Atypical Small Acinar Proliferation: Repeat Biopsy and Detection of High Grade Prostate Cancer

Atypical small acinar proliferation and its significance in pathological reports in modern urological times

Atypical small acinar proliferation is a histopathological diagnosis of unspecified importance in prostate needle-biopsy reports, suggestive but not definitive for cancer. The terminology corresponds to some uncertainty in the biopsy report, as the finding might represent an underlying non-cancerous pathology mimicking cancer or an under-sampled prostate cancer site. Therefore, traditional practice favors an immediate repeat biopsy. However, in modern urological times, the need of urgent repeat biopsy is being challenged by some authors as in the majority of cases, the grade of cancer found in subsequent biopsy is reported to be low or the disease to be non-significant. On the other hand, high risk disease cannot be excluded, whereas no clinical or pathological factors can predict the final outcome. In this review, we discuss the significance of the diagnosis of atypical small acinar proliferation in the biopsy report, commenting on its importance in modern urological practice.

Atypical Small Acinar Proliferation and High Grade Prostatic Intraepithelial Neoplasia: Should We Be Concerned? An Observational Cohort Study with a Minimum Follow-Up of 3 Years

Introduction

Atypical small acinar proliferation (ASAP) and high grade prostatic intraepithelial neoplasia (HGPIN) are considered precancerous. We aimed to measure the rate of repeat biopsy and adenocarcinoma in patients with ASAP and HGPIN and identify any clinico-pathologic parameters at diagnosis of ASAP/HGPIN that are predictive of adenocarcinoma.

Materials and Methods

Patients with a diagnosis of ASAP/HGPIN with no previous or concomitant cancer were identified. Prostate specific antigen (PSA) and magnetic resonance imaging (MRI) changes were monitored. Re-biopsy was at clinician discretion.

Results

Nineteen were diagnosed with ASAP and 17 with HGPIN. Seven with ASAP (37%) and 6 with HGPIN (35%) underwent re-biopsy. Three (16%) with ASAP and 5 with HGPIN (29%) were diagnosed with adenocarcinoma. The difference in cancer detection rates between ASAP and HGPIN was not significant (p = 0.35). Five (14%) in total required definitive therapy for adenocarcinoma. Twenty-three (64%) did not undergo repeat biopsy. Parameters at diagnosis of HGPIN and ASAP, including PSA, prostate volume and PSA density, were compared between the cancer and non-cancer cohorts with none found to be predictive of adenocarcinoma.

Conclusion

By monitoring PSA and MRI changes, we managed to spare re-biopsy in two-thirds of patients. Further evaluation is necessary to characterize a surveillance protocol in these populations.

Managing high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical glands on prostate biopsy

Prostate biopsy is the gold standard for diagnosing prostate cancer and reliable pathological assessment is essential for guiding management. Research efforts over the past few years have aimed to establish a more universal approach to management according to pathological grading; however, high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical glands suspicious for carcinoma are two diagnoses without standardized follow-up and treatment pathways. Much of this uncertainty is due to limited evidence describing the subsequent rates of cancer and high-grade cancer when HGPIN or atypical glands are detected on initial biopsy. Fortunately, data from the past decade have shed light on these phenomena, and an improved understanding of the implications of the presence of HGPIN and atypical glands on prostate biopsy means that clinical recommendations can be made for the management of patients with these diagnoses.

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.

Long-term supplementation of decaffeinated green tea extract does not modify body weight or abdominal obesity in a randomized trial of men at high risk for prostate cancer

Background

Evidence continues to demonstrate the role of obesity in prostate carcinogenesis and prognosis, underscoring the need to identify and continue to evaluate the effective interventions to reduce obesity in populations at high risk. The aim of the study was to determine the effect of daily consumption of decaffeinated green tea catechins (GTC) formulation (Polyphenon E^® (PolyE)) for 1 year on biomarkers of obesity in men who are at high risk for prostate cancer.

Materials and Methods

A randomized, double-blinded trial was conducted targeting 97 men diagnosed with HGPIN or ASAP. Subjects were randomized to receive GTC (PolyE) (n = 49) or placebo (n = 48) for 1 year. Anthropometric data were collected at baseline, 6 and 12 months and data analyzed to observe change in weight, body mass index (indicator of obesity) and waist: hip ratio (indicator of abdominal obesity).

Results

Decaffeinated GTC containing 400 mgs of the bioactive catechin, EGCG administered for 1 year to men diagnosed with ASAP and HGPIN appears to be bioavailable, well tolerated but not effective in reducing biomarkers of obesity including body weight, body mass index and waist: hip ratio.

Conclusions

The results of our trial demonstrates that men who are obese and at high risk for prostate cancer should resort to effective weight management strategies to reduce obesity and not resort to ineffective measures such as taking supplements of green tea to reduce biomarkers of obesity. Changes in body mass index and abdominal obesity seen in other studies were potentially due to caffeine and not GTC.

Racial Variation in the Outcome of Subsequent Prostate Biopsies in Men With an Initial Diagnosis of Atypical Small Acinar Proliferation

BACKGROUND

African American (AA) men are known to have more aggressive prostate cancer (PCa) compared with Caucasian American men. We sought to determine predictors of subsequent detection and risk stratification of PCa in a racially diverse group of men with atypical small acinar proliferation (ASAP) on initial prostate biopsy.

MATERIALS AND METHODS

A retrospective analysis was conducted on data from men with ASAP on initial prostate biopsy who subsequently received confirmatory biopsies between September 2000 and July 2015. Biopsies with more than 3 years between initial and confirmatory biopsies were excluded. Race, age, body mass index, transrectal ultrasound volume, serum prostate-specific antigen (PSA), PSA velocity, PSA density, and elapsed time between biopsies were assessed for predictive value in subsequent PCa diagnosis after an initial finding of ASAP.

RESULTS

Of 106 men analyzed, 75 (71%) were AA and 31 (29%) were non-AA. Baseline variables revealed AA men had higher PSA levels, PSA velocity, and PSA density (all P < .05). PCa was diagnosed in subsequent biopsy in 42 (40%) patients without significant racial variation; 30 (40%) AA versus 12 (39%) non-AA. Of the 42 PCa patients, 25 (24%) met Epstein criteria for significant disease without racial variation; 18 (24%) AA versus 7 (23%) non-AA. Only 10 (9%) patients had any component of Gleason 4; 7 (9%) AA versus 3 (10%) non-AA. In multivariate analysis, increasing age, PSA level, and PSA density were significant predictors of PCa.

CONCLUSION

AA men diagnosed with ASAP on initial prostate biopsy do not have increased risk of PCa on confirmatory biopsy compared with non-AA men.

Diagnostic Difficulties With Atrophy, Atypical Adenomatous Hyperplasia, and Atypical Small Acinar Proliferation: A Systematic Review of Current Literature

Prostate cancer is the second leading cause of cancer death in men, behind only lung cancer. In some cases, the proper diagnosis of prostatic neoplasia can be challenging, and the differential diagnosis includes atypical nonmalignant lesions such as atrophy, atypical adenomatous hyperplasia (AAH), and atypical small acinar proliferation (ASAP). Atrophy and AAH have a benign clinical outcome, and if detected on needle biopsy or transurethral resection of the prostate, clinical follow-up seems appropriate. In contrast, ASAP cannot be determined to be benign or malignant. In clinical practice, the diagnosis of ASAP is an indication for repeat biopsy because the chance of finding prostate adenocarcinoma is even greater than that with an earlier diagnosis of high-grade prostatic intraepithelial neoplasia. Malignant lesions require more restrictive treatment; therefore, differentiation among atrophy, AAH, ASAP, and adenocarcinoma is essential. We performed a systematic review of the current data allow to the creation of a diagnostic algorithm for atrophy, AAH, ASAP, and adenocarcinoma. We propose an algorithm that covers the practical issues related to interpretation of the biopsy findings and how to proceed further.