Perineural Invasion and Risk of Lethal Prostate Cancer

Perineural Invasion as a Risk Factor For Soft Tissue Progression in Patients With Metastatic Castration-Resistant Prostate Cancer After Abiraterone Resistance

BACKGROUND

Prostate cancer presents with soft tissue progression (STP) is highly aggressive. We analyzed the risk factor for STP in patients with metastatic castration-resistant prostate cancer (mCRPC) who developed abiraterone acetate (AA) resistance.

METHODS

This retrospective study included patients with mCRPC who received AA between February 2018 and July 2022. STP was defined as recurrent lesions in situ, multiple regional lymph node metastases (mLNM), or visceral metastases. Clinical features of patients with STP were analyzed, and risk factors for STP were further investigated.

RESULTS

Sixty-three patients (mean age, 75.0 years; median follow-up time, 22.3 months) were included in this study. Twenty-three patients (36.5%) presented STP during follow up, the overall survival (OS) after STP was 4.6 months. The serum neuron-specific enolase (NSE) were significantly elevated in patients with STP. Biopsies for 8 patients with STP showed neuroendocrine prostate cancer (NEPC, n = 5) was the major pathological types. Further analysis showed that perineural invasion (PNI) in primary tumor were the independent risk factors (HR = 3.145, P = 0.020) for STP, and PNI was related to the aggressiveness of tumor. Patients with PNI showed shorter castration-resistant progression free survival (median, 23.73 months vs. 25.59 months) and STP progression free survival (median, 19.7 months vs. not reached) compared with patients without PNI.

CONCLUSIONS

STP showed extremely poor prognoses in patients with mCRPC after AA resistance, NEPC is the main pathological type of STP, and PNI in primary tumor was an independent risk factor for STP and indicated poor prognosis of prostate cancer.

Differential analysis of histopathological and genetic markers of cancer aggressiveness, and survival difference in EBV-positive and EBV-negative prostate carcinoma

Several studies have shown an association between prostate carcinoma (PCa) and Epstein-Barr virus (EBV); however, none of the studies so far have identified the histopathological and genetic markers of cancer aggressiveness associated with EBV in PCa tissues. In this study, we used previously characterized EBV-PCR-positive (n = 39) and EBV-negative (n = 60) PCa tissues to perform an IHC-based assessment of key histopathological and molecular markers of PCa aggressiveness (EMT markers, AR expression, perineural invasion, and lymphocytic infiltration characterization). Additionally, we investigated the differential expression of key oncogenes, EMT-associated genes, and PCa-specific oncomiRs, in EBV-positive and -negative tissues, using the qPCR array. Finally, survival benefit analysis was also performed in EBV-positive and EBV-negative PCa patients. The EBV-positive PCa exhibited a higher percentage (80%) of perineural invasion (PNI) compared to EBV-negative PCa (67.3%) samples. Similarly, a higher lymphocytic infiltration was observed in EBV-LMP1-positive PCa samples. The subset characterization of T and B cell lymphocytic infiltration showed a trend of higher intratumoral and tumor stromal lymphocytic infiltration in EBV-negative tissues compared with EBV-positive tissues. The logistic regression analysis showed that EBV-positive status was associated with decreased odds (OR = 0.07; p-value < 0.019) of CD3 intratumoral lymphocytic infiltration in PCa tissues. The analysis of IHC-based expression patterns of EMT markers showed comparable expression of all EMT markers, except vimentin, which showed higher expression in EBV-positive PCa tissues compared to EBV-negative PCa tissues. Furthermore, gene expression analysis showed a statistically significant difference (p < 0.05) in the expression of CDH1, AR, CHEK-2, CDKN-1B, and CDC-20 and oncomiRs miR-126, miR-152-3p, miR-452, miR-145-3p, miR-196a, miR-183-3p, and miR-146b in EBV-positive PCa tissues compared to EBV-negative PCa tissues. Overall, the survival proportion was comparable in both groups. The presence of EBV in the PCa tissues results in an increased expression of certain oncogenes, oncomiRs, and EMT marker (vimentin) and a decrease in CD3 ITL, which may be associated with the aggressive forms of PCa.

Physician Perception of Grade Group 1 Prostate Cancer

BACKGROUND

Despite its low-risk nature, grade group 1 (GG 1) prostate cancer (PCa) remains overtreated. This suggests a disconnect between daily physician practice and the standard of care. We hypothesized that GG 1 disease is overtreated because of common misconceptions regarding its true natural history.

OBJECTIVE

To survey physicians worldwide to better understand their approach to management of GG 1 PCa.

DESIGN, SETTING, AND PARTICIPANTS

A 17-question survey was sent to urology, radiation oncology, and pathology societies on six continents, and was posted on Twitter. Responses were collected and analyzed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Pearson's χ2 test was used to assess correlation between physician-related variables and the perception of active surveillance (AS) for GG 1 PCa. Logistic regression was used for multivariable analysis. Statistical analysis was performed using SPSS version 21.

RESULTS AND LIMITATIONS

Among 1303 participants, 55% were urologists, 47% had completed fellowship, and 49% practice in an academic setting. Among the clinicians, 724 (83%) routinely recommend AS for GG 1 PCa and have never/rarely regretted it, while 18 (2%) "often" regretted it. Routine AS was more common among physicians aged <40 yr, those in practice for <10 yr, and those living in North America, Europe, or Australia/New Zealand. More than one-third of the respondents practicing in nonacademic settings reported 15-yr PCa mortality in low-risk PCa of >3%. Regarding reclassification of GG 1 to a precancerous lesion, 428 (39%) felt that this is a good idea, 340 (31%) disagreed, and 323 (30%) were uncertain. Those in support were more likely to be aged <40 yr (p = 0.001), in practice for <5 yr (p = 0.005), urologists (p < 0.001), and fellows trained in urologic oncology (p < 0.001). Opposition was common among pathologists (61%). Among terminologies proposed to replace "cancer" for GG 1 are neoplasm of low malignant potential (51% approval), indolent neoplasm rarely requiring treatment (23%), and indolent lesion of epithelial origin (8%).

CONCLUSIONS

AS is more commonly recommended by physicians who are younger, are fellowship-trained in urologic oncology, practice in academic settings, and are based in North America, Europe, or Australia/New Zealand. Misconceptions regarding AS outcomes may hinder its adoption. Frequent use of AS is associated with support for changing the "cancer" nomenclature.

PATIENT SUMMARY

In this study, we found that active surveillance remains underused in the management of low-risk prostate cancer because of incorrect perceptions regarding cancer outcomes. Omitting the word "cancer" for low-risk lesions is a challenging but promising effort that is favored by many clinicians, particularly by those who advocate for active surveillance.

Grossing and reporting of radical prostatectomy specimens: An evidence-based approach

Radical prostatectomy (RP) constitutes the primary treatment option for patients with clinically localized, biopsy-proven prostate cancer that requires local treatment with curative intent. Accurate reporting of radical prostatectomy specimens is required to guide further risk stratification and management of patients. Hence, for the handling and reporting of RP specimens, a standardized protocol should be followed. Many general pathologists may not be well-versed with the guidelines for the handling of radical prostatectomy specimens. This article discusses a detailed approach to grossing techniques, including specimen description, fixation requirements, gross cut-up, and reporting of the grade and stage of RP specimens. This will enable the pathologist to aid in multidisciplinary management.

Unraveling the Mysteries of Perineural Invasion in Benign and Malignant Conditions

Perineural invasion (PNI) is defined as the dissemination of neoplastic cells within the perineural space. PNI can be a strong indicator of malignancy and is linked to poor prognosis and adverse outcomes in various malignant neoplasms; nevertheless, it can also be seen in benign pathologic conditions. In this review article, we discuss various signaling pathways and neurotrophic factors implicated in the development and progression of PNI. We also describe the methodology, benefits, and limitations of different in vitro, ex vivo, and in vivo models of PNI. The spectrum of presentation for PNI can range from diffuse spread within large nerves ("named" nerves) all the way through localized spread into unnamed microscopic nerves. Therefore, the clinical significance of PNI is related to its extent rather than its mere presence or absence. In this article, we discuss the guidelines for the identification and quantification of PNI in different malignant neoplasms based on the College of American Pathologists (CAP) and World Health Organization (WHO) recommendations. We also describe benign pathologic conditions and neoplasms demonstrating PNI and potential mimics of PNI. Finally, we explore avenues for the future development of targeted therapy options via modulation of signaling pathways involved in PNI.

Neuropeptide Y and its receptors in prostate cancer: associations with cancer invasiveness and perineural spread

PURPOSE

Neuropeptide Y (NPY) is a pleiotropic peptide, which is involved in many biological mechanisms important in regulation of cell growth and survival. The aim of this study was a comprehensive analysis of the NPY system in prostate pathology.

METHODS

The study was based on immunohistochemical analysis of NPY and its receptors, Y1R, Y2R and Y5R, in tissue samples from benign prostate (BP), primary prostate cancer (PCa) and PCa bone metastases. Tissue microarray (TMA) technique was employed, with analysis of multiple cores from each specimen. Intensity of the immunoreactivity and expression index (EI), as well as distribution of the immunostaining in neoplastic cells and stromal elements were evaluated. Perineural invasion (PNI) and extraprostatic extension (EPE) were areas of special interests. Moreover, a transwell migration assay on the LNCaP PCa cell line was used to assess the chemotactic properties of NPY.

RESULTS

Morphological analysis revealed homogeneous membrane and cytoplasmic pattern of NPY staining in cancer cells and its membrane localization with apical accentuation in BP glands. All elements of the NPY system were upregulated in pre-invasive prostate intraepithelial neoplasia, PCa and metastases. EI and staining intensity of NPY receptors were significantly higher in PCa then in BP with correlation between Y2R and Y5R. The strength of expression of the NPY system was further increased in the PNI and EPE areas. In bone metastases, Y1R and Y5R presented high expression scores.

CONCLUSION

The results of our study suggest that the NPY system is involved in PCa, starting from early stages of its development to disseminated states of the disease, and participates in the invasion of PCa into the auto and paracrine matter.

Quantification of perineural invasion in pancreatic ductal adenocarcinoma: proposal of a severity score system

Perineural invasion (PNI) is a common feature in pancreatic ductal adenocarcinoma (PDAC) and correlates with an aggressive tumor behavior already at early stages of disease. PNI is currently considered as a "present vs. absent" feature, and a severity score system has not yet been established. The aim of the present study was thus to develop and validate a score system for PNI and to correlate it with other prognostic features. In this monocentric retrospective study, 356 consecutive PDAC patients (61.8% upfront surgery patients, 38.2% received neoadjuvant therapy) were analyzed. PNI was scored as follows: 0: absent; 1: the presence of neoplasia along nerves < 3 mm in caliber; and 2: neoplastic infiltration of nerve fibers ≥ 3 mm and/or massive perineural infiltration and/or the presence of necrosis of the infiltrated nerve bundle. For every PNI grade, the correlation with other pathological features, disease-free survival (DFS), and disease-specific survival (DSS) were analyzed. Uni- and multivariate analysis for DFS and DSS were also performed. PNI was found in 72.5% of the patients. Relevant trends between PNI score and tumor differentiation grade, lymph node metastases, vascular invasion, and surgical margins status were found. The latter was the only parameter statistically correlated with the proposed score. The agreement between pathologists was substantial (Cohen's K 0.61). PNI severity score significantly correlated also with decreased DFS and DSS at univariate analysis (p < 0.001). At multivariate analysis, only the presence of lymph node metastases was an independent predictor of DFS (HR 2.235 p < 0.001). Lymph node metastases (HR 2.902, p < 0.001) and tumor differentiation grade (HR 1.677, p = 0.002) were independent predictors of DSS. Our newly developed PNI score correlates with other features of PDAC aggressiveness and proved to have a prognostic role though less robust than lymph nodes metastases and tumor differentiation grade. A prospective validation is needed.

Lymphovascular or perineural invasion is associated with lymph node metastasis and survival outcomes in patients with gastric cancer

BACKGROUND

Lymphovascular invasion (LVI) and perineural invasion (PNI) are associated with poorer prognosis in several human malignancies, but their significance in gastric cancer (GC) remains to be clearly defined. Our study aimed to investigate the prognostic value of LVI/PNI in patients with curative resected GC.

METHODS

Records of 1488 patients with stage I--III GC and 3327 patients with stage I-III colorectal cancer (CRC) were reviewed retrospectively, and difference in the incidence of LVI/PNI between GC and CRC was compared. Univariate and multivariate analyses were used to evaluate whether LVI/PNI was an independent risk factor for lymph node metastasis (LNM) and overall survival (OS) in GC.

RESULTS

Patients with stage I-III GC had a significantly higher incidence of LVI/PNI than patients with stage I-III CRC (50.54% vs. 21.91%, p  < 0.001). LVI/PNI was significantly associated with higher CEA, higher CA199, deeper tumor invasion, more lymph node metastasis, and advanced TNM stage in GC ( p  < 0.05). Multivariate logistic regression analysis identified LVI/PNI (OR = 2.64, 95%CI: 2.05-3.40, p  < 0.001) as an independent risk factor for LNM in GC. The OS rate was significantly lower in the LVI/PNI-positive GC group than that in the LVI/PNI-negative GC group ( p  < 0.001). On multivariate Cox regression analysis, LVI/PNI (HR = 1.34, 95%CI: 1.04-1.71, p  = 0.023) was an independent prognostic factor for OS in GC.

CONCLUSION

GC has a high incidence of LVI/PNI, which was closely associated with disease progression. LVI/PNI could serve as an independent risk factor for LNM and the prognosis of patients with curative resected GC. These findings will be helpful in predicting survival outcomes more accurately and establishing individualized treatment plans.

Neural Component of the Tumor Microenvironment in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive primary malignancy of the pancreas, with a dismal prognosis and limited treatment options. It possesses a unique tumor microenvironment (TME), generating dense stroma with complex elements cross-talking with each other to promote tumor growth and progression. Diversified neural components makes for not having a full understanding of their influence on its aggressive behavior. The aim of the study was to summarize and integrate the role of nerves in the pancreatic tumor microenvironment. The role of autonomic nerve fibers on PDAC development has been recently studied, which resulted in considering the targeting of sympathetic and parasympathetic pathways as a novel treatment opportunity. Perineural invasion (PNI) is commonly found in PDAC. As the severity of the PNI correlates with a poorer prognosis, new quantification of this phenomenon, distinguishing between perineural and endoneural invasion, could feature in routine pathological examination. The concepts of cancer-related neurogenesis and axonogenesis in PDAC are understudied; so, further research in this field may be warranted. A better understanding of the interdependence between the neural component and cancer cells in the PDAC microenvironment could bring new nerve-oriented treatment options into clinical practice and improve outcomes in patients with pancreatic cancer. In this review, we aim to summarize and integrate the current state of knowledge and future challenges concerning nerve-cancer interactions in PDAC.

Perineural invasion-associated biomarkers for tumor development

Perineural invasion (PNI) is the process of neoplastic invasion of peripheral nerves and is considered to be the fifth mode of cancer metastasis. PNI has been detected in head and neck tumors and pancreatic, prostate, bile duct, gastric, and colorectal cancers. It leads to poor prognostic outcomes and high local recurrence rates. Despite the increasing number of studies on PNI, targeted therapeutic modalities have not been proposed. The identification of PNI-related biomarkers would facilitate the non-invasive and early diagnosis of cancers, the establishment of prognostic panels, and the development of targeted therapeutic approaches. In this review, we compile information on the molecular mediators involved in PNI-associated cancers. The expression and prognostic significance of molecular mediators and their receptors in PNI-associated cancers are analyzed, and the possible mechanisms of action of these mediators in PNI are explored, as well as the association of cells in the microenvironment where PNI occurs.

The Role of Nerve Fibers in the Tumor Immune Microenvironment of Solid Tumors

The importance of neurons and nerve fibers in the tumor microenvironment (TME) of solid tumors is now acknowledged after being unexplored for a long time; this is possible due to the development of new technologies that allow in situ characterization of the TME. Recent studies have shown that the density and types of nerves that innervate tumors can predict a patient's clinical outcome and drive several processes of tumor biology. Nowadays, several efforts in cancer research and neuroscience are taking place to elucidate the mechanisms that drive tumor-associated innervation and nerve-tumor and nerve-immune interaction. Assessment of neurons and nerves within the context of the TME can be performed in situ, in tumor tissue, using several pathology-based strategies that utilize histochemical and immunohistochemistry principles, hi-plex technologies, and computational pathology approaches to identify measurable histopathological characteristics of nerves. These features include the number and type of tumor associated nerves, topographical location and microenvironment of neural invasion of malignant cells, and investigation of neuro-related biomarker expression in nerves, tumor cells, and cells of the TME. A deeper understanding of these complex interactions and the impact of nerves in tumor biology will guide the design of better strategies for targeted therapy in clinical trials.

The Role of Perineural Invasion in Prostate Cancer and Its Prognostic Significance

Simple Summary

Prostate cancer is one of the most frequently diagnosed cancers in men worldwide. Perineural invasion (PNI), the movement of cancer cells along nerves, is a commonly observed approach to tumor spread and is important in both research and clinical practice of prostate cancer. However, despite many studies reporting on molecules and pathways involved in PNI, understanding its clinical relevance remains insufficient. In this review, we aim to summarize the current knowledge of mechanisms and prognostic significance of PNI in prostate cancer, which may provide new perspectives for future studies and improved treatment.

Abstract

Perineural invasion (PNI) is a common indication of tumor metastasis that can be detected in multiple malignancies, including prostate cancer. In the development of PNI, tumor cells closely interact with the nerve components in the tumor microenvironment and create the perineural niche, which provides a supportive surrounding for their survival and invasion and benefits the nerve cells. Various transcription factors, cytokines, chemokines, and their related signaling pathways have been reported to be important in the progress of PNI. Nevertheless, the current understanding of the molecular mechanism of PNI is still very limited. Clinically, PNI is commonly associated with adverse clinicopathological parameters and poor outcomes for prostate cancer patients. However, whether PNI could act as an independent prognostic predictor remains controversial among studies due to inconsistent research aim and endpoint, sample type, statistical methods, and, most importantly, the definition and inclusion criteria. In this review, we provide a summary and comparison of the prognostic significance of PNI in prostate cancer based on existing literature and propose that a more standardized description of PNI would be helpful for a better understanding of its clinical relevance.

Spatial and Transcriptomic Analysis of Perineural Invasion in Oral Cancer

PURPOSE

Perineural invasion (PNI), a common occurrence in oral squamous cell carcinomas, is associated with poor survival. Consequently, these tumors are treated aggressively. However, diagnostic criteria of PNI vary and its role as an independent predictor of prognosis has not been established. To address these knowledge gaps, we investigated spatial and transcriptomic profiles of PNI-positive and PNI-negative nerves.

EXPERIMENTAL DESIGN

Tissue sections from 142 patients were stained with S100 and cytokeratin antibodies. Nerves were identified in two distinct areas: tumor bulk and margin. Nerve diameter and nerve-to-tumor distance were assessed; survival analyses were performed. Spatial transcriptomic analysis of nerves at varying distances from tumor was performed with NanoString GeoMx Digital Spatial Profiler Transcriptomic Atlas.

RESULTS

PNI is an independent predictor of poor prognosis among patients with metastasis-free lymph nodes. Patients with close nerve-tumor distance have poor outcomes even if diagnosed as PNI negative using current criteria. Patients with large nerve(s) in the tumor bulk survive poorly, suggesting that even PNI-negative nerves facilitate tumor progression. Diagnostic criteria were supported by spatial transcriptomic analyses of >18,000 genes; nerves in proximity to cancer exhibit stress and growth response changes that diminish with increasing nerve-tumor distance. These findings were validated in vitro and in human tissue.

CONCLUSIONS

This is the first study in human cancer with high-throughput gene expression analysis in nerves with striking correlations between transcriptomic profile and clinical outcomes. Our work illuminates nerve-cancer interactions suggesting that cancer-induced injury modulates neuritogenesis, and supports reclassification of PNI based on nerve-tumor distance rather than current subjective criteria.

The association between perineural invasion in mpMRI-targeted and/or systematic prostate biopsy and adverse pathological outcomes in robot-assisted radical prostatectomy

INTRODUCTION AND OBJECTIVES

This study aims to investigate the relationship between perineural invasion (PNI) in targeted (TBx) and/or systematic (SBx) prostate needle biopsy and adverse pathological features of prostate cancer (PCa) in prostatectomy specimens.

MATERIALS AND METHODS

A total of 95 male patients who underwent transperineal TBx and/or concomitant SBx subsequently treated with robot-assisted radical prostatectomy for PCa between October 2015 and June 2020 were included. The performance of PNI as a classification test (sensitivity, specificity, positive and negative predictive values) and its correlation with clinically significant PCa, surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy were computed.

RESULTS

The median age of the patients was 65 (60-70) years. TBx and concomitant SBx were performed in 78 (82.1%) patients, while 16 (16.8%) patients underwent SBx alone and one (1.1%) patient underwent TBx alone. The frequency of PNI in TBx and SBx was 17 (21.5%) and 32 (34.0%), respectively. The specificity/negative predictive values of PNI for surgical margin positivity, extraprostatic extension, and seminal vesicle invasion were 79.7/88.7%, 92.5/79.0%, and 83.3/96.8%, in TBx, and 71.1/87.1%, 80.7/74.2%, and 69.5/91.9%, in SBx, respectively. There was also a statistically significant correlation between PNI in biopsy and surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy as well as the ISUP grade group and pT stage.

CONCLUSIONS

The absence of PNI in prostate needle biopsy may predict localized PCa with a pT stage ≤ 2c and negative surgical margins in contrast to its presence which appears to be an indicator of unfavorable factors in final pathology.

Multiparametric MRI and Machine Learning Based Radiomic Models for Preoperative Prediction of Multiple Biological Characteristics in Prostate Cancer

Objectives

This study aims to develop and evaluate multiparametric MRI (MP-MRI)-based radiomic models as a noninvasive diagnostic method to predict several biological characteristics of prostate cancer.

Methods

A total of 252 patients were retrospectively included who underwent radical prostatectomy and MP-MRI examinations. The prediction characteristics of this study were as follows: Ki67, S100, extracapsular extension (ECE), perineural invasion (PNI), and surgical margin (SM). Patients were divided into training cohorts and validation cohorts in the ratio of 4:1 for each group. After lesion segmentation manually, radiomic features were extracted from MP-MRI images and some clinical factors were also included. Max relevance min redundancy (mRMR) and recursive feature elimination (RFE) based on random forest (RF) were adopted to select features. Six classifiers were included (SVM, KNN, RF, decision tree, logistic regression, XGBOOST) to find the best diagnostic performance among them. The diagnostic efficiency of the construction models was evaluated by ROC curves and quantified by AUC.

Results

RF performed best among the six classifiers for the four groups according to AUC values (Ki67 = 0.87, S100 = 0.80, ECE = 0.85, PNI = 0.82). The performance of SVM was relatively the best for SM (AUC = 0.77). The number and importance of DCE features ranked first in the models of each group. The combined models of MP-MRI and clinical characteristics showed no significant difference compared with MP-MRI models according to Delong’s tests.

Conclusions

Radiomics models based on MP-MRI have the potential to predict biological characteristics and are expected to be a noninvasive method to evaluate the risk stratification of prostate cancer.

Digital image analysis using video microscopy of human-derived prostate cancer vs normal prostate organoids to assess migratory behavior on extracellular matrix proteins

The advent of perpetuating living organoids derived from patient tissue is a promising avenue for cancer research but is limited by difficulties with precise characterization. In this brief communication, we demonstrate via time-lapse imaging distinct phenotypes of prostate organoids derived from patient material- without confirmation of cellular identity. We show that organoids derived from histologically normal tissue more readily spread on a physiologic extracellular matrix (ECM) than on pathologic ECM (p<0.0001), while tumor-derived organoids spread equally on either substrate (p=0.2406). This study is an important proof-of-concept to defer precise characterization of organoids and still glean information into disease pathology.

Clinicopathological Analysis of the ISUP Grade Group And Other Parameters in Prostate Cancer: Elucidation of Mutual Impact of the Various Parameters

Background

Prostate cancer has become increasingly common worldwide. Although Grade group (GG) is widely accepted as an indicator of prostate cancer grade, there are malignancies that cannot be defined by GG alone. Moreover, the relationship between GG and other parameters remains unclear. Herein, we aimed to explore the biological characteristics of prostate cancer.

Methods

This study included 299 radical prostatectomy cases. The Chi-square test and analysis of variance were used to analyze the association of GG with binary and continuous variables. We then conducted morphological analyses. Multivariate analyses were performed to extract the data on risk factors for biochemical recurrence (BCR) and lymph node metastasis.

Results

The lymphatic, venous, perineural, and seminal vesicle invasion rates were 37/299 (12.4%), 25/299 (8.4%), 280/299 (93.6%), and 23/299 (7.7%), respectively. The extraprostatic extension (EPE), positive surgical margin, tertiary Gleason pattern 5, intraductal carcinoma of the prostate gland, and lymph node metastasis rates were 89/299 (29.8%), 106/299 (35.5%), 33/260 (12.7%), 56/299 (18.7%), and 23/299 (7.7%), respectively. As GG increased, various parameters became easier to visualize; however, there were differences between the parameters. Postoperative BCR was observed in 31/242 (12.8%) cases without preoperative hormone therapy; GG2, GG3, GG4, and GG5 accounted for 4, 7, 7, and 13 cases, respectively. Multivariate analyses revealed that GG and tumor diameter were significant risk factors for early BCR, whereas lymphatic invasion, EPE, and seminal vesicle invasion were significant risk factors for lymph node metastasis. For BCR, the odds ratios (ORs) for GG and tumor diameter were 2.253 (95% confidence interval (CI]): 1.297–3.912; P=0.004) and 1.074 (95% CI: 1.011–1.142; P=0.022), respectively. For lymph node metastasis, ORs for the presence of lymphatic invasion, EPE, and seminal vesicle invasion were 7.425 (95% CI: 1.688–22.583; P=0.004), 4.391 (95% CI: 1.037–18.589; P=0.044), and 5.755 (95% CI: 1.308–25.316; P=0.021), respectively.

Conclusions

We summarized various parameters correlating with each GG. Through multivariate analyses, we established the independent risk factors for early BCR and lymph node metastasis. In addition to GG, other important indices of malignancy were determined and weighted to provide a basis for future investigations.

Investigation of Neural Microenvironment in Prostate Cancer in Context of Neural Density, Perineural Invasion, and Neuroendocrine Profile of Tumors

Background

Cancer stroma contains the neural compartment with specific components and action. Neural microenvironment processing includes among others axonogenesis, perineural invasion (PNI), neurosignaling, and tumor cell neural/neuroendocrine differentiation. Growing data suggest that tumor-neural crosstalk plays an important function in prostate cancer (PCa) biology. However, the mechanisms involved in PNI and axonogenesis, as well as their patho-clinical correlations in this tumor are unclear.

Methods

The present study was carried out on FFPE samples of 73 PCa and 15 benign prostate (BP) cases. Immunohistochemistry with neural markers PGP9.5, TH, and NFP was performed on constructed TMAs and selected tissue sections. The analyzed parameters of tumor innervation included small nerve density (ND) measured on pan-neural marker (PGP9.5) and TH s4tained slides, as well assessment of PNI presence and morphology. The qualitative and topographic aspects were studied. In addition, the expression of neuroendocrine marker chromogranin and NPY was assessed with dedicated indexes. The correlations of the above parameters with basic patho-clinical data such as patients’ age, tumor stage, grade, angioinvasion, and ERG status were examined.

Results

The study showed that innervation parameters differed between cancer and BP. The neural network in PCa revealed heterogeneity, and ND PGP9.5 in tumor was significantly lower than in its periphery. The density of sympathetic TH-positive fibers and its proportion to all fibers was lower in cancer than in the periphery and BP samples. Perineural invasion was confirmed in 76% of cases, usually multifocally, occurring more commonly in tumors with a higher grade. NPY expression in PCa cells was common with its intensity often rising towards PNI. ERG+ tumors showed higher ND, more frequent PNI, and a higher stage. Moreover, chromogranin-positive cells were more pronounced in PCa with higher NPY expression.

Conclusions

The analysis showed an irregular axonal network in prostate cancer with higher neural density (panneural and adrenergic) in the surroundings and the invasive front. ND and PNI interrelated with NPY expression, neuroendocrine differentiation, and ERG status. The above findings support new evidence for the presence of autocrine and paracrine interactions in prostate cancer neural microenvironment.

Nerve fibers in the tumor microenvironment in neurotropic cancer-pancreatic cancer and cholangiocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA) are both deadly cancers and they share many biological features besides their close anatomical location. One of the main histological features is neurotropism, which results in frequent perineural invasion. The underlying mechanism of cancer cells favoring growth by and through the nerve fibers is not fully understood. In this review, we provide knowledge of these cancers with frequent perineural invasion. We discuss nerve fiber crosstalk with the main different components of the tumor microenvironment (TME), the immune cells, and the fibroblasts. Also, we discuss the crosstalk between the nerve fibers and the cancer. We highlight the shared signaling pathways of the mechanisms behind perineural invasion in PDAC and CCA. Hereby we have focussed on signaling neurotransmitters and neuropeptides which may be a target for future therapies. Furthermore, we have summarized retrospective results of the previous literature about nerve fibers in PDAC and CCA patients. We provide our point of view in the potential for nerve fibers to be used as powerful biomarker for prognosis, as a tool to stratify patients for therapy or as a target in a (combination) therapy. Taking the presence of nerves into account can potentially change the field of personalized care in these neurotropic cancers.

Should Grade Group 1 (GG1) be called cancer?

INTRODUCTION

ISUP Grade Group 1 prostate cancer is the lowest histologic grade of prostate cancer with a clinically indolent course. Removal of the term 'cancer' has been proposed and has historical precedent both in urothelial and thyroid carcinoma.

METHODS

Evidence-based review identifying arguments for and against Grade Group 1 being referred to as cancer.

RESULTS

Grade Group 1 has histologic evidence of tissue microinvasion and 0.3-3% rate of extraprostatic extension. Genomic evaluation suggests overlap of a minority of Grade Group 1 cancers with those of Grade Group 2. Conversely, Grade Group 1 tumors appear to have distinct genetic and genomic profiles from Grade Group 3 or higher tumors. Grade Group 1 has no documented ability for regional or distant metastasis and long-term follow up after treatment or active surveillance is safe with excellent oncologic outcomes.

DISCUSSION

Grade Group 1 prostate cancer, while showing evidence of neoplasia on histology has a remarkably indolent natural history more akin to non-neoplastic precursor lesions. Consideration should be given to renaming Grade Group 1 prostate cancer, which has the potential to minimize overtreatment, treatment-related side effects, patient anxiety, and financial burden on the healthcare system.

Perineural invasion in prostate needle biopsy: Prognostic value on radical prostatectomy and active surveillance

PURPOSE

The aim of this study was to evaluate the clinical impact of perineural invasion (PNI) in prostate biopsy in patients submitted to radical prostatectomy and on active surveillance (AS).

MATERIALS AND METHODS

We performed a single center, retrospective, cohort study on patients diagnosed with clinically localized prostate cancer and submitted to radical prostatectomy between January 2010 and December 2016. We evaluated clinical and anatomopathological characteristics from the biopsy and radical prostatectomy specimen and correlated with biochemical recurrence (BCR) using a survival analysis. We also evaluated the impact of PNI in patients with criteria for active surveillance.

RESULTS

The cohort analyzed consists of 107 patients, with a mean age of 63.1 years and a mean PSA prior to biopsy of 7.8 ng/ml. In prostate biopsy, 66.4% of the patients had a Gleason score of 6, 30.9% had a Gleason score of 7, and 2.7% had a Gleason score of 8 or higher, with PNI being detected in 57 (53.3%) of the patients. Regarding the anatomopathological characteristics of the surgical specimen, invasion of the seminal vesicles was observed in 6.5%, lymph nodes involvement in 9.3% and positive surgical margins in 27.1% of the cases. During follow-up, BCR was recorded in 24.3% of cases. Clinicopathological features were stratified according to the presence or absence of PNI, with statistical significance in relation to the Gleason Score (p = 0.001), pathologic T stage (p = 0.001), D'Amico risk (p = 0.002) and upstaging of the Gleason score (p = 0.045). The survival analysis revealed a relationship between PNI and BCR (hazard ratio = 2.98; 95% CI: 1.36-6.58; p = 0.007). Regarding the men potentially eligible for AS, the presence of PNI on the biopsy presented a significant relation with Gleason upgrade (p = 0.004) and extraprostatic extension (p = 0.017).

CONCLUSIONS

The presence of PNI in prostate biopsy is related to adverse anatomopathological factors, being a potential predictor of BCR and have a possible role in the selection of patients for AS.

SNAIL Transctiption factor in prostate cancer cells promotes neurite outgrowth

Neurite outgrowth involves reciprocal signaling interactions between tumor cells and nerves where invading tumor cells have acquired the ability to respond to pro-invasive signals within the nerve environment. Neurite outgrowth could serve as a mechanism leading to invasion of cancer cells into the nerve sheath and subsequent metastasis. Snail transcription factor can promote migration and invasion of prostate cancer cells. We hypothesized that prostate cancer cell interaction with nerve cells will be mediated by Snail expression within prostate cancer cells. For this study we utilized various prostate cancer cell lines: C4-2 non-silencing (NS, control); C4-2 Snail shRNA, (stable Snail knockdown); LNCaP Neo (empty vector control) and LNCaP Snail (stably over-expressing Snail). Cancer cell adhesion and migration towards nerve cells (snF96.2 or NS20Y) was examined by co-culture assays. Conditioned media (CM) collected from C4-2 cells was cultured with nerve cells (PC-12 or NS20Y) for 48 h followed by qualitative or quantitative neurite outgrowth assay. Our results showed that cancer cells expressing high levels of Snail (LNCaP Snail/C4-2 NS) displayed significantly higher migration adherence to nerve cells, compared to cells with lower levels of Snail (LNCaP Neo/C4-2 Snail shRNA). Additionally, LNCaP Snail or C4-2 NS (Snail-high) CM led to a higher neurite outgrowth compared to the LNCaP Neo or C4-2 Snail shRNA (Snail-low). In conclusion, Snail promotes migration and adhesion to nerve cells, as well as neurite outgrowth via secretion of soluble factors. Therefore, targeting cancer cell interaction with nerves may contribute to halting prostate cancer progression/metastasis.

Prostate cancer evolution from multilineage primary to single lineage metastases with implications for liquid biopsy

The evolutionary progression from primary to metastatic prostate cancer is largely uncharted, and the implications for liquid biopsy are unexplored. We infer detailed reconstructions of tumor phylogenies in ten prostate cancer patients with fatal disease, and investigate them in conjunction with histopathology and tumor DNA extracted from blood and cerebrospinal fluid. Substantial evolution occurs within the prostate, resulting in branching into multiple spatially intermixed lineages. One dominant lineage emerges that initiates and drives systemic metastasis, where polyclonal seeding between sites is common. Routes to metastasis differ between patients, and likely genetic drivers of metastasis distinguish the metastatic lineage from the lineage that remains confined to the prostate within each patient. Body fluids capture features of the dominant lineage, and subclonal expansions that occur in the metastatic phase are non-uniformly represented. Cerebrospinal fluid analysis reveals lineages not detected in blood-borne DNA, suggesting possible clinical utility.

Perineural Invasion in Adenoid Cystic Carcinoma of the Salivary Glands: Where We Are and Where We Need to Go

Adenoid cystic carcinoma of the salivary gland (SACC) is a rare malignant tumors of the head and neck region, but it is one of the most common malignant tumors that are prone to perineural invasion (PNI) of the head and neck. The prognosis of patients with SACC is strongly associated with the presence of perineural spread (PNS). Although many contributing factors have been reported, the mechanisms underlying the preferential destruction of the blood-nerve barrier (BNB) by tumors and the infiltration of the tumor microenvironment by nerve fibers in SACC, have received little research attention. This review summarizes the current knowledge concerning the characteristics of SACC in relation to the PNI, and then highlights the interplay between components of the tumor microenvironment and perineural niche, as well as their contributions to the PNI. Finally, we provide new insights into the possible mechanisms underlying the pathogenesis of PNI, with particular emphasis on the role of extracellular vesicles that may serve as an attractive entry point in future studies.

The biology and engineered modeling strategies of cancer-nerve crosstalk

A recent finding critical to cancer aggravation is the interaction between cancer cells and nerves. There exist two main modes of cancer-nerve interaction: perineural invasion (PNI) and tumor innervation. PNI occurs when cancer cells infiltrate the adjacent nerves, and its relative opposite, tumor innervation, occurs when axons extend into tumor bodies. Like most cancer studies, these crosstalk interactions have mostly been observed in patient samples and animal models at this point, making it difficult to understand the mechanisms in a controlled manner. As such, in recent years in vitro studies have emerged that have helped identify various microenvironmental factors responsible for cancer-nerve crosstalk, including but not limited to neurotrophic factors, neurotransmitters, chemokines, cancer-derived exosomes, and Schwann cells. The versatility of in vitro systems warrants continuous development to increase physiological relevance to study PNI and tumor innervation, for example by utilizing biomimetic three-dimensional (3D) culture systems. Despite the wealth of 3D in vitro cancer models, comparatively there exists a lack of 3D in vitro models of nerve, PNI, and tumor innervation. Native-like 3D in vitro models of cancer-nerve interactions may further help develop therapeutic strategies to curb nerve-mediated cancer aggravation. As such, we provide an overview of the key players of cancer-nerve crosstalk and current in vitro models of the crosstalk, as well as cancer and nerve models. We also discuss a few future directions in cancer-nerve crosstalk research.

Quantification of perineural invasion focus after radical prostatectomy could improve predictive power of recurrence

Perineural invasion (PNI) after radical prostatectomy (RP) is a common feature of prostate cancer (PCa) and has been associated with unfavorable tumor characteristics. However, its prognostic relevance is controversial. In this study, we evaluated the impact of both PNI status (PNI+ versus PNI-) and quantified number of PNI focus on the long-term prognosis of biochemical recurrence (BCR) after RP. After reevaluating PNI of a total of 721 patients with localized PCa who underwent RP at our institution between 2000 and 2002, we examined associations between PNI status or PNI focus number and clinicopathological factors including tumor stage, Gleason score, margin status, tumor location, preoperative prostate specific antigen, age, prostate weight as well as BCR outcome. PNI was present in 530 of 721 cases (73.5%) of the RP specimens and was associated with more aggressive disease. BCR occurred in 19.4% of all patients within a median follow-up period of 8.5 years. PNI+ status was associated with poor BCR prognosis in univariate analysis but lost in multivariate analysis. Based on the number of PNI focus, PNI was further divided into 2 distinct group: PNI+ a (≤3) and PNI+ b (>3). In a multivariate Cox regression model, PNI+ b (>3) was identified as an independent BCR prognostic factor. Quantification of PNI focus number beside the dichotomized status recording will not only provide more detailed information but also be a novel prognostic indicator for risk stratification. Further external validation will be needed for an optimal cut-off value of the PNI focus number. Our findings will help further research on the relevance of PNI in the pretreatment setting and support ongoing efforts to understand its role of cancer progression.

Perineural invasion by prostate adenocarcinoma in needle biopsies predicts bone metastasis: Ten year data from the TROG 03.04 RADAR Trial

AIMS

Perineural invasion (PNI) by prostatic adenocarcinoma is debated as a prognostic parameter. This study investigates the prognostic predictive value of PNI in a series of patients with locally advanced prostate cancer treated with radiotherapy and androgen deprivation using 10 years outcome data from the TROG 03.04 RADAR trial.

METHODS

Diagnostic prostate biopsies from 976 patients were reviewed and the presence of PNI noted. Patients were followed for 10 years according to the trial protocol or until death. The primary endpoint for the study was time to bone metastasis. Secondary endpoints included time to soft tissue metastasis, transition to castration resistance, prostate cancer-specific mortality and all-cause mortality.

RESULTS

PNI was detected in 449 cases (46%), with 234 cases (24%) having PNI in more than one core. The presence of PNI was significantly associated with higher ISUP grade, clinical T staging category, National Comprehensive Cancer Network risk group, and percent positive biopsy cores. The cumulative probability of bone metastases according to PNI status was significant over the 10 years follow-up interval of the study (log-rank test P < 0.0001). PNI was associated with all endpoints on univariable analysis. After adjusting for baseline clinicopathological and treatment factors, bone metastasis was the only endpoint in which PNI retained its prognostic significance (hazard ratio 1.42, 95% confidence interval 1.05-1.92, P = 0.021).

CONCLUSIONS

The association between PNI and the development of bone metastases supports the inclusion of this parameter as a component of the routine histology report. Further this association suggests that evaluation of PNI may assist in selecting those patients who should be monitored more closely during follow-up.

Perineural invasion as a prognostic factor in patients with stage I-III rectal cancer – 5-year follow up

BACKGROUND

Rectal cancer (RC) is one of the most common diagnosed cancers, and one of the major causes of cancer-related death nowadays. Majority of the current guidelines rely on TNM classification regarding therapy regiments, however recent studies suggest that additional histopathological findings could affect the disease course.

AIM

To determine whether perineural invasion alone or in combination with lymphovascular invasion have an effect on 5-years overall survival (OS) of RC patients.

METHODS

A prospective study included newly diagnosed stage I-III RC patients treated and followed at the Digestive Surgery Clinic, Clinical Center of Serbia, between the years of 2014–2016. All patients had their diagnosis histologically confirmed in accordance with both TMN and Dukes classification. In addition, the patient’s demographics, surgical details, postoperative pathological details, differentiation degree and their correlation with OS was investigated.

RESULTS

Of 245 included patients with stage I-III RC, lymphovascular invasion (LVI) was identified in 92 patients (38%), whereas perineural invasion (PNI) was present in 46 patients (19%). Using Kaplan-Meier analysis for overall survival rate, we have found that both LVI and PNI were associated with lower survival rates (P < 0.01). Moreover when Cox multiple regression model was used, LVI, PNI, older age, male gender were predictors of poor prognosis (HR = 5.49; 95%CI: 2.889-10.429; P < 0.05).

CONCLUSION

LVI and PNI were significant factors predicting worse prognosis in early and intermediate RC patients, hence more aggressive therapy should be reserved for these patients after curative resection.

Clinical implications of perineural invasion in patients with colorectal cancer

Perineural invasion (PNI) is a prominent characteristic of multiple solid tumors and indicates poor prognosis. Previous data concerning the impact of PNI on prognosis of patients with colorectal cancer (CRC) are conflicting, and little is known about risk factors of PNI. The aim of our study was to reveal the clinical implication of PNI on survival outcome and identify risk factors for the poor prognosis in patients with CRC.We retrospectively reviewed 627 patients who were diagnosed with CRC and underwent curative surgical resection. The differences in several clinicopathologic characteristics were compared between PNI positive and PNI negative groups. Multivariate logistic regression analysis was performed to identify predictors of CRC with PNI. Five-year overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method, and the difference in survival rate was assessed by the log-rank test. The variables that had prognostic potential, as indicated by univariate analyses, were subjected to multivariate analyses with the Cox proportional hazards regression model.PNIs were identified in 79 patients (12.6%). Age, T classification, N classification, M classification, UICC classification, and lymphovascular invasion were significantly associated with PNI. Multivariate logistic regression analysis demonstrated that only lymphovascular invasion was a predictor of PNI. Pathologic evidence of PNI was not associated with survival outcome (the 5-year OS [P = .560] and DFS [P = .083]). Cox proportional hazards regression model revealed that age and N2/3 classification were independent prognostic factors for poorer OS and DFS. M1 stage (95% confidence interval [CI] = 0.228-0.585, P = .000), III/IV stage (95% CI = 0.335-0.920, P = .022), and number of sampled lymph nodes (95% CI = 0.951-0.987, P = .001) were independently prognostic for poorer OS, while history of other malignancy (95% CI = 1.133-2.813, P = .012) was identified as an independent prognostic factor for poorer DFS.Our study indicates that PNI is not an independent poor prognostic factor in patients with CRC and those patients with PNI may not benefit from postoperative adjuvant chemotherapy.

Prognostic Value of Clinical Biochemistry-Based Indexes in Nasopharyngeal Carcinoma

Inflammation and nutritional status have significant effects on the prognosis of cancer patients. This study investigated the predictive value of clinical biochemistry-based indexes in nasopharyngeal carcinoma (NPC). This retrospective study included 559 NPC patients and 500 patients with chronic rhinitis. Continuous variables were measured by t-test. The area under curves (AUC) was used to determine the diagnostic and prognostic value for NPC. Kaplan-Meier methods and the log-rank test were used to analyze overall survival (OS) and disease-free survival (DFS) of the patients. Cox and logistic regression analysis were used to analyze the independent prognostic risk factors for survival and influencing factors of side effects after treatment, respectively. The study results revealed that most indexes of NPC and rhinitis were significantly different between the two groups. In the survival analysis, the systemic inflammation score (SIS), prognostic nutritional index (PNI), albumin/globulin ratio (AGR), albumin (ALB), urea nitrogen (BUN) and creatinine (CREA) had significant influence on the OS and DFS. AGR was the optimal prognostic indicator for NPC. Among these indexes, SIS, AGR, BUN and CERA were independent prognostic factors of OS, AGR and PNI were independent prognostic factors of DFS. Most indexes were risk factors of side effects occurred in radiotherapy. In conclusion, the clinical biochemistry-based indexes, are reliable and of low-cost, therefore, they can be used in predicting diagnosis, prognosis and treatment plans of NPC.

Nerve growth factor (NGF)-TrkA axis in head and neck squamous cell carcinoma triggers EMT and confers resistance to the EGFR inhibitor erlotinib

Understanding the molecular mechanisms regulating tumor dissemination and therapeutic resistance is of central importance for effective cancer therapies. Here, we report that nerve growth factor (NGF) and its receptor TrkA facilitate epithelial-mesenchymal transition (EMT) and EGFR inhibitor resistance via STAT3 activation in head and neck squamous cell carcinoma (HNSCC). Both NGF and TrkA expression were elevated in HNSCC, indicating poor clinical outcomes. NGF was highly expressed in cancer cells and nerves in perineural niche, whereas TrkA expression was higher in cancer cells with perineural invasion. The NGF/TrkA axis could promote HNSCC cell dissemination and trigger EMT via STAT3 activation. Moreover, we discovered that the NGF/TrkA axis conferred resistance to the EGFR inhibitor erlotinib via EMT processes in HNSCC cells. Blocking TrkA signaling markedly reversed EMT and sensitized HNSCC cells to erlotinib in both in vitro and in vivo models. Overall, our results demonstrate novel evidence that the paracrine NGF/TrkA axis favors EMT and confers EGFR-targeted therapeutic resistance in HNSCC.

The clinical predictive factors and postoperative histopathological parameters associated with upgrading after radical prostatectomy: A contemporary analysis with grade groups

BACKGROUND AND AIM

Upgrading after radical prostatectomy (RP) is an ongoing problem since first description of Gleason score. In this retrospective study, our aim is to investigate upgrading after RP in grade groups (GG) and clinical predictive, and postoperative histopathological factors associated with GG upgrading (GGU).

PATIENTS AND METHODS

A total of 753 patients undergoing RP between January 2006 and June 2019 at our institution were investigated. Overall cohort were divided into two groups according to GGU status after RP as nonupgrading and upgrading. Retrospectively documented preoperative clinical and postoperative histopathological parameters were compared between two groups. Furthermore, we investigated a subgroup of institutional cohort (n = 398) whose prostate biopsy (Pbx) and RP were performed in our institution and we also divided this cohort into two groups according to GGU status. χ² and Mann-Whitney U tests were used for comparative analyses. The independent preoperative predictive and postoperative histopathological factors associated with GGU were investigated using multivariate logistic regression analysis.

RESULTS

The total GGU was 55.8% in overall cohort and 45.2% in institutional cohort. The GGU was found as the most common in bioptic GG1 group in both overall (64.0%), and institutional (54.5%) cohorts. In multivariate analyses, the noninstitutional Pbx (odds ratio [OR] = 2.56; 95% confidence interval [CI]: 1.86-3.51; P < .001), tumor positive core numbers in Pbx (OR = 1.11; 95%CI: 1.04-1.19; P = .003), increased prostate specific antigen (PSA) density (OR = 3.59; 95%CI: 1.03-12.52, P = .045) and age (OR = 1.03; 95%CI: 1.00-1.05, P = .046) were independent clinical predictors of GGU in overall cohort whereas only increased PSA density (OR = 5.94; 95%CI: 1.28-27.50; P = .023) was independent predictor in institutional cohort. Among postoperative histopathological factors, perineural invasion (OR = 1.57; 95%CI: 1.70-3.87; P < .001 and OR = 2.53; 95%CI: 1.46-4.40; P = .001, respectively), increased maximum tumor diameter (OR = 1.46; 95%CI: 1.23-1.73; P < .001 and OR = 1.33; 95%CI: 1.07-1.66; P = .010, respectively), and high-grade prostatic intraepithelial neoplasia (HGPIN) existence at tumor surrounding tissue (OR = 1.96; 95%CI: 1.32-2.90; P = .001 and OR = 1.87; 95%CI: 1.10-3.21; P = .022, respectively) were independently associated with GGU after RP, in both of overall and institutional cohorts.

CONCLUSIONS

Noninstitutional prostate biopsy, increased PSA density, higher tumor positive cores in Pbx and older age are the clinical predictors of upgrading after RP in contemporary GG. Perineural invasion, increased maximum tumor diameter, and HGPIN existence at tumor surrounding tissue are postoperative histopathological factors associated with GGU.

Tumour innervation and neurosignalling in prostate cancer

Prostate cancer progression has been shown to be dependent on the development of autonomic nerves into the tumour microenvironment. Sympathetic nerves activate adrenergic neurosignalling that is necessary in early stages of tumour progression and for initiating an angiogenic switch, whereas parasympathetic nerves activate cholinergic neurosignalling resulting in tumour dissemination and metastasis. The innervation of prostate cancer seems to be initiated by neurotrophic growth factors, such as the precursor to nerve growth factor secreted by tumour cells, and the contribution of brain-derived neural progenitor cells has also been reported. Current experimental, epidemiological and clinical evidence shows the stimulatory effect of tumour innervation and neurosignalling in prostate cancer. Using nerves and neurosignalling could have value in the management of prostate cancer by predicting aggressive disease, treating localized disease through denervation and relieving cancer-associated pain in bone metastases.

Single-nucleotide polymorphism rs13426236 contributes to an increased prostate cancer risk via regulating MLPH splicing variant 4

A prostate cancer risk single-nucleotide polymorphism (SNP), rs13426236, is significantly associated with melanophilin (MLPH) expression. To functionally characterize role of the rs13426236 in prostate cancer, we first performed splicing-specific expression quantitative trait loci analysis and refined the significant association of rs13426236 allele G with an increased expression of MLPH splicing transcript variant 4 (V4) (P = 7.61E-5) but not other protein-coding variants (V1-V3) (P > .05). We then performed an allele-specific reporter assay to determine if SNP-containing sequences functioned as an active enhancer. Compared to allele A, allele G of rs13426236 showed significantly higher luciferase activity on the promoter of the splicing transcript V4 (P < .03) but not on the promoter of transcript V1 (P > .05) in two prostate cancer cell lines (DU145 and 22Rv1). Cell transfection assays showed stronger effect of transcript V4 than V1 on promoting cell proliferation, invasion, and antiapoptotic activities. RNA profiling analysis demonstrated that transcript V4 overexpression caused significant expression changes in glycosylation/glycoprotein and metal-binding gene ontology pathways (FDR < 0.01). We also found that both transcripts V4 and V1 were significantly upregulated in prostate adenocarcinoma (P ≤ 2.49E-6) but only transcript V4 upregulation was associated with poor recurrence-free survival (P = .028, hazard ratio = 1.63, 95% confidence interval = 1.05-2.42) in The Cancer Genome Atlas data. This study provides strong evidence showing that prostate cancer risk SNP rs13426236 upregulates expression of MLPH transcript V4, which may function as a candidate oncogene in prostate cancer.

A Prospective Study of Intraprostatic Inflammation, Focal Atrophy, and Progression to Lethal Prostate Cancer

BACKGROUND

Inflammation and focal atrophy are common features adjacent to prostate tumors. Limited evidence exists on whether these features have prognostic significance.

METHODS

In the Health Professionals Follow-Up Study and Physicians' Health Study, we studied 1,035 men diagnosed with prostate cancer. A genitourinary pathologist centrally reviewed tumor and normal areas of hematoxylin and eosin slides from prostate cancer specimens for the presence of acute and chronic inflammation, and four subtypes of focal atrophy. Cox proportional hazards models adjusted for potential confounders were used to estimate HRs and 95% confidence intervals (CI) for the association of these features with lethal prostate cancer, defined as development of metastatic disease or death during follow-up.

RESULTS

During a median of 12 years of follow-up, 153 men developed lethal prostate cancer. A total of 84% of men had histologic evidence of chronic inflammation and 30% had acute inflammation. Both chronic and acute inflammation were inversely associated with lethal prostate cancer in age- and lifestyle-adjusted models. Chronic inflammation remained inversely associated with lethal prostate cancer after additionally adjusting for prognostic clinical features (HR = 0.45; 95% CI, 0.30-0.69 for mild and HR = 0.51; 95% CI, 0.33-0.80 for moderate to severe). None of the atrophic lesions were associated with lethal prostate cancer.

CONCLUSIONS

Our data suggest that the presence of inflammation, particularly chronic inflammation, in prostate cancer tissue is associated with better prognosis among patients with prostate cancer.

IMPACT

This is the largest prospective cohort study to examine the association between inflammation, focal atrophy, and lethal prostate cancer.

Multivariate analysis of prognostic factors in primary squamous cell vulvar cancer: The role of perineural invasion in recurrence and survival

OBJECTIVE

to assess the prognostic role in recurrence and survival of perineural invasion (PNI) in vulvar squamous cell cancer (VSCC).

METHODS

Patients underwent primary surgery for VSCC from January 2009 to December 2016 served as the study cohort. We collected demographic, clinical, pathological characteristics and follow-up data, and we compared them among PNI-negative versus -positivepatients. We calculated disease-free survival (DFS) and overall survival (OS) using Kaplan-Meier and univariate log-rank test. We conducted a multivariate analysis with cox-proportional hazard models for DFS and OS, including age, tumor size, depth of invasion, free tumor margin <8 mm, high-grade histology, lymph vascular space invasion, PNI, extracapsular lymph nodal disease, lymph nodal ratio >0.2 and FIGO Stage 2009 (Early I-II versus Advanced III-IV).

RESULTS

We found 74 patients with a PNI prevalence of 31.1%. The 5-year DFS was favourable for PNI-negative patients (72% versus 18%; p = 0.00). The 5-year OS was 75% versus 35% in favor of PNI-negative patients (p = 0.00). The subgroup analysis conducted among stage confirmed a decreased DFS and OS in PNI-positive patients. Multivariate analysis showed that PNI (HR 2.74; CI95% 1.10-7.13; p = 0.03) and extracapsular lymph nodal disease (HR 13.54; CI95% 2.87-64.07; p = 0.01) are independent prognostic factors for earlier recurrence. OS was significantly reduced in case of PNI (HR 4.93; CI95% 1.33-18.35; p = 0.01) and extracapsular lymph nodal disease (HR 10.63; CI95% 1.65-68.57; p = 0.01).

CONCLUSIONS

PNI is an independent prognostic factor for aggressive behavior and unfavorable course in VSCC and should be considered in adjuvant treatment planning.

The clinical significance of perineural invasion in patients with de novo metastatic prostate cancer

BACKGROUND

The clinical value of perineural invasion (PNI) in patients with localized prostate cancer (PCa) is widely explored. However, its role in metastatic PCa (mPCa) remains unknown.

OBJECTIVES

We aim to investigate the clinical significance of PNI in patients with mPCa.

MATERIALS AND METHODS

Data of 515 mPCa patients between 2012 and 2018 were retrospectively studied. PNI and its intensity were identified by prostate biopsy. The prognostic value of PNI was evaluated by Kaplan-Meier curves and Cox proportional-hazards model.

RESULTS

Perineural invasion was detected in 170/515 (33.0%) cases. Among them 73/170 (42.9%) and 97/170 (57.1%) harbored unifocal PNI (uni-PNI) and multifocal PNI (multi-PNI), respectively. Compared to patients without PNI, those with PNI had statistically shorter castration-resistant PCa-free survival (CFS) and numerically shorter overall survival (OS) (mCFS: 15.4- vs. 18.5-Mo, p = 0.015; mOS: 63.8- vs. 71.4-Mo, p = 0.108). Patients harboring multi-PNI were associated with poorer clinical outcomes than those with uni-PNI (mCFS: 12.4- vs. 18.0-Mo, p = 0.040; mOS: 39.7-Mo vs. NR, p = 0.018) or those without PNI (mCFS: 12.4- vs. 18.5-Mo, p = 0.002; mOS: 39.7- vs. 71.4-Mo, p = 0.002). Totally, neither uni-PNI nor multi-PNI was an independent risk factor impacting survival outcomes in multivariate analyses. While remarkably, for patients with favorable/intermediate-risk mPCa, multi-PNI was an independent adverse prognosticator for both CFS and OS (CFS: HR: 1.705, 95% CI: 1.029-2.825, p = 0.038; OS: HR: 3.294, 95% CI: 1.464-7.413, p = 0.004).

DISCUSSION AND CONCLUSION

This study filled the blank of the clinical significance of PNI in mPCa. We found that multi-PNI could distinguish men with relatively poor prognosis from patients initially regarded as with favorable survival outcomes by other prognosticators, and thus, avoid disease underestimation in this group of patients. Our finding would help physicians have a deeper understanding of the heterogeneity of mPCa and make better individualized therapeutic strategy.

The Tumor Microenvironments of Lethal Prostate Cancer

Localized prostate cancer (confined to the gland) generally is considered curable, with nearly a 100% 5-year-survival rate. When the tumor escapes the prostate capsule, leading to metastasis, there is a poorer prognosis and higher mortality rate, with 5-year survival dropping to less than 30%. A major research question has been to understand the transition from indolent (low risk) disease to aggressive (high risk) disease. In this chapter, we provide details of the changing tumor microenvironments during prostate cancer invasion and their role in the progression and metastasis of lethal prostate cancer. Four microenvironments covered here include the muscle stroma, perineural invasion, hypoxia, and the role of microvesicles in altering the extracellular matrix environment. The adaptability of prostate cancer to these varied microenvironments and the cues for phenotypic changes are currently understudied areas. Model systems for understanding smooth muscle invasion both in vitro and in vivo are highlighted. Invasive human needle biopsy tissue and mouse xenograft tumors both contain smooth muscle invasion. In combination, the models can be used in an iterative process to validate molecular events for smooth muscle invasion in human tissue. Understanding the complex and interacting microenvironments in the prostate holds the key to early detection of high-risk disease and preventing tumor invasion through escape from the prostate capsule.

Regular aspirin use and gene expression profiles in prostate cancer patients

PURPOSE

Pharmacoepidemiology studies suggest prognostic benefits of aspirin in prostate cancer. We hypothesized that aspirin induces transcriptional changes in tumors or normal prostate tissue.

METHODS

We analyzed the prostatic transcriptome from men diagnosed with prostate cancer during follow-up of the Physicians' Health Study 1 (PHS, n = 149), initially a randomized controlled trial of aspirin. Aspirin target genes were identified through systematic literature review and a drug target database. We compared target gene expression according to regular aspirin use at cancer diagnosis and used whole-transcriptome gene set enrichment analysis to identify gene sets associated with aspirin use. Results were validated in the Health Professionals Follow-up Study (HPFS, n = 254) and in Connectivity Map.

RESULTS

Of 12 target genes identified from prior studies and 540 genes from the drug target database, none were associated with aspirin use. Twenty-one gene sets were enriched in tumor tissue of aspirin users, 18 of which were clustered around ribosome function and translation. These gene sets were associated with exposure to cyclooxygenase inhibitors in Connectivity Map. Their association with cancer prognosis was U-shaped in both cohorts. No gene sets were enriched in normal tissue. In HPFS, neither the target genes nor the gene sets were associated with aspirin use.

CONCLUSIONS

Regular aspirin use may affect ribosome function in prostate tumors. Other putative target genes had similar expression in tumors from aspirin users and non-users. If results are corroborated by experimental studies, a potential benefit of aspirin may be limited to a subset of prostate cancer patients.

Should reporting of peri-neural invasion and extra prostatic extension be mandatory in prostate cancer biopsies? correlation with outcome in biopsy cases treated conservatively

The identification of perineural invasion (PNI) and extraprostatic extension (ECE) in prostate cancer (PC) biopsies is time consuming and can be difficult. Although this is required information in many datasets, there is little evidence on their effect on outcome in patients treated conservatively. Cases of PC were identified from three cancer registries in the UK from men with clinically localized prostate cancer diagnosed by needle biopsy from 1990-2003. The endpoint was prostate cancer death (DOD). Patients treated radically within 6 months, those with objective evidence of metastases or who had prior hormone therapy were excluded. Follow-up was through cancer registries up until 2012. Deaths were divided into those from PC and those from other causes, according to WHO criteria. 988 biopsy cases (6522 biopsy cores) were centrally reviewed by three uropathologists and assigned a Gleason score and Grade Group (GG). The presence of both PNI and ECE was recorded. Of 988 patients, PNI was present in 288 (DOD = 75) and ECE in 23 (DOD = 5). On univariable analysis PNI was highly significantly associated with DOD (hazard ratio [HR] 2.28, 95% CI: 1.68, 3.1, log-rank test p-value = 4.8 × 10-8), but ECE was not (log-rank test p-value = 0.334). On multivariable analysis with GG, serum PSA (per 10%), clinical stage and extent of disease (per 10%), PNI lost significance (HR 1.16, 95% CI: 0.83, 1.63, likelihood ratio test p-value = 0.371). The utility of routinely examining prostate biopsies for ECE and PNI is doubtful as it is not independently associated with higher grade, stage or prognosis.

Effects of perineural invasion on biochemical recurrence and prostate cancer-specific survival in patients treated with definitive external beam radiotherapy

OBJECTIVES

Perineural invasion (PNI) has not yet gained universal acceptance as an independent predictor of adverse outcomes for prostate cancer treated with external beam radiotherapy (EBRT). We analyzed the prognostic influence of PNI for a large institutional cohort of prostate cancer patients who underwent EBRT with and without androgen deprivation therapy (ADT).

MATERIAL AND METHODS

We, retrospectively, reviewed prostate cancer patients treated with EBRT from 1993 to 2007 at our institution. The primary endpoint was biochemical failure-free survival (BFFS), with secondary endpoints of metastasis-free survival (MFS), prostate cancer-specific survival (PCSS), and overall survival (OS). Univariate and multivariable Cox proportional hazards models were constructed for all survival endpoints. Hazard ratios for PNI were analyzed for the entire cohort and for subsets defined by NCCN risk level. Additionally, Kaplan-Meier survival curves were generated for all survival endpoints after stratification by PNI status, with significant differences computed using the log-rank test.

RESULTS

Of 888 men included for analysis, PNI was present on biopsy specimens in 187 (21.1%). PNI was associated with clinical stage, pretreatment PSA level, biopsy Gleason score, and use of ADT (all P<0.01). Men with PNI experienced significantly inferior 10-year BFFS (40.0% vs. 57.8%, P = 0.002), 10-year MFS (79.7% vs. 89.0%, P = 0.001), and 10-year PCSS (90.9% vs. 95.9%, P = 0.009), but not 10-year OS (67.5% vs. 77.5%, P = 0.07). On multivariate analysis, PNI was independently associated with inferior BFFS (P<0.001), but not MFS, PCSS, or OS. In subset analysis, PNI was associated with inferior BFFS (P = 0.04) for high-risk patients and with both inferior BFFS (P = 0.01) and PCSS (P = 0.05) for low-risk patients. Biochemical failure occurred in 33% of low-risk men with PNI who did not receive ADT compared to 8% for low-risk men with PNI treated with ADT (P = 0.01).

CONCLUSION

PNI was an independently significant predictor of adverse survival outcomes in this large institutional cohort, particularly for patients with NCCN low-risk disease. PNI should be carefully considered along with other standard prognostic factors when treating these patients with EBRT. Supplementing EBRT with ADT may be beneficial for select low-risk patients with PNI though independent validation with prospective studies is recommended.

Therapy-induced developmental reprogramming of prostate cancer cells and acquired therapy resistance

Treatment-induced neuroendocrine transdifferentiation (NEtD) complicates therapies for metastatic prostate cancer (PCa). Based on evidence that PCa cells can transdifferentiate to other neuroectodermally-derived cell lineages in vitro, we proposed that NEtD requires first an intermediary reprogramming to metastable cancer stem-like cells (CSCs) of a neural class and we demonstrate that several different AR+/PSA+ PCa cell lines were efficiently reprogrammed to, maintained and propagated as CSCs by growth in androgen-free neural/neural crest (N/NC) stem medium. Such reprogrammed cells lost features of prostate differentiation; gained features of N/NC stem cells and tumor-initiating potential; were resistant to androgen signaling inhibition; and acquired an invasive phenotype in vitro and in vivo. When placed back into serum-containing mediums, reprogrammed cells could be re-differentiated to N-/NC-derived cell lineages or return back to an AR+ prostate-like state. Once returned, the AR+ cells were resistant to androgen signaling inhibition. Acute androgen deprivation or anti-androgen treatment in serum-containing medium led to the transient appearance of a sub-population of cells with similar characteristics. Finally, a 132 gene signature derived from reprogrammed PCa cell lines distinguished tumors from PCa patients with adverse outcomes. This model may explain neural manifestations of PCa associated with lethal disease. The metastable nature of the reprogrammed stem-like PCa cells suggests that cycles of PCa cell reprogramming followed by re-differentiation may support disease progression and therapeutic resistance. The ability of a gene signature from reprogrammed PCa cells to identify tumors from patients with metastasis or PCa-specific mortality implies that developmental reprogramming is linked to aggressive tumor behaviors.

GDNF secreted by nerves enhances PD-L1 expression via JAK2-STAT1 signaling activation in HNSCC

Programmed death ligand 1 (PD-L1) functions as a key immune inhibitory factor by binding with its receptor, programmed death 1 (PD-1), to induce immune cell dysfunction and escape of the immune system. However, the mechanisms of PD-L1 expression under growth factor stimulation are not well characterized. Here, we demonstrate a novel role for glial cell line-derived neurotrophic factor (GDNF) in upregulating PD-L1 expression in head and neck squamous cell carcinoma (HNSCC). The expression and correlation of PD-L1, GDNF and perineural invasion (PNI) status were evaluated by bioinformatics analysis of TCGA database and IHC assays from 145 HNSCC patients. PD-L1 expression was investigated by flow cytometry, Western blot and real-time PCR analyses in HNSCC cells after GNDF incubation. The cell signaling pathways activated by GDNF were analyzed with an antibody array and blocked by specific signaling inhibitors in cancer cell lines. PD-L1 expression was significantly higher in cancer cells that exhibited PNI in the HNSCC specimens, and elevated PD-L1 expression was significantly correlated with GDNF levels. GDNF not only enhanced cancer cell PNI in a co-culture of dorsal root ganglions and cancer cells but also had a potent role in inducing PD-L1 expression through the JAK2-STAT1 signaling pathway. Moreover, a JAK2 inhibitor attenuated GDNF-induced PD-L1 and enhanced tumor cell susceptibility to NK cell killing. Our findings provide clinically novel evidence that nerve-derived GDNF can increase PD-L1 levels in cancer cells around the perineural niche and that regulatory signaling is critical for cancer cell escape from immune surveillance in the nerve-cancer microenvironment.