Significance of atypical small acinar proliferation and high-grade prostatic intraepithelial neoplasia in prostate biopsy

What is cancer? A focus on Grade Group 1 prostate cancer

Since the widespread adoption of prostate-specific antigen-based screening for prostate cancer, the prevalence of Grade Group 1 (GG1) prostate cancer has risen. Historically, these patients were subjected to overtreatment of this otherwise indolent disease process, leading to significant quality-of-life detriments. Active surveillance as a primary management strategy has allowed for a focus on early detection while minimising morbidity from unnecessary intervention. Here we provide a comprehensive overview of the characteristics of GG1 prostatic adenocarcinoma, including its histological features, genomic differentiators, clinical progression, and implications for treatment guidelines, all supporting the movement to reclassify GG1 disease as a non-cancerous entity.

Clinical strategy of repeat biopsy in patients with atypical small acinar proliferation (ASAP)

Atypical small acinar proliferation (ASAP) occurs in approximately 5% of prostate biopsies. Approximately 30–40% of patients with ASAP have biopsy detectable prostate cancer (PCa) within 5 years. Current guidelines recommend a repeat biopsy within 3–6 months after the initial diagnosis. The aim of the present study was to examine the association between ASAP and subsequent diagnosis of clinically significant PCa (csPCa). The need for immediate repeat biopsy was also evaluated. We identified 212 patients with an ASAP diagnosis on their first biopsy at our institution between February 2006 and March 2018. Of these patients, 102 (48.1%) had at least one follow-up biopsy. Clinicopathologic features including rates of subsequent PCa and csPCa were assessed. Thirty-five patients subsequently underwent radical prostatectomy (RP). Their pathologic results were reviewed. csPCa was defined as the presence of Gleason score (GS) ≥ 3 + 4 in ≥ 1 biopsy core. Adverse pathology (AP) was defined as high-grade (primary Gleason pattern ≥ 4) or non-organ-confined disease (pT3/N1) after RP. Of 102 patients, 87 (85.3%), 13 (12.7%), and 2 (2.0%) had one, two, and three follow-up biopsies, respectively. Median time from the initial ASAP diagnosis to the 2nd follow-up biopsy and the last follow-up biopsy were 21.9 months (range 1–129 months) and 27.7 months (range 1–129 months), respectively. Of these patients, 46 (45.1%) were subsequently diagnosed with PCa, including 20 (19.6%) with csPCa. Only 2 (2.0%) patients had GS ≥ 8 disease. Five (4.9%) patients had number of positive cores > 3. Of 35 patients who subsequently underwent RP, seven (20%) had AP after RP and 17 (48.6%) showed GS upgrading. Of these 17 patients, the vast majority (16/17, 94.1%) had GS upgrading from 3 + 3 to 3 + 4. 45.1% of patients with an initial diagnosis of ASAP who had repeat prostate biopsy were subsequently diagnosed with PCa and 19.6% were found to have csPCa. Our findings add further evidence that after a diagnosis of ASAP, a repeat biopsy is warranted and that the repeat biopsy should not be postponed.

Rate of clinically significant prostate cancer on repeat saturation biopsy after a diagnosis of atypical small acinar proliferation

BACKGROUND

Atypical small acinar proliferation (ASAP) occurs in approximately 5% of prostate biopsies. Approximately 30%-40% of these patients may develop prostate cancer (PCa) within a 5-year period, often not clinically significant. Current guidelines recommend a repeat biopsy within 3-6 months after the initial diagnosis, but it seem not to be the best strategy.

METHODS

Objectives-evaluating the natural history of ASAP, stratifying the risk of csPCa after ASAP, identifying predictive factors of PCa after atypical diagnosis. Materials and methods-retrospective single-institutional study on patients undergoing prostate biopsy for suspicious PCa (2005-2016). We evaluated the incidence of overall PCa, intermediate-high risk of PCa and csPCa in case of ASAP, according to D'Amico classification and Epstein modified criteria.

RESULTS

Out of 4.567 patients undergoing prostate biopsy, ASAP was detected in 2.6% of cases. All patients with ASAP underwent repeat saturation biopsy within 6 months and PCa was diagnosed in 34.5%. According to D'Amico classification, 26%, 5.9%, and 2.5% had low, intermediate, and high-risk disease, respectively. According modified Epstein criteria, the incidence of csPCa was 12.6%. LRT showed that the overall probability to develop PCa doubled when PSA density (PSAD) moved from values lower than 0.13 ng/ml/cc to class 0.13-0.30 ng/ml/cc, and it tripled when PSAD was higher than 0.30 ng/ml/cc.

CONCLUSIONS

The rate of csPCa in patients with an initial diagnosis of ASAP who had repeat biopsy was 12.6%. The overall PCa rate was 34.5%. Among patient undergoing RP, an upgrading from ncsPCa to csPCa was reported in 35% of cases. PSAD is the only predictive factor directly associated to the risk of developing PCa on repeat biopsy. These findings suggest that immediate repeat biopsy remains the correct strategy in absence of novel predictor factors and non-invasive diagnostic evaluations.

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.

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.

Application of transrectal ultrasound-guided repeat needle biopsy in the diagnosis of prostate cancer in Chinese population: A retrospective study

BACKGROUND

Transrectal ultrasound-guided repeat needle biopsy (TUGRNB) is widely used for diagnosis of prostate cancer (PCa). However, significance of TUGRNB in Chinese population was rarely reported. A retrospective study was conducted to evaluate the significance of TUGRNB applied in prediction of PCa in Chinese population.

MATERIALS AND METHODS

A total of 960 from January 2009 to December 2012 were included. Repeat needle biopsy rate and PCa positive detection rate were evaluated. Relationship between prostate specific antigen (PSA) levels and PCa positive rates was analyzed.

RESULTS

PCa positive detection rate after initial needle biopsy was 28.4%, which was lower than the rate of repeat needle biopsy (40%). The rate for immediate transurethral resection (TUR), surgery after initial needle biopsy, was 27.1%, however with a low PCa positive detection rate (0.66%). The repeat needle biopsy rate was lower compared with the initial biopsy rate (P < 0.05). Meanwhile, immediate TUR rate was significantly higher than that of the repeat needle biopsy rate (P < 0.05). Among the three groups, the PCa positive detection rate in repeat needle biopsy group was the highest. In subgroups with different PSA levels, the PCa positive rate increased with the elevation of PSA level. In cases with PSA > 20 ng/ml, PCa positive rate was significantly higher than those with PSA < 20 ng/ml (P < 0.05).

CONCLUSION

PCa positive detection rate following repeat needle biopsy in Chinese population was higher, although the repeated needle biopsy rate was still in a low level. TUGRNB should attract more attention in the diagnosis of PCa.

Multiple cores of high grade prostatic intraepithelial neoplasia and any core of atypia on first biopsy are significant predictor for cancer detection at a repeat biopsy

Purpose

To investigate the differences in the cancer detection rate and pathological findings on a second prostate biopsy according to benign diagnosis, high-grade prostatic intraepithelial neoplasia (HGPIN), and atypical small acinar proliferation (ASAP) on first biopsy.

Materials and Methods

We retrospectively reviewed the records of 1,323 patients who underwent a second prostate biopsy between March 1995 and November 2012. We divided the patients into three groups according to the pathologic findings on the first biopsy (benign diagnosis, HGPIN, and ASAP). We compared the cancer detection rate and Gleason scores on second biopsy and the unfavorable disease rate after radical prostatectomy among the three groups.

Results

A total of 214 patients (16.2%) were diagnosed with prostate cancer on a second biopsy. The rate of cancer detection was 14.6% in the benign diagnosis group, 22.1% in the HGPIN group, and 32.1% in the ASAP group, respectively (p<0.001). When patients were divided into subgroups according to the number of positive cores, the rate of cancer detection was 16.7%, 30.5%, 31.0%, and 36.4% in patients with a single core of HGPIN, more than one core of HGPIN, a single core of ASAP, and more than one core of ASAP, respectively. There were no significant differences in Gleason scores on second biopsy (p=0.324) or in the unfavorable disease rate after radical prostatectomy among the three groups (benign diagnosis vs. HGPIN, p=0.857, and benign diagnosis vs. ASAP, p=0.957, respectively).

Conclusions

Patients with multiple cores of HGPIN or any core number of ASAP on a first biopsy had a significantly higher cancer detection rate on a second biopsy. Repeat biopsy should be considered and not be delayed in those patients.

Prostate cancer: the need for biomarkers and new therapeutic targets

Prostate cancer (PCa) incidence and mortality have decreased in recent years. Nonetheless, it remains one of the most prevalent cancers in men, being a disquieting cause of men's death worldwide. Changes in many cell signaling pathways have a predominant role in the onset, development, and progression of the disease. These include prominent pathways involved in the growth, apoptosis, and angiogenesis of the normal prostate gland, such as androgen and estrogen signaling, and other growth factor signaling pathways. Understanding the foundations of PCa is leading to the discovery of key molecules that could be used to improve patient management. The ideal scenario would be to have a panel of molecules, preferably detectable in body fluids, that are specific and sensitive biomarkers for PCa. In the early stages, androgen deprivation is the gold standard therapy. However, as the cancer progresses, it eventually becomes independent of androgens, and hormonal therapy fails. For this reason, androgen-independent PCa is still a major therapeutic challenge. By disrupting specific protein interactions or manipulating the expression of some key molecules, it might be possible to regulate tumor growth and metastasis formation, avoiding the systemic side effects of current therapies. Clinical trials are already underway to assess the efficacy of molecules specially designed to target key proteins or protein interactions. In this review, we address that recent progress made towards understanding PCa development and the molecular pathways underlying this pathology. We also discuss relevant molecular markers for the management of PCa and new therapeutic challenges.

Two sequential diagnoses of atypical foci suspicious for carcinoma on prostate biopsy: a follow-up study of 179 cases

OBJECTIVE

To follow-up the outcomes with patients who have had 2 consecutive "atypical foci suspicious for carcinoma (ATYP)" diagnoses from prostate biopsies.

MATERIALS AND METHODS

A total of 516 men who had prostate core biopsy specimens with 2 sequential diagnoses of ATYP from 2003 to 2012 from 1 institution were studied.

RESULTS

Of the 516 men, 179 underwent additional repeat biopsy (34.8%) after 2 ATYP diagnoses. No difference was found between the patients with and without a repeat biopsy after 2 ATYPs in terms of patient age, serum prostate-specific antigen levels, and digital rectal examination and transrectal ultrasound findings. On repeat biopsy after 2 ATYP findings, 95 of the 179 men (53.1%) had benign prostatic tissue or high-grade prostatic intraepithelial neoplasia, 65 (36.3%) had cancer, and 19 (10.6%) had a third finding of ATYP. The Gleason score in the cancer group was 3+3=6 (50 patients, 77%), 3+4=7 (12 patients, 18.5%), 4+3=7 (1 patient, 1.5%), and 4+4=8 (2 patients, 3%). No difference was seen between those without (benign, high-grade prostatic intraepithelial neoplasia, or ATYP) and with cancer in terms of patient age, serum prostate-specific antigen level, digital rectal examination and transrectal ultrasound findings, and interval between the 2 ATYP biopsies and the interval between the first ATYP and last biopsy.

CONCLUSION

The results of our study have shown that 36.3% men will be diagnosed with cancer on biopsy after 2 ATYP diagnoses, with 23% having a Gleason score of ≥7. Because no clinical features were predictive of which patients would have cancer on the follow-up biopsy, close follow-up and repeat biopsy are warranted.