Past, Current, and Future Strategies to Target ERG Fusion-Positive Prostate Cancer

Cribiform and intraductal carcinoma in hereditary prostate cancer: clinical and pathological analysis of 20 cases

Cribiform and intraductal carcinoma are patterns of aggressive prostate carcinoma. This study investigated the clinical and pathological features of hereditary prostate cancer. Twenty cases of hereditary prostate cancer from 11 family lines treated at the First Affiliated Hospital of Zhejiang University School of Medicine between 2016-2022 were included to summarize the clinical and pathological features by analyzing clinical information including follow up the survival of the patients and pathological features. Of the 20 hereditary prostate cancer cases, 19 were radical prostate specimens and 1 was a biopsy specimen. The mean age at diagnosis of the patients was 67.55 years and the mean PSA was 15.44 ng/ml, of which 10 cases had PSA ≥ 10 ng/ml and 5 cases had PSA ≥ 20 ng/ml. Of the 19 radical prostate specimens, Gleason cribriform pattern (Gleason grade 4) of PCa is observed in 15 cases (78.95%), and intraductal carcinoma, usually a rare form, is seen in 9 cases (47.3%). Two cases demonstrated pelvic lymph node metastasis, and 7 cases (35%) belonged to high-risk or very high-risk PCa. One case (5.26%) showed partial deletion of expression of RB1, and 13 cases (68.42%) showed deletion of expression of PTEN. Follow-up was 4-90 months, 2 cases had biochemical recurrence and 1 case died from prostate cancer. The mean age at diagnosis of this group of patients with hereditary prostate cancer was 67.55 years, the mean preoperative PSA was 15.44 ng/ml, and their histomorphology was characterized by a high percentage of intraductal carcinoma and cribriform pattern of the prostate.

Molecular biomarkers in prostate cancer tumorigenesis and clinical relevance

Prostate cancer (PCa) is the second most frequent type of cancer in men and assessing circulating tumor cells (CTCs) by liquid biopsy is a promising tool to help in cancer early detection, staging, risk of recurrence evaluation, treatment prediction and monitoring. Blood-based liquid biopsy approaches enable the enrichment, detection and characterization of CTCs by biomarker analysis. Hence, comprehending the molecular markers, their role on each stage of cancer development and progression is essential to provide information that can help in future implementation of these biomarkers in clinical assistance. In this review, we studied the molecular markers most associated with PCa CTCs to better understand their function on tumorigenesis and metastatic cascade, the methodologies utilized to analyze these biomarkers and their clinical significance, in order to summarize the available information to guide researchers in their investigations, new hypothesis formulation and target choice for the development of new diagnostic and treatment tools.

'High proliferative cribriform prostate cancer' defines a patient subgroup with an inferior prognosis

AIMS

A cribriform pattern, reactive stroma (RS), PTEN, Ki67 and ERG are promising prognostic biomarkers in primary prostate cancer (PCa). We aim to determine the relative contribution of these factors and the Cancer of the Prostate Risk Assessment Postsurgical (CAPRA-S) score in predicting PCa prognosis.

METHODS AND RESULTS

We included 475 patients who underwent radical prostatectomy (2010-12, median follow-up = 8.7 years). Cribriform pattern was identified in 57% of patients, PTEN loss in 55%, ERG expression in 51%, RS in 39% and high Ki67 in 9%. In patients with multiple samples from the same malignant focus and either PTEN loss or high Ki67, intrafocal heterogeneity for PTEN and Ki67 expression was detected in 55% and 89%, respectively. In patients with samples from two or more foci, interfocal heterogeneity was detected in 46% for PTEN and 6% for Ki67. A cribriform pattern and Ki67 were independent predictors of biochemical recurrence (BCR) and clinical recurrence (CR), whereas ERG expression was an independent predictor of CR. Besides CAPRA-S, a cribriform pattern provided the highest relative proportion of explained variation for predicting BCR (11%), and Ki67 provided the highest relative proportion of explained variation for CR (21%). In patients with a cribriform pattern, high Ki67 was associated with a higher risk of BCR [hazard ratio (HR) = 2.83, P < 0.001] and CR (HR = 4.35, P < 0.001).

CONCLUSIONS

High Ki67 in patients with a cribriform pattern identifies a patient subgroup with particularly poor prognosis, which we termed 'high proliferative cribriform prostate cancer'. These results support reporting a cribriform pattern in pathology reports, and advocate implementing Ki67.

The relevance of ERG immunoexpression intensity for prostatic adenocarcinoma in radical prostatectomy of 635 samples

Prostate cancer is the world's most frequently diagnosed malignancy in men. Recent work suggests that patients with high ERG expression intensity are significantly more likely to develop biochemical relapse and metastasis, and die of prostate cancer. The objective of this study was to determine the relationship between the intensity of ERG protein expression and the staging of prostate cancer and the formation of metastases in 635 samples. A retrospective cohort analysis was performed using immunohistochemistry reactions in tissue microarray samples taken from non-neoplastic and neoplastic prostate tissue from patients who underwent radical prostatectomies at a reference hospital from 2009 to 2016. For the ERG marker analysis, the samples were scored for the presence or absence of nuclear signals. Weak, moderate, or strong intensity of the nuclei of the observable tumor cells was considered to be positive markers. All told, 635 samples were evaluated, and the ERG expression was inconclusive in 9% of cases, while 30% were positive and 61% were negative. Of the samples with positive result: 25.8% were weak and focal, 53.2% were moderate, and 21% were strong. Finally, 21% of the cases with a positive ERG had a high Gleason score. Metastasis was detected in 41% of the patients who were ERG positive, and of these, the majority had moderate marking and were aged older than 60 years, although there was no statistically significant difference between the older and younger age groups. Patients with moderate to strong ERG staining had higher staging compared to the others, and no increase in metastasis was detected in patients with more intense ERG expression. More studies should be carried out to corroborate these results and to reach a consensus on the intensity and scoring of the expression levels of ERG markers.

Immunohistochemical Expression of Alpha-Methyl-Coa (AMACR) and ERG in Prostatic Adenocarcinoma and Prostatic Hyperplasia: A Comparative Study

OBJECTIVE

This observational comparative study aimed at investigating the diagnostic accuracy of ERG in differentiating benign and malignant prostatic lesions and comparing it to the diagnostic accuracy of AMACR. We also aimed at comparing AMACR and ERG expression to Gleason grade of the carcinoma cases.

METHODS

Seventy- two cases (22 prostatic hyperplasia and 50 prostatic carcinoma) were collected from the pathology department at Cairo university. The cases were immunostained by antibodies against AMACR and ERG. Immunohistochemical expressions of both markers were differentially examined in benign and malignant cases, compared to each other's, as well as, to the grade group of the malignant cases.

RESULTS

AMACR showed 62% sensitivity and 86.4% specificity for the diagnosis of PC, with a statistically significant differential expression in benign and malignant lesions (P=0.001). Its expression also correlated significantly with the age (p=0.007), Gleason grade (P=0.006) and perineural invasion (P=0.011). Although ERG showed 100% specificity to PC with no expression in hyperplasia cases, it showed only 22% sensitivity for PC cases. ERG expression also showed statistically significant correlation with the Gleason grade. No association between ERG and AMACR expression was detected in our study (P=0.151). Regarding the diagnostic accuracy, although ERG accuracy was much lower than that of AMACR, combining both markers yielded a higher diagnostic accuracy.

CONCLUSION

Although ERG proved no superior value than AMACR in diagnosing prostatic lesions, combining both markers may lead to higher diagnostic accuracy owing to higher ERG specificity for PC.

Unravelling the Role of P300 and TMPRSS2 in Prostate Cancer: A Literature Review

Prostate cancer is one of the most common malignant diseases in men, and it contributes significantly to the increased mortality rate in men worldwide. This study aimed to review the roles of p300 and TMPRSS2 (transmembrane protease, serine 2) in the AR (androgen receptor) pathway as they are closely related to the development and progression of prostate cancer. This paper represents a library-based study conducted by selecting the most suitable, up-to-date scientific published articles from online journals. We focused on articles that use similar techniques, particularly those that use prostate cancer cell lines and immunohistochemical staining to study the molecular impact of p300 and TMPRSS2 in prostate cancer specimens. The TMPRSS2:ERG fusion is considered relevant to prostate cancer, but its association with the development and progression as well as its clinical significance have not been fully elucidated. On the other hand, high p300 levels in prostate cancer biopsies predict larger tumor volumes, extraprostatic extension of disease, and seminal vesicle involvement at prostatectomy, and may be associated with prostate cancer progression after surgery. The inhibition of p300 has been shown to reduce the proliferation of prostate cancer cells with TMPRSS2:ETS (E26 transformation-specific) fusions, and combining p300 inhibitors with other targeted therapies may increase their efficacy. Overall, the interplay between the p300 and TMPRSS2 pathways is an active area of research.

Synthesis and evaluation of 7-(3-aminopropyloxy)-substituted flavone analogue as a topoisomerase IIα catalytic inhibitor and its sensitizing effect to enzalutamide in castration-resistant prostate cancer cells

Prostate cancer patients primarily receive androgen receptor (AR)-targeted drugs as a primary treatment option because prostate cancer is associated with highly activated AR signaling. AR amplification made prostate cancer cells viable under treatment of AR-targeted therapy, leading to castration resistance. AR amplification was more common in enzalutamide-resistant patients. As a strategy to overcome castration resistance and to improve the efficacy of enzalutamide, second-generation nonsteroidal antiandrogen drugs for castration-resistant prostate cancer (CRPC) including topoisomerase II (topo II) poisons such as etoposide and mitoxantrone, have been administered in combination with enzalutamide. In the present study, it was confirmed that amplification of topo IIα, but not I and IIβ, was directly and proportionally associated with poor clinical outcome of Prostate cancer. Among a novel series of newly designed and synthesized 7-(3-aminopropyloxy)-substituted flavone analogues, compound 6, the most potent derivative, was further characterized and identified as a topo IIα catalytic inhibitor that intercalates into DNA and binds to the DNA minor groove with better efficacy and less genotoxicity than etoposide, a topo II poison. Compound 6 showed remarkable efficacy in inhibiting AR-negative CRPC cell growth and sensitizing activity to enzalutamide in AR-positive CRPC cells, thus confirming the potential of topo IIα catalytic inhibitor to overcome resistance to androgen deprivation therapy.

Prospective evaluation of the role of imaging techniques and TMPRSS2:ERG mutation for the diagnosis of clinically significant prostate cancer

Objectives

To test the hypothesis of a relationship between a specific genetic lesion (T2:ERG) and imaging scores, such as PI-RADS and PRI-MUS, and to test the effectiveness of these parameters for the diagnosis of prostate cancer (PCa) and clinically significant PCa (csPCa).

Materials and methods

This is a prospective study of men with suspected PCa enrolled between 2016 and 2019 at a high-volume tertiary hospital. Patients underwent systematic US-guided biopsy, plus targeted biopsy if they were presenting with >=1 suspicious lesion (PI-RADS>2) at mpMRI or PR-IMUS >2 at micro-ultrasound assessment. For each patient, one core from the highest PI-RADS or PRI-MUS lesion was collected for T2:ERG analysis. Multivariable logistic regression models (LRMs) were fitted for csPCa with a clinical model (age, total PSA, previous biopsy, family history for PCa), a clinical plus PI-RADS, clinical plus T2:ERG, clinical plus PI-RADS plus T2:ERG, and T2:ERG plus PI-RADS alone.

Results

The cohort consists of 158 patients: 83.5% and 66.2% had respectively a diagnosis of PCa and csPCa after biopsy. A T2:ERG fusion was found in 37 men and 97.3% of these patients harbored PCa, while 81.1% were diagnosed with csPCa. SE of T2:ERG assay for csPCa was 28.8%, SP 87.0%, NPV 38.8%, and PPV 81.1%. Of 105 patients who performed mpMRI 93.% had PIRADS ≥3. SE of mpMRI for csPCa was 98.5%, SP was 12.8%, NPV was 83.3%, and PPV was 65.7%. Among 67 patients who were subjected to micro-US, 90% had a PRI-MUS ≥3. SE of micro-US for csPCa was 89.1%, SP was 9.52%, NPV was 28.6%, and PPV was 68.3%. At univariable LRM T2:ERG was confirmed as independent of mpMRI and micro-US result (OR 1.49, p=0.133 and OR 1.82, p=0.592, respectively). At multivariable LRM the clinical model alone had an AUC for csPCa of 0.74 while the clinical model including PI-RADS and T2:ERG achieved an AUC of 0.83.

Conclusions

T2:ERG translocation and imaging results are independent of each other, but both are related csPCa. To evaluate the best diagnostic work-up for PCa and csPCa detection, all available tools (T2:ERG detection and imaging techniques) should be employed together as they appear to have a complementary role.

In situ expression of ERG protein in the context of tumor heterogeneity identifies prostate cancer patients with inferior prognosis

Prognostic biomarkers for prostate cancer are needed to improve prediction of disease course and guide treatment decisions. However, biomarker development is complicated by the common multifocality and heterogeneity of the disease. We aimed to determine the prognostic value of candidate biomarkers transcriptional regulator ERG and related ETS family genes, while considering tumor heterogeneity. In a multisampled, prospective, and treatment‐naïve radical prostatectomy cohort from one tertiary center (2010–2012, median follow‐up 8.1 years), we analyzed ERG protein (480 patients; 2047 tissue cores), and RNA of several ETS genes in a subcohort (165 patients; 778 fresh‐frozen tissue samples). Intra‐ and interfocal heterogeneity was identified in 29% and 33% (ERG protein) and 39% and 27% (ETS RNA) of patients, respectively. ERG protein and ETS RNA was identified exclusively in a nonindex tumor in 31% and 32% of patients, respectively. ERG protein demonstrated independent prognostic value in predicting biochemical (P = 0.04) and clinical recurrence (P = 0.004) and appeared to have greatest prognostic value for patients with Grade Groups 4–5. In conclusion, when heterogeneity is considered, ERG protein is a robust prognostic biomarker for prostate cancer.

The Expression of Proto-Oncogene ETS-Related Gene (ERG) Plays a Central Role in the Oncogenic Mechanism Involved in the Development and Progression of Prostate Cancer

The ETS-related gene (ERG) is proto-oncogene that is classified as a member of the ETS transcription factor family, which has been found to be consistently overexpressed in about half of the patients with clinically significant prostate cancer (PCa). The overexpression of ERG can mostly be attributed to the fusion of the ERG and transmembrane serine protease 2 (TMPRSS2) genes, and this fusion is estimated to represent about 85% of all gene fusions observed in prostate cancer. Clinically, individuals with ERG gene fusion are mostly documented to have advanced tumor stages, increased mortality, and higher rates of metastasis in non-surgical cohorts. In the current review, we elucidate ERG’s molecular interaction with downstream genes and the pathways associated with PCa. Studies have documented that ERG plays a central role in PCa progression due to its ability to enhance tumor growth by promoting inflammatory and angiogenic responses. ERG has also been implicated in the epithelial–mesenchymal transition (EMT) in PCa cells, which increases the ability of cancer cells to metastasize. In vivo, research has demonstrated that higher levels of ERG expression are involved with nuclear pleomorphism that prompts hyperplasia and the loss of cell polarity.