Perineural invasion as an independent predictor of biochemical recurrence in prostate cancer following radical prostatectomy or radiotherapy: a systematic review and meta-analysis

Impact of Autonomic Nerve Invasion on Biochemical Recurrence for Intermediate Risk T3a Prostate Cancer With Negative Surgical Margins After Radical Prostatectomy

OBJECTIVE

To assess the impact of autonomic nerve invasion (ANI) on subsequent biochemical recurrence (BCR) or early adjuvant therapy in the patients with extraprostatic spread (EPS) and negative margins after radical prostatectomy (RP).

METHODS

A total of 218 men with EPS (T3a) and negative margins were identified who underwent RP in Western Australia from January 2014 to December 2016. The t-test, Pearson chi-square test and Kaplan-Meier method with the log-rank test were used to evaluate differences between the ANI and non-ANI. Univariate and multivariable Cox proportional hazard regression models were applied to assess the impact of these parameters on BCR or early treatment and a model calibration was performed by the internal validation method.

RESULTS

ANI group had a significantly higher incidence in BCR or early adjuvant therapy compared to non-ANI group (hazard ratio 1.94, 95% CI 1.12-3.37, P = .02). Further analyses showed that ANI was significantly associated with BCR or early adjuvant therapy (hazard ratio 3.03, 95% CI 1.28-7.15, P = .01) in intermediate-risk cases (Gleason sum (GS)= 7, ie, International Society of Urological Pathology (ISUP) groups 2/3) but not in high-risk group (GS≥8/ISUP 4/5).

CONCLUSION

For the patients with EPS (T3a) and negative margins, ANI significantly and independently increases the chances of BCR or early adjuvant therapy for intermediate-risk disease (GS=7/ISUP 2/3) but it is not an independent predictor for high-risk disease (GS≥8/ISUP 4/5). This provides a simple cost-effective method to further stratify margin negative intermediate-risk T3a prostate cancer.

Systematic Biopsy vs. Prostatectomy: Evaluating Correlations and Grading Discrepancies in Prostate Cancer

Background Prostate Cancer (PCa) represents a growing global health challenge. The main factor in predicting PCa prognosis is represented by the Gleason Score (GS) therefore, the accuracy of pathological features from preoperative biopsy is critical in the management of the patient. We aimed to investigate the correlation between prostate biopsy parameters and the prostatectomy specimen pathological features and to identify factors that lead to over- and under-grading tumors in biopsy samples. Materials and methods We performed a retrospective study that included 110 male patients with confirmed PCa, selected based on specific inclusion criteria. Biopsy and radical prostatectomy (RP) specimens were analyzed using standard histopathological techniques, and pathological features were assessed according to the latest guidelines. Statistical analysis was performed using IBM SPSS Statistics version 26.0.0 (IBM Corp., Armonk, NY). Results The study included 110 male patients with a median age of 67 years old, ranging from 48 to 79 years old. Correlations between biopsy parameters and RP outcomes were assessed and revealed several key findings. The tumoral length on biopsy was correlated with positive surgical margin (r=0.289, p<0.01) and with tumoral volume (r=0.526, p<0.001) on prostatectomy. Patients with higher grade groups (GG) on biopsy had an approximately four times higher chance of exhibiting extraprostatic extension. We demonstrated a significant correlation between Gleason Pattern 4 (%GP4) on biopsy and pT stage, with pT4 showing the highest %GP4, and a noticeable increase in %GP4 as the pT stage progressed from pT2b to pT4. The study found a significantly higher rate of undergrading at biopsy (30.90%) compared to overgrading (6.36%). Additionally, greater tumor length and higher tumor percentages in biopsies improved grading accuracy (p<0.001). Conclusion Our findings suggest that systemic biopsies play a key role in predicting pathological outcomes, especially through parameters that serve as key prognostic markers. However, due to the potential of the biopsy results to be under- or overgraded, urologists should take into consideration the advantages of using repeat biopsies or additional imaging techniques to achieve a more precise diagnosis and treatment strategy.

Validation of prostate and breast cancer detection artificial intelligence algorithms for accurate histopathological diagnosis and grading: a retrospective study with a Japanese cohort

Prostate and breast cancer incidence rates have been on the rise in Japan, emphasising the need for precise histopathological diagnosis to determine patient prognosis and guide treatment decisions. However, existing diagnostic methods face numerous challenges and are susceptible to inconsistencies between observers. To tackle these issues, artificial intelligence (AI) algorithms have been developed to aid in the diagnosis of prostate and breast cancer. This study focuses on validating the performance of two such algorithms, Galen Prostate and Galen Breast, in a Japanese cohort, with a particular focus on the grading accuracy and the ability to differentiate between invasive and non-invasive tumours. The research entailed a retrospective examination of 100 consecutive prostate and 100 consecutive breast biopsy cases obtained from a Japanese institution. Our findings demonstrated that the AI algorithms showed accurate cancer detection, with AUCs of 0.969 and 0.997 for the Galen Prostate and Galen Breast, respectively. The Galen Prostate was able to detect a higher Gleason score in four adenocarcinoma cases and detect a previously unreported cancer. The two algorithms successfully identified relevant pathological features, such as perineural invasions and lymphovascular invasions. Although further improvements are required to accurately differentiate rare cancer subtypes, these findings highlight the potential of these algorithms to enhance the precision and efficiency of prostate and breast cancer diagnosis in Japan. Furthermore, this validation paves the way for broader adoption of these algorithms as decision support tools within the Asian population.

Nerve-tumor crosstalk in tumor microenvironment: From tumor initiation and progression to clinical implications

The autonomic nerve system (ANS) innervates organs and tissues throughout the body and maintains functional balance among various systems. Further investigations have shown that excessive activation of ANS not only causes disruption of homeostasis, but also may promote tumor formation. In addition, the dynamic interaction between nerve and tumor cells in the tumor microenvironment also regulate tumor progression. On the one hand, nerves are passively invaded by tumor cells, that is, perineural invasion (PNI). On the other hand, compared with normal tissues, tumor tissues are subject to more abundant innervation, and nerves can influence tumor progression through regulating tumor proliferation, metastasis and drug resistance. A large number of studies have shown that nerve-tumor crosstalk, including PNI and innervation, is closely related to the prognosis of patients, and contributes to the formation of cancer pain, which significantly deteriorates the quality of life for patients. These findings suggest that nerve-tumor crosstalk represents a potential target for anti-tumor therapies and the management of cancer pain in the future. In this review, we systematically describe the mechanism by which nerve-tumor crosstalk regulates tumorigenesis and progression.

circVAPA-rich small extracellular vesicles derived from gastric cancer promote neural invasion by inhibiting SLIT2 expression in neuronal cells

Gastric cancer (GC) is one of the most common cancer worldwide. Neural invasion (NI) is considered as the symbiotic interaction between nerves and cancers, which strongly affects the prognosis of GC patients. Small extracellular vesicles (sEVs) play a key role in intercellular communication. However, whether sEVs mediate GC-NI remains unexplored. In this study, sEVs release inhibitor reduces the NI potential of GC cells. Muscarinic receptor M3 on GC-derived sEVs regulates their absorption by neuronal cells. The enrichment of sEV-circVAPA in NI-positive patients' serum is validated by serum high throughput sEV-circRNA sequencing and clinical samples. sEV-circVAPA promotes GC-NI in vitro and in vivo. Mechanistically, sEV-circVAPA decreases SLIT2 transcription by miR-548p/TGIF2 and inhibits SLIT2 translation via binding to eIF4G1, thereby downregulates SLIT2 expression in neuronal cells and finally induces GC-NI. Together, this work identifies the preferential absorption mechanism of GC-derived sEVs by neuronal cells and demonstrates a previously undefined role of GC-derived sEV-circRNA in GC-NI, which provides new insight into sEV-circRNA based diagnostic and therapeutic strategies for NI-positive GC patients.

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.

Clinical significance of location of perineural cancer invasion detected on prostate needle core biopsy

The clinical impact of site-specific perineural invasion (PNI) in prostate cancer remains poorly understood. We compared radical prostatectomy findings and oncologic outcomes in 434 patients with single-site PNI on systematic sextant biopsy. PNI was present in the right apex (n = 62; 14%), right mid (n = 70; 16%), right base (n = 89; 21%), left apex (n = 64; 15%), left mid (n = 58; 13%), and left base (n = 91; 21%). There were no significant differences in biopsy or prostatectomy findings, when comparing apex vs. mid vs. base PNI. Univariate analysis revealed that apex-localized PNI was associated with a significantly higher risk of progression, compared with base (P = 0.037) or mid/base (P = 0.024) PNI. Multivariable analysis showed that apex-localized PNI was an independent risk factor for progression (hazard ratio 2.049, P = 0.002). Among biopsies demonstrating PNI at one sextant site, apex-localized PNI is independently associated with poorer prognosis, though not worse histopathologic features on prostatectomy, compared with mid or base PNI.

Clinical impact of perineural invasion encircled completely vs. incompletely by prostate cancer on needle core biopsy

The clinical significance of the pattern or degree of perineural invasion (PNI) by prostate cancer remains largely unknown. We herein assessed radical prostatectomy findings and postoperative oncologic outcomes in 125 patients who had undergone systematic sextant prostate biopsy exhibiting only a single focus of PNI encircled completely (n = 57; 46 %) vs. incompletely (n = 68; 54 %) by cancer. Between these two cohorts, there were no significant differences in clinicopathological features on biopsy or prostatectomy, including tumor grade, stage, and length or volume, and surgical margin status, as well as the need for adjuvant therapy immediately after prostatectomy. Similarly, survival analysis demonstrated no significant difference in the risk of disease progression following prostatectomy in patients with encircled vs. non-encircled PNI on biopsy (P = 0.679). When the non-encircled cases were further divided into four groups [i.e. 1-25 % enclosed (n = 12; 18 %), 26-50 % enclosed (n = 18; 26 %), 51-75 % enclosed (n = 10; 15 %), 76-99 % enclosed (n = 28; 41 %)], the rates of progression-free survival were comparable among the five groups (P = 0.954). In prostate biopsy specimens exhibiting PNI at only one focus, the degree of nerve involvement thus appears to have little clinical impact. Accordingly, PNI detected on prostate biopsy may need to be similarly taken into consideration irrespective of the degree of nerve involvement.

Perineural invasion confers poorer clinical outcomes in patients with T1/T2 intrahepatic cholangiocarcinoma: a single center, retrospective cohort study

Background

Intrahepatic cholangiocarcinoma (ICC) poses a significant clinical challenge, demanding a thorough understanding of prognostic indicators for effective patient management. Despite reports suggesting the impact of perineural invasion (PNI) on the prognosis of early-stage ICC patients, there has been a dearth of comprehensive research specifically targeting this subgroup. This study seeks to investigate the influence of PNI on survival outcomes in early-stage ICC patients and aims to enhance the prognostic value of the American Joint Committee on Cancer (AJCC) T category.

Methods

A cohort of 268 early-stage (T1-T2N0M0) ICC patients, who underwent curative-intent resection (R0) between 2011 and 2015 at the Eastern Hepatobiliary Surgery Hospital, were enrolled in this study. Lasso and Cox regression analyses were employed to explore differences in clinical and prognostic data. Kaplan-Meier curves were generated to illustrate the clinical significance of the combination of PNI and T category.

Results

Among the 268 patients, 24.6% exhibited PNI. Patients with PNI demonstrated shorter recurrence-free survival (RFS) [median RFS: 16 months (interquartile range, 9.5-19 months)] and overall survival (OS) [median OS: 16.53 months (interquartile range, 10-25 months)]. PNI emerged as an independent risk factor for both RFS and OS in T1- and T2-stage patients (all P<0.05), whereas tumor size was only an independent risk factor for OS (P=0.004). PNI was associated with all prognostic markers for ICC patients, including gender, jaundice, cholangitis, hepatitis B virus (HBV) infection, cancer antigen 199 (CA199), preoperative serum albumin, and preoperative platelet count (all P<0.05). However, there was no significant difference in RFS (P=0.270) and OS (P=0.360) between T2 patients without PNI and T1 patients with PNI.

Conclusions

This study underscores PNI as a robust prognostic factor in early-stage ICC, emphasizing the necessity of incorporating PNI into the AJCC T category for precise risk stratification. Clinically, understanding the impact of PNI on survival outcomes can guide tailored treatment strategies for early ICC patients.

Crosstalk Between Peripheral Innervation and Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy, characterized by late diagnosis, aggressive growth, and therapy resistance, leading to a poor overall prognosis. Emerging evidence shows that the peripheral nerve is an important non-tumor component in the tumor microenvironment that regulates tumor growth and immune escape. The crosstalk between the neuronal system and PDAC has become a hot research topic that may provide novel mechanisms underlying tumor progression and further uncover promising therapeutic targets. In this review, we highlight the mechanisms of perineural invasion and the role of various types of tumor innervation in the progression of PDAC, summarize the potential signaling pathways modulating the neuronal-cancer interaction, and discuss the current and future therapeutic possibilities for this condition.

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.

Role of lymphatic invasion in predicting biochemical recurrence after radical prostatectomy

Objective

Lymphatic invasion in prostate cancer is associated with poor prognosis. However, there is no consensus regarding the clinical and prognostic value of lymphatic invasion. This study aimed to investigate the prognostic value of lymphatic invasion in biochemical recurrence (BCR) and compare the recurrence rates between patients with lymphatic invasion and lymph node metastasis.

Methods

We retrospectively analyzed 2,207 patients who underwent radical prostatectomy (RP) without pelvic lymph node dissection (PLND) and 742 patients who underwent RP with PLND for clinically localized or locally advanced prostate cancer, between 1993 and 2020, at Seoul National University Hospital. Kaplan-Meier analysis was performed to estimate BCR-free survival (BCRFS) using the log-rank test. The Cox proportional hazards model was used to identify the significant factors for BCR. Propensity score matching was performed with a 1:2 ratio to match age, initial PSA level, pathological T stage, and Gleason score to exclude confounding effects.

Results

Of the 2,207 patients who underwent RP without PLND, lymphatic invasion (L1Nx) was observed in 79 (3.5%) individuals. Among the 742 patients who underwent RP with PLND, lymph node metastases were found in 105 patients (14.2%). In patients with lymph node metastasis, lymphatic invasion was observed in 50 patients (47.6%), whereas lymphatic invasion was observed in 53 patients (8.3%) among those without lymph node metastasis. In patients who underwent RP without PLND, Kaplan-Meier analysis showed significantly poorer BCR-free survival in the L1Nx group than in the L0Nx group (p < 0.001). In patients who underwent RP with PLND, the L1N0, L0N1, and L1N1 groups showed significantly worse prognoses than the L0N0 group (p < 0.001). However, there was no significant difference in BCRFS between the L1N0 and lymph node metastasis groups, including the L0N1 and L1N1 groups. After propensity score matching at a 1:2 ratio, the L1Nx group showed significantly poorer outcomes in terms of BCRFS than the L0Nx group (p = 0.05). In addition, the L1N0 group showed a significantly worse prognosis than the L0N0 group after propensity score matching.

Conclusion

Lymphatic invasion in radical prostatectomy specimens is an independent prognostic factor, which can complement lymph node status for predicting biochemical recurrence. Considering lymphatic invasion as an adverse pathological finding, similar to lymph node metastasis, adjuvant therapy could be considered in patients with lymphatic invasion.

Biopsy prostate cancer perineural invasion and tumour load are associated with positive posterolateral margins at radical prostatectomy: implications for planning of nerve-sparing surgery

AIMS

Radical prostatectomy (RP) for prostate cancer is frequently complicated by erectile dysfunction and urinary incontinence. However, sparing of the nerve bundles adjacent to the posterolateral sides of the prostate reduces the number of complications at the risk of positive surgical margins. Preoperative selection of men eligible for safe, nerve-sparing surgery is therefore needed. Our aim was to identify pathological factors associated with positive posterolateral surgical margins in men undergoing bilateral nerve-sparing RP.

METHODS AND RESULTS

Prostate cancer patients undergoing RP with standardised intra-operative surgical margin assessment according to the NeuroSAFE technique were included. Preoperative biopsies were reviewed for grade group (GG), cribriform and/or intraductal carcinoma (CR/IDC), perineural invasion (PNI), cumulative tumour length and extraprostatic extension (EPE). Of 624 included patients, 573 (91.8%) received NeuroSAFE bilaterally and 51 (8.2%) unilaterally, resulting in a total of 1197 intraoperative posterolateral surgical margin assessments. Side-specific biopsy findings were correlated to ipsilateral NeuroSAFE outcome. Higher biopsy GG, CR/IDC, PNI, EPE, number of positive biopsies and cumulative tumour length were all associated with positive posterolateral margins. In multivariable bivariate logistic regression, ipsilateral PNI [odds ratio (OR) = 2.98, 95% confidence interval (CI) = 1.62-5.48; P < 0.001] and percentage of positive cores (OR = 1.18, 95% CI = 1.08-1.29; P < 0.001) were significant predictors for a positive posterolateral margin, while GG and CR/IDC were not.

CONCLUSIONS

Ipsilateral PNI and percentage of positive cores were significant predictors for a positive posterolateral surgical margin at RP. Biopsy PNI and tumour volume can therefore support clinical decision-making on the level of nerve-sparing surgery in prostate cancer patients.

Perineural Invasion in Papillary Thyroid Cancer: A Rare Indicator of Aggressive Disease

BACKGROUND

Perineural invasion (PNI) is associated with aggressive tumor behavior, increased locoregional recurrence, and decreased survival in many carcinomas. However, the significance of PNI in papillary thyroid cancer (PTC) is incompletely characterized.

METHODS

Patients diagnosed with PTC and PNI from 2010-2020 at a single, academic center were identified and matched using a 1:2 scheme to patients without PNI based on gross extrathyroidal extension (ETE), nodal metastasis, positive margins, and tumor size (±4 cm). Mixed and fixed effects models were used to analyze the association of PNI with extranodal extension (ENE)-a surrogate marker of poor prognosis.

RESULTS

In total, 78 patients were included (26 with PNI, 52 without PNI). Both groups had similar demographics and ultrasound characteristics preoperatively. Central compartment lymph node dissection was performed in most patients (71%, n = 55), and 31% (n = 24) underwent a lateral neck dissection. Patients with PNI had higher rates of lymphovascular invasion (50.0% vs. 25.0%, p = 0.027), microscopic ETE (80.8% vs. 44.0%, p = 0.002), and a larger burden [median 5 (interquartile range [IQR] 2-13) vs. 2 (1-5), p = 0.010] and size [median 1.2 cm (IQR 0.6-2.6) vs. 0.4 (0.2-1.4), p = 0.008] of nodal metastasis. Among patients with nodal metastasis, those with PNI had an almost fivefold increase in ENE [odds ratio [OR] 4.9 (95% confidence interval [CI] 1.5-16.5), p = 0.008] compared with those without PNI. More than a quarter (26%) of all patients had either persistent or recurrent disease over follow-up (IQR 16-54 months).

CONCLUSIONS

PNI is a rare, pathologic finding that is associated with ENE in a matched cohort. Additional investigation into PNI as a prognostic feature in PTC is warranted.

Expectation-maximization algorithm leads to domain adaptation for a perineural invasion and nerve extraction task in whole slide digital pathology images

In addition to lymphatic and vascular channels, tumor cells can also spread via nerves, i.e., perineural invasion (PNI). PNI serves as an independent prognostic indicator in many malignancies. As a result, identifying and determining the extent of PNI is an important yet extremely tedious task in surgical pathology. In this work, we present a computational approach to extract nerves and PNI from whole slide histopathology images. We make manual annotations on selected prostate cancer slides once but then apply the trained model for nerve segmentation to both prostate cancer slides and head and neck cancer slides. For the purpose of multi-domain learning/prediction and investigation on the generalization capability of deep neural network, an expectation-maximization (EM)-based domain adaptation approach is proposed to improve the segmentation performance, in particular for the head and neck cancer slides. Experiments are conducted to demonstrate the segmentation performances. The average Dice coefficient for prostate cancer slides is 0.82 and 0.79 for head and neck cancer slides. Comparisons are then made for segmentations with and without the proposed EM-based domain adaptation on prostate cancer and head and neck cancer whole slide histopathology images from The Cancer Genome Atlas (TCGA) database and significant improvements are observed.

Clinical Significance of Perineural Invasion by Prostate Cancer Detected on Needle Core Biopsy

OBJECTIVES

The clinical impact of the laterality of perineural invasion (PNI) by prostate cancer remains poorly understood. We herein compared radical prostatectomy (RP) findings and long-term oncologic outcomes in patients with prostate cancer with PNI in two prostate biopsy (PBx) sites.

METHODS

We retrospectively assessed 170 consecutive patients undergoing systematic sextant PBx where PNI had been detected in two of six PBx sites, followed by RP.

RESULTS

PNI occurred unilaterally in 140 (82.4%) cases and bilaterally in 30 (17.6%) cases. Compared with unilateral PNI, bilateral PNI was significantly associated with a higher number of cancer-positive sites and longer total tumor length on PBx. However, there were no significant differences in RP findings, including tumor grade/stage and tumor volume, between unilateral and bilateral PNI cohorts. Kaplan-Meier analysis revealed that patients with bilateral PNI had a significantly higher risk of disease progression after RP than those with unilateral PNI (P = .038). In multivariate analysis, bilateral PNI (vs unilateral PNI) showed significance for progression (hazard ratio, 2.281; P = .023).

CONCLUSIONS

In PBx specimens exhibiting PNI in two sextant sites, bilateral PNI was found to be associated with poorer prognosis as an independent predictor but not worse histopathologic features in RP specimens compared with unilateral PNI.

Single-cell RNA sequencing reveals intratumoral heterogeneity and potential mechanisms of malignant progression in prostate cancer with perineural invasion

Background: Prostate cancer (PCa) is the second most common cancer among men worldwide. Perineural invasion (PNI) was a prominent characteristic of PCa, which was recognized as a key factor in promoting PCa progression. As a complex and heterogeneous disease, its true condition is difficult to explain thoroughly with conventional bulk RNA sequencing. Thus, an improved understanding of PNI-PCa progression at the single-cell level is needed. Methods: In this study, we performed scRNAseq on tumor tissues of three PNI-PCa patients. Principal component analysis (PCA) and Uniform manifold approximation and projection (UMAP) were used to reduce dimensionality and visualize the cellular composition of tumor tissues. The differently expressed genes among each cluster were identified by EdgeR. GO enrichment analysis was used to understand the roles of genes within the clusters. Pseudotime cell trajectory was used to reveal the molecular pathways underlying cell fate decisions and identify genes whose expression changed as the cells underwent transition. We applied CellPhoneDB to identify cell-cell interactions among the epithelial and neural cells in PNI-PCa. Results: Analysis of the ∼17,000 single-cell transcriptomes in three PNI prostate cancer tissues, we identified 12 major cell clusters, including neural cells and two epithelial subtypes with different expression profiles. We found that basal/intermediate epithelial cell subtypes highly expressed PCa progression-related genes, including PIGR, MMP7, and AGR2. Pseudotime trajectory analysis showed that luminal epithelial cells could be the initiating cells and transition to based/intermediate cells. Gene ontology (GO) enrichment analysis showed that pathways related to cancer progressions, such as lipid catabolic and fatty acid metabolic processes, were significantly enriched in basal/intermediate cells. Our analysis also suggested that basal/intermediate cells communicate closely with neural cells played a potential role in PNI-PCa progression. Conclusion: These results provide our understanding of PNI-PCa cellular heterogeneity and characterize the potential role of basal/intermediate cells in the PNI-PCa progression.

Predicting Tumor Perineural Invasion Status in High-Grade Prostate Cancer Based on a Clinical-Radiomics Model Incorporating T2-Weighted and Diffusion-Weighted Magnetic Resonance Images

PURPOSE

To explore the role of bi-parametric MRI radiomics features in identifying PNI in high-grade PCa and to further develop a combined nomogram with clinical information.

METHODS

183 high-grade PCa patients were included in this retrospective study. Tumor regions of interest (ROIs) were manually delineated on T2WI and DWI images. Radiomics features were extracted from lesion area segmented images obtained. Univariate logistic regression analysis and the least absolute shrinkage and selection operator (LASSO) method were used for feature selection. A clinical model, a radiomics model, and a combined model were developed to predict PNI positive. Predictive performance was estimated using receiver operating characteristic (ROC) curves, calibration curves, and decision curves.

RESULTS

The differential diagnostic efficiency of the clinical model had no statistical difference compared with the radiomics model (area under the curve (AUC) values were 0.766 and 0.823 in the train and test group, respectively). The radiomics model showed better discrimination in both the train cohort and test cohort (train AUC: 0.879 and test AUC: 0.908) than each subcategory image (T2WI train AUC: 0.813 and test AUC: 0.827; DWI train AUC: 0.749 and test AUC: 0.734). The discrimination efficiency improved when combining the radiomics and clinical models (train AUC: 0.906 and test AUC: 0.947).

CONCLUSION

The model including radiomics signatures and clinical factors can accurately predict PNI positive in high-grade PCa patients.

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.

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.

Nerve invasion as an independent predictor of poor prognosis in gastric cancer after curative resection

The study aims to reveal the clinical significance of perineural invasion (PNI) for gastric cancer prognosis and determine the risk factors of PNI in gastric cancer. This study retrospectively analyzed 350 patients who were diagnosed with GC and underwent curative surgical resection. Variables used to analyze survival included gender, age, degree of differentiation, T classification, lymph node metastasis, lymphovascular invasion, nerve invasion, mucinous adenocarcinoma component, and signet ring cell carcinoma component. The tumors of all patients were surgically resected. All resected specimens were stained with hematoxylin-eosin and immunohistochemical. The data for the patient's lymphovascular invasion and PNI came from the collected pathological reports. The results of the survival analysis showed that T staging (P < .001), lymph node metastasis (P < .001), lymphovascular invasion (P = .013), PNI (P = .001), and signet ring cell carcinoma components (P = .046) affect the survival time and have a statistically significant difference. Multivariate analysis indicated that the positivity of PNI was an independent prognostic factor (P = .014). T staging (P = .006) and lymph node metastasis (P = .013) were independent prognostic parameters too. Using the Spearman correlation analysis, the following clinicopathological indicators were associated with PNI positivity, such as tumor differentiation, T staging, lymph node metastasis, vascular invasion, and signet ring cell carcinoma components (P < .05). PNI is an independent marker of poor prognosis in patients with gastric cancer.

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.

The Clinical Significance of Perineural Invasion by Prostate Cancer on Needle Core Biopsy

CONTEXT.—

Perineural invasion (PNI) by prostate cancer has been associated with adverse pathology, including extraprostatic extension. However, the significance of PNI quantification on prostate biopsy (PBx) remains unclear.

OBJECTIVE.—

To compare radical prostatectomy (RP) findings and long-term outcomes in patients whose PBx had exhibited PNI.

DESIGN.—

We assessed 497 consecutive patients undergoing sextant (6-site/≥12-core) PBx showing conventional adenocarcinoma followed by RP.

RESULTS.—

PNI was found in 1 (n = 290)/2 (n = 132)/3 (n = 47)/4 (n = 19)/5 (n = 5)/6 (n = 4) of the sites/regions of PBx. Compared with a single PNI site, multiple PNIs were significantly associated with higher preoperative prostate-specific antigen, higher Grade Group (GG) on PBx or RP, higher pT or pN category, positive surgical margin, and larger estimated tumor volume. When compared in subgroups of patients based on PBx GG, significant differences in RP GG (GG1-3), pT (GG1-2/GG1-3/GG2/GG3), surgical margin status (GG1-3/GG3/GG5), or tumor volume (GG1-2/GG1-3/GG2/GG3) between 1 versus multiple PNIs were observed. Moreover, there were significant differences in prostate-specific antigen (PNI sites: 1-2 versus 3-6/1-3 versus 4-6/1-4 versus 5-6), RP GG (1-3 versus 4-6/1-4 versus 5-6), pT (1-2 versus 3-6/1-3 versus 4-6), pN (1-3 versus 4-6), or tumor volume (1-2 versus 3-6/1-4 versus 5-6). Outcome analysis revealed significantly higher risks of disease progression in the entire cohort or PBx GG1-2/GG1-3/GG2/GG3/GG5 cases showing 2 to 6 PNIs, compared with respective controls with 1-site PNI. In multivariate analysis, multisite PNI was an independent predictor for progression (hazard ratio = 1.556, P = .03).

CONCLUSIONS.—

Multiple sites of PNI on PBx were associated with worse histopathologic features in RP specimens and poorer prognosis. PNI may thus need to be specified, if present, in every sextant site on PBx, especially those showing GG1-3 cancer.

Transperineal multiparametric magnetic resonance imaging-ultrasound fusion-targeted prostate biopsy combined with standard template improves perineural invasion detection

Perineural invasion (PNI) on biopsy is associated with adverse features in prostate cancer (PCa). Transrectal multiparametric magnetic resonance imaging (MRI)-targeted biopsy (TBx) has shown to detect higher presence of PNI than standard template biopsy (SBx). Transperineal biopsy provides effective cancer detection with lower complications than the transrectal approach. We compared PNI detection efficiency between SBx and TBx through transperineal approach. We identified patients with PCa who underwent transperineal TBx and concomitant standard 20-core template SBx from September 2019 to February 2021. Clinical, MRI imaging and biopsy characteristics were evaluated and compared between TBx and SBx. Two hundred thirty-eight patients with PCa underwent concomitant transperineal SBx and TBx procedures. Combined PNI+ (SBxPNI+ and/or TBxPNI+) was identified in 77 of 238 (32.4%) patients. SBx detected 23.9% PNI-positive patients and TBx detected 19.3% PNI-positive patients of all patients with PCa. Patients with PNI were with significantly different clinicopathological characteristics than patients without PNI. Although significantly more positive PCa cores and higher positive PCa core rate were found in the SBx method, patients with SBxPNI+ only shared similar features as TBxPNI+only patients. Of 176 cases with both SBxPCa and TBxPCa, TBx could detect 19 (15.1%) more PNI cases than SBx while SBx could detect 24 (18.3%) more PNI cases than TBx. Multiparametric MRI fusion-targeted biopsy in combination with template biopsy through transperineal approach achieved PNI detection rate over 30% of PCa cases. The increased PNI detection may improve the model to select active surveillance candidates in clinical practice.

Atypical Metastases in the Abdomen and Pelvis From Biochemically Recurrent Prostate Cancer: 11C-Choline PET/CT Imaging With Multimodality Correlation

PET imaging with targeted radiotracers has become integral for mapping the location and burden of recurrent disease in patients with biochemical recurrence (BCR) of prostate cancer (PCa). PET with 11C-choline is part of the National Comprehensive Cancer Network and European Association of Urology guidelines for evaluation of BCR. With advances in PET technology, increasing use of targeted radiotracers, and improved survival of patients with BCR due to novel therapeutics, atypical sites of metastases are being increasingly encountered, challenging the conventional view that PCa rarely metastasizes beyond bones or lymph nodes. We describe such atypical metastases in the abdomen and pelvis on 11C-choline PET (including in the liver, pancreas, genital tract, urinary tract, peritoneum, and abdominal wall, as well as perineural spread), presenting multimodality imaging features and relevant imaging pitfalls. Given atypical metastases' inconsistent relationship with serum PSA and non-specific presenting symptoms, they are often first detected on imaging. Awareness of their imaging features is important as their detection impacts clinical management, patient counseling, prognosis, and clinical trial eligibility. Such awareness is particularly critical as the role of radiologists in the imaging and management of BCR will continue to increase given the expanding regulatory approvals of other targeted and theranostic radiotracers.

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.

How Much Reliable Is the Current Belief on Grade Group 1 Prostate Cancer?

Objective: To evaluate the clinicopathological characteristics of grade group 1 (GG1) prostate cancer in Korean populations.

Methods: We retrospectively analyzed 492 consecutive radical prostatectomy specimens from our institution, which included those from 322 men with clinical GG1 and 170 with clinical GG2 tumors between years 2009 and 2018. The incidence of Gleason score (GS) upgrading, extraprostatic extension (EPE), and seminal vesicle invasion (SVI) were evaluated in patients with clinical GG1. In pathological GG1 cases, the distribution of adverse pathological features including EPE, lymphovascular invasion (LVI), perineural invasion (PNI), and biochemical recurrence (BCR) was analyzed.

Results: Altogether, 78 (24.2%) out of 322 men in the clinical GG1 group demonstrated upgrading of GS, including 19 men with pathological Gleason score 4 + 3 = 7 and 6 with ≥ pathological Gleason score 4 + 4 = 8 cases. EPE was found in 37 (11.5%) and 22 (8.9%) men in clinical GG1 and pathological GG1 group, respectively. The incidence of LVI and PNI in the pathological GG1 cases was 2.8% (n = 7) and 28.6% (n = 71), respectively. BCR was observed in 4 men in pathological GG1 T2 (n = 226) and 2 men in GG1 T3 (n = 22) group. When we compared the pathological features between pathological GG1 T3 vs. GG2 T2, there was no statistical differences in the incidence of LVI and PNI between the two groups.

Conclusions: Contrary to the current concept that GG1 is almost always clinically insignificant, it seems that GG1 still possess its respectable position as a group of cancer with aggressiveness. These findings should be kept in mind when deciding on treatment options for prostate cancer patients in the Asian populations.

Biochemical recurrence of pathological T2+ localized prostate cancer after robotic-assisted radical prostatectomy: A 10-year surveillance

BACKGROUND

pT2+ prostate cancer (PCa), a term first used in 2004, refers to organ-confined PCa characterized by a positive surgical margin (PSM) without extracapsular extension. Patients with a PSM are vulnerable to biochemical recurrence (BCR) following radical prostatectomy (RP); however, whether adjuvant radiotherapy (aRT) is imperative to PSM after RP remains controversial. This study had the longest follow-up on pT2+ PCa after robotic-assisted RP since 2004. Moreover, we discussed our viewpoints on pT2+ PCa based on real-world experiences.

AIM

To conclude a 10-year surveillance on pT2+ PCa and compare our results with those of the published literature.

METHODS

Forty-eight patients who underwent robotic-assisted RP between 2008 and 2011 were enrolled. Two serial tests of prostate specific antigen (PSA) ≥ 0.2 ng/mL were defined as BCR. Various designed factors were analyzed using statistical tools for BCR risk. SAS 9.4 was applied and significance was defined as P < 0.05. Univariate, multivariate, linear regression, and receiver operating characteristic (ROC) curve analyses were performed for statistical analyses.

RESULTS

With a median follow-up period of 9 years, 25 (52%) patients had BCR (BCR group), and the remaining 23 (48%) patients did not (non-BCR group). The median time for BCR test was 4 years from the first postoperative PSA nadir. Preoperative PSA was significantly different between the BCR and non-BCR groups (P < 0.001), and ROC curve analysis of preoperative PSA suggested a cut-off value of 19.09 ng/mL (sensitivity, 0.600; specificity: 0.739). The linear regression analysis showed no correlation between time to BCR and preoperative PSA (Pearson’s correlation, 0.13; adjusted R² = 0.026).

CONCLUSION

Robotic-assisted RP in pT2+ PCa of worse conditions can provide better BCR-free survival. A surgical technique limiting the PSM in favorable situations is warranted to lower the pT2+ PCa BCR rate. Preoperative PSA cut-off value of 19.09 ng/mL is a predictive factor for BCR. Based on our experiences and review of the literature, we do not recommend routine aRT for pT2+ PCa.

Interobserver reproducibility of perineural invasion of prostatic adenocarcinoma in needle biopsies

Numerous studies have shown a correlation between perineural invasion (PNI) in prostate biopsies and outcome. The reporting of PNI varies widely in the literature. While the interobserver variability of prostate cancer grading has been studied extensively, less is known regarding the reproducibility of PNI. A total of 212 biopsy cores from a population-based screening trial were included in this study (106 with and 106 without PNI according to the original pathology reports). The glass slides were scanned and circulated among four pathologists with a special interest in urological pathology for assessment of PNI. Discordant cases were stained by immunohistochemistry for S-100 protein. PNI was diagnosed by all four observers in 34.0% of cases, while 41.5% were considered to be negative for PNI. In 24.5% of cases, there was a disagreement between the observers. The kappa for interobserver variability was 0.67–0.75 (mean 0.73). The observations from one participant were compared with data from the original reports, and a kappa for intraobserver variability of 0.87 was achieved. Based on immunohistochemical findings among discordant cases, 88.6% had PNI while 11.4% did not. The most common diagnostic pitfall was the presence of bundles of stroma or smooth muscle. It was noted in a few cases that collagenous micronodules could be mistaken for a nerve. The distance between cancer and nerve was another cause of disagreement. Although the results suggest that the reproducibility of PNI may be greater than that of prostate cancer grading, there is still a need for improvement and standardization.

Impact of uni- or multifocal perineural invasion in prostate cancer at radical prostatectomy

Background

Aim of this study was to correlate perineural invasion (PNI) with other clinical-pathological parameters in terms of prognostic indicators in prostate cancer (PC) cases at the time of radical prostatectomy (RP).

Methods

Prospective study of 288 consecutive PC cases undergoing RP. PNI determination was performed either in biopsy or in RP specimens classifying as uni- and multifocal PNI. The median follow-up time was 22 (range, 6-36) months.

Results

At biopsy PNI was found in 34 (11.8%) cases and in 202 (70.1%) cases at the time of surgery. Among those identified at RP 133 (46.1%) and 69 (23.9%) cases had uni- and multi-PNI, respectively. Presence of PNI was significantly (P<0.05) correlated with unfavorable pathological parameters such higher stage and grade. The percentage of extracapsular extension in PNI negative RP specimens was 18.6% vs. 60.4% of PNI positive specimens. However, the distribution of pathological staging and International Society of Urological Pathology (ISUP) grading did not vary according to whether PNI was uni- or multifocal. The risk of biochemical progression increased 2.3 times in PNI positive cases was significantly associated with the risk of biochemical progression (r=0.136; P=0.04). However, at multivariate analysis PNI was not significantly associated with biochemical progression [hazard ratio (HR): 1.87, 95% confidence interval (CI): 0.68-3.12; P=0.089]. Within patients with intermediate risk disease, multifocal PNI was able to predict cases with lower mean time to biochemical and progression free survival (chi-square 5.95; P=0.04).

Conclusions

PNI at biopsy is not a good predictor of the PNI incidence at the time of RP. PNI detection in surgical specimens may help stratify intermediate risk cases for the risk of biochemical progression.

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.

Prostate cancer incidence and diagnosis in men with PSA levels >20 ng/ml: is it possible to decrease the number of biopsy cores?

OBJECTIVES

To define if less number of cores would be sufficient to diagnose prostate cancer (PCa) in men with PSA levels >20 ng/ml and to reveal the cancer detection rates in this population.

METHODS

The data of the men who had 12-core prostate biopsy with a PSA value >20 ng/mg were reviewed. We recorded age, prostate volume, PSA level, and pathology report findings. Patients grouped according to PSA levels and compared for PCa detection rates, and several parameters. We created 16 prostate biopsy scenarios (S1-S16) and applied these to our database to find out the best biopsy protocol to detect PCa.

RESULTS

A total of 336 patients with a mean age of 70.5 (47-91) years were included. Mean PSA level was 190.6 (20-5474) ng/ml. PCa detection rates were 55.3%, 81.0%, and 97.7% in patients with PSA levels 20-49.99, 50-99.99, and ≥100 ng/ml, respectively. PSA level was correlated to clinically more important digital rectal examination findings. We selected 2 cores in S1-S6, 4 cores in S7-S12, and 6 cores in S13-S16. We calculated the sensitivity of each scenario and found that all scenarios in PSA Group 3 had a sensitivity >95%. In Group 2, S8, S10, S13, and S14 and in Group 1, only S14 had sensitivity >95%.

CONCLUSIONS

It is not necessary to take 10-12 core biopsy samples in men with PSA levels >20 ng/ml. We recommend taking 2, 4, and 6 samples for patients with PSA levels ≥100 ng/ml, 50-99.99 ng/ml, and 20-49.99 ng/ml, respectively.

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.

Complexity of Neural Component of Tumor Microenvironment in Prostate Cancer

The tumor microenvironment (TME) plays an essential role in the development and progression of neoplasms. TME consists of the extracellular matrix and numerous specialized cells interacting with cancer cells by paracrine and autocrine mechanisms. Tumor axonogenesis and neoneurogenesis constitute a developing area of investigation. Prostate cancer (PC) is one of the most common malignancies in men worldwide. During the past years, more and more studies have shown that mechanisms leading to the development of PC are not confined only to the epithelial cancer cell, but also involve the tumor stroma. Different nerve types and neurotransmitters present within the TME are thought to be important factors in PC biology. Moreover, perineural invasion, which is a common way of PC spreading, in parallel creates the neural niche for malignant cells. Cancer neurobiology seems to have become a new discipline to explore the contribution of neoplastic cell interactions with the nervous system and the neural TME component, also to search for potential therapeutic targets in malignant tumors such as PC.

Prognostic value of perineural invasion in prostate needle biopsies: a population-based study of patients treated by radical prostatectomy

AIMS

Despite being one of the major pathways for the spread of malignant tumours, perineural invasion (PNI) has not conclusively been shown to have an independent prognostic value for prostate cancer. Prostatic biopsy constitutes the major pathology workload in prostate cancer and is the foundation for primary treatment decisions and for this reason we aimed to estimate the prognostic value of PNI in biopsies.

METHODS

We followed 918 men who underwent radical prostatectomy (RP) from the prospective and population based STHLM3 study until biochemical recurrence with a median follow-up of 4.1 years. To strengthen the evidence, we combined the estimates from the largest studies targeting the prognostic value of PNI in the biopsy. We also estimated the OR of advanced stage as radical prostatectomy for PNI positive and negative men.

RESULTS

The estimated prognostic value based on our data suggested an approximately 50% increased risk of biochemical recurrence if PNI was present in the biopsy (p=0.06). Even though not statistically significant on the 5% level, this estimate is consistent with similar studies, and by combining the estimates there is in fact strong evidence in support of an independent prognostic value of PNI in the biopsy (p<0.0001). There was also an independent increased risk of advanced stage at RP for positive men (OR 1.85, p=0.005).

CONCLUSIONS

The evidence supporting a clinically relevant and independent prognostic value of PNI is strong enough to be considered for pathology reporting guidelines.

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.

Perineural invasion as a predictive factor for survival outcome in gastric cancer patients: a systematic review and meta-analysis

AIMS

The prognostic significance of perineural invasion (PNI) for gastric cancer (GC) patients was under debate. This study aimed to review relevant studies and evaluate the impact of PNI on the survival outcome of GC patients.

METHODS

Systematic literature search was performed using PubMed and Embase databases. The relevant data were extracted, and the association between PNI and clinicopathological characteristics or survival outcome in GC patients were evaluated using a fixed-effect model or random-effect model.

RESULTS

A total 13 studies involving 7004 GC patients were included in this meta-analysis. The positive rate of PNI was 35.9% (2512/7004) in GC patients, ranging from 6.9% to 75.6%. There were significant relationships between PNI and a series of unfavourable clinicopathological factors including undifferentiated histology type (OR: 1.78, 95% CI 1.37 to 2.33, p<0.001; I²=75.3%), diffuse type (OR: 1.96, 95% CI 1.07 to 3.60, p=0.029; I²=79.5%), lymphatic invasion (OR: 7.00, 95% CI 3.76 to 13.03, p<0.001; I²=83.6%), vascular invasion (OR: 5.79, 95% CI 1.59 to 21.13, p=0.008; I²=95.8%), deeper tumour invasion (OR: 4.79, 95% CI 3.65 to 6.28, p<0.001; I²=65.0%) and lymph node metastasis (OR: 3.60, 95% CI 2.37 to 5.47, p<0.001; I²=89.6%). In addition, PNI was significantly associated with worse survival outcome in GC patients (HR: 1.69, 95% CI 1.38 to 2.06, p<0.001; I²=71.0%).

CONCLUSION

PNI was frequently detected in surgically resected specimens of GC patients, and it was a predictive factor for survival outcomes in these patients.

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.

Impact of the Proportion of Biopsy Positive Core in Predicting Biochemical Recurrence in Patients with Pathological Pt2 and Negative Resection Margin Status after Radical Prostatectomy

This study aimed to determine the prognostic factors associated with biochemical recurrence (BCR) after radical prostatectomy (RP) in patients with pathological T2 (pT2) prostate cancer (PCa) and negative resection margin (RM) status at a single institution. In this retrospective study, we examined 386 patients who were diagnosed with pT2 PCa with negative RM after RP. The length of the tumor was provided for each biopsy core and the overall percentage of PCa was calculated by a pathologist at our institution. We estimated the BCR-free survival (BRFS) in these patients. Univariate and multivariate analyses were performed using the Cox proportional hazard model to determine the risk factors of BCR. The median age of the participants was 68 years, and their initial prostate-specific antigen level was 6.55 ng/mL. The median follow-up period was 85.7 months. The 5-year BRFS rate of the participants was 89.0%. The 5-year BRFS rates were 89.8% in patients with a biopsy Gleason score of 6, 90.4% in those with 7, and 64.1% in those with ≥8 (P = 0.007). The BRFS rate was 93.3% in patients who had a biopsy positive core ≤20% and 82.0% in those who had ≥21% (P = 0.001). Based on the multivariate analysis, the proportion of biopsy positive core was significantly associated with BCR. The proportion of biopsy positive core may predict preoperative covariates in patients with pT2 PCa and negative RM status after RP.

Long-Term Outcomes and Prognoses of Elderly Patients (≥65-Years-Old) With Distant Metastases From Well-Differentiated Thyroid Cancer During Radioiodine Therapy and Follow-Up

OBJECTIVE

The objective of this study was to investigate the clinicopathological characteristics, long-term outcomes, and prognostic factors of elderly patients with distant metastases at initial diagnosis from well-differentiated thyroid cancer (WDTC) during radioactive iodine (¹³¹I) treatment and follow-up.

METHODS

A retrospective review of medical records identified 183 elderly patients with DTC who underwent ¹³¹I treatment at our institution between 2006 and 2019.

RESULTS

In total, 57 elderly WDTC patients with distant metastases were enrolled in this study. After ¹³¹I treatment, 32 (56.14%) patients had ¹³¹I avidity and 25 (43.86%) had non-¹³¹I avidity; 35 (61.40%) cases were classified as radioiodine refractory (RR)-WDTC and 22 (38.60%) as non-RR-WDTC. At the end of follow-up, 25 (43.86%) patients had died and 32 (56.14%) were alive. The 5- and 10-year overall survival (OS) rates were 71.50% and 30.49%, respectively, while the 5- and 10-year disease-specific survival (DSS) rates were 76.89% and 48.71%, respectively. Multivariate analyses showed that gross extrathyroidal extension and RR-DTC were independent prognostic factors for poor OS (P=0.04 and P=0.03, respectively), while gross extrathyroidal extension, extrapulmonary distant metastases, and RR-WDTC were independent prognostic factors for poor DSS at the end of follow-up (P=0.02, P=0.03, and P=0.02, respectively).

CONCLUSIONS

WDTC with distant metastases at initial diagnosis accounted for 31.15% of all elderly patients with DTC. Gross extrathyroidal extension and RR-DTC were the major factors associated with poor OS; gross extrathyroidal extension, extrapulmonary distant metastases, and RR-DTC were independent prognostic factors for poor DSS in elderly DTC patients with distant metastases.

Impact of biopsy perineural invasion on the outcomes of patients who underwent radical prostatectomy: a systematic review and meta-analysis

Objectives: To investigate the association between biopsy perineural invasion (PNI) and oncological outcomes of prostate cancer (PCa) after radical prostatectomy (RP).Materials and methods: A systematic literature search was performed using PubMed, EMBASE and Web of Science up to December 2018 to identify the eligible studies that included localized PCa patients who underwent biopsy and subsequently RP as well as follow-up information. Meta-analyses were conducted using available hazard ratios (HRs) of biopsy PNI from both univariate and multivariate analyses.Results: Eighteen studies including 14,855 patients with treatment follow-up information were included in the current systematic review. The rate of biopsy PNI varied between 7.0% and 33.0%. Seven out of the 18 studies that demonstrated biopsy PNI were associated with adverse pathologic features. Thirteen out of the 18 studies showed biopsy PNI correlated significantly with higher rates of biochemical recurrence (BCR)/cancer progression status or worse prognostic outcomes. With pooled data based on four studies with available univariate analysis results and four studies with multivariate analysis, statistically significant associations were found between biopsy PNI and BCR with univariate analysis (HR = 2.05; 95% CI = 1.57-2.68; p < 0.001) and with multivariate analysis (HR = 1.57; 95% CI = 1.28-1.93; p < 0.001).Conclusion: Evidence from the included observational studies indicated that biopsy PNI was not only correlated with adverse pathologic characteristics but also with worse BCR prognosis of local PCa after RP. The status of biopsy PNI could serve as a promising risk-stratification factor to help the decision-making process, considering active surveillance (AS) or further treatment for PCa patients.

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.

Perineural invasion of cancer: a complex crosstalk between cells and molecules in the perineural niche

Perineural invasion (PNI) can be found in a variety of malignant tumors. It is a sign of tumor metastasis and invasion and portends the poor prognosis of patients. The pathological description and clinical significance of PNI are clearly understood, but exploration of the underlying molecular mechanism is ongoing. It was previously thought that the low-resistance channel in the anatomic region led to the occurrence of PNI. However, with rapid development of precision medicine and molecular biology, we have gradually realized that the occurrence of PNI is not the result of a single factor. The latest study suggests that PNI of cancer is a continuous and multistep process. A specific peripheral microenvironment, also called the perineural niche, is formed by neural cells, supporting cells, recruited inflammatory cells, altered extracellular matrix, blood vessels, and immune components in the background of carcinoma. Various soluble signaling molecules and their receptors comprise a complex signal network, which achieves the interaction between nerve and tumor. Nerve cells and tumor cells can interact directly or through the opening and closing of the signal transduction pathways and/or the recognition and response of the ligands and receptors. The information is transferred to the targets accurately and effectively, leading to the specific interactions between the nerve cells and the malignant tumor cells. PNI occurs through changes in nerve cells and supporting cells in the background of cancer; change and migration of the perineural matrix; enhancement of the viability, mobility, and invasiveness of the tumor cells; injury and regeneration of nerve cells; interaction, chemotactic movement, contact, and adherence of the nerve cells and the tumor cells; escape from autophagy, apoptosis, and immunological surveillance of tumor cells; and so on. Certainly, exploring the mechanism of PNI clearly has great significance for blocking tumor progression and improving patient survival. The current review aims to elucidate the cellular and molecular mechanisms of PNI, which may help us find a strategy for improving the prognosis of malignant tumors.

The Perineural Invasion Paradox: Is Perineural Invasion an Independent Prognostic Indicator of Biochemical Recurrence Risk in Patients With pT2N0R0 Prostate Cancer? A Multi-Institutional Study

Purpose

Perineural invasion (PNI) is a histologic feature that is present in as many as 84% of patients with prostate cancer. The prognostic significance of PNI is controversial, with recent studies yielding contradictory results. This study aims to assess whether PNI, on the surgical pathology of patients with pT2N0M0 disease and with negative surgical margins, is an independent prognostic indicator of the risk of biochemical recurrence.

Methods and materials

We identified 1549 patients who received a diagnosis of margin-negative pT2N0M0 prostate cancer at 3 separate institutions between January 1, 2008 and December 31, 2014. We reviewed the electronic medical records of these patients and collected clinical and histologic data. A multivariable analysis was performed to assess the association between PNI and biochemical recurrence.

Results

Of the 1549 patients identified, 936 (60.4%) had PNI and 96 (6.2%) had biochemical recurrence. The median time until recurrence was 16 months. The median follow-up in patients without recurrence was 26.5 months. PNI was associated with pT2c disease. The proportion of patients with pT2c was 89% in patients with PNI compared with 79% in patients without PNI (P < .001). PNI was also associated with a higher surgical Gleason score (of those with vs without PNI, 21% vs 50% had Gleason score 3 + 3; 62% vs 41% had a Gleason score 3 + 4, 12% vs 5% had a Gleason score 4 + 3; and 5% vs 3% had a Gleason score 8-10; P < .001). On univariate analysis, patients with PNI appeared to be more likely to have disease recurrence (hazard ratio: 1.7; 95% confidence interval, 1.1-2.6; P = .015). However, after adjusting for other variables, there was not a significant association between PNI and recurrence (hazard ratio: 1.1; 95% confidence interval, 0.70-1.8: P = .65).

Conclusions

We found that PNI was not an independent indicator of the risk of biochemical recurrence. Instead, PNI may be an indicator of unfavorable histology such as a high Gleason score or diffuse disease within the prostate in pT2N0 patients.