Neuroepithelial interactions in prostate cancer are enhanced in the presence ofprostatic stroma

Prognostic value of perineural invasion in resected non-small cell lung cancer: A meta-analysis

Objective

The prognostic role of perineural invasion (PNI) in resected non-small cell lung cancer (NSCLC) remains unclear. A meta-analysis was performed to compare the overall survival (OS) of patients with resected NSCLC with and without PNI.

Methods

The PubMed, EMBASE, and Web of Science databases were systematically searched to identify relevant studies investigating the effect of PNI on OS in patients with resected NSCLC. Pooled hazard ratio (HR) and 95% confidence intervals (CI) were estimated using a random-effects model. Separate meta-analyses using adjusted or unadjusted HR for OS were performed using Stata/SE 12.0.

Results

Eleven studies comprising 2,279 patients were included. In total, PNI was identified in 9% (median, 4%-31%) of patients with resected NSCLC. The unadjusted pooled effect of the PNI was significantly associated with worse OS (HR, 2; 95% CI, 1.65-2.43). Adjusting for potential confounders yielded a similar result, with OS being significantly worse (HR, 2.13; 95% CI, 1.8-2.51) for patients exhibiting PNI.

Conclusion

This meta-analysis indicates that the PNI is a strong prognostic factor for unfavorable outcomes in patients with resected NSCLC. Further large-scale prospective lung cancer trials are required to validate these results.

Neuroepithelial Interactions in Cancer

Nerves not only regulate the homeostasis and energetic metabolism of normal epithelial cells but also are critical for cancer, as cancer recapitulates the biology of neural regulation of epithelial tissues. Cancer cells rarely develop in denervated organs, and denervation affects tumorigenesis, in vivo and in humans. Axonogenesis occurs to supply the new malignant epithelial growth with nerves. Neurogenesis happens later, first in ganglia around organs or the spinal column and subsequently through recruitment of neuroblasts from the central nervous system. The hallmark of this stage is regulation of homeostasis and energetic metabolism. Perineural invasion is the most efficient interaction between cancer cells and nerves. The hallmark of this stage is increased proliferation and decreased apoptosis. Finally, carcinoma cells transdifferentiate into a neuronal profile in search of neural independence. The latter is the last stage in neuroepithelial interactions. Treatments for cancer must address the biology of neural regulation of cancer.

Perineural Invasion Predicts Local Recurrence and Poor Survival in Laryngeal Cancer

(1) Background: Perineural invasion (PNI) in head and neck cancer is associated with a poor prognosis; however, the effect of PNI on the prognosis of laryngeal cancer remains under debate. This retrospective study aimed to investigate the effect of PNI in fresh or salvaged larynges on survival in patients who had undergone laryngectomy for squamous cell carcinoma. (2) Methods: This study enrolled 240 patients diagnosed with laryngeal cancer who had undergone open surgery at Seoul St. Mary's Hospital, Korea. The effects of PNI, other histopathologic factors, and treatment history on survival and recurrence patterns were assessed. (3) Results: PNI was observed in 30 of 240 patients (12.5%). PNI (HR: 3.05; 95% CI: 1.90-4.88; p = 0.01) was a significant predictor of poor 5-year disease-free survival. In fresh cases, preepiglottic invasion (HR: 2.37; 95% CI: 1.45-3.88; p = 0.01) and PNI (HR: 2.96; 95% CI: 1.62-2.96; p = 0.01) were negative prognostic factors for 5-year disease-free survival. In the salvage group, however, only PNI (HR: 2.74; 95% CI: 1.26-5.92; p = 0.01) was a significant predictor of disease-free survival. Further, PNI significantly influenced high local recurrence (HR: 5.02, 95% CI: 1.28-9.66; p = 0.02). (4) Conclusions: Independent of treatment history, PNI is a prognostic factor for poor survival and local recurrence in laryngeal cancer.

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.

Intraductal Carcinoma of the Prostate on Diagnostic Needle Biopsy Predicts Prostate Cancer Mortality: A Population-Based Study

BACKGROUND

Intraductal carcinoma of the prostate (IDC-P) is a distinct histopathologic feature associated with high-grade, advanced prostate cancer. Although studies have shown that IDC-P is a predictor of progression following surgical or radiation treatment for prostate cancer, there are sparse data regarding IDC-P on diagnostic needle biopsy as a prognosticator of prostate cancer mortality.

MATERIALS AND METHODS

This was a population-based study of all prostate cancer patients diagnosed using needle biopsy and without evidence of systemic disease between 1991 and 1999 within a defined geographic region of Norway. Patients were identified by cross-referencing the Norwegian Cancer Registry. Of 318 eligible patients, 283 had biopsy specimens available for central pathology review. Clinical data were obtained from medical charts. We examined whether IDC-P on diagnostic needle biopsy was associated with adverse clinicopathological features and prostate cancer mortality.

RESULTS

Patients with IDC-P on diagnostic needle biopsy had a more advanced stage and a higher Gleason score compared to patients without IDC-P. IDC-P was also associated with an intensively reactive stroma. The 10-year prostate cancer-specific survival was 69% for patients with IDC-P on diagnostic needle biopsy and 89% for patients without IDC-P (Log rank P-value < 0.005). The presence of IDC-P on diagnostic needle biopsy remained an independent predictor of prostate cancer mortality after adjustments for clinical prognostic factors and treatment. After adjustment for the newly implemented Grade Group system of prostate cancer, IDC-P showed a strong tendency toward statistical significance. However, IDC-P did not remain a statistically significant predictor in the multivariable analysis.

CONCLUSION

IDC-P on diagnostic needle biopsy is an indicator of prostate cancer with a high risk of mortality. Accordingly, a diagnosis of IDC-P on needle biopsy should be reported and considered a feature of high-risk prostate cancer. Moreover, the association between IDC-P and reactive stroma provides evidence in support of the idea that stromal factors facilitate carcinoma invasion to the prostatic acini and ducts. Prostate 77:859-865, 2017. © 2017 Wiley Periodicals, Inc.

Characterization of reactive stroma in prostate cancer: involvement of growth factors, metalloproteinase matrix, sexual hormones receptors and prostatic stem cells

INTRODUCTION AND OBJECTIVES

Reactive Stroma (RStr) is observed in many human cancers and is related to carcinogenesis. The objectives of the present study were to stablish a relationship of the RStr microenvironment with prostate cancer (Pca) through a morphological and molecular characterization, and to identify a possible relationship between RStr with worse prognosis factors and occurrence of malignant prostatic stem cells.

MATERIALS AND METHODS

Forty prostatic samples were selected from men with Pca diagnosis submitted to radical prostatectomy; they were divided in two groups: Group-1 (n=20): samples without reactive stroma; Group-2 (n=20): samples of PCa with intense stroma reaction. Prostatic samples were evaluated for RStr intensity by Masson Trichromic stain and posteriorly submitted to histopathological and immunohistochemistry analysis for antigens: a-actin, vimentin, IGF-1, MMP-2, FGF-2, C-Myc, PSCA, AR, Era and ERß.

RESULTS

Reactive stroma with intense desmoplastic reactivity was significantly more frequent in intermediate (Gleason 7, 3+4) and high grade tumors (Gleason 7, 4+3). The group with intense stromal reactivity showed significant higher levels of Vimentin, IGF-1, MMP-2, FGF-2, C-Myc, PSCA and ERa.

CONCLUSIONS

It can be concluded that RStr may be a predictive marker of Pca progression, since it was associated with increase of growth factors, imbalance of androgen and estrogen receptors and presence of malign prostatic stem cells.

Prognostic factors in the patients with T2N0M0 colorectal cancer

BACKGROUND

The 5-year survival rate of the patients with stage I colorectal cancer is about 90%; therefore, adjuvant therapy has not been recommended after radical resection; however, about 16-26% of T2N0M0 patients will be dead at 5 years despite radical curative resection. It indicated that there is a defined group of patients who are at high risk for relapse or metastasis despite radical operation. This study aimed to find the patients with T2N0M0 colorectal cancer at high risk for relapse or metastasis.

METHODS

From January 1993 to December 2014, 812 patients with histologically confirmed stage T2N0M0 primary colorectal cancer treated by radical surgery with complete clinical follow-up data were eligible for this study. The medical records of all patients were collected and were retrospectively analyzed. Survival rates were calculated using Kaplan-Meier method, and survival cures were compared using the log-rank test. Cox proportional hazards model was used to analyze the significant factors defined in univariate test.

RESULTS

The 5-year and 10-year overall survival rates were 81.9 and 67.7%, respectively. Male gender, old age, lymphovascular permeation, perineural invasion, and poor differentiation were associated with low cancer-specific survival rates in Kaplan-Meier analysis. Multivariate analyses revealed old age, lymphovascular permeation, perineural invasion, and poor differentiation as significant independent factors predicting worse prognosis (P < 0.05).

CONCLUSIONS

Old age, lymphovascular permeation, perineural invasion, and poor differentiation are risk factors for the worse prognostic patients with T2N0M0 colorectal patients who would potential benefit from more aggressive therapy.

Hedgehog Signaling in Pancreatic Fibrosis and Cancer

The hedgehog signaling pathway was first discovered in the 1980s. It is a stem cell-related pathway that plays a crucial role in embryonic development, tissue regeneration, and organogenesis. Aberrant activation of hedgehog signaling leads to pathological consequences, including a variety of human tumors such as pancreatic cancer. Multiple lines of evidence indicate that blockade of this pathway with several small-molecule inhibitors can inhibit the development of pancreatic neoplasm. In addition, activated hedgehog signaling has been reported to be involved in fibrogenesis in many tissues, including the pancreas. Therefore, new therapeutic targets based on hedgehog signaling have attracted a great deal of attention to alleviate pancreatic diseases. In this review, we briefly discuss the recent advances in hedgehog signaling in pancreatic fibrogenesis and carcinogenesis and highlight new insights on their potential relationship with respect to the development of novel targeted therapies.

The relationship between perineural invasion, tumor grade, reactive stroma and prostate cancer-specific mortality: A clinicopathologic study on a population-based cohort

BACKGROUND

In vitro and in vivo studies have shown that nerves, tumor epithelium, and stroma interact and promote prostate cancer (PC) progression. Perineural invasion (PNI) is established amidst these interactions and may therefore indicate an aggressive PC phenotype. The purpose of the present study was to determine the relationship between PNI, tumor grade, reactive stroma, and PC-specific mortality.

METHODS

A population-based study on 318 patients, encompassing all cases of PC diagnosed by needle biopsies and without evidence of systemic metastasis at the time of diagnosis in Aust-Agder County in the period of 1991-1999. Patients were identified by cross-referencing the Cancer Registry of Norway. Clinical data were obtained by review of medical charts. Diagnostic prostate needle biopsies were reviewed with respect to presence of PNI, percentage of biopsy cores with PNI, Gleason score (GS), and reactive stromal grade (RSG). The endpoint was PC-specific mortality.

RESULTS

The presence of PNI was significantly associated with high tumor grade and abundant reactive stroma. The 10-year PC-specific survival for patients with and without PNI was 72% and 91%, respectively (P = 0.001, log rank). PNI predicted PC-specific mortality independently of clinical factors, though the effect of PNI was attenuated when adjusting for GS and RSG. However, a percentage of biopsy cores with PNI >50% was found to predict PC-specific mortality independently of other clinicopathologic parameters.

CONCLUSIONS

The present population-based study shows that PNI on diagnostic prostate needle biopsy is associated with increased risk of PC-specific mortality. Our findings demonstrate that the prognostic effect of PNI is dependent on an association with high grade carcinoma and reactive stroma. However; the impact of PNI on clinical outcome becomes stronger and independent of other clinicopathologic factors upon increased percentage of PNI positive biopsy cores. Thus, our study highlights the importance of PNI and microenvironmental interactions for the long-term outcome of PC.

Sonic hedgehog paracrine signaling activates stromal cells to promote perineural invasion in pancreatic cancer

PURPOSE

Pancreatic cancer is characterized by stromal desmoplasia and perineural invasion (PNI). We sought to explore the contribution of pancreatic stellate cells (PSC) activated by paracrine Sonic Hedgehog (SHH) in pancreatic cancer PNI and progression.

EXPERIMENTAL DESIGN

In this study, the expression dynamics of SHH were examined via immunohistochemistry, real-time PCR, and Western blot analysis in a cohort of carcinomatous and nonneoplastic pancreatic tissues and cells. A series of in vivo and in vitro assays was performed to elucidate the contribution of PSCs activated by paracrine SHH signaling in pancreatic cancer PNI and progression.

RESULTS

We show that SHH overexpression in tumor cells is involved in PNI in pancreatic cancer and is an important marker of biologic activity of pancreatic cancer. Moreover, the overexpression of SHH in tumor cells activates the hedgehog pathway in PSCs in the stroma instead of activating tumor cells. These activated PSCs are essential for the promotion of pancreatic cancer cell migration along nerve axons and nerve outgrowth to pancreatic cancer cell colonies in an in vitro three-dimensional model of nerve invasion in cancer. Furthermore, the coimplantation of PSCs activated by paracrine SHH induced tumor cell invasion of the trunk and nerve dysfunction along sciatic nerves and also promoted orthotropic xenograft tumor growth, metastasis, and PNI in in vivo models.

CONCLUSIONS

These results establish that stromal PSCs activated by SHH paracrine signaling in pancreatic cancer cells secrete high levels of PNI-associated molecules to promote PNI in pancreatic cancer.

Biological correlates of prostate cancer perineural invasion diameter

Perineural invasion is a symbiotic relationship between cancer cells and nerves and is most frequently seen in "neurotropic" cancers such as prostate cancer. It results in increased perineural space cancer cell growth and decreased apoptosis and induces nerve growth. Tissue microarrays were constructed from 640 radical prostatectomy specimens with prostate cancer. The perineural diameter was measured as previously described. Multiple biomarkers have been previously performed on this tissue microarray cohort, and all data were kept in the same database. The biomarker results database was queried for correlations between perineural invasion diameter and tissue biomarkers. Increased perineural invasion diameter correlated with increased proliferation of prostate cancer cells and with apoptosis. It also correlated with proteins involved in survival pathways such as nuclear factor κB, c-Myc, phosphorylated AKT, and its downstream effector FHKR, but not with GSK. Unlike nerve density, it did not correlate with decreased PTEN expression. Increased perineural invasion diameter was associated with higher levels of hormonal receptors such as androgen receptor, but not estrogen receptor. Also associated with perineural invasion diameter were coregulators and corepressors including SRC1 and TIF2. Perineural invasion diameter had the strongest correlation with tumor volume (ρ = 0.579, P = .000), not identified with nerve density. These data demonstrate that perineural invasion has the same biologic correlations as neural density. However, we found a distinct and very strong correlation with increased tumor volume. These data confirm that perineural invasion is the ultimate and most successful interaction between cancer cells and nerve fibers, resulting in increased tumor growth.

The reciprocal interactions between astrocytes and prostate cancer cells represent an early event associated with brain metastasis

Tumor establishment, growth, and survival are supported by interactions with microenvironment components. Here, we investigated whether the interactions between prostate cancer cells and cortical astrocytes are associated to a potential role for astrocytes in tumor establishment. We demonstrate that astrocytes interact in vitro with prostatic cancers cells derived from different metastatic sites. Astrocytes and their secreted extracellular matrix, stimulate DU145 cell (a brain-derived prostate tumor cell line) proliferation while inhibiting cell death and modulating the expression of several genes related to prostate cancer progression, suggesting the activation of EMT process in these cells. In contrast, DU145 cells and their conditioned medium inhibited cell proliferation and induced cell death of astrocytes. On the other hand, the astrocytes were unable to significantly induce an increment of LNCaP cell (a lymph node-derived prostate tumor cell line) proliferative activity. In addition, LNCaP cells were also unable to induce cell death of astrocytes. Thus, we believe that DU145 cells, but not LNCaP cells, present an even more aggressive behavior when interacting with astrocytes. These results provide an important contribution to the elucidation of the cellular mechanisms involved in the brain microenvironment colonization.

Computerized quantification and planimetry of prostatic capsular nerves in relation to adjacent prostate cancer foci

BACKGROUND

Perineural invasion is discussed as a significant route of extraprostatic extension in prostate cancer (PCa). Recent in vitro studies suggested a complex mechanism of neuroepithelial interaction.

OBJECTIVE

The present study was intended to investigate whether the concept of neuroepithelial interaction can be supported by a quantitative analysis and planimetry of capsular nerves in relation to adjacent PCa foci.

DESIGN, SETTING, AND PARTICIPANTS

Whole-mount sections of the prostate were created from patients undergoing non-nerve-sparing laparoscopic radical prostatectomy. For each prostate, adjacent sections were created and stained both to identify capsular nerves (S100) and to localize cancer foci (hematoxylin and eosin).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Computerized quantification and planimetry of capsular nerves (ImageJ software) were performed after applying a digital grid to define 12 capsular sectors. For statistical analyses, mixed linear models were calculated using the SAS 9.3 software package.

RESULTS AND LIMITATIONS

Specimens of 33 prostates were investigated. A total of 1957 capsular nerves and a total capsular nerve surface area of 26.44 mm(2) were measured. The major proportion was found in the dorsolateral (DL) region (p<0.001). Adjacent tumor was associated with a statistically significant higher capsular nerve count compared with the capsules of tumor-free sectors (p<0.005). Similar results were shown for capsular nerve surface area (p<0.006). Subsequent post hoc analyses at the sector level revealed that the effect of tumor on capsular nerve count or nerve surface area is most pronounced in the DL region.

CONCLUSIONS

The presence of PCa foci resulted in a significantly increased capsular nerve count and capsular nerve surface area compared with tumor-free sectors. The present study supports former in vitro findings suggesting that the presence of PCa lesions may lead to complex neuroepithelial interactions resulting in PCa-induced nerve growth.

Stereological Quantification of Nerve Fibers Immunoreactive to PGP 9.5, NPY, and VIP in Rat Prostate During Postnatal Development

This work was undertaken to study prostate innervation during the postnatal development of rats. It deals with the quantification of nervous fibers throughout all the regions of the rat prostate during the postnatal development using a general marker for nervous tissue, protein gene product 9.5, and 2 neuropeptides (NPY and VIP). Forty male Wistar rats (prepubertals, pubertals, young, and aged adults) were studied for immunohistochemistry of protein gene product (PGP 9.5), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP). They were also evaluated for length density of nerve fibers (L(V) PGP 9.5, L(V) NPY, L(V) VIP). Nerve fibers immunoreactive to the 3 antigens studied were detected in all the groups and in all the prostate zones. Periductal L(V) NPY evidenced a significant increase in the pubertal group, maintained throughout adult life. Periductal L(V) VIP showed a significant increase in young adults. The length densities of VIP and NPY fibers were significantly higher in periductal and ampular locations in comparison with dorsal and ventral sites. It can be concluded that the relative amount of nerve fibers in rat prostate, detected by PGP 9.5, does not change during postnatal development. There were significant changes in NPY and VIP fibers, showing an increase in periurethral ducts at puberty. The abundance of peptidergic innervation around the excretory ducts is related to their contractility. The development of innervation of periurethral ducts is regulated by androgens.

The reactive stroma microenvironment and prostate cancer progression

Reactive stroma initiates during early prostate cancer development and coevolves with prostate cancer progression. Previous studies have defined the key markers of reactive stroma and have established that reactive stroma biology influences prostate tumorigenesis and progression. The stem/progenitor cells of origin and the mechanisms that regulate their recruitment and activation to myofibroblasts or carcinoma-associated fibroblasts are essentially unknown. Key regulatory factors have been identified, including transforming growth factor β, interleukin-8, fibroblast growth factors, connective tissue growth factor, wingless homologs-Wnts, and stromal cell-derived factor-1, among others. The biology of reactive stroma in cancer is similar to the more predictable biology of the stroma compartment during wound repair at sites where the epithelial barrier function is breached and a stromal response is generated. The coevolution of reactive stroma and the biology of how reactive stroma-carcinoma interactions regulate cancer progression and metastasis are targets for new therapeutic approaches. Such approaches are strategically designed to inhibit cancer progression by uncoupling the reactive stroma niche.

Radiation impairs perineural invasion by modulating the nerve microenvironment

Purpose

Perineural invasion (PNI) by cancer cells is an ominous clinical event that is associated with increased local recurrence and poor prognosis. Although radiation therapy (RT) may be delivered along the course of an invaded nerve, the mechanisms through which radiation may potentially control PNI remain undefined.

Experimental Design

An in vitro co-culture system of dorsal root ganglia (DRG) and pancreatic cancer cells was used as a model of PNI. An in vivo murine sciatic nerve model was used to study how RT to nerve or cancer affects nerve invasion by cancer.

Results

Cancer cell invasion of the DRG was partially dependent on DRG secretion of glial-derived neurotrophic factor (GDNF). A single 4 Gy dose of radiation to the DRG alone, cultured with non-radiated cancer cells, significantly inhibited PNI and was associated with decreased GDNF secretion but intact DRG viability. Radiation of cancer cells alone, co-cultured with non-radiated nerves, inhibited PNI through predominantly compromised cancer cell viability. In a murine model of PNI, a single 8 Gy dose of radiation to the sciatic nerve prior to implantation of non-radiated cancer cells resulted in decreased GDNF expression, decreased PNI by imaging and histology, and preservation of sciatic nerve motor function.

Conclusions

Radiation may impair PNI through not only direct effects on cancer cell viability, but also an independent interruption of paracrine mechanisms underlying PNI. RT modulation of the nerve microenvironment may decrease PNI, and hold significant therapeutic implications for RT dosing and field design for patients with cancers exhibiting PNI.

Periacinar retraction clefting in nonneoplastic and neoplastic prostatic glands: artifact or molecular involvement

A space between neoplastic acini and prostatic stroma is not rare and studies have interpreted this as an artifact, considering the absence of endothelial cells indicating vascular invasion. Thus, the aims of this work were to characterize and correlate the occurrence and extent of retraction clefting with the reactivities of α and β dystroglycan (αDG, βDG), laminin, matrix metalloproteinase 2 (MMP-2), p63, insulin-like growth factor 1(IGF-1), vimentin, and fibroblast growth factor 2 (FGF-2). The study was based on nonneoplastic and neoplastic prostatic tissues obtained from necropsies and retropubic radical prostatectomies. The results showed that periacinar retraction clefting was significantly more frequent in prostatic carcinoma samples than in normal prostatic acini. Most of the neoplastic acini (72.0%) showed retraction clefting of more than 50% of circumference, which were significantly more frequent in Gleason score 7 and 6. Decreased collagen and reticular and elastic fibers were verified in the stroma around neoplastic acini. Weak and discontinuous αDG, βDG, and laminin immunoreactivities and intensified MMP-2, vimentin, IGF-1 and FGF-2 immunoreactivities were verified in the neoplastic acini; p63 immunoreactivity was negative in all carcinomas. Thus, these findings showed that the lack of epithelial basal cells, DGs, and laminin and increased MMP-2, IGF-1, and FGF-7 could be considered important pathways in periacinar retraction occurrence. This study demonstrated the origin of and the biological mechanisms responsible for periacinar retraction clefting in prostatic carcinoma.

Neurogenesis in colorectal cancer is a marker of aggressive tumor behavior and poor outcomes

BACKGROUND

Colorectal cancer staging criteria do not rely on examination of neuronal tissue. The authors previously demonstrated that perineural invasion is an independent prognostic factor of outcomes in colorectal cancer. For the current study, they hypothesized that neurogenesis occurs in colorectal cancer and portends an aggressive tumor phenotype.

METHODS

In total, samples from 236 patients with colorectal cancer were used to create a tissue array and database. Tissue array slides were immunostained for protein gene product 9.5 (PGP9.5) to identify nerve tissue. The correlation between markers of neurogenesis and oncologic outcomes was determined. The effect of colorectal cancer cells on stimulating neurogenesis in vitro was evaluated using a dorsal root ganglia coculture model.

RESULTS

Patients whose tumors exhibited high degrees of neurogenesis had 50% reductions in 5-year overall survival and disease-free survival compared with patients whose tumors contained no detectable neurogenesis (P = .002 and P = .006, respectively). Patients with stage II disease and high degrees of neurogenesis had greater reductions in 5-year overall survival and disease-free survival compared with lymph node-negative patients with no neurogenesis (P = .002 and P = .008, respectively). Patients with stage II disease and high degrees of neurogenesis had lower 5-year overall survival and disease-free survival compared with patients who had stage III disease with no neurogenesis (P = .01 and P = .008, respectively). Colorectal cancer cells stimulated neurogenesis and exhibited evidence of neuroepithelial interactions between nerves and tumor cells in vitro.

CONCLUSIONS

Neurogenesis in colorectal cancer appeared to play a critical role in colorectal cancer progression. Furthermore, the current results indicated that neurogenesis functions as an independent predictor of outcomes and may play a role in therapy stratification for patients with lymph node-negative disease.

Perineural invasion and associated pain in pancreatic cancer

Perineural invasion (PNI) is a prominent characteristic of pancreatic cancer. PNI is a process whereby cancer cells invade the surrounding nerves, thus providing an alternative route for metastatic spread and pain generation. PNI is thought to be an indicator of aggressive tumour behaviour and has been shown to correlate with poor prognosis of patients with pancreatic cancer. Recent studies demonstrated that some signalling molecules and pathways that are involved in PNI are also involved in pain generation. Targeting these signalling pathways has shown some promise in alleviating pain and reducing PNI, which could potentially improve treatment outcomes for patients with pancreatic cancer.

Invasion of the hypoglossal nerve by adenoid cystic carcinoma of the tongue: case report and review of the literature

Adenoid cystic carcinoma (ACC) is a rare but highly aggressive malignancy mainly originating from the salivary glands. ACC is well known for its propensity toward neural invasion (NI). NI is the process of neoplastic invasion in and along nerves. It is a distinct and well-documented phenomenon in ACC; however, it is an underestimated route of metastatic spread. Multiple distant metastases can be established through NI route, and NI is believed to portend a poor prognosis. Despite increasing recognition of NI in many malignancies, the molecular mechanism behind NI is not well established. We present a unique case of hypoglossal nerve invasion by ACC arising from the minor salivary glands in the tongue of a 34-year-old man. We also review and discuss current theories on the pathogenesis and mechanism of NI.

Determining prostate cancer-specific death through quantification of stromogenic carcinoma area in prostatectomy specimens

We previously reported that reactive stroma grading in prostate cancer (PCa) is predictive of biochemical recurrence in prostatectomies and biopsies. In this study, we tested whether quantifying the percentage of reactive stromal grade 3 (RSG 3; stromogenic carcinoma pattern) in the entire tumor is predictive of PCa-specific death. Whole-mount prostatectomies operated by a single surgeon obtained between 1983 and 1998 were reviewed. Reactive stroma was evaluated as described previously, and areas of RSG 3 in the entire tumor were registered as percentages of total tumor. Statistical analysis was performed using Spearman, Kaplan-Meier, and Cox analyses. In all, 872 cases were evaluable. Quantification of RSG 3 percentage was an independent predictor of biochemical recurrence, analyzed as a continuous or grouped variable. Patients with higher RSG 3 percentages (larger tumor areas with RSG 3) had a significantly decreased biochemical recurrence-free survival than those with a lower RSG 3 percentage, even within the Gleason score 7 subset of patients. A nomogram introduced this new variable to the model. Furthermore, quantification of RSG 3 percentage was significantly predictive of PCa-specific death. Quantification of the RSG 3 (stromogenic carcinoma) area in PCa provides additional novel information on prognosis. These data substantiate the concept that the tumor microenvironment holds significant predictive information, as well as biological significance.

Morphological parameters associated with perineural invasion (PNI) in carcinoma of the cervix uteri

The study determines morphological features that are associated with perineural invasion (PNI) in patients with cervical carcinoma (CX). Histological slides from 194 patients from surgically treated squamous cell carcinoma were re-examined for PNI and correlated to morphological factors of tumor growth. Material from 68 patients (35.1%) represented PNI. PNI was significantly correlated with advanced tumor stage (P < .001). Patients with deep cervical stromal invasion (>66%) showed more PNI than those with more superficial invasion (41% vs 16.9%; P = .001). Tumors with spray-like PI showed significantly more PNI (48.4%) when compared with finger-like PI (26.7%) and those with pushing borders (18.8%; P = .007). Strong peritumoral desmoplastic stromal reaction and absence of peritumoral inflammation were associated with a higher frequency of PNI (P < .001). PNI is associated with advanced tumor stage, deep cervical stromal invasion (>66%), high grade of tumor cell dissociation (ie, spray-like pattern of invasion), strong peritumoral desmoplastic stromal reaction, and reduced peritumoral inflammation.

Proliferative, structural and molecular features of the Mdx mouse prostate

The prostate is fundamental to the male reproductive process, and the stroma-epithelium interaction has an important role in prostate maintenance. Studies suggest that dystroglycan (DG) plays a role in cancer development in various organs. Thus, the aims of this work were to characterize morphological and proliferative features of the prostatic stroma and epithelium of mdx mice; to verify the immunolocalization of the α and β DG, IGF-1 and laminin α3 receptors; and to relate those structural and molecular events to prostate pathogenesis and to verify the viability of this experimental model in prostate studies. Thirty male mice (mdx and C57BL10/Uni) were divided into control and mdx groups. Samples from the ventral prostate were collected for immunological, Western Blotting, transmission electron microscopy and morphometric analyses. Oestradiol and testosterone measurements were verified. The results showed diminished testosterone and increased oestradiol levels in the mdx group. Atrophied cells and hypertrophied stroma were seen in the mdx mice. Weak α and β DG and laminin α3 immunolocalization was demonstrated in the mdx group. Intense insulin-like growth factor receptor α-1 (IGFRα-1) localization was identified in the mdx animals. Thus, mdx animals showed changes in molecular and structural integrity and proliferation signals, leading to glandular homoeostasis imbalance, and compromise of prostate function. Also, the steroid hormone imbalance and the increased IGF-1 receptor level detected in mdx mice could be considered as a crucial factor in the pathogenesis of prostatic disorders.

The laminin binding integrin alpha6beta1 in prostate cancer perineural invasion

Metastasizing prostate tumor cells invade along nerves innervating the encapsulated human prostate gland in a process known as perineural invasion. The extracellular matrix laminin class of proteins line the neural route and tumor cells escaping from the gland express the laminin binding integrin alpha6beta1 as a prominent cell surface receptor. Integrin alpha6beta1 promotes aggressive disease and supports prostate tumor cell metastasis to bone. Laminins and their integrin receptors are necessary for the development and maintenance of the peripheral nervous system, indicating the potential role for integrin receptors in directing prostate tumor cell invasion on nerves during perineural invasion.

Prostatic diseases in the senescence: structural and proliferative features

Senescence is one of the main aetiological factors which are responsible for natural androgen ablation in men and occurrence of prostatic diseases. However, it is unclear how the prostatic lesions are signallised in the prostate. Thus, the aim of this study is to characterise the structural, the ultrastructural and the proliferative aspects of the peripheral prostatic zone in the elderly men with and without diagnoses of prostatic lesions and with potential precursors of prostate cancer. Sixty samples of prostatic tissue, from 60 to 90-year-old patients with and without lesions obtained from autopsied or prostatectomised patients were divided into four groups (15 samples per group): standard group (no lesions), benign prostatic hyper-plasia group, high-grade prostatic intra-epithelial neoplasia group and prostatic carcinoma group. The samples were submitted to morphometrical, structural and ultrastructural analyses in addition to cellular apoptosis and proliferative analyses. The results showed morphological damages in the stroma and cellular organelles involved in the secretory process of the prostate. Moreover, the prostatic lesions in elderly men demonstrated disturbance in the proliferation/apoptosis rate, indicating a prevalence of the proliferative process. Finally, the imbalance in prostatic stroma-epithelium interaction was a harmful feature in the elderly men as a result of structural changes, which are crucial factors for the development and progression of carcinogenesis.

Predictors of positive surgical margins after laparoscopic robot assisted radical prostatectomy

PURPOSE

We identified the predictors of positive surgical margins in a series of patients undergoing robot assisted laparoscopic radical prostatectomy.

MATERIALS AND METHODS

We prospectively collected data from 322 patients who underwent robot assisted laparoscopic radical prostatectomy for clinically localized prostate cancer between April 2005 and October 2008, and who had not received any prior hormonal therapy.

RESULTS

Positive surgical margins were observed in 95 cases (29.5%). Specifically positive surgical margins were at the apex in 22 cases (6.8%), anterior in 5 (1.6%) and posterolateral in 68 (21%). Among the preoperative variables prostate volume on transrectal ultrasound (HR 0.420, p = 0.002) and cT stage (HR 2.217, p = 0.008) were independent predictors of the presence of any positive surgical margin in the cohort while cT stage (HR 2.070, p = 0.025) and biopsy Gleason score (p = 0.019) were predictors of posterolateral positive surgical margins. Considering pathological variables only extraprostatic extension of the primary tumor was an independent predictor of any positive surgical margin (HR 11.852, p <0.001) and posterolateral positive surgical margins (HR 7.484, p <0.001) in the series. Of those patients with organ confined disease positive surgical margins were present in 21 (10.6%). Only perineural invasion was an independent predictor of any positive surgical margin (HR 4.096, p = 0.028) while a not statistically significant trend was identified with regard to posterolateral positive surgical margins (HR 6.938, p = 0.067).

CONCLUSIONS

Pathological extension of the primary tumor was the most relevant predictor of positive surgical margins. In patients with organ confined disease the presence of perineural invasion was significantly associated with positive surgical margins.

Perineural invasion is an independent predictor of outcome in colorectal cancer

PURPOSE

Perineural invasion (PNI) is associated with decreased survival in several malignancies, but its significance in colorectal cancer (CRC) remains to be clearly defined. We evaluated PNI as a potential prognostic indicator in CRC, focusing on its significance in node-negative patients.

PATIENTS AND METHODS

We identified 269 consecutive patients who had CRC resected at our institution. Tumors were re-reviewed for PNI by a pathologist blinded to the patients' outcomes. Overall and disease-free survivals were determined using the Kaplan-Meier method, with differences determined by multivariate analysis using the Cox multiple hazards model. Results were compared using the log-rank test.

RESULTS

PNI was identified in less than 0.5% of the initial pathology reports. On rereview, 22% of tumors in our series were found to be PNI positive. The 5-year disease-free survival rate was four-fold greater for patients with PNI-negative tumors versus those with PNI-positive tumors (65% v 16%, respectively; P < .0001). The 5-year overall survival rate was 72% for PNI-negative tumors versus 25% for PNI-positive tumors. On multivariate analysis, PNI was an independent prognostic factor for both cancer-specific overall and disease-free survival. In a subset analysis comparing patients with node-negative disease with patients with stage III disease, the 5-year disease-free survival rate was 56% for stage III patients versus 29% for patients with node-negative, PNI-positive tumors (P = .0002). Similar results were seen for overall survival.

CONCLUSION

PNI is grossly underreported in CRC and could serve as an independent prognostic factor of outcomes in these patients. PNI should be considered when stratifying CRC patients for adjuvant treatment.

Perineural invasion in cancer: a review of the literature

Perineural invasion (PNI) is the process of neoplastic invasion of nerves and is an under-recognized route of metastatic spread. It is emerging as an important pathologic feature of many malignancies, including those of the pancreas, colon and rectum, prostate, head and neck, biliary tract, and stomach. For many of these malignancies, PNI is a marker of poor outcome and a harbinger of decreased survival. PNI is a distinct pathologic entity that can be observed in the absence of lymphatic or vascular invasion. It can be a source of distant tumor spread well beyond the extent of any local invasion; and, for some tumors, PNI may be the sole route of metastatic spread. Despite increasing recognition of this metastatic process, there has been little progress in the understanding of molecular mechanisms behind PNI and, to date, no targeted treatment modalities aimed at this pathologic entity. The objectives of this review were to lay out a clear definition of PNI to highlight its significance in those malignancies in which it has been studied best. The authors also summarized current theories on the molecular mediators and pathogenesis of PNI and introduced current research models that are leading to advancements in the understanding of this metastatic process.

Dystroglycan patterns on the prostate of non-obese diabetic mice submitted to glycaemic control

Dystroglycan (DG) is an adhesion protein which plays a crucial role in the maintenance of tissue integrity. Diabetes has been pointed out as a disease which causes harmful effects on prostate function. Therefore, the main objective of this work was to verify DG distribution and structure features in diabetic mice with and without glycaemic control and to relate these parameters to prostate pathogenesis. Thirty mice (Nod and BALB/c) were divided into three groups after 20 days of diabetic state: the control group received a 5 ml/kg dose of physiological saline daily for 20 days; the diabetic group had the same treatment as the control group; the diabetic-insulin group received 4-5 IU doses of Neutral Protamine Hagedorn (NPH) insulin daily for 20 days. After 20 days of treatment, all animals were killed and samples from the ventral prostate were processed for immunological and light microscopy analyses. The results showed diminished beta- and alpha-DG receptors in the diabetic group. However, there was a recovery of both beta-and alpha-DG receptor immunolocalization after insulin administration. Epithelial and stromal morphological changes were verified in the diabetic group, which also presented recovery after insulin treatment. Thus, it could be concluded that diabetes disturbed prostate structure integrity and altered the occurrence of alpha and beta-DG receptors, indicating decreased cell-matrix extracellular and cell-basal membrane attachment. However, insulin treatment could partially restore glandular homeostasis. The decrease in epithelial-stromal interaction certainly predisposes this gland in diabetic mice to be a prostate disease target.

Parameters of perineural invasion in radical prostatectomy specimens lack prognostic significance

The prognostic significance of perineural invasion by prostate cancer is debated. We have evaluated the association between biochemical failure and measurements of perineural invasion in radical prostatectomy specimens. Perineural invasion was identified in sections using S-100 protein immunostaining. For nerves showing invasion, the involved nerve closest to the edge of the prostate and to the surgical excision margin, as well as the diameter of these nerves, the largest nerve showing perineural invasion and its proximity to the excision margin, and the percentage of nerves showing perineural invasion up to 1.75 mm from the excision margin was determined and tested against time to prostate-specific antigen failure, along with preoperative prostate-specific antigen levels, highest Gleason primary grade, Gleason score and TNM T category. Perineural invasion was present in 90% of cases, with extraprostatic perineural invasion in 25% of tumors. Diameter of nerves showing perineural invasion ranged from 11 to 680 microm and the shortest distance to the surgical excision margin ranged from 33 to 2.57 mm. Perineural invasion density ranged from 6 to 96%. Gleason scores were six in 58 cases, seven in 43 cases, eight in three cases and nine in one case. Clinical T categories were T1c in 75 cases, T2a in 22 cases, T2b in five cases, T2c in two cases, T3 in one case. During a follow-up period of 11 to 55 months (median 26 months), 27 patients showed prostate-specific antigen failure. On univariate analysis only presence of extraprostatic perineural invasion, among parameters of perineural invasion, showed a weak correlation with outcome, while on multivariate analysis this lost significance and preoperative prostate-specific antigen levels, Gleason score and excision margin status were independently associated with biochemical failure. We conclude that the investigated parameters of perineural invasion do not predict prostate-specific antigen recurrence in radical prostatectomy specimens.

Soluble cadherins as cancer biomarkers

Molecular activities, regulating a balanced tissue organisation, are frequently disturbed during cancer progression. These include protein ectodomain shedding, a post-translational process that substantially changes the functional properties of the substrate protein. In comparison with normal epithelia, cancer cells almost invariably show diminished cadherin-mediated intercellular adhesion. This review will address cadherin ectodomain shedding and its functional consequence in normal physiology and in the tumor environment. Soluble cadherin fragments may retain specific biological activities during cancer cell invasion, angiogenesis and perineural invasion. When diffusion barriers disappear, soluble cadherins are detected in sera from cancer patients. Soluble N-(neural) cadherin may represent a novel diagnosis/prognostic biomarker showing a correlation with PSA in sera of prostate cancer patients. Furthermore, therapeutic monitoring in pancreas adenomacarcinoma revealed a correlation between circulating soluble N-cadherin and CA 19-9. A better understanding of cadherin regulation in cancer progression will likely increase our awareness of the importance of the combinatorial signals that regulate tissue integrity and eventually result in the identification of new therapeutics targeting cadherins.

Enhanced survival in perineural invasion of pancreatic cancer: an in vitro approach

Pancreatic cancer (PanCa) is characterized by perineural invasion (PNI), early lymph node and liver metastasis, and poor prognosis. PNI is one of the important causes of local recurrence. Little is known about the mechanism of PNI in PanCa. We presented a novel model system that may shed light on the mystery of PNI in PanCa. In this study, mouse dorsal root ganglia (DRGs) and human PanCa cell line (MIA PaCa-2) were cocultured in Matrigel matrix (BD Biosciences, San Jose, CA) to build this PNI model. MIA PaCa-2 cell line alone (control 1) or DRG alone (control 2) was cultured with Matrigel matrix as controls. Neurite outgrowth, cell colony growth, neurite-colony contact, and retrograde extension were observed under inverted microscopy and then were photographed and quantitated with the Optimas imaging system (Optimas Corp., Bothell, MA). At day 14, both the experimental and control 2 samples were harvested and subjected to total RNA isolation and fixed in paraffin-embedded blocks. Slides cut from paraffin blocks were studied with Ki-67 immunostaining and TUNEL assay. Gene profiling was performed using complementary DNA microarray. Overexpressed target genes were verified by quantitative reverse transcriptase polymerase chain reaction. The results showed that reciprocity was observed between neurites and MIA PaCa colonies with 24 hours of coculture. Neurite outgrowth was stimulated in the presence of pancreatic carcinoma cells, which showed 2-fold more area than did control 2. After 72 hours, MIA PaCa colonies cocultured with DRG exhibited 58% more colony area than did control 1. The Ki-67 index of the DRG/MIA PaCa cells (mean, 5.02%) was significantly higher than that in control 1 (mean, 1.18%) (P < .05); in contrast, the apoptotic index in the DRG/MIA PaCa cells was significantly lower (mean, 0.45%) than that in the control 1 (mean, 1.85%) (P < .001). Prosurvival genes MALT1 and TRAF were increased 2-fold in DRG/MIA PaCa compared with controls. We demonstrated that neural-epithelial interaction is a mutually beneficial process for the growth of nerves and PanCa cells. It is possible that oncogenes and growth factors might act synergistically in promoting proliferation and/or inhibiting apoptosis, a survival strategy crucial to the development of PNI in PanCa.

Morphometric and morphological features of the ventral prostate in rats submitted to chronic nicotine and alcohol treatment

Clinical studies analyzing simultaneous nicotine-alcohol use by patients showed important alterations in various organic systems such as: respiratory, digestory, and genital. Also, the prostatic morphology and physiology have been analyzed, specially due to large occurrence of prostatic diseases. Then, this work aimed at determining the structure and ultrastructure of the prostatic stroma and epithelium, as well as the stroma epithelium interactions from rats submitted to simultaneous long-term alcohol-nicotine treatment. A total of 40 male rats were divided into four groups: control group (10 animals) received tap water; alcoholic group (10 animals) received diluted 10% Gay Lussac ethanol; nicotine group (10 animals) received a 0.125mg/100g of body weight dose of nicotine injected subcutaneosly on a daily basis; nicotine-alcohol group (10 animals) received simultaneous alcohol and nicotine treatment. After 90 days of treatment, the animals were sacrificed and samples from the ventral lobe of the prostate were collected and processed for transmission electron and light microscopies. The results showed atrophied epithelium; prostatic intra-epithelial neoplasia; dilated cisterns of the granular endoplasmic reticulum, large amounts of collagen fibers besides inflammatory cells, specially in the alcoholic and nicotine-alcohol groups. Therefore, it could be concluded that the association between alcohol and nicotine caused the impairment of the prostatic secretory process. Moreover, this association is related to prostatic pathogenesis, which could lead to late glandular malignancy.

Lymphovascular invasion is a pathological feature of biologically aggressive disease in patients treated with radical prostatectomy

We examined whether invasion of lymphatic and/or vascular vessels (LVI), or perineural spaces (PNI) is associated with prostate cancer features and outcome.

MATERIALS AND METHODS

A total of 630 consecutive men underwent radical retropubic prostatectomy for clinically localized disease. LVI and PNI examination was part of the routine specimen evaluation.

RESULTS

Foci of LVI were identified in 32 patients (5%) and 381 (60.5%) had PNI. LVI and PNI were associated with clinical stage T2 disease, higher biopsy and final Gleason sum, extraprostatic extension, seminal vesicle involvement, positive surgical margins and a higher percent of positive biopsy cores (p <0.001). LVI was associated with metastases to regional lymph nodes and higher preoperative serum prostate specific antigen (p <0.001 and 0.004, respectively). PNI and LVI were associated with an increased risk of rapid biochemical progression after radical prostatectomy on univariate (p <0.001 and 0.001, respectively) but not on multivariate analysis. LVI was associated with shorter prostate specific antigen doubling time after biochemical progression (p = 0.012) and higher probabilities of failed local salvage radiation therapy (p = 0.0169), distant metastases (p <0.001) and death (p <0.001).

CONCLUSIONS

Only LVI is associated with metastases to regional and distant sites, and most importantly with overall survival. LVI and PNI are associated with established markers of biologically aggressive disease and rapid biochemical progression in patients who underwent radical prostatectomy. Our findings support the routine evaluation of LVI status in radical prostatectomy specimens and its inclusion in predictive models for clinical outcomes, since it appears to be a pathological marker of the lethal phenotype of prostate cancer.