Radical Prostatectomy Specimens Research Articles

A simple risk stratification model for prostate cancer using histopathologic findings of radical prostatectomy.

To develop a simple postoperative risk stratification based on histopathologic findings from radical prostatectomy specimens. This study included 3 cohorts of patients with a preoperative diagnosis of clinically localized prostate cancer: 1 derivation cohort (n=432) and 2 validation cohorts (n=506 and n=720). First, a postoperative risk stratification model was developed in the derivation cohort using the factors extraprostatic extension, surgical margin status, seminal vesicle invasion, and lymph node involvement. Each of the first 3 factors was assigned 0 or 1 point for negative or positive results, respectively, and the sum of the points, ranging from 0 to 3, was scored. pN1 was not scored but was analyzed separately. Validation cohorts were then used to evaluate the predictive accuracy of the model. Additionally, we compared the model with the Cancer of the Prostate Risk Assessment (CAPRA) score. Because the log-rank test showed no statistically significant differences between scores 1 vs 2 or score 3 vs pN1 in the derivation cohort, the following 3-level risk stratification was created: low risk (score 0), intermediate risk (score 1-2), and high risk (score 3 or pN1). There were statistically significant differences in recurrence-free survival between any of 2 groups of 3-level risk stratification. This model similarly worked in both validation cohorts. The C indexes for the model were higher than those for the CAPRA score. This simple postoperative risk stratification model, based on radical prostatectomy findings, has a prognostic impact that has been validated in a multicenter population.

SnRNAs from Radical Prostatectomy Specimens Have the Potential to Serve as Prognostic Factors for Clinical Recurrence after Biochemical Recurrence in Patients with High-Risk Prostate Cancer.

In patients with high-risk prostate cancer (HRPC) after radical prostatectomy (RP), biochemical recurrence (BCR) increases the risk of distant metastasis. Accordingly, additional prognostic biomarkers are required to identify the subpopulation of patients with HRPC who develop clinical recurrence (CR) after BCR. The objective of this study was to identify biomarkers in formalin-fixed paraffin-embedded (FFPE) RP samples that are prognostic for CR in patients with HRPC who experience BCR after RP (post-RP BCR). First, we performed a preliminary RNA sequencing analysis to comprehensively profile RNA expression in FFPE RP samples obtained from patients with HRPC who developed CR after post-RP BCR and found that many snRNAs were very abundant in preserved FFPE samples. Subsequently, we used quantitative polymerase chain reaction (qPCR) to compare the expression levels of highly abundant snRNAs in FFPE RP samples from patients with HRPC with and without CR after post-RP BCR (21 CR patients and 46 non-CR patients who had more than 5 years of follow-up after BCR). The qPCR analysis revealed that the expression levels of snRNA RNU1-1/1-2 and RNU4-1 were significantly higher in patients with CR than in patients without CR. These snRNAs were significantly correlated with clinical recurrence-free survival (RFS) in patients with HRPC who experienced post-RP BCR. Furthermore, snRNA RNU1-1/1-2 could serve as an independent prognostic factor for clinical RFS in post-RP BCR of HRPC cases where known prognostic factors (e.g., Gleason score) cannot distinguish between CR and non-CR patients. Our findings provide new insights into the involvement of snRNAs in prostate cancer progression.

The Performance of Different Parametric Ultrasounds in Prostate Cancer Diagnosis: Correlation with Radical Prostatectomy Specimens.

Prostate cancer is a prevalent cancer among men. Multiparametric ultrasound [mpUS] is a diagnostic instrument that uses various types of ultrasounds to diagnose it. This systematic review aims to evaluate the performance of different parametric ultrasounds in diagnosing prostate cancer by associating with radical prostatectomy specimens. A review was performed on various ultrasound parameters using five databases. Systematic review tools were utilized to eliminate duplicates and identify relevant results. Reviewers used the Quality Assessment of Diagnostic Accuracy Results [QUADAS-2] to evaluate the bias and applicability of the study outcomes. Between 2012 and 2023, eleven studies were conducted to evaluate the performance of the different ultrasound parametric procedures in detecting prostate cancer using grayscale TRUS, SWE, CEUS, and mpUS. The high sensitivity of these procedures was found at 55%, 88.6%, 81%, and 74%, respectively. The specificity of these procedures was found to be 93.4%, 97%, 88%, and 59%, respectively. This high sensitivity and specificity may be associated with the large lesion size. The studies revealed that the sensitivity of these procedures in diagnosing clinically significant prostate cancer was 55%, 73%, 70%, and 74%, respectively, while the specificity was 61%, 78.2%, 62%, and 59%, respectively. The mpUS procedure provides high sensitivity and specificity in PCa detection, especially for clinically significant prostate cancer.

Discrepancies in Gleason score between needle core biopsy and radical prostatectomy specimens with correlation between clinical and pathological staging.

The studies have shown that GS given after assessment of the entire prostate gland on the radical prostatectomy specimen may differ from GS given after examination of a small sample from needle core biopsy. We conducted this study to assess discrepancies in the Gleason score between NCB and RP specimens and to find out the correlation between the clinical stage and pathological stage. The study included 174 patients with carcinoma prostate which underwent robotic-assisted radical prostatectomy (RARP). Pre-operative Gleason score was determined on 12-core biopsy samples under trans-rectal ultrasound (TRUS) guidance. The Gleason score obtained from the radical prostatectomy specimen was compared with that of the NCB Gleason score to find out differences. The preoperative Gleason score (GS) ranges from 6 to 9 with a mean GS of 6.97 ± 1.02. The post-operative GS ranges between 6 and 10 with mean and GS of 7.5 ± 1.10. On the pre-operative assessment of biopsy specimens, 70 (43.2%) patients had a GS of 6, while 44 patients had a GS of 7 (27.1%) and 48 (29.8%) patients had a GS of more than 7. On the postoperative assessment of specimens, 31 (19.1%) patients had post-operative GS of 6, while 66 (41%) patients had GS of 7 and 74 (41.1%) patients had GS of more than 7. When pre-operative GS and post-operative GS were compared, no changes were observed in the GS of 79 patients, whereas 83 patients showed the difference in GS, with 75 patients showing up-gradation and eight patients marked as down-graded. concordance between biopsy and the pathology results directly affects the prognosis of the patient. The results of our study demonstrated the rate of discordance between Gleason scores obtained from transrectal prostate biopsy and RP surgical specimens. This rate brings into question the accuracy of the chosen treatment.

Abstract CT023: Prostate cancer in situ autovaccination with the intratumoral viral mimic poly-ICLC: Making a cold tumor hot

Abstract PURPOSE To test the safety of sequential intratumoral plus systemic intramuscular injection of poly-ICLC, and its efficacy in priming antitumor immune responses in patients with prostate cancer (PCa). EXPERIMENTAL PROCEDURES This is an open-label dose-escalating phase 1 neoadjuvant clinical trial of poly-ICLC (NCT03262103) in 12 patients diagnosed with clinically localized PCa with plans to undergo radical prostatectomy (RP). Poly-ICLC was administered intratumorally (Artemis MRI-TRUS-guided) and intramuscularly (e.g., deltoid muscle). Comprehensive transcriptional profiling of tissues, phenotypic and transcriptional analysis of longitudinally collected peripheral blood, and analysis of the prostate tumor microenvironment (TME) were performed before and after poly-ICLC treatment in order to identify innate and adaptive antitumor immune responses within the tumor and in peripheral blood. This trial is the first to use human intratumoral immunotherapy instead of systemic immunomodulation for high-risk PCa patients. RESULTS Poly-ICLC was well tolerated (safe) in all 12 patients. There were no dose-limiting toxicities or TEAE (treatment-emergent adverse events) withdrawals during treatment. Eight of 10 evaluable patients (80%) had undetectable PSA (<0.1 ng/ml) at 1 year of follow-up post-RP. Eight of 12 evaluable patients (66.7%) and 7 of 10 patients (70%) with biopsy Gleason 8-10 had a lower Gleason score in the post-treatment RP specimen. Transcriptome profiling of paired biopsy and RP specimens showed significant upregulation of gene signatures associated with immune cell infiltration and TP53-associated metabolic genes, but downregulation of gene signatures associated with metastasis and DNA replication. Genes upregulated by poly-ICLC were associated with a good prognosis. Treatment with poly-ICLC increased systemic immune responses, as demonstrated by an increase in cytolytic signatures, T- and NK-cell signatures, and NK-cell subsets in the blood. Multiplex immunohistochemistry analysis revealed a significant increase in the densities of CD4- and CD8-T cells and B cells, as well as evidence of tertiary lymphoid structures (TLS) within the TME of post-treatment RP specimens compared to baseline. CONCLUSIONS Poly-ICLC treatment can reliably transform the cold TME of PCa into a hot, immune-enhanced ecosystem. The identified baseline and response biomarkers, tertiary lymphoid structures, potential clinical benefit, and immunologic correlates require validation in larger studies. Citation Format: Sujit S. Nair, Dimple Chakravarty, Sreekumar Balan, Alexander Hakansson, Manuel Duval, Elai Davicioni, Yang Liu, Swati Bhardwaj, Tin Htwe Thin, Monica Garcia-barros, Kenneth Haines, Majd Al Shaarani, Rachel Weil, Marcia Meseck, Parita Ratnani, Monali Fatterpekar, Ivan Jambor, Elena Gonzalez-Gugel, Adam Farkas, Vinayak Wagaskar, Kacie Schlussel, Cristina Pasat-karasik, Kamala Bhatt, Zachary Dovey, Adriana Pedraza, Akriti Gupta, Dara Lundon, Ante Peros, Sneha Parekh, Lily Davenport, Xiangfu Zhang, Raghav Gupta, Macy Robison, Cynthia Knauer, Ethan Ellis, Dmitry Rykunov, Boris Reva, Babu Padanilam, Matthew D. Galsky, Rachel Brody, Mani Menon, Andres Salazar, Nina Bhardwaj, Ashutosh K. Tewari. Prostate cancer in situ autovaccination with the intratumoral viral mimic poly-ICLC: Making a cold tumor hot [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT023.

Assessment of the accuracy of biparametric MRI/TRUS fusion-guided biopsy for index tumor evaluation using postoperative pathology specimens

BackgroundMultiparametric MRI (mpMRI) is widely used for the diagnosis, surveillance, and staging of prostate cancer. However, it has several limitations, including higher costs, longer examination times, and the use of gadolinium-based contrast agents. This study aimed to investigate the accuracy of preoperatively assessed index tumors (ITs) using biparametric MRI (bpMRI)/transrectal ultrasound (TRUS) fusion biopsy compared with radical prostatectomy (RP) specimens.MethodsWe included 113 patients diagnosed with prostate cancer through bpMRI/TRUS fusion-guided biopsies of lesions with a Prostate Imaging Reporting and Data System (PI-RADS) category ≥ 3. These patients underwent robot-assisted laparoscopic radical prostatectomy (RARP) at our institution between July 2017 and March 2023. We examined the localization of preoperative and postoperative ITs, the highest Gleason score (GS), and tumor diameter in these patients.ResultsThe preoperative cT stage matched the postoperative pT stage in 53 cases (47%), while 31 cases (27%) were upstaged, and 29 cases (26%) were downstaged (Weighted Kappa = 0.21). The preoperative and postoperative IT localizations were consistent in 97 cases (86%). The concordance rate between Gleason groups in targeted biopsies and RP specimens was 51%, with an upgrade in 25 cases (23%) and a downgrade in 27 cases (25%) (Weighted Kappa = 0.42). The maximum diameter of the IT and the maximum cancer core length on biopsy were correlated with the RP tumor's maximum diameter (p < 0.001 for both).ConclusionThe diagnostic accuracy of bpMRI/TRUS fusion biopsy is comparable to mpMRI, suggesting that it can be a cost-effective and time-saving alternative.

An integrated radiology-pathology machine learning classifier for outcome prediction following radical prostatectomy: Preliminary findings

ObjectivesTo evaluate the added benefit of integrating features from pre-treatment MRI (radiomics) and digitized post-surgical pathology slides (pathomics) in prostate cancer (PCa) patients for prognosticating outcomes post radical-prostatectomy (RP) including a) rising prostate specific antigen (PSA), and b) extraprostatic-extension (EPE). MethodsMulti-institutional data (N = 58) of PCa patients who underwent pre-treatment 3-T MRI prior to RP were included in this retrospective study. Radiomic and pathomic features were extracted from PCa regions on MRI and RP specimens delineated by expert clinicians. On training set (D1, N = 44), Cox Proportional-Hazards models MR, MP and MRaP were trained using radiomics, pathomics, and their combination, respectively, to prognosticate rising PSA (PSA > 0.03 ng/mL). Top features from MRaP were used to train a model to predict EPE on D1 and test on external dataset (D2, N = 14). C-index, Kalplan-Meier curves were used for survival analysis, and area under ROC (AUC) was used for EPE. MRaP was compared with the existing post-treatment risk-calculator, CAPRA (MC). ResultsPatients had median follow-up of 34 months. MRaP (c-index = 0.685 ± 0.05) significantly outperformed MR (c-index = 0.646 ± 0.05), MP (c-index = 0.631 ± 0.06) and MC (c-index = 0.601 ± 0.071) (p < 0.0001). Cross-validated Kaplan-Meier curves showed significant separation among risk groups for rising PSA for MRaP (p < 0.005, Hazard Ratio (HR) = 11.36) as compared to MR (p = 0.64, HR = 1.33), MP (p = 0.19, HR = 2.82) and MC (p = 0.10, HR = 3.05). Integrated radio-pathomic model MRaP (AUC = 0.80) outperformed MR (AUC = 0.57) and MP (AUC = 0.76) in predicting EPE on external-data (D2). ConclusionsResults from this preliminary study suggest that a combination of radiomic and pathomic features can better predict post-surgical outcomes (rising PSA and EPE) compared to either of them individually as well as extant prognostic nomogram (CAPRA).

Quantification and molecular correlates of tertiary lymphoid structures in primary prostate cancer.

To morphologically describe tertiary lymphoid structures (TLS) in prostatectomy specimens and correlate them with clinical and transcriptomic features. A total of 72 consecutive cases of entirely submitted radical prostatectomy (RP) patients tested with the Decipher Genomic Classifier were included in the study. Images were manually annotated using QuPath tools to denote tumor regions and each cluster of TLS. Clusters of lymphocytes that were surrounded on all four sides by tumor were defined as intra-tumor TLS (IT-TLS). Clusters of lymphocytes at the leading edge of carcinoma with either the prostatic pseudocapsule or benign parenchyma at one end were defined as peri-tumor TLS (PT-TLS). A classification algorithm to distinguish lymphocytes from non-lymphocytic cells using a supervised machine learning model was used. The associations between TLS formation and 265 gene expression-based signatures were examined. The magnitude of total TLS correlations with primary tumor gene expression signatures was moderate (~0.35-0.5) with several HLA, T-cell and B-cell Cluster signatures, showing positive correlation with various metrics for quantification of TLS. On the other hand, immune suppressive signatures (Treg, MDSC) were negatively correlated. While signatures for macrophages, NK cells and other immune cell types were uncorrelated for the most part. PT-TLS was associated with MHC signatures while IT TLS correlated with MHC andT-cell signatures. Clusters of inflammatory cells in the RP specimen can be divided spatially into PT TLS and IT-TLS, each with its unique molecular correlates of tumor immune microenvironment. The presence of TLS is positively correlated with MHC signatures, T- cell and B-cell cluster signatures but, negatively correlated with immune suppressive signatures. A subset of prostate cancer demonstrate a robust inflammatory response, and warrant further characterization in larger cohorts.

Abstract 5558: Whole-slide multiplexed tissue imaging of prostate adenocarcinoma reveals distinct immune niches in high- versus low-grade tumors

Abstract Objectives Tumor-immune interactions are a critical determinant of tumor evolution and are increasingly targeted by novel therapeutics (e.g. immune checkpoint blockade). However, their significance in treatment-naive localized prostate cancer remains largely unknown. Here, we employ multiplexed tissue imaging on radical prostatectomy specimens across Gleason grades to create a single-cell spatial atlas of primary prostate tumors and characterize their innate and adaptive immune landscape. Methods Whole-slide radical prostatectomy (RP) specimens were obtained from 28 patients: 14 with Gleason Grade Group ≤ 3 (Low-grade; LG) and 14 with Gleason Grade Group ≥ 4 (High-grade; HG). Tumors were imaged with our cyclic immunofluorescence (CyCIF) platform using a 27-marker panel encompassing epithelial, T-cell, innate immune and stromal markers. Tumor and stromal compartments were manually annotated by a pathologist. Cell densities were compared between tumor and stromal compartments of LG and HG tumors. Results Across the 28 RP specimens, we identified and spatially resolved over 27 million individual cells. Overall, higher Gleason grade was associated with a significantly increased innate and adaptive immune reaction. CD8+ cytotoxic T-cell density was significantly higher in HG vs LG (p = 0.003) specimens, although this effect was largely due to enrichment in adjacent stroma rather than direct tumor infiltration. By contrast, FOXP3+ T-cells were significantly increased throughout the tumor and stromal compartments of HG compared with LG tumors (p = 0.001). Tertiary lymphoid structures (TLS) and CD163+ myeloid cells were also significantly enriched in HG tumors relative to LG tumors (p = 0.029 and 0.039, respectively). PD-1+ cells were specifically enriched in TLS structures in HG tumors (p &amp;lt; 0.001). There were no significant differences in CD11c+ and CD103+ cell densities between LG and HG tumors. Conclusions This spatially resolved single-cell atlas of localized prostate cancer reveals that high-grade tumors exhibit significant inflammation, particularly of TLSs and stromal CD8+, and are enriched in markers of T-cell anergy and myeloid-derived suppression. These findings raise the hypothesis that immunotherapy may have activity in treatment-naïve high-grade prostate cancer, despite the failure of immune checkpoint blockade in mCRPC. Citation Format: Jeremiah Wala, Jia-Ren Lin, Brian Labadie, Daniel Peiffer, Andreánne Gagne, Kiranj Chaudagar, Yu-An Chen Chen, Eliezer Van Allen, Peter Sorger, Akash Patnaik. Whole-slide multiplexed tissue imaging of prostate adenocarcinoma reveals distinct immune niches in high- versus low-grade tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5558.

Abstract 3516: AI-derived features of 3D glandular networks are associated with likelihood of biochemical recurrence post radical prostatectomy

Abstract Introduction: Prostate cancer is the most common cancer in American men and is mainly diagnosed from two-dimensional histology sections. Recently, three-dimensional (3D) prostate histopathology has emerged as a valuable strategy to enhance the understanding of the disease by increasing microscopic sampling of specimens. This strategy enhances the microscopic examination of specimens by facilitating the analysis of the volumetric shape of cells and glands, as well as the pathway structures through entire biopsies and other morphological features. These aspects hold the potential to be linked with biochemical recurrence (BCR) outcomes. This study highlights the potential of features derived from the 3D structure of glands in samples of patients with prostate cancer for identifying patients who are at higher risk of BCR. Methods: Radical prostatectomy specimens were collected from 50 patients along with 5-year postoperative BCR follow-up from the University of Washington. A total of 118 ex vivo whole-biopsy 3D pathology images were obtained from RP by an open-top light-sheet microscopy platform. Images were converted into a synthetic CK8 immunofluorescence dataset using an image-sequence translation model. From these 3D images, a glandular structure mask was generated by a computer-vision algorithm. The 3D structure of prostate glands was modeled through a Tree-structure Extraction Algorithm for Accurate and Robust Skeletons (TEASER), which provides a simplification of the length of the gland, its shape, and its pathway. 91 features were then extracted from the glandular skeleton architecture. A 3-fold cross-validation approach was used in which patients were divided into training (D1) and test (D2) sets of 33 and 17 patients, respectively. Fisher’s score, used to select features based on their correlation to the outcome, was applied to D1 to identify the top 5 features most correlated with BCR. We then utilized these features to train a K-Nearest Neighbors classifier on D1, aimed at predicting whether a patient would experience BCR. The model’s performance was evaluated on D2 and averaged across all folds. Results: The classifier was able to accurately differentiate between BCR+ and BCR- patients, achieving an average ROCAUC of 0.73 (±0.04) in D2. Significant differences in 3D skeletal features were observed between BCR+ and BCR- groups (p&amp;lt;0.05). Among the five selected features, three were related to the length and diameter of the gland, with the longest glands observed in BCR- patients. The remaining two features pertained to gland curvature and tortuosity, revealing more twisted glands in BCR+ patients. Conclusion: Features derived from a skeleton model of the 3D glandular structure of biopsies showed promise in identifying patients with prostate cancer who are at a higher risk of BCR. Additional, multi-site independent validation of these findings is warranted. Citation Format: Jennifer Salguero, Hisham Abdeltawab, Kamal Hammouda, German Corredor, Sarah Hawley, Pushkar Mutha, Rohan Dhamdhere, Sebastian Medina, Tilak Pathak, Kevin Bishop, Rob Serafin, Tuomas Mirtti, Priti Lal, Lawrence True, Jonathan Liu, Anant Madabhushi. AI-derived features of 3D glandular networks are associated with likelihood of biochemical recurrence post radical prostatectomy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3516.

Abstract 5323: Inflammation drives lineage plasticity and a club cell-like phenotype in prostate epithelial cells

Abstract Background: Club cells are a type of bronchiolar epithelial cell that serve a protective and antimicrobial function in the lung. An epithelial cell population in adult human prostates was recently identified as sharing a similar transcriptomic profile and morphology to lung club cells. Club-like epithelial cells were identified in the prostatic urethra, collecting ducts, and rarely in the peripheral zone of normal organ donor prostates. However, we recently reported that cells expressing club cell markers (CP, LTF, MMP7, PIGR, SCGB1A1) are present in the peripheral zone of radical prostatectomy specimens. Here, expression of club cell markers was restricted to luminal epithelial cells in an inflammation-associated lesion termed proliferative inflammatory atrophy (PIA). We also demonstrated that these club-like cells within PIA express the same markers as intermediate cells, a proposed prostate cancer progenitor cell. We now aim to identify exogenous factors that drive the club cell phenotype in vitro. Our ultimate goal is to understand how club cell gene expression affects the oncogenic and metastatic potential of prostate epithelial cells. Methods: We characterized the expression of club cell genes in prostate cell lines (LNCaP, PREC, and PREC-AR-Myc) following exposure to inflammatory stimuli (TNFα, hydrogen peroxide, uropathogenic Escherichia coli) in vitro. We performed quantitative reverse transcription PCR (RT-qPCR) to measure expression of club cell markers (LTF, MMP7, PIGR) and intermediate cell markers (AR, NKX3.1, SMOX). Additionally, we used chromogenic RNA in situ hybridization (RISH) to visualize LTF, MMP7, and PIGR expression following exposure to inflammatory stimuli. Results: We report that TNFα exposure in vitro increased expression of club cell genes (LTF, MMP7, PIGR). Surprisingly, TNFα exposure induced LTF expression in LNCaP cells, despite prior findings that LTF is silenced by CpG island hypermethylation in prostate cancer and in LNCaP cells. This finding was confirmed by both RT-qPCR and RISH. Additionally, we found that TNFα exposure altered intermediate cell markers (AR, NKX3.1, SMOX) expression consistent with the previously reported gene expression pattern of luminal epithelial cells in PIA. Conclusions: Overall, our results suggest that TNFα-mediated signaling drives the expression of club cell markers associated with lineage plasticity. Our next step will be to analyze inflammation-driven alterations to methylation and chromatin accessibility around loci associated with club cell genes, proton-oncogenes, and tumor suppressor genes. Citation Format: Megan Hess, Hanbing Song, Jessica Hicks, Luke Mummert, Angelo De Marzo, Franklin W. Huang, Karen Sfanos. Inflammation drives lineage plasticity and a club cell-like phenotype in prostate epithelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5323.

Abstract 773: Overexpression of phosphoserine phosphatase (PSPH) in prostate cancer and in tumor microenvironment promotes tumor cell proliferation

Abstract Reprogrammed cellular metabolism is one of the key features of cancer and tumor microenvironment. L-3-phosphoserine phosphatase (PSPH) is one of the five rate-limiting enzymes in the biosynthesis of serine from glucose that supports cell proliferation. Here, we aim to study the role of PSPH in prostate cancer (PCa) and its tumor microenvironment. We find that PSPH not only is overexpressed in prostate cancer cell lines compared to normal prostate epithelial cells (PrEC) and benign prostate epithelial cells (BPH-1), but also exhibits a higher level in patient-derived carcinoma-associated fibroblasts (CAFs) compared to the matched benign associated fibroblasts (BAFs), which are derived from fresh radical prostatectomy specimens of African American (AA) and European American (EA) men. Notably, MDAPCa2b cells derived from an AA prostate cancer patient and AA CAFs have even higher expression of PSPH protein. The mRNA levels of PSPH are also significantly elevated in prostate cancer tissues in AA men compared to EA men and predict poor survival in PCa patients. Knock-down of PSPH expression significantly inhibits the proliferation and colony formation of prostate cancer cells. Growth of xenograft tumors derived from PSPH knockdown MDAPCa2b cells has also been suppressed markedly. Gene expression profiling revealed that suppression of PSPH expression by shRNAs in LNCaP and MDAPCa2b cells is associated with the regulation of gene expression related to metabolism, immunity, extracellular matrix remodeling, and Ion channels. Similarly, analysis of publicly available PCa RNA seq databases also demonstrates that PSPH amplification or over-expression is associated with alterations of gene expression related to metabolism and immunity. Our results suggest that PSPH is upregulated in prostate cancer cells and their surrounding fibroblasts to support tumor growth via reprogramming metabolic pathways and transcriptomes. Citation Format: Liankun Song, Noriko Yokoyama, Jun Xie, Yunjie Hu, Zhenyu (Arthur) Jia, Beverly Wang, Dan Mercola, Edward Uchio, Thomas Ahlering, Michael Lilly, Xiaolin Zi. Overexpression of phosphoserine phosphatase (PSPH) in prostate cancer and in tumor microenvironment promotes tumor cell proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 773.

Abstract 3521: Robust inference of PTEN deletion in prostate cancer from routine histopathology whole slide images using attention-based deep learning

Abstract The diagnostic workup of prostate cancer (PCa) requires a thorough manual histopathological inspection of prostate tissue specimens stained with hematoxylin and eosin (H&amp;E). While immunohistochemistry and advanced molecular tests like FISH could uncover key genetic alterations, they are not cost-effective and often require special training, necessitating the development of more effective tools that can accurately infer the status of such alterations directly from the tissue morphology depicted in routine H&amp;E-stained glass slides. PTEN deletion, which is present in 15-20% of PCa, is significantly associated with tumor aggressiveness and negative prognostic impact. Deep learning (DL) models can be trained to predict the presence of PTEN deletion on routine whole slide images (WSIs) and select patients that could benefit from further treatment. In this study, we trained and tested the performance of a weakly supervised, multiple-instance learning network on a cohort of 449 WSIs radical prostatectomy specimens stained with hematoxylin &amp; eosin. Our model demonstrated robust performance in predicting PTEN loss based on tumor morphology alone. Through the model, we also generated attention heatmaps of the most informative tiles of each slide, allowing us to quantify the different cellular components, thus inferring the morphological features associated with PTEN loss. This study shows that DL is a potential tool that can assist the pathologist in accurately inferring the molecular status of key genetic alterations using the tissue morphology depicted in histopathology slides. Moreover, the morphological information that can be obtained by attention-based models can be leveraged to close the gap between the pathologist’s morphological analysis and the interpretability of artificial intelligence models. Citation Format: Federico Scarfò, Mohamed Omar, Luigi Marchionni. Robust inference of PTEN deletion in prostate cancer from routine histopathology whole slide images using attention-based deep learning [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3521.

O266: Transcriptomic signature from spatially inferred histologically benign ancestral clone predicts high risk prostate cancer

Abstract Introduction Prostate cancer (PCa) is a multifocal disease driven by heterogenous spatial and temporal branching evolution of tumour clones. Spatial transcriptomic analysis has revealed, clonally distributed copy number alterations even in histologically benign regions. We aim to evaluate if the genetic signature comprised within these genetically aberrant histologically benign regions, or “ancestral clones” may predict presence of high-risk disease. Methods Fresh-frozen, radical prostatectomy specimen was profiled using the 10x Genomics Visium Spatial Gene Expression platform. Via hierarchical clustering, spatial tumour clonal relations were inferred. Differentially expressed genes (DEGs) between high-grade tumour and histologically benign ancestral clones were identified. DEGs (|log2FC|&amp;gt;0.75) were input into a LASSO regression algorithm with normalised mRNA expression of normal adjacent tissue from the TCGA PCa database to train a genetic risk model to predict presence of high risk PCa (Gleason&amp;gt;8). Derived risk score was validated on an external cohort (GSE21032). Results A total of 683 DEGs were identified. These were enriched for organic acid metabolic pathways. Regression analysis on 57 normal adjacent tissue samples from TCGA PCa dataset was performed to develop a predictive model comprising of 3 genes (SLC22A3, CRIP2, LSAMP). External validation of the genetic risk score on matched histologically benign tissue from 131 patients, had good performance for prediction of high-risk PCa (AUC 0.807; 95% CI 0.693-0.921). Conclusion Our model has good performance for predicting high-risk PCa from matched normal tissue. Developed genetic risk score has translational potential to improve detection of unsampled clinically significant prostate cancer from histologically benign biopsy cores.

Prognostic factors among patients with pathological Grade Group 5 prostate cancer based on robot-associated radical prostatectomy specimens from a large Japanese cohort (MSUG94).

There are no definitive prognostic factors for patients with pathological Grade Group 5 (pGG 5) prostate cancer (PCa) undergoing robot-associated radical prostatectomy (RARP). This study aimed to explore the prognostic factors among patients with pGG 5 PCa in a large Japanese cohort (MSUG94). This retrospective, multi-institutional cohort study was conducted between 2012 and 2021 at ten centers in Japan and included 3195 patients. Patients with clinically metastatic PCa (cN1 or cM1) and those receiving neoadjuvant and/or adjuvant therapy were excluded. Finally, 217 patients with pGG5 PCa were analyzed. The median follow-up period was 28.0months. The 3- and 5-year biochemical recurrence-free survival (BCRFS) rates of the overall population were 66.1% and 57.7%, respectively. The optimal threshold value (47.2%) for the percentage of positive cancer cores (PPCC) with any GG by systematic biopsy was chosen based on receiver operating characteristic curve analysis. Univariate analysis revealed that the prostate-specific antigen level at diagnosis, pT, pN, positive surgical margins (PSMs), lymphovascular invasion, and PPCC were independent prognostic factors for BCRFS. A multivariate analysis revealed that PSMs and PPCC were independent prognostic factors for BCRFS. Using these two predictors, we stratified BCRFS, metastasis-free survival (MFS), and castration-resistant PCa-free survival (CRPC-FS) among patients with pGG 5 PCa. The combination of PSMs and PPCC may be an important predictor of BCRFS, MFS, and CRPC-FS in patients with pGG 5 PCa undergoing RARP.

Utility of positive core number on MRI-ultrasound fusion targeted biopsy in combination with PI-RADS scores for predicting unexpected extracapsular extension of clinically localized prostate cancer.

To evaluate the utility of magnetic resonance imaging (MRI) and MRI-ultrasound fusion targeted biopsy (TB) for predicting unexpected extracapsular extension (ECE) in clinically localized prostate cancer (CLPC). This study enrolled 89 prostate cancer patients with one or more lesions showing a Prostate Imaging-Reporting and Data System (PI-RADS) score ≥3 but without morphological abnormality in the prostatic capsule on pre-biopsy MRI. All patients underwent TB and systematic biopsy followed by radical prostatectomy (RP). Each lesion was examined by 3-core TB, taking cores from each third of the lesion. The preoperative variables predictive of ECE were explored by referring to RP specimens in the lesion-based analysis. Overall, 186 lesions, including 81 (43.5%), 73 (39.2%), and 32 (17.2%) with PI-RADS 3, 4, and 5, respectively, were analyzed. One hundred and twenty-two lesions (65.6%) were diagnosed as cancer on TB, and ECE was identified in 33 (17.7%) on the RP specimens. The positive TB core number was ≤2 in 129 lesions (69.4%) and three in 57 lesions (30.6%). On the multivariate analysis, PI-RADS ≥4 (p = 0.049, odds ratio [OR] = 2.39) and three positive cores on TB (p = 0.005, OR = 3.07) were independent predictors of ECE. Lesions with PI-RADS ≥4 and a positive TB core number of 3 had a significantly higher rate of ECE than those with PI-RADS 3 and a positive TB core number ≤2 (37.5% vs. 7.8%, p < 0.001). Positive TB core number in combination with PI-RADS scores is helpful to predict unexpected ECE in CLPC.

Radical prostatectomy cancer grade and percentage of Gleason pattern 4 estimated by global vs individual tumor grading correlate differently with the risk of biochemical recurrence in Grade Group 2 and 3 cancers.

There are 2 grading approaches to radical prostatectomy (RP) in multifocal cancer: Grade Group (GG) and percentage of Gleason pattern 4 (GP4%). We investigated whether RP GG and GP4% generated by global vs individual tumor grading correlate differently with biochemical recurrence. We reviewed 531 RP specimens with GG2 or GG3 cancer. Each tumor was scored separately with assessment of tumor volume and GP4%. Global grade and GP4% were assigned by combining Gleason pattern 3 and 4 volumes for all tumors. Correlation of GG and GP4% generated by 2 methods with biochemical recurrence was assessed by Cox proportional hazard regression and receiver operating characteristic curves, with optimism adjustment using a bootstrap analysis. Median age was 63 (range, 42-79) years. Median prostate-specific antigen was 6.3 (range, 0.3-62.9) ng/mL. In total, the highest-grade tumor in 371 (36.9%) men was GG2 and in 160 (30.1%) men was GG3. Global grading was downgraded from GG3 to GG2 in 37 of 121 (30.6%) specimens with multifocal disease, and 145 of 404 (35.9%) specimens had GP4% decreased by at least 10%. Ninety-eight men experienced biochemical recurrence within a median of 13 (range, 3-119) months. Men without biochemical recurrence were followed up for a median of 47 (range, 12-205) months. Grade Group, GP4%, and margin status correlated with the risk of biochemical recurrence using highest-grade tumor and global grading, but the degrees of these correlations varied and were statistically significantly different between the 2 grading approaches. Grade Group, GP4%, and margin status derived by global vs individual tumor grading predict postoperative biochemical recurrence statistically significantly differently. This difference has important implications if results derived from cohorts graded using different methods are compared.

Addition of cribriform pattern 4 and intraductal prostatic carcinoma into the CAPRA-S tool improves post-radical prostatectomy patient stratification in a multi-institutional cohort

AimsPre-surgical risk classification tools for prostate cancer have shown better patient stratification with the addition of cribriform pattern 4 (CC) and intraductal prostatic carcinoma (IDC) identified in biopsies. Here, we...

Prognostication in Lymph Node-Positive Prostate Cancer with No PSA Persistence After Radical Prostatectomy.

This study aimed to create a prognostic model to predict disease recurrence among patients with lymph node involvement but no prostate-specific antigen (PSA) persistence and to explore its clinical utility. The study analyzed patients with lymph node involvement after pelvic lymph node dissection with radical prostatectomy in whom no PSA persistence was observed between 2006 and 2019 at 33 institutions. Prognostic factors for recurrence-free survival (RFS) were analyzed by the Cox proportional hazards model. Among 231 patients, 127 experienced disease recurrence. The factors prognostic for RFS were PSA level at diagnosis (≥ 20 vs. < 20ng/mL: hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.09-2.52; P = 0.017), International Society of Urological Pathology grade group at radical prostatectomy (RP) specimen (group ≥ 4 vs. ≤ 3: HR, 1.63; 95% CI 1.12-2.37; P = 0.010), pathologic T-stage (pT3b/4 vs. pT2/3a: HR, 1.70; 95% CI 1.20-2.42; P = 0.0031), and surgical margin status (positive vs. negative: HR, 1.60; 95% CI 1.13-2.28; P = 0.0086). The prognostic model using four parameters were associated with RFS and metastasis-free survival. The prognostic model in combination with postoperative PSA value and number of lymph nodes is clinically useful for discussing treatment choice with patients.

Expression of the microtubule-associated protein 2 (MAP2) as a potential independent prognostic marker in prostate cancer

PurposeInvestigation of Microtubuli-associated Protein 2 (MAP2) expression and its clinical relevance in prostate cancer.Material and MethodsMAP2 expression was immunohistochemically analysed on radical prostatectomy specimens using whole block sections (n = 107) and tissue microarrays (TMA; n = 310). The staining intensity was evaluated for carcinoma, benign tissue and prostatic intraepithelial neoplasia. Expression data were correlated with clinicopathological parameters and biochemical recurrence-free survival. Additionally, MAP2 protein expression was quantitatively analysed in the serum of histologically confirmed prostate carcinoma patients and the control group using a commercial enzyme-linked immunosorbent assay.ResultsMAP2 staining was significantly stronger in neoplastic tissue than in non-neoplastic prostatic glands, both in whole block sections (p < 0.01) and in TMA sections (p < 0.05). TMA data revealed significantly stronger MAP2 staining in high-grade tumors. Survival analysis showed a significant correlation between strong MAP2 staining in carcinoma and shortened biochemical recurrence-free survival after prostatectomy (p < 0.001). Multivariate Cox regression analysis confirmed MAP2 as an independent predictor for an unfavourable course. Mean MAP2 serum levels for non-PCA vs. PCA patients differed significantly (non-PCA = 164.7 pg/ml vs. PCA = 242.5 pg/ml, p < 0.001).ConclusionThe present data support MAP2 as a novel biomarker in PCA specimens. MAP2 is correlated with tumor grade and MAP2 high-expressing PCA is associated with an increased risk of biochemical recurrence after radical prostatectomy. Future studies are necessary to evaluate MAP2 as a valuable immunohistochemical biomarker in preoperative PCA diagnostic procedures, in particular with regard to treatment modalities.