tool to a large extent and to a lesser though significant extent the application of extended multiple core biopsy schemes (Master et al. 2005). In fact, 75% of men in the United States aged 50 years and older have been screened with the PSA test (Sirovich et al. 2003). Outside of the screening context, which is dealt with in depth in Chap. 5, clinical suspicion of prostate cancer is raised usually by abnormal digital rectal examination (DRE) and/or by abnormal levels of serum PSA. Final diagnosis is achieved only based on positive prostate biopsies.

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.

Widespread High-grade Prostatic Intraepithelial Neoplasia on Prostatic Needle Biopsy: A Significant Likelihood of Subsequently Diagnosed Adenocarcinoma

In comparison with earlier studies, recent reports have demonstrated a lower incidence of prostate carcinoma after an initial diagnosis of high-grade prostatic intraepithelial neoplasia (HGPIN). The latter has led to a general tendency to reconsider the absolute need for a rebiopsy in this setting. The current retrospective study assesses the subsequent likelihood of identifying prostatic adenocarcinoma (PCa) in 41 patients with an initial diagnosis of "widespread" HGPIN defined as HGPIN present in 4 or more biopsy cores. All patients underwent at least 1 follow-up (F/U) sampling procedure in a period of 1 to 41 months. PCa was found in 16/41 patients (39%), all except 1 identified on the first F/U biopsy with the remaining patients diagnosed on a transurethral resection after a negative first F/U biopsy. All but 1 prostatic carcinoma diagnoses were obtained within 2 years from initial biopsy with 10 rendered within the first year. On average, prostate cancer was identified at 10.4 months (range: 1 to 36). One-fourth of all identified prostatic carcinomas were of Gleason score 7 or more. In 4 additional patients (9.7%), F/U biopsy revealed HGPIN with adjacent atypical small glands suspicious but not diagnostic of carcinoma (PINATYP). Of 41 patients, 10 (24.3%) continued to show HGPIN with the remaining 11/41 patients (26.8%) showing benign prostatic tissue. Patients >or=70 years of age at the time of initial biopsy had a statistically significant higher rate of PCa or HGPIN/PINATYP diagnosis on repeat biopsy compared with younger patients (P=0.02), with 55% of older men being diagnosed with cancer as compared with 33% in younger men. Patients with fewer cores sampled on initial biopsy were more likely to be diagnosed with carcinoma as opposed to HGPIN/PINATYP on F/U (P=0.015). Other factors such as the number of F/U procedures, serum prostate-specific antigen level before initial HGPIN biopsy, number of cores per F/U biopsy, and F/U interval length did not affect the likelihood of finding carcinoma. In summary, our study reveals a 39% risk of finding PCa on repeat biopsies obtained after an initial diagnosis of widespread HGPIN. Our findings support the need for a repeat biopsy in this subset of patients.

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

PURPOSE

We identified information critical for patient treatment on prostate needle biopsies diagnosed with prostatic intraepithelial neoplasia or atypical foci suspicious for carcinoma.

MATERIALS AND METHODS

A search was performed using the MEDLINE database and referenced lists of relevant studies to obtain articles addressing the significance of finding PIN or atypical foci suspicious for carcinoma on needle biopsy.

RESULTS

There were certain results concerning PIN. 1) Low grade PIN should not be documented in pathology reports due to poor interobserver reproducibility and a relatively low risk of cancer following re-biopsy. 2) The expected incidence of HGPIN on needle biopsy is between 5% and 8%. 3) Although the diagnosis of HGPIN is subjective, interobserver reproducibility for its diagnosis is fairly high among urological pathologists, and yet only moderate among pathologists without special expertise in prostate pathology. 4) The median risk recorded in the literature for cancer following the diagnosis of HGPIN on needle biopsy is 24.1%, which is not much higher than the risk reported in the literature for repeat biopsy following a benign diagnosis. 5) The majority of publications that compared the risk of cancer in the same study following a needle biopsy diagnosis of HGPIN to the risk of cancer following a benign diagnosis on needle biopsy show no differences between the 2 groups. 6) Clinical and pathological parameters do not help stratify which men with HGPIN are at increased risk for a cancer diagnosis. 7) A major factor contributing to the decreased incidence of cancer following a diagnosis of HGPIN on needle biopsy in the contemporary era is related to increased needle biopsy core sampling, which detects many associated cancers on initial biopsy, such that re-biopsy, even with good sampling, does not detect many additional cancers. 8) It is recommended that men do not need routine repeat needle biopsy within the first year following the diagnosis of HGPIN, while further studies are needed to confirm whether routine repeat biopsies should be performed several years following a HGPIN diagnosis on needle biopsy. There were certain results concerning atypical glands suspicious for carcinoma. 1) An average of 5% of needle biopsy pathology reports are diagnosed as atypical glands suspicious for carcinoma. 2) Cases diagnosed as atypical have the highest likelihood of being changed upon expert review and urologists should consider sending such cases for consultation in an attempt to resolve the diagnosis as definitively benign or malignant before subjecting the patient to repeat biopsy. 3) Ancillary techniques using basal cell markers and AMACR (alpha-methyl-acyl-coenzyme A racemase) can decrease the number of atypical diagnoses, and yet one must use these techniques with caution since there are numerous false-positive and false-negative results. 4) The average risk of cancer following an atypical diagnosis is approximately 40%. 5) Clinical and pathological parameters do not help predict which men with an atypical diagnosis have cancer on repeat biopsy. 6) Repeat biopsy should include increased sampling of the initial atypical site, and adjacent ipsilateral and contralateral sites with routine sampling of all sextant sites. Therefore, it is critical for urologists to submit needle biopsy specimens in a manner in which the sextant location of each core can be determined. 7) All men with an atypical diagnosis need re-biopsy within 3 to 6 months.

CONCLUSIONS

It is critical for urologists to distinguish between a diagnosis of HGPIN and that of atypical foci suspicious for cancer on needle biopsy. These 2 entities indicate different risks of carcinoma on re-biopsy and different recommendations for followup.

Significación pronóstica del PIN y la atípia glandular focal en la Biopsia Transrectal Ecodirigida de Próstata

OBJECTIVE

To review the incidence of PIN and Atypical Small Acinar Proliferation (ASAP) on first biopsy, the risk to find cancer on following biopsies and what is the importance given to this findings, analizing how frequently and how long after the initial finding this patients are rebiopsied.

METHOD

We selected 6000 patients who underwent TRUS biopsy between 1994 and 2002. Patients with prior cancer diagnosis were not included. 861 of them underwent more than one biopsy, adding up to a total of 7127 biopsies. A descriptive study has been done including percentages and percentiles for qualitative variables, mean and median for continuous variables.

RESULTS

Incidence of cancer on the first biopsy was 39,1%. PIN and ASAP are stable or slightly increase from 2 and 2,1% respectively on the first biopsy to more than 6% on the fourth and fifth ones. Mean time between biopsies when ASAP or PIN are the initial findings is 180 +/- 221,6 and 264 +/- 213,8 days respectively. Just 42 and 40% of patients with prior PIN or ASAP diagnose are rebiopsied. On subsequent biopsies 45 and 40% of cancers were respectively found.

CONCLUSIONS

Presence of PIN or ASAP implies a higher cancer risk on subsequent biopsies; in spite of that, less than half of them are biopsied again. Performing two more biopsies or an amplified biopsy can find most of the tumors associated.

High-grade prostatic intraepithelial neoplasia in needle biopsy as risk factor for detection of adenocarcinoma: current level of risk in screening population

OBJECTIVES

To assess the current incidence of prostate carcinoma detection in serial biopsies in a prostate-specific antigen-based screening population after a diagnosis of isolated high-grade prostatic intraepithelial neoplasia (HG-PIN) in needle biopsy tissue.

METHODS

We retrospectively identified 190 men with a diagnosis of isolated HG-PIN in needle biopsy tissue. Most men (86%) were diagnosed from 1996 to 2000. Logistic regression analysis was used to predict the presence of carcinoma in these 190 men and in a control group of 1677 men with only benign prostatic tissue in needle biopsy tissue.

RESULTS

The cumulative risk of detection of carcinoma on serial sextant follow-up biopsies was 30.5% for those with isolated HG-PIN compared with 26.2% for the control group (P = 0.2). Patient age (P = 0.03) and serum prostate-specific antigen level (P = 0.02) were significantly linked to the risk of cancer detection, but suspicious digital rectal examination findings (P = 0.1), the presence of HG-PIN (P = 0.2), and the histologic attributes of PIN were not (all with nonsignificant P values). HG-PIN found on the first repeat biopsy was associated with a 41% risk of subsequent detection of carcinoma compared with an 18% risk if benign prostatic tissue was found on the first repeat biopsy (P = 0.01).

CONCLUSIONS

The results of our study have shown that the current level of risk for the detection of prostate carcinoma in a screened population is 30.5% after a diagnosis of isolated HG-PIN in a needle biopsy. This risk level is lower than the previously reported risk of 33% to 50%. HG-PIN is a risk factor for carcinoma detection only when found on consecutive sextant biopsies. The data presented here should prompt reconsideration of repeat biopsy strategies for HG-PIN, and re-evaluation of the absolute necessity of repeat biopsy for all patients with HG-PIN.

Predictors of prostate cancer on extended biopsy in patients with high-grade prostatic intraepithelial neoplasia: a multivariate analysis model

OBJECTIVE

To define the importance of extended biopsy in patients with high-grade prostatic intraepithelial neoplasia (HGPIN) and to define predictors of cancer in extended biopsy in patients with HGPIN, using multivariate analysis.

PATIENTS AND METHODS

In all, 83 patients with previous sextant biopsy of HGPIN had an extended 11-core biopsy taken. Patients with a negative biopsy for cancer were followed by serum prostate-specific antigen (PSA) and digital rectal examination (DRE) every 6 months. The extended biopsy was repeated in 21 patients. The criteria for second biopsy were an increase in PSA and/or abnormal changes on DRE. Overall, 49 patients had a transurethral resection of the prostate (TURP). The cancer-detection rate on extended biopsy was correlated with risk factors using the chi-square test and multivariate analysis.

RESULTS

Extended biopsy detected prostate cancer in 30 of the 83 men (36%), with positive cores in only 20 sextant biopsy sites (67%), in only seven in additional sites (23%), and both in three (10%). Of the 21 patients who had repeat extended biopsy, four (19%) had cancers. There were two carcinomas in the 49 TURP specimens (4%). The PSA level, DRE and transrectal ultrasonography findings were not predictive of cancer in extended biopsies (chi-square test). Patient age, PSA density and the number of cores with HGPIN (all P < 0.001) had a significant effect on the cancer-detection rate, and multivariate analysis showed that all three were independent predictors of cancer. A logistic regression model was designed to predict the probability of cancer in extended biopsy, with an overall accuracy of 78%.

CONCLUSION

Extended biopsy improved the cancer detection rate by 23% in patients with HGPIN. Patient age, PSA density and the number of cores with HGPIN were the only independent predictors of cancer.

Analysis of alpha-methylacyl-CoA racemase (P504S) expression in high-grade prostatic intraepithelial neoplasia

Alpha-methylacyl-CoA racemase (AMACR), also known as P504S, is a recently identified molecular marker for prostate cancer. The expression of AMACR/P504S has also been observed in high-grade prostatic intraepithelial neoplasia (PIN), a precursor lesion of prostate cancer. However, a detailed study focusing on the analysis of AMACR/P504S expression in high-grade PIN has not been performed. In this study, we analyzed AMACR/P504S expression by immunohistochemistry in 3954 prostatic ducts and acini with high-grade PIN from 140 prostatectomy specimens. AMACR/P504S immunoreactivity was measured as negative (0), weakly positive (+1), moderately positive (+2), and strongly positive (+3). AMACR/P504S immunoreactivity was detected in 90.0% (126/140) of high-grade PIN cases, although only 41.5% (1642/3954) of prostatic glands involved by PIN showed AMACR/P504S immunoreactivity. A significantly higher AMACR/P504S-positive rate (56.0%) was found in isolated high-grade PIN glands adjacent to cancer (distance less than 5 mm) compared with those away from cancer (distance more than 5 mm; 14%, P < 0.0001). High-grade PIN glands adjacent to cancer also showed a higher (P < 0.0004) AMACR/P504S intensity (1.62) than did those away from cancer (1.11). Our results suggest that PIN strongly positive for AMACR/P504S might be more closely associated with cancer than PIN negative or weakly positive for AMACR/P504S. This study provides additional evidence to link high-grade PIN as a precursor lesion to prostatic adenocarcinoma.

Monofocal and plurifocal high-grade prostatic intraepithelial neoplasia on extended prostate biopsies: factors predicting cancer detection on extended repeat biopsy

OBJECTIVES

To evaluate factors predicting cancer detection by extended repeat prostate biopsies in patients with an initial, isolated, monofocal or plurifocal, high-grade prostatic intraepithelial neoplasia (HGPIN) diagnosis.

METHODS

From 1995 to 2002, after a first set of 10 to 12 systematic biopsy cores, 47 patients with an initial HGPIN diagnosis underwent repeat biopsy using the same technique (mean repeat biopsy cores 11.5) after a median follow-up of 11.4 months (range 3 to 24).

RESULTS

Cancer was detected at the second biopsy in 21 patients (44.6%). Cancer detection was significantly greater in patients with plurifocal HGPIN than in those with monofocal HGPIN (70% vs. 10%, respectively; P <0.005) and in patients who underwent repeat biopsy more than 6 months after the first biopsy set (65%) compared with patients who underwent repeat biopsy within 6 months (25%; P <0.01; mean follow-up 15.5 and 3.8 months, respectively). Multivariate analysis showed that prostate-specific antigen, prostate-specific antigen density, digital rectal examination, and transrectal ultrasound findings were not statistically significant predictors of prostate cancer, and HGPIN multifocality and interval between biopsies (more than a 6-month follow-up interval) were independent prognostic factors (odds ratio 4.65 and 2.65, respectively). After radical prostatectomy (14 patients), no statistically significant differences were found in the pathologic stage between patient groups stratified by repeat biopsy interval (within or after 6 months).

CONCLUSIONS

After a 10 to 12-core biopsy, patients with initial, isolated monofocal or plurifocal HGPIN diagnoses had an overall cancer detection rate of 45% on repeat extended biopsies. Plurifocal HGPIN on the first biopsy set was the strongest independent predictive factor in cancer detection. A 12 to 18-month interval before repeat biopsy could permit a significantly greater cancer detection rate, with no apparent likelihood of clinical cancer progression.

High-grade Prostatic Intraepithelial Neoplasia on Needle Biopsy

The importance of isolated high-grade prostatic intraepithelial neoplasia (HGPIN) on needle biopsy is its association with synchronous invasive carcinoma. The relevance of this relationship has been called into question in recent years. In our study, we examined whether the histologic subtype of HGPIN (ie, tufting, micropapillary, cribriform, flat) and/or the number of core biopsies involved by HGPIN was predictive of a subset of men who were at higher risk of having invasive carcinoma on follow-up biopsies. We examined 200 sets of needle biopsies with a diagnosis of isolated HGPIN. Patient age ranged from 46 to 90 years (mean 66.4 years). The breakdown of the histologic subtypes of HGPIN is as follows: tufting 59%, micropapillary 34.3%, cribriform 6.2%, and flat 0.5%. A total of 132 patients (66%) had follow-up biopsies. Prostatic adenocarcinoma was identified in 28.8% of patients with 89.5% of cancers identified on the first two follow-up biopsies. For men that had two or more cores with HGPIN on the initial biopsy, 35.9% eventually had cancer on follow-up whereas men with only single core involvement had cancer in 22% of cases. Men with tufting/flat HGPIN on the initial biopsy had cancer on follow-up in 31.9% of cases, whereas the micropapillary/cribriform subtype was associated with cancer in 22% of follow-up biopsies. The histologic findings on the first repeat biopsy can be quite informative as to the risk of synchronous invasive carcinoma. Of the men with HGPIN on the first repeat biopsy, 32% eventually had cancer on follow-up. Additionally, if multiple cores were involved by HGPIN on the first repeat biopsy, the risk of finding cancer was 50%, regardless of single or multiple core involvement on the initial biopsy. Men with a benign diagnosis on the first repeat biopsy had a 14% risk of having cancer on follow-up. These data indicate that the multiple core involvement by HGPIN, both on initial and first repeat biopsy, defines a subset of men that are at increased risk of harboring synchronous invasive carcinoma. The histologic subtype of PIN does not appear to be as informative.

Is low-grade prostatic intraepithelial neoplasia a risk factor for cancer?

INTRODUCTION

High-grade prostatic intraepithelial neoplasia (HGPIN) is generally accepted to be a precursor lesion of prostate cancer. The likely outcome of isolated low-grade PIN (LGPIN) lesions in prostate biopsies remains unclear. A follow-up study of 106 patients with LGPIN- and HGPIN lesions was performed.

MATERIALS AND METHODS

In a 2-y period, 207 men were diagnosed with isolated PIN on standard systematic sextant biopsy of the prostate. In total, 104 patients had LGPIN and 103 had HGPIN. No patients had ever received androgen deprivation therapy, chemotherapy or radiation therapy. In all, 106 patients who underwent repeat second or third sextant biopsies were analysed in the study; 30% of these patients received a selenium-vitamin E supplement for at least 6 months.

RESULTS

In total, 43 had LGPIN and 63 HGPIN on the first biopsy. The mean age was 63.5 y (range 46-77) in the LGPIN group and 64.9 y in the HGPIN group. The mean total PSA was 6.96 ng/ml (range 0.59-34.13) in the LGPIN group and 8.44 ng/ml (range 0.59-35.3) in the HGPIN group. In the LGPIN group, 30% of the patients had cancer in at least one of the repeat biopsy cores. In the HGPIN group, 27% had cancer in at least one of the repeat biopsy cores. The mean total PSA of patients who had cancer in repeat biopsies with LGPIN was 7.84 ng/ml (range 2.92-34.13). The mean total PSA of the patients who had cancer in repeat biopsy in the HGPIN was 6.73 ng/ml (range 0.56-25). There was no significant difference in PSA and pathological stage between those patients who did and those who did not receive selenium-vitamin E supplements.

CONCLUSIONS

These data are intriguing since the risk of finding prostate carcinoma on repeat sextant biopsy in the LGPIN group is 30%. This is higher than commonly reported. The importance of recognising and re-biopsying HGPIN was confirmed. If chemoprevention could be shown to be effective, it might be beneficial not only in HGPIN but also in LGPIN. The possible activity of chemopreventive agents and their combination with iso-flavonoids needs further investigation.

Pathological and molecular aspects of prostate cancer

This review focuses on new findings and controversial issues in the the pathology and molecular biology of adenocarcinoma of the prostate. Since management of high-grade prostatic intraepithelial neoplasia on needle biopsy--the most common precursor lesion to prostate cancer--is the crucial issue with this lesion, we discuss the risk of cancer subsequent to this histological diagnosis and the issue of whether such neoplasia should be regarded as carcinoma-in-situ. We also look at prostate cancer itself, starting with its diagnosis, reporting on needle biopsy, and reviewing how the most frequently used grading system, the Gleason grading system, affects treatment. The molecular basis of prostate cancer includes inheritable and somatic genetic changes (tumour suppressor genes, loss of heterozygosity, gene targets and regions of chromosomal gain, CpG island promoter methylation, invasion and metastasis suppressor genes, telomere shortening, and genetic instability). Changed gene expression (eg, proliferation-related genes, changes in the androgen receptor, apoptosis and stress-response genes) have potential as biomarkers and therapeutic targets in prostate cancer.

Pathologic features the urologist should expect on a prostate biopsy

In recent years, the pathological evaluation of prostate biopsy specimens has made great improvements in diagnostic accuracy and comprehensiveness. In this article, we review major pathological findings on prostate biopsy, their interpretation and reporting, as well as their clinical significance and utility. We discuss especially the clinically relevant histological features in either a positive or negative biopsy. We emphasize that both Gleason score and extent of cancer involvement in a needle core biopsy are important predictors of clinical outcome after either radical prostatectomy or radiation. Special issues regarding diagnosis and grading of minimal cancer on needle core biopsies are discussed. We also highlight the current standards on high-grade prostatic intraepithelial neoplasia and atypical small acinar proliferation on needle core biopsies. In summary, the pathology reports on needle biopsies are far beyond the simple presence or absence of cancer; they contain invaluable information to clinicians on patient management and counseling.

Predictors of cancer in repeat extended multisite prostate biopsy in men with previous negative extended multisite biopsy

OBJECTIVES

To evaluate the factors influencing the cancer detection rate in men whose initial and repeat biopsies were both performed using an extended multisite biopsy scheme. Sextant biopsy of the prostate is associated with a significant false-negative rate, as evident from the high cancer detection rate after repeat prostate biopsy. Extended multisite biopsy schemes have therefore been recommended to maximize cancer detection.

METHODS

Between June 1997 and August 2001, 939 men underwent prostate biopsy for early detection of prostate cancer using the extended multisite scheme (10 or 11 cores incorporating the anterior horn of the peripheral zone with or without midline peripheral zone and/or the transition zone). Of these 939 men, 89 (9.5%) underwent a repeat extended multisite prostate biopsy. The median prostate-specific antigen level was 6.9 ng/mL (range 0.7-36.1). Twenty-four men (27%) had an abnormal digital rectal examination at presentation. Most men (86%) in the group undergoing repeat biopsy had two or more risk factors for a positive biopsy. The median interval between biopsies was 4 months.

RESULTS

Of the 89 men, 15 (17%) had prostate cancer in the repeat biopsy specimen. Seven cancers (47%) were found only in the alternate biopsy sites, 5 (33%) cancers were found only in the sextant sites, and 3 in both sextant and alternate sites. Cancer was present in only one biopsy core in 11 (73%) of the 15 men, and the median Gleason score was 6 (range 6-8). On multivariate analysis, the presence of atypical glands suspicious for carcinoma (AGSC) was the only independent predictor of cancer in repeat biopsy (P <0.004). Of the 79 men without AGSC in the initial biopsy, 8 (10%) had a positive repeat biopsy. The total and percent free prostate-specific antigen level, digital rectal examination, ultrasound findings, and presence of high-grade prostatic intraepithelial neoplasia were not predictive of cancer detection.

CONCLUSIONS

The probability of a positive result for a repeat prostate biopsy is lower after an initial extended multisite biopsy compared with an initial sextant biopsy. The presence of AGSC was the only significant predictor of cancer in the repeat biopsy. Because nearly 50% of cancers detected in the repeat biopsy were in alternate sites only, using a sextant biopsy scheme for repeat biopsy would have missed these cancers.

The value of a single biopsy with 12 transperineal cores for detecting prostate cancer in patients with elevated prostate specific antigen

PURPOSE

Prostate cancer detection on standard sextant biopsy is considered inadequate. Various biopsy protocols have been introduced to improve cancer diagnosis. We report our experience with transperineal 12-core prostate biopsy.

MATERIALS AND METHODS

In a prospective study 650 patients underwent prostate specific antigen (PSA) measurement during a 15-month period, of whom 141 with PSA greater than 4 ng./ml. also underwent transperineal 12-core prostate biopsy using the fan technique. Median PSA was 8 ng./ml. (range 4.1 to 5,000).

RESULTS

Prostate cancer was detected in 72 of the 141 patients (51%), including 44 of the 97 (45%) with PSA between 4.1 and 10 ng./ml. This incidence is higher than previously reported in the literature using other biopsy techniques. Disease was low grade Gleason 2 to 4 in 4 cases (5%), intermediate grade Gleason 5 to 6 in 26 (35%) and high grade Gleason 7 to 10 in the remaining 42 (60%).

CONCLUSIONS

A high cancer detection rate is achieved by 12-core transperineal prostate biopsy. Most tumors represent clinically significant cancer. Further randomized trials are required to confirm these data.

The predictive value for prostate cancer of lesions that raise suspicion of concomitant carcinoma: an evaluation from a randomized, population-based study of screening for prostate cancer

BACKGROUND

Suspicion of prostate carcinoma may persist after an initial negative biopsy result, and repeated biopsy is suggested. The authors assessed whether diagnostic follow-up of men with an initial diagnosis of isolated, high-grade prostatic intraepithelial neoplasia (HPIN) and a prostate biopsy suspicious for malignancy (PBSM) is needed.

METHODS

The frequency of isolated HPIN and PBSM was determined in 4057 participants of a population-based screening study who underwent systematic sextant transrectal biopsy. The predictive value for prostate carcinoma of HPIN and PBSM was determined by performing repeated biopsies at 6-week interval. The additional predictive value for malignant disease within a screened population was assessed by performing repeated biopsies at a 1-year interval in 462 consecutively recruited men with an initial benign biopsy result. Participants were subjected to a second screening at a 4-year interval. The biopsy and radical prostatectomy tumor features were determined.

RESULTS

Isolated HPIN and PBSM were diagnosed in 0.8% and 2.6% of biopsied men, respectively. The detection rates on repeated biopsy were 10.0% (3 of 30 men) for isolated HPIN, 38.7% (36 of 93 men) for PBSM, and 11.0% (51 of 462 men) for those with initial benign biopsy results. Except for two men (one with PBSM and one with HPIN), all others remained free of prostate carcinoma at their second screening. Features of the tumors that were detected after PBSM were comparable to those that were detected on initial biopsy, whereas the few tumors that were diagnosed after HPIN had highly favorable features.

CONCLUSIONS

Compared with men who have PBSM, men with isolated HPIN on initial biopsy are at no greater risk of being diagnosed with prostate carcinoma than if their initial biopsies were assessed as benign only. Moreover, the features of tumors that are diagnosed after an evaluation of HPIN warrant no early, extensive diagnostic follow-up.

[Prostatic intraepithelial neoplasm diagnosed with transrectal biopsy. Overall review]

OBJECTIVE

To review the incidence, clinical features and management guidelines for patients with isolated prostatic intraepithelial neoplasia (PIN) diagnosed through prostate transrectal biopsy.

METHODS AND RESULTS

Search in Medline database for papers published between 1990 and 2000 based on the following key words: "prostatic intraepithelial neoplasia and needle biopsy". Nineteen papers fulfilling the search criteria were selected.

CONCLUSIONS

The incidence of PIN in patients seen as part of an early diagnosis program is much lower than in patients attending standard Urology practices. PSA level and ultrasound changes are poor predictors of PIN presence in the biopsy. Prostate cancer incidence in successive biopsies ranges between 13.3% and 100%. None of the clinical variables used to diagnose prostate cancer (DRE, PSA and transrectal ultrasound) can predict accurately the existence of cancer associated to PIN, and only prostatic intraepithelial neoplasia grading is considered a good cancer predictor. There is no consensus with regard to diagnostic and therapeutic management in these patients.