Is high-grade prostatic intraepithelial neoplasia (HGPIN) a reliable precursor for prostate carcinoma? Implications for clonal evolution and early detection strategies

Tumor architecture and emergence of strong genetic alterations are bottlenecks for clonal evolution in primary prostate cancer

Prostate cancer (PCA) exhibits high levels of intratumoral heterogeneity. In this study, we developed a mathematical model to study the growth and genetic evolution of PCA. We explored the possible evolutionary patterns and demonstrated that tumor architecture represents a major bottleneck for divergent clonal evolution. Early consecutive acquisition of strong genetic alterations serves as a proxy for the formation of aggressive tumors. A limited number of clonal hierarchy patterns were identified. A biopsy study of synthetic tumors shows complex spatial intermixing of clones and delineates the importance of biopsy extent. Deep whole-exome multiregional next-generation DNA sequencing of the primary tumors from five patients was performed to validate the results, supporting our main findings from mathematical modeling. In conclusion, our model provides qualitatively realistic predictions of PCA genomic evolution, closely aligned with the evidence available from patient samples. We share the code of the model for further studies. A record of this paper's transparent peer review process is included in the supplemental information.

Molecular Alterations in Intraductal Carcinoma of the Prostate

Intraductal carcinoma of the prostate is most commonly associated with high-grade invasive prostate cancer. However, isolated IDC-P without adjacent cancer or high-grade cancer is also well known. Common genetic alterations present in IDC-P with adjacent high-grade prostate cancer are those described in high-grade tumors, such as PTEN loss (69-84%). In addition, the rate of LOH involving TP53 and RB1 is significantly higher. IDC-P is common in the TCGA molecular subset of SPOP mutant cancers, and the presence of SPOP mutations are more likely in IDC-P bearing tumors. IDC-P without adjacent high-grade cancers are by far less common. They are less likely to have PTEN loss (47%) and rarely harbor an ERG fusion (7%). Molecular alterations that may predispose a person to the development of IDC-P include the loss of BRCA2 and PTEN as well as mutations in SPOP. However, the causative nature of these genetic alterations is yet to be validated.

Implications of a diagnosis of atypical small acinar proliferation (ASAP) and high-grade prostatic intraepithelial neoplasia (HGPIN) on prostate biopsy: a 5-year follow-up study

BACKGROUND

In the era of active surveillance of low- and intermediate-risk prostatic cancer, a reconsideration of the implications of a biopsy report of ASAP and/or HGPIN may be timely.

AIMS

We investigated the implications of a diagnosis of atypical small acinar proliferation (ASAP) and high-grade prostatic intraepithelial neoplasia (HGPIN) on prostate biopsy.

METHODS

The rate of re-biopsy and the incidence of carcinoma on repeat biopsy for benign, HGPIN, and ASAP groups were compared. Mean PSA and PSA velocity was also compared between groups.

RESULTS

There was an increased risk of developing prostate cancer in the following 5 years with a biopsy diagnosis of ASAP compared to benign (20% vs 5.9%, p = 0.009), and with a biopsy of HGPIN compared with benign (14.8% vs 5.9%, p = 0.005). The frequency of repeat biopsy following a diagnosis of ASAP (54.2%) vs. HGPIN (37%) was not significantly different (p = 0.079). The risk of developing prostate cancer was highest following a biopsy with concomitant ASAP and HGPIN compared to benign (50% vs 5.9%, p < 0.001). There was no significant difference in PSA values between the 3 diagnostic groups at the time of initial biopsy (p = 0.206).

CONCLUSION

The findings of this study suggest that a biopsy diagnosis of ASAP ± HGPIN, on either initial or surveillance biopsy, provides support for earlier repeat mpMRI and/or re-biopsy. This may assist in directing to early re-biopsy those patients likely to have intermediate- and high-risk prostate cancer.

Inflammatory repercussions in female steroid responsive glands after perinatal exposure to bisphenol A and 17-β estradiol

The mammary gland (MG) and female prostate are plastic reproductive organs which are highly responsive to hormones. Thus, endocrine disruptors, such as bisphenol A (BPA) and exogenous estrogens, negatively affect glandular homeostasis. In addition to previously described alterations, changes in inflammatory markers expression also trigger the development of a microenvironment that contributes to tumor progression. The current work aimed to evaluate the inflammatory responses of the MG and prostate gland to BPA (50 µg/kg) and 17-β estradiol (35 µg/kg) exposure during the perinatal window of susceptibility. The results showed that at 6 months of age there was an increase in the number of phospho-STAT3 (P-STAT3) positive cells in the female prostate from animals perinatally exposed to 50 µg/kg BPA daily. In addition, the number of macrophages increased in these animals in comparison with nonexposed animals, as shown by the F4/80 marker. Despite an increase in the incidence of lobuloalveolar and intraductal hyperplasia, the MG did not show any difference in the expression of the four inflammatory markers evaluated: tumor necrosis factor-α, COX-2, P-STAT3, and F4/80. Analysis of both glands from the same animal led to the conclusion that exposure to endocrine disruptors during the perinatal window of susceptibility leads to different inflammatory responses in different reproductive organs. As the prostate is more susceptible to these inflammatory mechanisms, it is reasonable to affirm that possible neoplastic alterations in this organ are related to changes in the inflammatory pattern of the stroma, a characteristic that is not evident in the MG.

Intraductal Carcinoma of the Prostate: A Guide for the Practicing Pathologist

Intraductal carcinoma of the prostate gland (IDCP) is characterized by an expansile, architecturally, and cytologically atypical proliferation of prostatic epithelial cells within preexisting prostatic ducts and acini. There has been a wider recognition of IDCP by practicing pathologists since its recognition as a separate category in the World Health Organization (WHO) 2016 classification of tumours of the prostate gland. However, there is also a lack of clarity regarding the diagnosis and reporting of IDCP, which has been compounded by divergent expert recommendations regarding the grading of invasive prostate cancers associated with an intraductal component. The International Society of Urological Pathologists (ISUP) recommends that the IDCP component should be incorporated into the Gleason score, while the Genitourinary Pathology Society (GUPS) recommends excluding it when grading prostate cancer. This review seeks to clarify some of these issues and outline a pragmatic approach to reporting IDCP, particularly in needle biopsies. Diagnostic issues and terminology for lesions falling short of IDCP but exceeding that of high-grade prostatic intraepithelial neoplasia are discussed. The management of patients whose prostate biopsies show only IDCP without an associated invasive component is controversial. Some experts recommend radical therapy, while others recommend prompt repeat biopsy. An alternative clinicopathologic approach that takes into consideration the extent, histomorphology, and location (with respect to a radiologic abnormality) of IDCP, as well as radiologic features, is outlined.

Cellular and Molecular Mechanisms Underlying Prostate Cancer Development: Therapeutic Implications

Prostate cancer is the most frequent nonskin cancer and second most common cause of cancer-related deaths in man. Prostate cancer is a clinically heterogeneous disease with many patients exhibiting an aggressive disease with progression, metastasis, and other patients showing an indolent disease with low tendency to progression. Three stages of development of human prostate tumors have been identified: intraepithelial neoplasia, adenocarcinoma androgen-dependent, and adenocarcinoma androgen-independent or castration-resistant. Advances in molecular technologies have provided a very rapid progress in our understanding of the genomic events responsible for the initial development and progression of prostate cancer. These studies have shown that prostate cancer genome displays a relatively low mutation rate compared with other cancers and few chromosomal loss or gains. The ensemble of these molecular studies has led to suggest the existence of two main molecular groups of prostate cancers: one characterized by the presence of ERG rearrangements (~50% of prostate cancers harbor recurrent gene fusions involving ETS transcription factors, fusing the 5' untranslated region of the androgen-regulated gene TMPRSS2 to nearly the coding sequence of the ETS family transcription factor ERG) and features of chemoplexy (complex gene rearrangements developing from a coordinated and simultaneous molecular event), and a second one characterized by the absence of ERG rearrangements and by the frequent mutations in the E3 ubiquitin ligase adapter SPOP and/or deletion of CDH1, a chromatin remodeling factor, and interchromosomal rearrangements and SPOP mutations are early events during prostate cancer development. During disease progression, genomic and epigenomic abnormalities accrued and converged on prostate cancer pathways, leading to a highly heterogeneous transcriptomic landscape, characterized by a hyperactive androgen receptor signaling axis.

Essential Updates in Grading, Morphotyping, Reporting, and Staging of Prostate Carcinoma for General Surgical Pathologists

CONTEXT.—

Within this decade, several important updates in prostate cancer have been presented through expert international consensus conferences and influential publications of tumor classification and staging.

OBJECTIVE.—

To present key updates in prostate carcinoma.

DATA SOURCES.—

The study comprised a review of literature and our experience from routine and consultation practices.

CONCLUSIONS.—

Grade groups, a compression of the Gleason system into clinically meaningful groups relevant in this era of active surveillance and multidisciplinary care management for prostate cancer, have been introduced. Refinements in the Gleason patterns notably result in the contemporarily defined Gleason score 6 cancers having a virtually indolent behavior. Grading of tertiary and minor higher-grade patterns in radical prostatectomy has been clarified. A new classification for prostatic neuroendocrine tumors has been promulgated, and intraductal, microcystic, and pleomorphic giant cell carcinomas have been officially recognized. Reporting the percentage of Gleason pattern 4 in Gleason score 7 cancers has been recommended, and data on the enhanced risk for worse prognosis of cribriform pattern are emerging. In reporting biopsies for active surveillance criteria-based protocols, we outline approaches in special situations, including variances in sampling or submission. The 8th American Joint Commission on Cancer TNM staging for prostate cancer has eliminated pT2 subcategorization and stresses the importance of nonanatomic factors in stage groupings and outcome prediction. As the clinical and pathology practices for prostate cancer continue to evolve, it is of utmost importance that surgical pathologists become fully aware of the new changes and challenges that impact their evaluation of prostatic specimens.

Intraductal carcinoma of the prostate: a critical re-appraisal

Intraductal carcinoma of the prostate gland (IDCP), which is now categorised as a distinct entity by WHO 2016, includes two biologically distinct diseases. IDCP associated with invasive carcinoma (IDCP-inv) generally represents a growth pattern of invasive prostatic adenocarcinoma while the rarely encountered pure IDCP is a precursor of prostate cancer. This review highlights issues that require further discussion and clarification. The diagnostic criterion “nuclear size at least 6 times normal” is ambiguous as “size” could refer to either nuclear area or diameter. If area, then this criterion could be re-defined as nuclear diameter at least three times normal as it is difficult to visually compare area of nuclei. It is also unclear whether IDCP could also include tumours with ductal morphology. There is no consensus whether pure IDCP in needle biopsies should be managed with re-biopsy or radical therapy. A pragmatic approach would be to recommend radical therapy only for extensive pure IDCP that is morphologically unequivocal for high-grade prostate cancer. Active surveillance is not appropriate when low-grade invasive cancer is associated with IDCP, as such patients usually have unsampled high-grade prostatic adenocarcinoma. It is generally recommended that IDCP component of IDCP-inv should be included in tumour extent but not grade. However, there are good arguments in favour of grading IDCP associated with invasive cancer. All historical as well as contemporary Gleason outcome data are based on morphology and would have included an associated IDCP component in the tumour grade. WHO 2016 recommends that IDCP should not be graded, but it is unclear whether this applies to both pure IDCP and IDCP-inv.