Effect of neoadjuvant hormonal therapy on prostatic intraepithelial neoplasia and its prognostic significance

Neoadjuvant Hormonal Therapy for Prostate Cancer: Morphologic Features and Predictive Parameters of Therapy Response

The primary goals of neoadjuvant hormonal therapy (NHT) in prostate cancer (PCa) are to reduce the size of the tumor, lower positive surgical margin rate, attempt to reach pathologic remission, and improve survival. Although NHT has not been recommended by the National Comprehensive Cancer Network as a primary treatment option for patients with localized PCa, NHT is increasingly used in clinical trials for locally advanced PCa. More importantly, with the development of novel androgen signaling inhibitors, such as abiraterone and enzalutamide, there has been renewed interests in revisiting the role of such treatment in the neoadjuvant setting. Following NHT, the PCa tissues shows characteristic morphologic alterations. Of note, the collapse of malignant glands most likely leads to an artificial increase of Gleason score in the residual disease. Communicating these changes to the clinician in a way that can help assess the tumor's response poses a challenge for pathologists. In addition, little is known of morphologic features and predictive makers both in pretreated and posttreated specimens that can be of value in predicting tumor response to NHT. In the current review, we summarize the morphologic changes associated with neoadjuvant-treated PCa, focusing on the predictive value of pathologic parameters to therapy response. We also describe the evaluation system in the stratification of pathologic response to NHT in PCa management.

Current significance of the finding of high grade prostatic intraepithelial neoplasia in the prostate biopsy

INTRODUCTION

High grade prostatic intraepithelial neoplasia (HGPIN) is regarded as a precursor of prostate cancer (PC). However, its relationship to cancer has changed throughout the literature, being currently poorly defined and remains controversial for urologists in their clinical practice. Because of his frequency and the impact on patient outcomes that the lack of consensus clinical attitude could carry out, it seems advisable to review the understanding of this disease.

OBJECTIVE

The aim of this literature review is to summarize the main features of this entity (histopathology, molecular, epidemiological) and evaluate their relationship with prostate adenocarcinoma, explaining the variation of incidence seen in the literature and the clinical significance of their finding.

MATERIAL AND METHODS

Review of the literature, based on the research and analysis of publications found in Pubmed with the words "prostate" and "intraepithelial neoplasms".

RESULTS

The HGPIN detection rate has increased to the extent that it has increased the number of punctures in prostate biopsies. With the current biopsy schemes (10-12 punctures), the detection rate of PC in repeat biopsies is similar in patients with and without isolated HGPIN. However, HGPIN multifocality predicts increased risk of PC detection in repeat biopsy.

CONCLUSION

HGPIN detection is common with current biopsy schemes. Its genetic relationship with PC is clear and its multifocality is the most important predictor factor of PC.

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.

Concomitant high-grade prostatic intraepithelial neoplasia is associated with good prognosis factors and oncologic outcome after radical prostatectomy

OBJECTIVES

To assess correlations between concomitant high-grade prostatic intraepithelial neoplasia (HGPIN), pathological features and oncologic outcomes after radical prostatectomy (RP).

MATERIAL AND METHODS

We prospectively collected a single-institution database of 2,351 patients who underwent RP between 1998 and 2011.

RESULTS

1,272 (54.1%) patients had HGPIN on specimens. The mean follow-up was 28 months. Presence of HGPIN was significantly associated with a favorable preoperative risk status and with pathological factors of poor prognosis in RP specimens. Patients without HGPIN had a worse biochemical recurrence-free survival compared with those with HGPIN in RP specimen (log-rank test: p = 0.015). The 3-year RFS rate was 73.9% for the HGPIN group versus 67.2%. The absence of HGPIN was also significantly correlated with the use of androgen deprivation treatment during the follow-up (p < 0.001). In Cox multivariate analysis, taking into account the other prognostic pathological factors, HGPIN was not an independent predictive factor for PSA failure (p = 0.868).

CONCLUSION

HGPIN is associated with factors of good prognosis but fails to show independent significance when classical pathological prognostic factors are taken into account.

Precursors of prostate cancer

High-grade prostatic intraepithelial neoplasia (PIN) is the only accepted precursor of prostatic adenocarcinoma, according to numerous studies of animal models and man; other proposed precursors include atrophy and malignancy-associated changes (with no morphologic changes). PIN is characterized by progressive abnormalities of phenotype and genotype that are intermediate between benign prostatic epithelium and cancer, indicating impairment of cell differentiation and regulatory control with advancing stages of prostatic carcinogenesis. The only method of detection of PIN is biopsy because it does not significantly elevate serum prostate-specific antigen concentration and cannot be detected by ultrasonography. The mean incidence of PIN in biopsies is 9% (range, 4%-16%), representing about 115,000 new cases of isolated PIN diagnosed each year in the United States. The clinical importance of PIN is its high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent carcinoma, especially when multifocal or observed in association with atypical small acinar proliferation (ASAP). Carcinoma develops in most patients with PIN within 10 years. Androgen deprivation therapy and radiation therapy decrease the prevalence and extent of PIN, suggesting that these forms of treatment may play a role in prevention of subsequent cancer. Multiple clinical trials to date of men with PIN have had modest success in delaying or preventing subsequent cancer.

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.

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.

Functional heterogeneity of prostatic intraepithelial neoplasia: the duration of hormonal therapy influences the response

OBJECTIVES

To use a clinical model of androgen-deprivation therapy (ADT) followed by radical prostatectomy (RP) to test the hypothesis that prostatic intraepithelial neoplasia (PIN, a premalignant lesion of the prostate causally linked to prostate cancer) is heterogeneous for hormone responsiveness, which might explain aspects of the heterogeneity of the natural history of prostate cancer, for although ADT has been used to reduce prostate cancer, there are controversial data on the effect of ADT on PIN.

PATIENTS AND METHODS

We assessed retrospectively patients with biopsy-confirmed prostate cancer who had RP; some patients had received >or=3 months of ADT at the discretion of their surgeons, and patients from the same cohort who did not have ADT were used as controls. Patients were sequentially selected from the database and their pathology slides were reviewed by a pathologist unaware of the initial presence of PIN (assessed by an independent observer). Fisher's exact test was used to compare the proportions of patients who had residual PIN in the study and control groups. Exact logistic regression was used to evaluate the duration of ADT on PIN regression.

RESULTS

Eighteen patients initially diagnosed with PIN who had no ADT were identified, and 28 with PIN who had ADT were also assessed. All patients who had had no ADT had residual PIN, whereas seven of 28 receiving ADT had no residual PIN (P=0.043). The evaluation of ADT between responders and nonresponders showed a statistically significant association between PIN regression and the duration of ADT (P<0.001). However, the response of PIN to ADT was not uniform, as 16% of patients on ADT for >6 months had residual PIN, suggesting variable sensitivity of PIN to ADT.

CONCLUSION

These results show that ADT causes PIN to regress, and that there is heterogeneity in this effect with the duration of ADT. We propose future prospective, multicentre, randomized trials in which the effect of ADT on PIN is characterized further.

Flutamide in men with prostatic intraepithelial neoplasia: a randomized, placebo-controlled chemoprevention trial

High-grade prostatic intraepithelial neoplasia (HGPIN) has been identified as a premalignant change in the prostate that indicates increased risk of the subsequent development of prostate adenocarcinoma. Prior studies have suggested that androgen deprivation therapy causes a regression of HGPIN. We therefore conducted a chemoprevention trial assessing the efficacy of flutamide in reducing the rate of prostate adenocarcinoma development in men with HGPIN. Men with biopsyproven HGPIN but no evidence of prostate adenocarcinoma were randomized in a double-blind manner to either flutamide 250 mg/d or a placebo. Treatment was continued for 1 year. Repeat biopsies were obtained at 12 and 24 months. Quality of life and toxicities related to treatment were also measured. Sixty patients were randomized and began therapy with either flutamide or placebo. At 1 year, 14% of men receiving flutamide and 10% of men receiving placebo had developed prostate adenocarcinoma. Flutamide-associated toxicities were mild to moderate in severity. Quality-of-life measures did not show any differences between the 2 groups. This study showed no evidence of benefit from flutamide as a chemoprevention agent in men with HGPIN.

Toremifene for the prevention of prostate cancer in men with high grade prostatic intraepithelial neoplasia: results of a double-blind, placebo controlled, phase IIB clinical trial

PURPOSE

A randomized, double-blind, dose finding, placebo controlled, parallel group clinical study was done to determine the incidence of prostate cancer in men with high grade prostatic intraepithelial neoplasia treated with toremifene.

MATERIALS AND METHODS

A total of 514 patients with high grade prostatic intraepithelial neoplasia and no evidence of prostate cancer on screening biopsy were randomized to 20, 40 or 60 mg toremifene, or placebo daily for 12 months. Patients underwent re-biopsy at 6 and 12 months.

RESULTS

The number of evaluable patients, that is those with 1 on study biopsy who were compliant, was 447. The cumulative risk of prostate cancer was decreased in patients on 20 mg toremifene compared with placebo (24.4% vs 31.2%, p <0.05). The annualized rate of prevention was 6.8 cancers per 100 men treated. In patients with no biopsy evidence of cancer at baseline and 6 months, the 12-month incidence of prostate cancer was decreased by 48.2% with 20 mg toremifene compared with placebo (9.1% vs 17.4%, p <0.05). The 20 mg dose was most effective but cumulative and 12-month incidences of prostate cancer were lower for each toremifene dose vs placebo with a cumulative risk of 29.2% and 28.1%, and a 12-month incidence of 14.3% and 13.0% for 40 and 60 mg, respectively. Gleason scores were similar across treatments. The overall incidence of drug related and serious adverse events did not differ between any of the toremifene groups and the placebo group.

CONCLUSIONS

Toremifene decreased the incidence of prostate cancer by 1 year and had a tolerability profile comparable to that of placebo in a high risk population.

Bicalutamide 50 mg monotherapy in patients with isolated high-grade PIN: findings in repeat biopsies at 6 months

OBJECTIVES

To evaluate morphological findings in repeat biopsies in patients with isolated high-grade prostatic intraepithelial neoplasia (HGPIN) after a 6-month course of bicalutamide (Casodex) 50 mg/day.

METHODS

20 consecutive patients with isolated HGPIN in prostate biopsies were treated for 6 months with bicalutamide 50 mg/day. After treatment, the patients were resubmitted to prostate biopsy mapping. The control group included 22 untreated consecutive patients with isolated high-grade PIN with repeat biopsies taken 6 months after the initial biopsies.

RESULTS

In the initial biopsies of the treated group, HGPIN was monofocal in 12 patients and plurifocal in 8. In the repeat biopsies HGPIN was present in 2 patients, monofocal in both, whereas prostate adenocarcinoma (PCa) was discovered in one. In the control group, HGPIN was monofocal in 15 and plurifocal in 7. In the repeat biopsies HGPIN was present in six patients, being monofocal in three and plurifocal in the other three. PCa was present in one.

CONCLUSIONS

There was a lower incidence of HGPIN (treated group vs control: 10% vs 27.2%) after 6 months of bicalutamide. Reduction in its extent was also observed (treated group vs control: monofocal 100% vs 50%). Treatment did not affect the incidence of cancer (treated vs control: 5% vs 4.5%).

Pathological changes of high-grade prostatic intraepithelial neoplasia and prostate cancer after monotherapy with bicalutamide 150 mg

OBJECTIVES

To evaluate the morphological changes induced by a 3-month course of neoadjuvant bicalutamide 150 mg/day before radical prostatectomy (RP) on prostatic adenocarcinoma and high-grade prostatic intraepithelial neoplasia (HGPIN).

PATIENTS AND METHODS

In all, 90 patients with cT1-T2 prostate cancer and HGPIN on prostatic biopsy were randomized to receive bicalutamide (150 mg/day for 3 months) before RP, or to have immediate surgery. Surgical specimens were assessed for the histopathological features of cancer, HGPIN and benign epithelium in a blinded manner. The volumes of prostate cancer and HGPIN were evaluated using a stereological (i.e. grid) method.

RESULTS

Compared with the bicalutamide-treated group, the ratio of stroma to epithelium, evaluated by visual microscopic assessment in the normal epithelium of the three prostate zones, was significantly lower in the control group, at 2.27 (sd 1.13), than in the treated group, at 1.87 (sd 0.72) (P = 0.048). The mean (sd) tumour volume was significantly lower in the bicalutamide-treated than in the control group, at 0.914 (0.13) vs 1.47 (0.24) mL (P = 0.044). Similarly, the mean (sd) volume of HGPIN was significantly lower in the bicalutamide-treated than in the control group, at 0.34 (0.06) vs 0.62 (0.07) mL (P = 0.003). At RP, specimen Gleason scores in the bicalutamide-treated group were similar to those in the control group, and were no different from the biopsy Gleason scores.

CONCLUSIONS

Involution and epithelial shrinkage of prostate cancer and HGPIN were evident after neoadjuvant treatment with bicalutamide 150 mg. There was no evidence of the emergence of higher-grade cancer after treatment.

Do all patients with high-grade prostatic intraepithelial neoplasia on initial prostatic biopsy eventually progress to clinical prostate cancer?

OBJECTIVE

To assess the clinical outcome of patients with a diagnosis of high-grade prostatic intraepithelial neoplasia (PIN) on initial prostatic biopsy, with a minimum of 5 years of follow-up, as such patients are at greater risk of having prostate cancer on subsequent biopsy.

PATIENTS AND METHODS

Between November 1992 and October 1998, 21 patients were identified as having PIN on their initial transrectal ultrasonography-guided prostate biopsy. None of these patients had a focus of cancer on the initial biopsy. Their medical data were reviewed retrospectively to determine the natural history of PIN in these patients. Patients who were not identified as having cancer were followed every 6-12 months with prostate-specific antigen (PSA) testing and digital rectal examinations (DRE).

RESULTS

A mean (range) of 7 (2-8) cores were taken at initial biopsy; the mean age of the patients was 63 (53-77) years and mean PSA level 9.1 (4.9-17.6) ng/mL. Six patients had an abnormal DRE at presentation. A mean of 8 (7-10) cores were obtained on the second biopsy; six patients were diagnosed with cancer, with a mean Gleason score of 6 (5-7), while three were diagnosed with persistent PIN. These three patients had a third prostate biopsy which showed cancer of Gleason score 6 in one and benign prostatic hyperplasia in two. After a mean follow-up of 72.2 (60-84) months, none of the remaining 12 patients was diagnosed with clinically significant cancer. Five of these patients went on to a third prostate biopsy, with no evidence of cancer. One patient died from unrelated causes during this period.

CONCLUSION

This study affirms our current practice of following patients with PIN conservatively if a second or third subsequent prostate biopsy is negative. Whether PIN is a premalignant lesion or merely a lesion associated with cancer needs to be addressed in multicentre studies with a follow-up of > 10 years.

Apoptotic regulators in prostatic intraepithelial neoplasia (PIN): value in prostate cancer detection and prevention

Early diagnosis of prostate cancer holds tremendous promise for the effective therapy and impact on survival of prostate cancer patients. High-grade prostatic intraepithelial neoplasia (HGPIN) is generally accepted as a lesion indicative of a late pathological event in the premalignant changes leading to full development of prostate cancer. This review seeks to identify specific molecular events that may be linked directly to the molecular transition from benign prostate epithelial cells to prostate carcinoma. HGPIN is pathologically detected in a limited group of men undergoing prostate cancer screening for an elevated serum prostate-specific antigen (PSA) or abnormal digital rectal examination (DRE). Loss of apoptotic control provides a molecular basis for the contribution of specific defective steps in the pathway towards development and progression of prostate cancer. Comparative dissection of the apoptosis status and expression profile of key apoptotic regulators among foci of highly proliferative benign prostatic epithelium, PIN and prostate adenocarcinoma from adjacent areas of the same gland revealed a novel insight into the dysfunctional apoptosis events contributing to prostate carcinogenesis. The sequential and notable loss of the three critical signaling components of the apoptotic action of transforming growth factor-beta (TGF-beta), in the prostate, that is, the transmembrane receptor II (TbetaRII), the key cell cycle inhibitor p27(Kip1), as well as the protagonist downstream effector of the TGF-beta signaling mechanism, Smad4, points to their potential value to 'faithfully' characterize HGPIN, as a premalignant prostate lesion. Recent evidence on the molecular changes in apoptosis regulators contributing to HGPIN and their role as molecular markers of disease onset, as well as candidates for therapeutic targeting/chemoprevention of prostate cancer in its early stages will be discussed.

Prostatic Intraepithelial Neoplasia: An Update

High-grade prostatic intraepithelial neoplasia (HGPIN) is commonly encountered on prostate needle biopsies and, based on epidemiologic, molecular, and animal models, has proven to be the most significant risk factor for prostate cancer and likely represents the premalignant phase of prostatic adenocarcinoma. This lesion is characterized by cellular proliferations within pre-existing ducts and glands, with nuclear and nucleolar enlargement similar to prostate cancer. However, unlike cancer, HGPIN retains a basal cell layer identifiable by immunohistochemistry with the basal cell-specific antibody cytokeratin 34bE12. The incidence of HGPIN identified in needle biopsies is as high as 25%, increases with age, and coexists with prostate cancer in approximately 85% of cases. There appears to be no causal relationship between HGPIN and serum prostate-specific antigen (total, percent free, or density) or radiographic characteristics on transrectal ultrasound. In a large series, the identification of HGPIN on initial needle biopsy is associated with about a 35% risk of prostate cancer on subsequent biopsies. Thus, the finding of HGPIN on prostate needle biopsy necessitates a second biopsy in a patient eligible for curative treatment. As a precursor lesion, HGPIN is currently a target for chemopreventive strategies, including antiandrogens and nutritional supplementation.

High-grade prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (PIN) is now accepted as the most likely preinvasive stage of adenocarcinoma, almost two decades after its first formal description. PIN has a high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent invasive carcinoma. The only method of detection is biopsy; PIN does not significantly elevate serum prostate-specific antigen (PSA) concentration or its derivatives and cannot be detected by current imaging techniques, including ultrasound. Most patients with PIN will develop carcinoma within 10 years. PIN is associated with progressive abnormalities of phenotype and genotype, which are similar to cancer rather than normal prostatic epithelium, indicating impairment of cell differentiation with advancing stages of prostatic carcinogenesis. Androgen deprivation therapy decreases the prevalence and extent of PIN, suggesting that this form of treatment may play a role in chemoprevention.

Testosterone Replacement Therapy in Hypogonadal Men at High Risk for Prostate Cancer: Results of 1 Year of Treatment in Men With Prostatic Intraepithelial Neoplasia

PURPOSE

One of the greatest concerns among clinicians regarding testosterone replacement therapy (TRT) is the fear of causing or promoting prostate cancer. We evaluated prostatic changes in hypogonadal men with and without high grade prostatic intraepithelial neoplasia (PIN), which is considered a prostatic precancerous lesion, after 1 year of TRT.

MATERIALS AND METHODS

A total of 75 hypogonadal who completed 12 months of TRT were studied. All underwent prostate biopsy prior to initiating treatment. Of the men 55 had benign prostate biopsies (PIN-) and 20 had PIN without frank cancer (PIN+). All men with PIN underwent repeat biopsy to exclude cancer prior to the initiation of testosterone treatment. Prostate specific antigen (PSA), and total and free testosterone were determined prior to treatment and at 1 year. Repeat biopsy was performed for a change noted on digital rectal examination or for a PSA increase of 1 ng/l or greater.

RESULTS

PSA was similar at baseline in men with and without PIN (1.49 +/- 1.1 and 1.53 +/- 1.6 ng/dl, p >0.05) and after 12 months of TRT (1.82 +/- 1.1 and 1.78 +/- 1.6 ng/dl, respectively, p >0.05). A slight, similar increase in mean PSA was noted in the PIN- and PIN+ groups (0.25 +/- 0.6 and 0.33 +/- 0.6 ng/dl, p >0.05). One man in the PIN+ group had cancer after biopsy was performed due to abnormal digital rectal examination. Four additional men in the PIN- group and 2 in the PIN+ group underwent re-biopsy for elevated PSA and none had cancer. No differences were noted between the PIN- and PIN+ groups with regard to total and free testosterone at baseline and at 1 year (p = 0.267).

CONCLUSIONS

After 1 year of TRT men with PIN do not have a greater increase in PSA or a significantly increased risk of cancer than men without PIN. These results indicate that TRT is not contraindicated in men with a history of PIN.

Phase IIA Clinical Trial to Test the Efficacy and Safety of Toremifene in Men with High-Grade Prostatic Intraepithelial Neoplasia

Men with high-grade prostatic intraepithelial neoplasia (PIN) evident on prostate biopsy are at high risk for the eventual development of prostate cancer. The ability to reverse high-grade PIN may reduce the incidence or delay the development of prostate cancer. Toremifene (GTx-006, Acapodene trade mark ) is a selective estrogen receptor modulator that has been shown in the transgenic mouse model of prostate cancer to eliminate high-grade PIN and reduce the incidence of prostate cancer. This study was aimed at the evaluation of the safety and efficacy of toremifene in men diagnosed with high-grade PIN. This was an open-label, phase IIA clinical trial that enrolled 21 men (mean age, 64.7 years) with evidence of high-grade PIN on biopsy within 6 months of entry into the study. Eighteen of these men (86%) completed toremifene treatment (60 mg/day orally for 4 months) and then underwent follow-up prostate biopsy (8 cores) to determine high-grade PIN status. The effect of the drug on serum prostate-specific antigen (PSA), percentage of free PSA, testosterone, estradiol, and quality of life was also measured. After toremifene treatment, 72% of these 18 men (vs. 17.9% of historical controls) had no high-grade PIN on subsequent prostate biopsies. Mean PSA trended higher, and percentage of free PSA was increased. Quality of life was not significantly affected by treatment. There were 3 mild adverse events, and no serious adverse events. Toremifene appeared to reduce high-grade PIN in this small, exploratory trial. The drug was well tolerated. A double-blind, dose-finding, randomized, placebo-controlled phase IIB/III study is currently open to further study toremifene's activity against high-grade PIN and prostate cancer incidence.

High-grade prostatic intraepithelial neoplasia and prostate cancer risk reduction

High-grade prostatic intraepithelial neoplasia (PIN) is the earliest accepted stage in carcinogenesis, possessing most of the phenotypic and biochemical changes in cancer without invasion of the basal membrane of the acini. The support for high-grade PIN as the main premalignant lesion of prostate cancer is based on several lines of evidence derived from prostate cancer animal models, epidemiological, morphological, genetic, and molecular studies. The incidence of high-grade PIN averages 9% (range 4-16%) in prostate biopsies, representing 115,000 new cases of high-grade PIN diagnosed each year in the United States. Performing saturation prostate biopsies to rule out any coexistent prostate cancer followed by every 3-6 month serial repeated prostate biopsies is currently the only way in which to manage patients found to have high-grade PIN. Medical therapy for high-grade PIN may easily become the mainstay treatment for high-grade PIN. Treatment of high-grade PIN appears to be of clinical benefit notwithstanding the potential for prostate cancer risk reduction. These clinical benefits would reduce morbidity, enhance quality of life, delay surgery or radiation, and increase the interval for surveillance requiring invasive procedures.

Contemporary pathology of prostate cancer

In less than 20 years since the introduction of serum PSA and the spring-loaded 18-gauge prostatic biopsy needle, pathologists have adjusted to the limited tissue requirements of narrow needle specimens to apply criteria for diagnosis and grading of prostate cancer, borrowing from lessons learned from radical prostatectomies. Substantial gains have been made during this period in the understanding of precancerous lesions, mimics of malignancy, the criteria for minimal cancer, variants of cancer, and treatment-induced changes. The light microscopic findings remain the criterion standard for diagnosis against which all new techniques should be measured. Numerous findings have proven to be of value, including simple quantitation of histopathologic features, cancer volume, perineural invasion, and others.

Pathologic effects of neoadjuvant cyproterone acetate on nonneoplastic prostate, prostatic intraepithelial neoplasia, and adenocarcinoma: a detailed analysis of radical prostatectomy specimens from a randomized trial

Neoadjuvant hormonal therapy (NHT; androgen ablation) is used prior to radical prostatectomy (RP) in an attempt to pathologically "downstage" prostatic adenocarcinoma and ultimately to improve disease-free survival. This study describes the pathologic effects of NHT with the antiandrogen cyproterone acetate, 300 mg/day for 12 weeks, on the RP specimens from men with clinically localized (stage T1 or T2) prostatic adenocarcinoma. There were 101 men in the pretreatment group (CPA) and 91 men in a control group who were treated with surgery alone. The prevalence and extent of morphologic effects were recorded for the nonneoplastic prostate, high-grade prostatic intraepithelial neoplasia, and invasive adenocarcinoma. The commonest effects on the nonneoplastic prostate were atrophy and basal cell hyperplasia and prominence. High-grade prostatic intraepithelial neoplasia was more commonly identified in the surgery alone group than the CPA group (p <0.01). In the CPA group, flat and low tufted patterns of high-grade prostatic intraepithelial neoplasia predominated. Following NHT, the adenocarcinoma showed characteristic morphologic alterations, including reduction in cytoplasmic quantity, cytoplasmic vacuolation, nuclear pyknosis, reduced gland diameter, and mucinous breakdown. In many cases there was prominence of collagenous stroma, obscuring malignant glands. Compared with the surgery alone group, the CPA group RP specimens had a significantly lower mean specimen weight (40.3 g vs 46.5 g, p = 0.025) and less tumor extent by several measures. Organ-confined tumor (stage pT2, margin negative) was found in 41.6% of the CPA group compared with 19.8% of the surgery alone group (p = 0.0017). The overall rate of margin positivity was lower in the CPA group (27.7% vs 64.8%, p = 0.001). We consider that the difference in margin positivity is the result of tumor shrinkage with a decreased likelihood of sampling in routine sections. There was no significant difference in the rate of extraprostatic extension between the two groups. There was elevation of the Gleason score in the RP specimens versus baseline biopsy in 60% of the CPA group compared with 33% of the surgery alone group (p = 0.02). The higher rate of elevation in the CPA group largely resulted from an increase in primary or secondary Gleason score 5 tumor, a morphologic artifact introduced by NHT. Because of this, we recommend not giving a Gleason grade to RP specimens following NHT. Monotherapy with CPA has similar pathologic effects on benign and malignant prostate tissue as does dual agent androgen blockade. Prolonged follow-up of these patients is required to determine if NHT with CPA leads to improved disease-free survival.

Followup interval prostate biopsy 3 years after diagnosis of high grade prostatic intraepithelial neoplasia is associated with high likelihood of prostate cancer, independent of change in prostate specific antigen levels

PURPOSE

Repeat biopsy has been advocated following the diagnosis of high grade prostatic intraepithelial neoplasia to exclude coexisting prostate cancer. We further define the natural history of high grade prostatic intraepithelial neoplasia by determining the incidence of prostate cancer 3 years following diagnosis.

MATERIALS AND METHODS

A total of 31 men underwent followup interval biopsy 3 years after high grade prostatic intraepithelial neoplasia diagnosis in 1996 to 1997, regardless of change in serum prostate specific antigen (PSA) or digital rectal examination findings. A single pathologist reviewed all biopsy specimens. All men had a minimum of 12 biopsy cores taken at the time of diagnosis.

RESULTS

A 3-year followup interval biopsy eight (25.8%) men had prostate cancer, 11 (35.5%) had high grade prostatic intraepithelial neoplasia only and 12 (38.7%) had no disease. Mean serum PSA at diagnosis and before the followup biopsy was 6.88 and 9.69 ng./dl., respectively (p = 0.008). Of the men 48% had less than a 1.0 unit increase in serum PSA. Upon univariate regression analysis change in serum PSA was not associated with the detection of prostate cancer (p >0.10). All 4 patients who subsequently underwent radical prostatectomy had organ confined disease.

CONCLUSIONS

In a high proportion of men with high grade prostatic intraepithelial neoplasia prostate cancer will develop in a 3-year interval. Our findings support the concept that high grade prostatic intraepithelial neoplasia is a precursor to prostate cancer and that repeat biopsy at a delayed interval is recommended regardless of changes in PSA.

Effect of androgen deprivation therapy on prostatic intraepithelial neoplasia

There is a marked decrease in the prevalence and extent of high-grade prostatic intraepithelial neoplasia (PIN) in men with prostate cancer after androgen deprivation therapy (ADT) when compared with untreated cases. Basal cell hyperplasia, cytoplasmic clearing, and prominent atrophy of benign acini, with decreased ratio of acini to stroma, accompany this decrease. These findings indicate that the benign and dysplastic prostatic epithelium is androgen dependent. In the normal prostatic epithelium, luminal secretory cells are more sensitive to the absence of androgen than basal cells, and the proliferative cells of high-grade PIN share this androgen sensitivity. The loss of some normal, hyperplastic, and dysplastic epithelial cells with ADT is probably because of acceleration of programmed single-cell death. Remarkably little is known about the comparative effect of different forms of chemical ADT on PIN and cancer, although there appears to be a limited and consistent repertoire of morphologic responses to all forms of this therapy. Conversely, blockade of 5alpha-reductase with finasteride has little or no effect on PIN (or benign epithelium and cancer), unlike other forms of ADT. A recent international consensus conference sponsored by the World Health Organization concluded that identification of high-grade PIN offered the possibility of chemoprevention with hormonal therapy to block the development of clinical cancer. Multiple chemoprevention trials are planned or under way to address this hypothesis.

High grade prostatic intraepithelial neoplasia is a disease

High grade prostatic intraepithelial neoplasia (PIN) is now widely accepted as the main premalignant lesion that has the potential to progress to prostate adenocarcinoma. High grade PIN is a standard diagnosis that must be included as part of the reported pathologic evaluation of prostate biopsies. Premalignant lesions that affect other organs have been identified and are treated when diagnosed such that the premalignant lesions itself are a disease (eg, carcinoma in situ of the bladder, colon polyps, and cervical dysplasia). Urologists should recognize that high grade PIN is a dangerous lesion and that it should be aggressively managed either by saturation biopsies of the prostate following the diagnosis of high grade PIN, or the more common recommendation--repeated prostate biopsies every 3 to 6 months for 2 years, then annually. Treatment of these precancerous lesions would appear to be of clinical benefit notwithstanding the potential for cancer prevention. These clinical benefits would reduce morbidity, enhance the quality of life, delay surgery or radiation, and increase the interval for surveillance requiring invasive procedures.

Prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (PIN) is now accepted as the most likely pre-invasive stage of adenocarcinoma, a decade after its first formal description. PIN has a high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent invasive carcinoma. The only method of detection is biopsy; PIN does not significantly elevate serum prostate-specific antigen concentration or its derivatives and cannot be detected by ultrasound. Most studies suggest that most patients with PIN will develop carcinoma within 10 years. PIN is associated with progressive abnormalities of phenotype and genotype that are similar to cancer rather than normal prostatic epithelium, indicating impairment of cell differentiation with advancing stages of prostatic carcinogenesis. Androgen deprivation therapy decreases the prevalence and extent of PIN, suggesting that this form of treatment may play a role in chemoprevention.

Antiandrogens in prostate cancer

Antiandrogens competitively inhibit ligand binding to the androgen receptor (AR), and are used therapeutically in prostate cancer patients. The AR functions as a ligand dependent transcription factor that transduces androgen binding into increased transcription of androgen dependent genes. AR blockade induces programmed cell death in the vast majority of malignant and benign prostate cancer cells that have not previously been exposed to androgen ablation. The antiandrogens are divided structurally into the steroidal and non steroidal agents. The biological effects of the steroidal versus nonsteroidal agents are distinguished by differences in their effects on serum testosterone levels, and by their activity at receptors other than the androgen receptor. There is extensive clinical experience in the palliative and curative therapy of prostate cancer using antiandrogens as monotherapy or antiandrogens in combination with luteinizing hormone agonists or surgical castration. Prolonged therapy with antiandrogens selects for mutations in the AR that change the AR ligand specificity and permits stimulation by ligands that are usually inhibitory. These mutations give insight into one of the means by which prostate cancer progresses despite antiandrogen therapy, and also helps to explain the antiandrogen withdrawal syndrome. Areas of active research that may affect the future use of antiandrogens include the ongoing evaluation of antiandrogens in combination with 5 alpha reductase inhibitors to achieve AR blockade without inducing castrate testosterone levels. There is also interest in developing selective androgen receptor modulators (SARM) that can achieve AR blockade without causing the increased testosterone levels produced by the nonsteroidal antiandrogens currently in use.