The importance of the eosinophil in head and neck cancer

Eosinophils in Oral Disease: A Narrative Review

The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research.

Exploiting innate immunity for cancer immunotherapy

Immunotherapies have revolutionized the treatment paradigms of various types of cancers. However, most of these immunomodulatory strategies focus on harnessing adaptive immunity, mainly by inhibiting immunosuppressive signaling with immune checkpoint blockade, or enhancing immunostimulatory signaling with bispecific T cell engager and chimeric antigen receptor (CAR)-T cell. Although these agents have already achieved great success, only a tiny percentage of patients could benefit from immunotherapies. Actually, immunotherapy efficacy is determined by multiple components in the tumor microenvironment beyond adaptive immunity. Cells from the innate arm of the immune system, such as macrophages, dendritic cells, myeloid-derived suppressor cells, neutrophils, natural killer cells, and unconventional T cells, also participate in cancer immune evasion and surveillance. Considering that the innate arm is the cornerstone of the antitumor immune response, utilizing innate immunity provides potential therapeutic options for cancer control. Up to now, strategies exploiting innate immunity, such as agonists of stimulator of interferon genes, CAR-macrophage or -natural killer cell therapies, metabolic regulators, and novel immune checkpoint blockade, have exhibited potent antitumor activities in preclinical and clinical studies. Here, we summarize the latest insights into the potential roles of innate cells in antitumor immunity and discuss the advances in innate arm-targeted therapeutic strategies.

Preliminary Assessment of Tumor-Associated Tissue Eosinophilia (TATE) in Canine Mast Cell Tumors: Prevalence and Prognostic Relevance and Its Association with Neoangiogenesis

Mast cell tumor (MCT) is the most common malignant skin tumor in dogs. In order to gain more information on the prognostic markers in MCT, the role of the eosinophil granulocytes infiltrates was investigated and assessed by the evaluation of tumor-associated tissue eosinophilia (TATE) in 87 canine cutaneous MCTs. In human medicine, high TATE are often described in highly angiogenic tumors: we therefore assessed the vascular endothelial growth factor (VEGF) expression in neoplastic mast cells. TATE and VEGF expression were compared between themselves, with histological grading, immunohistochemical expression of KIT and Ki-67, and with the recurrence. We found a statistically significant correlation between TATE and Patnaik grading (p = 0.041), Kiupel grading (p = 0.022), immunohistochemical KIT expression (p = 0.015), and tumor recurrence (p = 0.000). No associations were observed with Ki-67 and VEGF expression. This is the first evaluation of TATE and its prognostic value in canine MCTs in veterinary oncology. This study suggest that this investigation could be an important source of information for this tumor and for other neoplasms.

Evaluation of peritumoral inflammatory infiltration and its relationship with different prognostic factors in cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin cancers. Prognostic factors, such as tumor thickness, play a crucial role in the management of these patients. Peritumoral inflammatory infiltration has been shown to influence the prognosis of malignancies. This study aimed to determine different prognostic factors and investigate peritumoral inflammatory infiltration in patients with cSCC.

METHODS

The study population consisted of 272 patients with a diagnosis of cSCC. Clinical data, such as age and tumor location, were extracted from pathology reports, and other information was gathered by contacting the patients via phone calls. All pathology slides were reviewed by an expert dermatopathologist, and the histopathological features and prognostic factors were evaluated.

RESULTS

The highest number of tumors was found in the scalp and forehead (21.3%), while the lowest number was found in the trunk and thighs (3.31%). The highest mean tumor thickness was observed in the group with no inflammatory cells; on the other hand, the lowest tumor thickness was found in the group of lymphocytes and plasma cells. The group with severe eosinophilic infiltration had the highest mean tumor thickness, while the group with no eosinophilic infiltration had the lowest mean tumor thickness.

CONCLUSION

Depending on the type of peritumoral inflammatory cells, the prognosis of cSCC may be predictable.

Histopathological prognosticators and their clinicopathological correlation in oral squamous cell carcinomas of the tongue

Background

Tongue carcinomas account for 25%-40% of intraoral squamous cell carcinomas (OSCCs). Although TNM staging systems is an international standard for cancer reporting, prognosis evaluation, and treatment planning, multiple histopathological risk assessment predictors such as tumor thickness (TT), tumor shape, tumor growth pattern, and invasive malignancy grading scoring systems have been studied and should form a basis for prediction and prognostication of such aggressive carcinomas.

Aim

To evaluate and characterize the histomorphological prognostic indicators in OSCCs of tongue and compare it with OSCCs of other anatomic sites within the oral cavity. Furthermore, to elucidate the significance of histopathological indicators in predicting prognosis of tongue squamous cell carcinomas (SCCs).

Materials and Methods

Forty SCC cases with 20 each of tongue and 20 from other intraoral sites were retrieved from department archives. Clinical data and staging were obtained for each case. Histomorphological parameters including pattern of invasion (POI), tumor budding (TB), depth of invasion (DOI), TT, lymphocytic host response, tumor-associated tissue eosinophilia (TATE), vascular invasion, perineural invasion (PNI), and muscular invasion were assessed. The results were statistically evaluated.

Results

TB, DOI, and sarcolemmal spread were significant histologic predictors in tongue SCC. Upon correlation of histomorphological parameters with clinical staging, TT, POI, and TATE were observed to be significantly correlated (P ≤ 0.05).

Conclusion

The histomorphological risk assessment model may serve as important addition to the existing prognosticators and may be used as a prognostic index to help plan and individualize treatment protocol in cases with aggressive high-risk disease for whom the use of multimodality treatment seems beneficial.

High TGF-β signature predicts immunotherapy resistance in gynecologic cancer patients treated with immune checkpoint inhibition

Various immune signatures predictive of resistance to immune checkpoint inhibitors (ICI) have been described in multiple solid cancers, but still under-investigated in gynecological (GYN) cancer. For 49 GYN cancer patients included in our study, without transcriptome signature, immune-related toxicity was the only clinical predictor of ICI treatment response (p = 0.008). The objective clinical response was the only predictor of progression-free survival (ICI-PFS, p = 0.0008) and overall survival (ICI-OS, p = 0.01). Commonly used ICI marker PD-L1 expression negatively correlated with progression-free survival (ICI-PFS) (p = 0.0019). We performed transcriptome and signaling pathway enrichment analyses based on ICI treatment responses and the survival outcome, and further estimated immune cell abundance using 547 gene markers. Our data revealed that TGF-β regulated signaling pathway was noted to play an important role in immunotherapy failure. Using our 6-genes TGF-β score, we observed longer ICI-PFS associated with lower TGF-β score (8.1 vs. 2.8 months, p = 0.046), which was especially more prominent in ovarian cancer (ICI-PFS 16.6 vs. 2.65 months, p = 0.0012). Further, abundant immunosuppressive cells like T-regulatory cells, eosinophils, and M2 macrophages were associated with shorter ICI-OS and correlated positively with CD274 and CTLA4 expressions. This study provides insight on the potential role of TGF-β in mediating immunotherapy resistance and cross-talking to immunosuppressive environment in GYN cancer. The TGF-β score, if validated in a larger cohort, can identify patients who likely to fail ICI and benefit from targeting this pathway to enhance the response to ICI.

Metabolic Interdependency of Th2 Cell-Mediated Type 2 Immunity and the Tumor Microenvironment

The function of T cells is critically dependent on their ability to generate metabolic building blocks to fulfil energy demands for proliferation and consecutive differentiation into various T helper (Th) cells. Th cells then have to adapt their metabolism to specific microenvironments within different organs during physiological and pathological immune responses. In this context, Th2 cells mediate immunity to parasites and are involved in the pathogenesis of allergic diseases including asthma, while CD8+ T cells and Th1 cells mediate immunity to viruses and tumors. Importantly, recent studies have investigated the metabolism of Th2 cells in more detail, while others have studied the influence of Th2 cell-mediated type 2 immunity on the tumor microenvironment (TME) and on tumor progression. We here review recent findings on the metabolism of Th2 cells and discuss how Th2 cells contribute to antitumor immunity. Combining the evidence from both types of studies, we provide here for the first time a perspective on how the energy metabolism of Th2 cells and the TME interact. Finally, we elaborate how a more detailed understanding of the unique metabolic interdependency between Th2 cells and the TME could reveal novel avenues for the development of immunotherapies in treating cancer.

Tumor-associated tissue eosinophilia versus tumor associated blood eosinophilia: A ratio of diagnostic importance in oral squamous cell carcinoma

Introduction

Eosinophils are multifunctional granulocytes, which play a pivotal role in health and disease. Tumor Associated Tissue Eosinophilia (TATE) has long been evaluated in the diagnosis and progression of oral squamous cell carcinomas (OSCCs). However, their association with Tumor Associated Blood Eosinophilia (TABE) in OSCCs is still far fetched. We, therefore, attempted to evaluate their individual roles and to achieve a ratio between TATE and TABE in order to signify its usage in objectifying the diagnosis.

Materials and Methods

TATE was evaluated using H and E stain per 10 high power fields in 33 previously diagnosed cases of OSCC which were retrieved from department archives. TABE values were achieved from complete blood hemogram reports of patients. TATE/TABE ratio was calculated. All the parameters were clinicopathologically correlated and statistically evaluated using SPSS.

Results

TATE represented higher values in well-differentiated squamous cell carcinoma (WDSCC) and poorly differentiated squamous cell carcinoma (PDSCC) and was least in moderately differentiated squamous cell carcinoma (MDSCC), whereas TABE linearly increased from WDSCC to PDSCC. TNM Stage II cases revealed the highest TATE and lowest TABE. TATE/TABE ratio was the highest in WDSCC.

Conclusion

Due to the dual nature of eosinophils in early and late carcinogenesis events, evaluation of only TATE might not be conclusive in determining tumor grade. Hence, in a first of its kind attempt, the TATE/TABE ratio may be suitable to achieve a criterion for the determination of tumor grade and may also help to unfold the underlying biologic events.

Quantitative assessment of CD15 positive tissue eosinophils in Oral Squamous Cell Carcinoma: effects on mast cells and tumor angiogenesis

BACKGROUND

The present study determines to correlate eosinophil, mast cell and microvessel densities with the histopathological grades and clinical staging of Oral Squamous Cell Carcinoma (OSCC) cases, as the potential role of inflammatory mediators within tumor stroma remains debatable.

METHODS

The study sample comprised 60 cases consisting of 40 cases of Well to moderately differentiated OSCC (group 1) and 20 cases of poorly differentiated OSCC (group 2). Immunohistochemistry with anti-CD15 antibody and antifactor VIII antibody; and toluidine blue special stain were employed for the detection of eosinophils, microvessels, and mast cells, respectively.

RESULTS

The mean numbers of eosinophils, mast cells, and microvessels per high power field in group 1 and group 2 were 15.37±11.86 and 12.62±14.30, 6.00±4.84 and 4.51±4.51, 13.96±6.25 and 6.62±2.05, respectively. Eosinophil density had a positive correlation with both mast cell and microvessel density. Also, the correlation of primary tumor size (T status) with microvessel density was found to be statistically significant (P≤0.05).

CONCLUSIONS

The cohesive interpretation of the aforementioned mediators in OSCC suggested that while these variables correlate well with the differentiation of tumor, the quantification did not correlate with the clinical staging of the disease.

Quantitative analysis of tumor-associated tissue eosinophils and tumor-associated blood eosinophils in oral squamous cell carcinoma

Background:

Stromal response to cancer is usually characterized by intense lymphoplasmacytic infiltrate. However, recently, the attention has shifted to tumor-associated tissue eosinophils (TATE). Tumor-associated blood eosinophils (TABE) are rare in solid cancers; however, carcinoma of the head and neck shows its prevalence.

Aim:

The aim of the study was to investigate the prevalence and relationship of tissue and blood eosinophils in various grades of oral cancer. The purpose of the article is to emphasize the possible clinical and biological significance of eosinophils in patients of oral squamous cell carcinoma (OSCC) so that appropriate therapeutic strategies can be devised accordingly.

Study Design:

Thirty histologically confirmed cases of oral squamous cell carcinoma were divided into well, moderate and poorly differentiated carcinoma. Eosinophilic infiltration in the tissue was graded as low, moderate and massive TATE. The number of eosinophils per 100 WBCs was taken as the differential eosinophil count. Blood eosinophilia (BE) >6% was considered to be TABE.

Materials and Methods:

Hematoxylin and eosin-stained tissue sections at 5 μ were evaluated. Prolonged staining in dilute 0.05% aqueous eosin demonstrated eosinophils selectively. Blood smears were stained by Leishman stain.

Statistical Analysis:

Student's t-test, Chi-square test, ANOVA, Newman–Keuls Multiple Comparison Test and Karl Pearson correlation coefficient® method were used.

Results:

The mean TATE value was highest in poorly differentiated carcinoma. TABE was seen only in a few cases and was associated mostly with poorly differentiated OSCC.

Conclusion:

There was a statistically significant correlation between TATE and histological grades of OSCC. Eosinophilia of the peripheral blood is an adverse sign in patients with carcinoma.

Eosinophils: An imperative histopathological prognostic indicator for oral squamous cell carcinoma

Background

Inflammation in tumor microenvironment assists in both promotion and growth of tumor. Tumor-associated tissue eosinophilia (TATE) is the term used when eosinophils are observed in a tumor tissue with inflammatory infiltrate. Although carcinogenesis with inflammation is one of the important hallmarks, the exact role of eosinophils remains unclear. Various studies on oral squamous cell carcinoma (OSCC) that focused on eosinophils reported both favorable and unfavorable prognosis in cancer tissue, because of which the exact function of eosinophils still remains uncertain.

Aims and Objectives

The present study aims at identifying the role of TATE in OSCC and in malignant transformation of oral epithelial dysplasia (OED).

Materials and Methods

The study includes 70 samples that divided into two groups, of which 50 histopathologically proven cases of different grades of OSCC and 20 cases of OED (oral leukoplakia). Congo red stain was used to stain the tissue sections. Each slide was viewed under high power in 10 consecutive microscopic fields for counting of eosinophils.

Results

Statistical analysis of values obtained was done using ANOVA, unpaired t-test and Mann-Whitney test. The results were statistically significant (P < 0.05) with a mean total eosinophil count of 2.12 in OED and 4.31 in OSCC.

Conclusion

The present study showed higher eosinophil counts in OSCC when compared to dysplasia which should prompt for a thorough evaluation of tumor front for invasiveness. Therefore, tissue eosinophil count may be used as an adjunct to predict the malignant transformation of dysplastic lesions to OSCC.

Prognostic Factors of Cervical Lymph Node Metastasis in Head and Neck Squamous Cell Carcinoma

Aims and background

The metastatic spread of squamous cell carcinoma of the head and neck (SCCHN) to the cervical lymph nodes is a negative prognostic factor in terms of survival. We have used multivariate analysis to identify the possible prognostic significance of a number of clinical and pathological characteristics in relation to possible involvement of the cervical lymph nodes in a series of 396 patients.

Method

396 patients with SCCHN were studied. Variables regarding the patient, the carcinoma and histology were analysed by multivariate analysis using BMDP's PLR programme.

Results

Some variables appear to represent predisposing factors for tumor spread to the lymph nodes: tumor site (supraglottic larynx: P=0.005; base of the tongue: P=0.02; hypopharynx: P=0.02), grading (P=0.001), and a number of histological parameters (lower degree of histological differentiation: P=0.001; vascular permeation: P=0.04; perineural invasion: P<0.05; prevalently plasmocytic infiltrate: P<0.05).

Conclusion

The identification of cases at risk for metastasis can be improved by the assessment of prognostic factors, with a consequent improvement in treatment strategies.

Intrapleural Administration of Interleukin-2 and Lak Cells in Locally Advanced Non-Small-Cell Lung Cancer. A Case Report

Aims and background

The systemic administration of recombinant interleukin-2 (rIL-2) and lymphokine-activated killer (LAK) cells is ineffective in non-small-cell lung cancer (NSCLC). However, there is some evidence that their intrapleural administration could be effective, since it increases the concentrations of the cytokine and the effector cells in the tumor area, thereby obtaining greater antitumor activity.

Study design

We report the case of a patient affected by a locally advanced lung adenocarcinoma with pleural effusion (T4 NO MO – stage 1Mb) treated with repetitive courses consisting of a priming continuous i.v. infusion (48 h) of rIL-2 (18 MIU/m2/day) intraplural administration of LAK cells (3 – 9 × 109/day), in a single daily bolus, for 3 consecutive days and concomitant administration of rlL-2 (1.8-7.2 × 106 IU/day), for 5 days.

Results

We observed early disappearance of neoplastic cells in the pleural effusion, progressive decrease until disappearance of the pleural effusion, cavitation of the primary lesion during the treatment, and its stabilization for 9 months until progression. Radiologic changes were accompanied by a marked eosinophilia (up to 50 × 109/L), and the intrapleural route of administration of rIL-2 induced a relevant increase in eosinophil count in peripheral blood. Immunologic changes in lymphocyte subpopulation phenotypes were also observed. The performance status of the patient improved, and she was still alive and eupnoic 25 months from the diagnosis and 23 months from the start of treatment.

Conclusions

This case suggests a therapeutic role for intrapleural rIL-2, and we believe that the relationship among intrapleural administration of rIL-2 and LAK cells, the development of peripheral eosinophilia, and clinical response should be further investigated.

The Impact of Peritumoral Retraction Clefting & Intratumoral Eosinophils on Overall Survival in Oral Squamous Carcinoma Patients

This retrospective study aimed to investigate the impact of peritumoral retraction clefts (RC) and tumor-associated tissue eosinophilia (TATE) as predictors of overall survival (OS) in oral squamous cell carcinoma (OSCC) patients. Their relationships with tumor-factors were also examined. Eighty-seven OSCC cases (pTNM: I + II/III + IV; 32/55), post-curative surgery, comprised the study cohort. Three observers independently estimated the percent RC semi-quantitatively in the selected tumor sections. Additionally, stromal eosinophils were counted in ten consecutive high-power fields of intratumoral and peritumoral regions to evaluate the corresponding TATE. The percent RC ranged between 0% -90% (Mean ± SD: 16 ± 24%; Median: 5%). The stromal eosinophils were greater in peritumoral as compared to intratumoral region. The events of death and tumor recurrence were reached in 16 (18.4%) and 36 (41%) cases respectively. The 3-years OS was 69% [Median OS: 1880 days; Mean follow up: 471(Range; 36-1880) days]. Increased percent RC exhibited relationship with pathologic stage (pTNM III&IV), primary tumor (pT III&IV), tumor depth > 4 mm and categorical tumor recurrence. Additionally, peritumoral eosinophilic infiltrates increased with increasing tumor depths and muscle invasion. Kaplan-Meier curves revealed significantly reduced OS in OSCC cases exhibiting: increased percent RC (>2.5%), mild -moderate/absent intratumoral TATE (versus intense TATE) or categorical tumor recurrence. In subsequent multivariate tests, all the three variables retained significance. Additionally, intraclass correlation coefficient demonstrated acceptable internal consistency for the observers who estimated percent RC. In conclusion, RC and intratumoral TATE proved to be independent predictors of OS in our OSCC cohort. Additionally, increased percent RC pointed towards aggressive tumor behaviour.

Emerging Roles for Eosinophils in the Tumor Microenvironment

Eosinophils are evolutionary conserved cells largely studied in the context of allergy. Although eosinophils were first described in tumors more than 120 years ago, their roles in cancer are often overlooked. This is puzzling given their potent immune modulatory, cytotoxic, and/or tissue repair capabilities, and recent studies demonstrating key roles for eosinophils in contexts far beyond their 'classical' field (e.g., metabolism, thermogenesis, and tissue regeneration). Recent data suggest that this frequently ignored cell is emerging as a potent immune effector and immune modulator in the tumor microenvironment. This review discusses the relevance of eosinophils to tumorigenesis and the potential to harness their function in cancer therapies.

Evaluation of myeloid cells (tumor-associated tissue eosinophils and mast cells) infiltration in different grades of oral squamous cell carcinoma

Background:

The multifunctional involvement and infiltration of myeloid cells (tumor-associated tissue eosinophils [TATE] and mast cells) can provide a unique opportunity to define relevant effectors functions that may represent novel, therapeutic options for modulation of tumor onset/growth.

Aim:

Our study aimed to evaluate infiltration of myeloid cells (TATE and Mast cells) infiltration in different grades (WHO grading) of oral squamous cell carcinoma (OSCC).

Materials and Methods:

Total 30 cases of OSCC were selected for this study. Hematoxylin and eosin stain and toluidine blue special stain, to evaluate TATE and the mast cells infiltration, were used. Three-year follow-up of OSCC cases was done.

Result:

Among 30 cases, 63.33% cases of OSCC showed TATE-positive and 36.66% cases showed TATE-negative. Regarding mast cells infiltration, 66.66% OSCC cases showed mast cells positive and 33.33% cases did not show significant mast cells infiltration. We found significant association of TATE and mast cells infiltration in OSCC cases. These myeloid cells infiltration significantly associated with age of patients but did not show any significant association with gender, site, and habit of cases. When we compared these cells infiltration with clinical stages and different histological grades of tumor, we found their infiltration is decreasing, from Stages 1 to Stage 3 of tumor and from well to poorly differentiated carcinoma. We have also found the less infiltration of these myeloid in recurrence cases of OSCC.

Conclusion:

As the infiltration of TATE and mast cells are correlated, along with evaluation of TATE, we should also evaluate the presence of mast cells infiltration in OSCC. The assessment of myeloid cells could become, in the future, useful for therapeutic approaches in this subset of the patient.

Tumour-Associated Tissue Eosinophilia in Oral Squamous Cell Carcinoma- A Boon or a Bane?

INTRODUCTION

The infiltration of tumour stroma by eosinophils, Tumour-Associated Tissue Eosinophilia (TATE) is known to modulate the evolution of Oral Squamous Cell Carcinoma (OSCC). Identification of eosinophils in the inflammatory stroma has been proven to be an important factor in prognostication of malignant tumours including cancers of mouth, oesophagus, larynx, pharynx, breast, lung, intestine and genitourinary tract.

AIM

Our study aimed to assess the role of TATE as a prognosticator in OSCC as visualized by Haematoxylin and Eosin (H&E) and congo red staining.

MATERIALS AND METHODS

Thirty histologically-proven cases of OSCC were retrieved from the archives of Department of Oral Pathology, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka, India. Two serial sections of 4μm thickness were made and subjected to routine staining with H&E and modified congo red staining, where eosinophil granules stained red and nuclei stained blue. In 40x magnification, 10 HPF at invasive tumour front were assessed for counting eosinophils by placing a 49 square grid (measuring 0.0289 sq mm).

STATISTICAL ANALYSIS

The TATE was compared with the prognosticators using Mann-Whitney U-test. The grades of carcinoma were correlated with TATE using Kruskal-Wallis test followed by Post-hoc Bonferronis correction. Agreement of the number of eosinophils counted in the two staining techniques (H&E and Congo red) in OSCC was achieved using interclass correlation coefficient, and Friedman's test. A value of p< 0.05 was considered statistically significant.

RESULTS

Our results showed that tissue eosinophil counts were higher in well-differentiated cases of OSCC, cases with lymph node involvement, decreased survival, without margin involvement and in cases that did not recur. H&E stain showed significantly better visualization of eosinophils resulting in higher eosinophil counts than when seen with Congo red (p=0.008).

CONCLUSION

Thus, TATE can be used as a surrogate marker in prediction of survival and recurrence in OSCC. H&E proved to be a better stain for evaluation of eosinophils.

Eosinophils in Colorectal Neoplasms Associated with Expression of CCL11 and CCL24

Background:

A decrease in the number of tissue eosinophils is known to reflect the malignancy potential of neoplastic lesions and even prognosis. Increased levels of the chemokines CCL11 and CCL24 in serum and tissue are also known to have diagnostic value as serum tumor markers or prognostic factors. The aim of this study was to evaluate the correlation between the degree of tissue eosinophilia and the expression of these chemokines in the glandular and stromal cells of colorectal neoplastic lesions ranging from benign to malignant tumors.

Methods:

We counted the number of infiltrating eosinophils in neoplastic lesion tissue and we evaluated the expression of CCL11 and CCL24 in glandular cells and stromal cells by immunohistochemical staining.

Results:

The results showed that the number of eosinophils decreased significantly and the expression of CCL11 and CCL24 in glandular cells decreased with tumor progression, whereas the stromal expression of CCL11 and CCL24 appeared to increase.

Conclusions:

The discrepancy in CCL11 and CCL24 expression between glandular cells and stromal cells might shed light on how colorectal cancer evades the immune system, which would enable further development of immunotherapies that target these chemokines. Further research on eosinophil biology and the expression pattern of chemokines in tumor cells is needed.

Quantitative Evaluation of Tumour--Associated Tissue Eosinophilia and Cyclo-oxegenase-2 Gene in Oral Cancer Patients with Assessment of Long Term Outcomes

Various histopathological parameters have been extensively studied for prognostication of oral cancer but the focus is now getting diverted towards the role of inflammatory mediators in cancer progression. The present study was undertaken to evaluate two such components of the inflammatory milieu, tumor-associated tissue eosinophilia (TATE) as well as Cyclo-oxygenase-2 (COX-2) gene expression, quantitatively in oral squamous cell carcinoma (OSCC) patients in relation to treatment outcomes and patterns of recurrence. A total of forty five patients with primary OSCC matching our inclusion criteria were selected for the study and followed up over a five year period. TATE was evaluated from the invasive front of the tumor using Haematoxylin and eosin (H & E) stained sections of histopathological specimens and graded as mild, moderate or intense. COX-2 gene expression was obtained from specimens using the reverse transcriptase--polymerase chain reaction (RT-PCR) method. A statistically significant association was observed between degree of TATE and locoregional recurrence (P < 0.001). The expression of COX-2 gene ranged from 0.4326 to 0.9998 and a higher mean COX-2 score was recorded in samples with intense degree of TATE followed by moderate and mild TATE. (P < 0.001). Using the t-test, the difference in mean COX-2 was found to be statistically significant (P < 0.001) between patients who developed locoregional recurrence and those who did not. The analysis of TATE may provide an indication of future recurrence at the time of diagnosis of OSCC. Also, the increased expression of COX-2 gene in OSCC strongly suggests its possible use as a chemopreventive/chemotherapeutic target.

Tumour associated tissue eosinophilia as a predictor of locoregional recurrence in oral squamous cell carcinoma

Objectives: The increasing global burden of oral cancer has driven much of the focus of research to the determination of reliable prognostic markers which may have significant effects on survival and the control of post-treatment morbidity. This study was undertaken to evaluate tumour associated tissue eosinophilia (TATE) quantitatively in oral cancer specimens and observe for its possible association with tumour stage, patterns of locoregional recurrence and overall prognosis. Study Design: 14 patients undergoing surgical resection for primary oral squamous cell carcinoma (OSCC) were subjected to grey scale ultrasonography (USG) to assess tumour dimensions. The findings were compared with the cTNM stage initially documented. TATE was evaluated along the invasive tumour front (ITF) using H & E stained sections of histopathological specimens for 10 continuous high power fields (HPF) and graded as mild, moderate or intense. Patients were followed up over 5 years and observed for patterns of recurrence. Results: Loco regional recurrence was significantly associated with intense degree of TATE. (p<0.001) cTNM stage as well as USG stage did not correlate with the degree of TATE with p=0.419 and 0.772 respectively. None of the patients with mild/ moderate dysplasia developed locoregional recurrence within the period of follow up. Conclusions: Analysis of TATE in OSCC patients may provide an early indication of future locoregional recurrence. Identification of an appropriate biopsy site representing the ITF where TATE analysis can be performed may be a simple, inexpensive method of obtaining valuable prognostic information at the time of diagnosis.

Key words:Tumour associated tissue eosinophilia, oral cancer, prognosis.

Eosinophil cytokines, chemokines, and growth factors: emerging roles in immunity

Eosinophils derive from the bone marrow and circulate at low levels in the blood in healthy individuals. These granulated cells preferentially leave the circulation and marginate to tissues, where they are implicated in the regulation of innate and adaptive immunity. In diseases such as allergic inflammation, eosinophil numbers escalate markedly in the blood and tissues where inflammatory foci are located. Eosinophils possess a range of immunomodulatory factors that are released upon cell activation, including over 35 cytokines, growth factors, and chemokines. Unlike T and B cells, eosinophils can rapidly release cytokines within minutes in response to stimulation. While some cytokines are stored as pre-formed mediators in crystalloid granules and secretory vesicles, eosinophils are also capable of undergoing de novo synthesis and secretion of these immunological factors. Some of the molecular mechanisms that coordinate the final steps of cytokine secretion are hypothesized to involve binding of membrane fusion complexes comprised of soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs). These intracellular receptors regulate the release of granules and vesicles containing a range of secreted proteins, among which are cytokines and chemokines. Emerging evidence from both human and animal model-based research has suggested an active participation of eosinophils in several physiological/pathological processes such as immunomodulation and tissue remodeling. The observed eosinophil effector functions in health and disease implicate eosinophil cytokine secretion as a fundamental immunoregulatory process. The focus of this review is to describe the cytokines, growth factors, and chemokines that are elaborated by eosinophils, and to illustrate some of the intracellular events leading to the release of eosinophil-derived cytokines.

Eosinophil Infiltrates in Pilocytic Astrocytomas of Children and Young Adults

Objective

Eosinophils may affect each stage of tumour development. Many studies have suggested that tumour-associated tissue eosinophilia (TATE) is associated with favourable prognosis in some malignant tumours. However, only a few studies exist on TATE in central nervous system (CNS) tumours. Our recent study exhibited eosinophils in atypical teratoid/rhabdoid tumours (AT/RTs), pediatric malignant CNS tumours with divergent differentiation. This study examines eosinophils in pilocytic astrocytomas (PAs).

Methods

The study included 44 consecutive cases of patients with PAs and no concurrent CNS inflammatory disease.

Results

We found eosinophils in 19 (43%) of 44 PAs (patient age range, 0.5-72 years). Eosinophils were intratumoural and clearly distinguishable. The density of eosinophils was rare to focally scattered. PAs containing eosinophils were located throughout the CNS. Furthermore, eosinophilic infiltration was identified in 18 (62%) of 29 pediatric (age range, 0.5-18 years) PAs but only 1 (7%) of 15 (p<0.001, significantly less) adult (age range, 20-72 years) PAs. Eosinophilic infiltration showed no significant differences between PAs with and without MRI cystic formation, surgical procedures, or PAs with and without leptomeningeal infiltration. In comparison, eosinophils were absent in 10 pediatric (age range, 0.5-15 years) ependymomas (or anaplastic ependymomas).

Conclusions

These results suggest that eosinophils are common in pediatric PAs but rare in adult PAs. This difference is probably related to the developing immune system and different tumour-specific antigens in children. TATE may play a functional role in the development of pediatric PAs, as well as some other pediatric CNS tumours such as AT/RTs.

Assessment of tissue eosinophilia as a prognosticator in oral epithelial dysplasia and oral squamous cell carcinoma-an image analysis study

Association of tissue eosinophilia with oral squamous cell carcinoma has shown variable results ranging from favourable to unfavourable or even having no influence on prognosis. Also, very few studies have been done to know the role of eosinophils in premalignancy. So the present study investigated role of eosinophilic infiltration in oral precancer and cancer and its possible use as a prognosticator. 60 histopathologically proven cases (20 cases each of metastatic and nonmetastatic oral squamous cell carcinoma and oral leukoplakia with dysplasia of various grades) were included. Congo red is used as a special stain for eosinophils. Each specimen slide was viewed under high power in 10 consecutive microscopic fields for counting of eosinophils. As a result, a significant increase in eosinophil count was found in oral carcinomas compared to dysplasia. Nonmetastatic cases showed higher counts than metastatic carcinomas. So, it is concluded that eosinophilia is a favourable histopathological prognostic factor in oral cancer. Moreover, higher eosinophil counts in carcinoma group compared to dysplasia group proved that they might have a role in stromal invasion thus suggesting that quantitative assessment of tissue eosinophilia should become a part of the routine histopathological diagnosis for oral precancer and OSCC.

Antiallergic effect of anti-Siglec-F through reduction of eosinophilic inflammation in murine allergic rhinitis

BACKGROUND

Sialic acid-binding Ig-like lectin-F (Siglec-F) in mice and its functional paralog Siglec-8 in humans are transmembrane receptors that play a role in the apoptosis of eosinophils. We aimed to evaluate the therapeutic potential of anti-Siglec-F antibodies in a murine model of allergic rhinitis.

METHODS

Twenty-eight BALB/c mice were used. In group A (control group, n = 7), mice were sensitized and challenged with saline. In group B (ovalbumin [OVA] challenge group, n = 7), OVA was used for i.p. sensitization and intranasal challenge. Mice in group C (control IgG group, n = 7) or those in group D (anti-Siglec-F group, n = 7) had been given rabbit control IgG or anti-Siglec-F antibody injections, respectively. We assessed the number of nose-scratching events; serum total/OVA-specific IgE; the number of eosinophils, neutrophils, and lymphocytes in bronchoalveolar lavage (BAL) fluid; histopathological changes in nasal cavity tissues; and the levels of IL-4, IL-5, and IL-13 in BAL fluid.

RESULTS

Mice in group D had significantly less nose scratching. Serum total and OVA-specific IgE were not significantly changed. The number of eosinophils in BAL fluid and in the lamina propria of the nasal cavity mucosa was significantly decreased with anti-Siglec-F antibody treatment. The levels of Th2 cytokines such as IL-4, IL-5, and IL-13 were also significantly decreased with anti-Siglec-F antibody treatment.

CONCLUSION

Anti-Siglec-F antibody has beneficial effects in a mouse model of experimental allergic rhinitis.

Sipuleucel-T (Provenge) autologous vaccine approved for treatment of men with asymptomatic or minimally symptomatic castrate-resistant metastatic prostate cancer

Sipuleucel-T (Provenge) (Sip-T) is first -in class as a therapeutic autologous vaccine approved for the treatment of men with asymptomatic or minimally symptomatic castrate-resistant metastatic prostate cancer. This product is the culmination of decades of basic immunological and prostate cancer investigations and 13 y of clinical trial investigations. Sip-T represents a paradigm shift in cancer therapeutics and represents the first approved autologous therapeutic cancer vaccine, which has demonstrated a survival benefit. The potential benefit of this product is the excellent risk to benefit ratio, which will allow for the combination of this approach with other more toxic therapies. The favorable risk to benefit will also afford the opportunity for trials investigating this product earlier in the disease state and in combination with local therapies. The ability to target more localized or lower volume disease will maximize the therapeutic benefit over a longer period of time. The novelty of the platform of this approach could be used to treat any cancer with a tumor-specific cell surface target. The main product of Sip-T is the re-infusion of a patient's antigen presenting cells from leukapheresis after ex-vivo exposure to a chimeric protein of human GM-CSF and PAP. In metastatic CRPC patients three infusions of these activated cells over a month lead to statistically significant 4.1 mo increase in median survival and a 22.5% reduction in risk of death. The main side effect from this re-infusion of activated immune cells is a "flu-like" syndrome that includes chills, fatigue, fevers, back pain, nausea, joints aches and headaches in decreasing order of frequency. Immune monitoring during the clinical trials also demonstrated a specific cellular and antibody immune response, suggesting the proposed mechanism of adoptive immunotherapy to PAP was behind this survival benefit. This product also serves as a proof of principle for targeted immunotherapy for others cancers with defined cell surface markers. In summary, the approval of Sip-T based on a survival benefit and very tolerable safety profile will 1) enhance our ability to care for men with advanced prostate cancer, 2) allow for further investigations of this approach in combination with others therapies with different mechanisms of action and non-overlapping toxicities, and 3) allow further investigations earlier in the course of the disease.

Therapeutic strategies for harnessing human eosinophils in allergic inflammation, hypereosinophilic disorders, and cancer

The eosinophil is a multifunctional granulocyte best known for providing host defense against parasites. Paradoxically, eosinophils are also implicated in the pathogenesis of allergic inflammation, asthma, and hypereosinophilic syndromes. Emerging evidence also supports the potential for harnessing the cytotoxic power of eosinophils and redirecting it to kill solid tumors. Central to eosinophil physiology is interleukin-5 (IL-5) and its receptor (IL-5R) which is composed of a ligand-specific alpha chain (IL-5Rα) and the common beta chain (βc). Eosinophil activation can lead to their degranulation, resulting in rapid release of an arsenal of tissue-destructive proinflammatory mediators and cytotoxic proteins that can be both beneficial and detrimental to the host. This review discusses eosinophil immunobiology and therapeutic strategies for targeting of IL-5 and IL-5R, as well as the potential for harnessing eosinophil cytotoxicity as a tumoricide.

Analysis of inflammatory infiltrate, perineural invasion, and risk score can indicate concurrent metastasis in squamous cell carcinoma of the tongue

PURPOSE

In this retrospective study, the aim was to compare individual histopathologic parameters of malignancy between nonmetastatic and metastatic squamous cell carcinoma of the tongue.

MATERIALS AND METHODS

Sixty-two cases of squamous cell carcinoma of the tongue were selected and examined according to the system established by Brandwein-Gensler et al (Am J Surg Pathol 29:167, 2005) and included the pattern of invasion (most to least favorable), lymphocytic infiltration, perineural invasion, risk score, keratinization, eosinophilia, perivascular invasion, and tumor thickness.

RESULTS

The least favorable pattern had no association with nodal metastasis (P > .05). The scarcity or density of the lymphocytic infiltration, perineural invasion, and a risk score ≥ 3 were associated with nodal metastasis (P < .05). Keratinization, eosinophilia, perivascular invasion, and tumor thickness had no association with nodal metastasis (P > .05). A significant positive correlation was found between the pattern of invasion and perineural invasion and between the pattern of invasion and tumor thickness (P < .05).

CONCLUSIONS

The scarcity or density of the lymphocytic infiltration, perineural invasion, and histopathologic risk score may be helpful as parameters of histologic malignancy for the evaluation of metastatic and nonmetastatic squamous cell carcinoma of the tongue.

Immune suppression in head and neck cancers: a review

Head and neck squamous cell carcinomas (HNSCCs) are the sixth most common cancer in the world. Despite significant advances in the treatment modalities involving surgery, radiotherapy, and concomitant chemoradiotherapy, the 5-year survival rate remained below 50% for the past 30 years. The worse prognosis of these cancers must certainly be link to the fact that HNSCCs strongly influence the host immune system. We present a critical review of our understanding of the HNSCC escape to the antitumor immune response such as a downregulation of HLA class I and/or components of APM. Antitumor responses of HNSCC patients are compromised in the presence of functional defects or apoptosis of T-cells, both circulating and tumor-infiltrating. Langerhans cells are increased in the first steps of the carcinogenesis but decreased in invasive carcinomas. The accumulation of macrophages in the peritumoral areas seems to play a protumoral role by secreting VEGF and stimulating the neoangiogenesis.

The role of eosinophils and eosinophil cationic protein in oral cancer: a review

Eosinophils are multifunctional leukocytes implicated in the pathogenesis of numerous inflammatory processes, such as allergies and parasitic infections. Increased number of these cells has been described in many human cancers, including oral squamous cell carcinoma, and its presence related to favourable as well as unfavourable prognosis. Although the exact role of eosinophils in tumours is not yet defined, the anti-tumour activity of these rare granulocytes has been associated with the release of their cytotoxic proteins, especially the eosinophil cationic protein, a single polypeptide chain with a molecular mass ranging from 15 to 22kDa encoded by the RNSE3 gene located on chromosome 14q11.2. Functional studies have implicated ECP in numerous processes, such as tissue remodelling in allergic inflammation; however its most striking function is the cytotoxic activity. The aim of this review is to summarise the role and functions of eosinophils and their granule-derived products in oral malignant tumours and the clinical value of the tumour-associated tissue eosinophilia for patients' prognosis.

Human eosinophils exert TNF-α and granzyme A-mediated tumoricidal activity toward colon carcinoma cells

Peripheral blood and tissue eosinophilia is a prominent feature in allergic diseases and helminth infections. In cancer patients, tumor-associated tissue eosinophilia is frequently observed. Tumor-associated tissue eosinophilia can be associated with a favorable prognosis, notably in colorectal carcinoma. However, underlying mechanisms of eosinophil contribution to antitumor responses are poorly understood. We have in this study investigated the direct interactions of human eosinophils with Colo-205, a colorectal carcinoma cell line, and show that eosinophils induce apoptosis and directly kill tumor cells. Using blocking Abs, we found that CD11a/CD18 complex is involved in the tumoricidal activity. Coculture of eosinophils with Colo-205 led to the release of eosinophil cationic protein and eosinophil-derived neurotoxin as well as TNF-α secretion. Moreover, eosinophils expressed granzyme A, which was released upon interaction with Colo-205, whereas cytotoxicity was partially inhibited by FUT-175, an inhibitor of trypsin-like enzymatic activity. Our data present the first demonstration, to our knowledge, that granzyme A is a cytotoxic mediator of the eosinophil protein arsenal, exerting eosinophil tumoricidal activity toward Colo-205, and provide mechanistic evidence for innate responses of eosinophil against tumor cells.

Eosinophils and oral squamous cell carcinoma: a short review

The eosinophil cell has been related as a prognostic indicator for cancers. However, its exact function in tumour behaviour is still not clearly defined. In the oral cavity the presence of eosinophils can be a favourable prognostic indicator as well as it may be associated with a poor prognosis. In this short review, we briefly summarize the role of the eosinophils in the general context of immunoregulation and its relation to oral squamous cell carcinoma.

Rejection of intradermally injected syngeneic tumor cells from mice by specific elimination of tumor-associated macrophages with liposome-encapsulated dichloromethylene diphosphonate, followed by induction of CD11b(+)/CCR3(-)/Gr-1(-) cells cytotoxic against the tumor cells

Tumor cell expansion relies on nutrient supply, and oxygen limitation is central in controlling neovascularization and tumor spread. Monocytes infiltrate into tumors from the circulation along defined chemotactic gradients, differentiate into tumor-associated macrophages (TAMs), and then accumulate in the hypoxic areas. Elevated TAM density in some regions or overall TAM numbers are correlated with increased tumor angiogenesis and a reduced host survival in the case of various types of tumors. To evaluate the role of TAMs in tumor growth, we here specifically eliminated TAMs by in vivo application of dichloromethylene diphosphonate (DMDP)-containing liposomes to mice bearing various types of tumors (e.g., B16 melanoma, KLN205 squamous cell carcinoma, and 3LL Lewis lung cancer), all of which grew in the dermis of syngeneic mouse skin. When DMDP-liposomes were injected into four spots to surround the tumor on day 0 or 5 after tumor injection and every third day thereafter, both the induction of TAMs and the tumor growth were suppressed in a dose-dependent and injection number-dependent manner; and unexpectedly, the tumor cells were rejected by 12 injections of three times-diluted DMDP-liposomes. The absence of TAMs in turn induced the invasion of inflammatory cells into or around the tumors; and the major population of effector cells cytotoxic against the target tumor cells were CD11b(+) monocytic macrophages, but not CCR3(+) eosinophils or Gr-1(+) neutrophils. These results indicate that both the absence of TAMs and invasion of CD11b(+) monocytic macrophages resulted in the tumor rejection.

Prognostic significance of stromal eosinophilic infiltration in oral squamous cell carcinoma

Tumor-associated tissue eosinophilia (TATE) has been described in many sites, including head and neck. The aim of this study was to investigate the prevalence and possible role of TATE as a prognostic factor in oral squamous cell carcinoma (OSCC). Seventy-six consecutive patients with a diagnosis of OSCC were evaluated, and the number of eosinophils was obtained in 3 different areas in the tumor. The possible role of TATE as a prognostic factor in OSCC was investigated with respect to tumor differentiation; perineural, vascular, and muscular invasion (histopathologic parameters); and locoregional metastasis (clinical parameter). Tumor-associated tissue eosinophilia was low in most cases in 3 different areas. The mean eosinophil count was higher in the invasive front of tumor than intratumoral stroma and stroma subjacent the surface epithelium. The relations between TATE and tumor differentiation; perineural, vascular, and muscular invasion; and locoregional metastasis were not statistically significant (P > 0.05). Tumor-associated tissue eosinophilia has no correlation with prognostic parameters in OSCC.

Head and neck tumour immunology: basic concepts and new clinical implications

An understanding of the immune system and its modes of action is fundamental to understanding the causes, natural history, management and treatment of many diseases. As such, a grasp of the principles of immunology is essential for every physician.

This paper represents a succinct overview of the immune system, discussing the major components in turn, in respect of structure, function and integrated organisation, in relation to head and neck cancer.

Eosinophil-rich squamous carcinoma of the oral cavity: a study of 13 cases and delineation of a possible new microscopic entity

We report 13 cases of squamous cell carcinoma (SCC) of the oral cavity characterized by a prominent eosinophilic infiltration of the stroma. All patients were adults, 10 men and 3 women (aged 54 to 92 years; median, 71 years). They presented with tumors of the gingiva (5 cases), tongue (3 cases), palatine tonsil (2 cases), palate (2 cases), and mucosal aspect of lip (1 case). Metastatic involvement of regional lymph nodes was seen in 5 cases. The metastatic foci were associated with heavy eosinophilia as well. No patient had an abnormal eosinophil count in blood. Microscopically, the clusters of eosinophils were characteristically noticed in intimate admixture with the advancing edge of squamous carcinoma, either as nests or small tumor cords. The pattern of eosinophilic infiltration was comparable, regardless of tumor site or grade. Data from our series indicate that SCC with a reactive inflammatory infiltrate rich in eosinophils is consistently associated with stromal invasion. This observation may be useful in dealing with small tissue fragments where subepithelial stromal invasion cannot be easily assessed by conventional criteria. In addition, our data seem to confirm that eosinophil-rich SCC, although associated with metastatic involvement of cervical lymph node, seems to pursue a less aggressive course if compared with ordinary SCC.

The Potential Role of Innate Immunity in the Pathogenesis of Hodgkin's Lymphoma

The innate immune system is our first line of defense against danger signals but in Hodgkin's lymphoma the role seems opposite, favoring malignant development. In this article we describe interactions between Hodgkin's and Reed-Sternberg cells and the cells of the innate immune system: eosinophils, mast cells, neutrophils, and macrophages. These cells clearly contribute to the pathogenesis of this disease and to the prognosis. Cytokines and chemokines released from the activated immune cells probably promote tumor cell growth and survival along with angiogenesis. Mast cells and eosinophils seem also to contribute to the fibrosis that is so characteristic for nodular sclerosis.

Th2-mediated anti-tumour immunity: friend or foe?

The concept that the immune system can recognise tumour cells and either eliminate them (tumour immune surveillance) or select for immunologically resistant variants (immunoediting) is gaining general acceptance by immunologists. In terms of an adaptive immune response to cancer, however, much of the research has focused on the response of cytotoxic CD8+ T lymphocytes to tumour-specific antigens and the production of Th1 cytokines by CD4+ and CD8+ T cells. In contrast, Th2-mediated immunity has traditionally been viewed as favouring tumour growth, both by promoting angiogenesis and by inhibiting cell-mediated immunity and subsequent tumour cell killing. While there is evidence that components of type 2 inflammation, such as B cells and interleukin-10, do promote tumour growth, there are also many studies demonstrating the anti-tumour activity of CD4+ Th2 cells, particularly in collaboration with tumour-infiltrating granulocytes, such as eosinophils. In this review, we examine all the components of type 2 immunity and their effects on tumour growth. Collectively, from this analysis, we conclude that there is a great potential for the development of Th2-mediated immunotherapies that harness the cytotoxic activity of eosinophils.

Recent advances in eosinophil biology

Eosinophils are pleiotropic multi-functional leukocytes involved in initiation and propagation of diverse inflammatory responses. Recent studies examining eosinophil biology have focused on delineating the molecular basis of FIP1L1/PDGRFalpha-fusion gene induced HES, the molecular steps involved in eosinophil recruitment in tumor-associated eosinophilia and EGID, and the role of eosinophils in asthma. In this review, these studies are summarized, focusing on the implications of these findings in the understanding the role of eosinophils in diseases.

Eosinophilic granulocytes and damage-associated molecular pattern molecules (DAMPs): role in the inflammatory response within tumors

The development of a tumor over many years typically leads to reciprocal alternations in the host and the tumor, enabling tumor growth paradoxically in the setting of substantial necrosis and inflammation. When evaluating a tumor, it is important to assess 3 elements: (1) the quantity and quality of tumor-associated leukocytes, (2) their state of activation, and (3) tumor microenvironment. Peripheral blood eosinophilia and tumor-associated tissue eosinophilia are frequently associated with some tumor types and also found after immunotherapy with IL-2, IL-4, granulocyte-macrophage colony-stimulating factor, and antibody to CTLA-4. Within several tumor types including gastrointestinal tumors, tumor-associated tissue eosinophilia is associated with a significantly better prognosis. The converse is true in other tumor types such as differentiated oral squamous cell carcinoma. On the basis of the emergent data, tumor-associated eosinophils have at least 2 dominant nonoverlapping activities: (1) destructive effector functions potentially limiting tumor growth as well as causing recruitment and activation of other leukocytes, (2) immunoregulative and remodeling activities which suppress immune response and promote tumor proliferation. The mechanism by which eosinophils in particular are recruited into tumor tissue is largely unknown. Candidates for causing eosinophil chemotaxis into tumor tissue are the released damage-associated molecular pattern molecules (DAMPs) including the nuclear protein high mobility group box 1. High mobility group box 1 is released upon necrotic cell death and secreted by many cells, particularly during periods of nutrient, hypoxic, or oxidant stress. This overview on eosinophil biology in the context of cancer and necrosis, introduces intriguing and novel strategies targeting eosinophils to enable more effective biologic therapy for cancer patients.

Significance of neo-angiogenesis and immuno-surveillance cells in squamous cell carcinoma of the tongue

Background

Neo-angiogenesis is an essential process in physiological and pathological conditions. However, it is a complex process. Several studies demonstrated that intra-tumoural microvessel number is a significant predictor of metastasis and clinical outcome in many tumours, including oral malignancies. The immuno-surveillance cells, mast cells and eosinophils are implicated in the biological behaviour of tumours. Nevertheless, their function in tissues is uncertain. Mast cells are involved in homeostatic regulation of blood vessels as well as host defence. In some malignancies, high mast cell density has been found to correlate with favourable prognosis. However, others reported unfavourable associations. Tumour associated tissue eosinophilia is a well-known phenomena. It has been associated with good and poor prognosis. However, the role of eosinophils in tumours remains controversial. Therefore, this study was designed to investigate the prognostic value of microvessel, mast cell and eosinophil densities in the context of clinico-pathological parameters and survival in squamous cell carcinoma of the tongue.

Materials and Methods

Anti-CD105 and anti-tryptase monoclonal antibodies were utilized to highlight and count microvessels and mast cells respectively in 81 cases of tongue squamous cell carcinoma. Eosinophils were demonstrated using carbol chromotrope histochemical stain. The densities were counted per mm2 and correlated with patients’ outcome and other clinico-pathological parameters using non-parametric tests and student's t-test. Clinically, the cases were divided into 4 main groups depending on survival time, lymph-node or distant metastasis.

Results

The 5 year survival was significantly lower in patients with a low mast cell density than those with a high density (p=0.006, Kruskal-Wallis test). The survival group-A demonstrated significantly higher mast cell and microvessel numbers than group-D (p=0.007, student's t-test) respectively. Patients with well- differentiated squamous cell carcinoma had significantly higher numbers of mast cells when compared to patients with poorly differentiated squamous cell carcinoma (p<0.05, student's t-test). The lymph node involvement correlation between the survival group-A and survival group-D was also significant (p=0.001, Mann-Whitney U test).

Conclusion

Data from this study indicates that accumulating mast cells in tumours play a part in inhibiting tumour progression and is potentially angiogenic in tumours.

Pivotal Advance: eosinophil infiltration of solid tumors is an early and persistent inflammatory host response

Tumor-associated eosinophilia has been observed in numerous human cancers and several tumor models in animals; however, the details surrounding this eosinophilia remain largely undefined and anecdotal. We used a B16-F10 melanoma cell injection model to demonstrate that eosinophil infiltration of tumors occurred from the earliest palpable stages with significant accumulations only in the necrotic and capsule regions. Furthermore, the presence of diffuse extracellular matrix staining for eosinophil major basic protein was restricted to the necrotic areas of tumors, indicating that eosinophil degranulation was limited to this region. Antibody-mediated depletion of CD4+ T cells and adoptive transfer of eosinophils suggested, respectively, that the accumulation of eosinophils is not associated with T helper cell type 2-dependent immune responses and that recruitment is a dynamic, ongoing process, occurring throughout tumor growth. Ex vivo migration studies have identified what appears to be a novel chemotactic factor(s) released by stressed/dying melanoma cells, suggesting that the accumulation of eosinophils in tumors occurs, in part, through a unique mechanism dependent on a signal(s) released from areas of necrosis. Collectively, these studies demonstrate that the infiltration of tumors by eosinophils is an early and persistent response that is spatial-restricted. It is more important that these data also show that the mechanism(s) that elicit this host response occur, independent of immune surveillance, suggesting that eosinophils are part of an early inflammatory reaction at the site of tumorigenesis.

Tissue Eosinophilic Infiltration

The assessment of stromal invasion in aerodigestive neoplastic squamous proliferation often poses diagnostic and therapeutic challenges. Eosinophilic infiltration is thought to be an adjunctive histologic criterion in determining tumor aggressiveness and invasion. We investigated whether an eosinophilic infiltration in head and neck squamous cell carcinoma measured in biopsies would aid in predicting tumor invasion, response to treatment, locoregional recurrence, and survival.

METHODS

Eighty-seven patients with in situ and invasive squamous cell carcinoma of the head and neck region were evaluated and treated according to their staging. The number of eosinophils per high-power field (eosinophil/HPF), and per 10 high-power fields (eosinophil/10 HPF) at the tumor interface and in tumor tissue, was counted and classified as focally or diffusely present. Each sample was assigned an eosinophilic index of 1-4 based on the number of eosinophils/HPF or 10 HPF. Of 87 patients, 20 patients were followed up after appropriate treatment for locoregional recurrence, distant metastasis, and disease-free survival.

RESULTS

Eosinophilic counts were elevated focally and/or diffusely more frequently in invasive squamous cell carcinoma than in noninvasive tumors. The increased eosinophilic counts, specifically > 10/HPF and > 20/10 HPF, were both significantly associated with stromal invasion. Greater than 10 eosinophils/HPF and/or > 20 eosinophils/10 HPF had the highest predictive power for invasion, with sensitivity, specificity, and positive predictive values of 66%, 94%, 96% and 61%, 100%, and 100%, respectively. Eosinophilic counts greater than 20 eosinophils/10 HPF and eosinophilic indices > 2 were virtually diagnostic for tumor invasion. Patients' biopsies with eosinophilic indices < 2 had a better survival (P = 0.0156). Using Cox regression analysis, we found that most patients' biopsies that had eosinophilic indices > 2 recurred locally or regionally.

CONCLUSIONS

The elevated eosinophilic counts in biopsies and eosinophilic indices in specimens of squamous cell carcinoma of the aerodigestive tract are a histopathologic marker associated with tumor invasion and a clinical predictor for aggressive tumor biology. Similarly, the presence of eosinophils meeting these thresholds in an excisional specimen should indicate the need for additional therapeutic measures and close surveillance to detect earlier locoregional recurrence and possible distant metastasis.

Prognostic significance of Langerhans cell infiltration in cancer of the larynx

OBJECTIVE

Determine the effect on prognosis of Langerhans cell infiltration in cancer of the larynx.

STUDY DESIGN AND SETTING

Retrospective review of 72 surgically treated patients with T1-3 lesions. The streptavidin-biotin method to determine Langerhans cell infiltration, which was graded as 1+, 2+, and 3+.

RESULTS

A higher degree of Langerhans cell infiltration was significantly associated with less cervical lymph node metastasis, longer disease-free survival, less locoregional recurrence, and less clinical N-positivity ( P < 0.05). According to multivariant analysis, Langerhans cell infiltration was independently related to disease-free survival and recurrence ( P < 0.05).

CONCLUSIONS

Langerhans cell infiltration is prognostically important in cancer of the larynx. More intense infiltration is significantly related to prolonged disease-free survival, less locoregional recurrence, less cervical lymph node metastasis, and less clinical N-positivity.

SIGNIFICANCE

Langerhans cell infiltration may be determined on a biopsy specimen and this information may be useful in deciding about elective neck dissection. Patients with mild infiltration may have a higher risk of locoregional recurrence, shorter disease-free survival, and therefore they suggest a poor prognosis.

Tissue eosinophilia: a morphologic marker for assessing stromal invasion in laryngeal squamous neoplasms

Background

The assessment of tumor invasion of underlying benign stroma in neoplastic squamous proliferation of the larynx may pose a diagnostic challenge, particularly in small biopsy specimens that are frequently tangentially sectioned. We studied whether thresholds of an eosinophilic response to laryngeal squamous neoplasms provides an adjunctive histologic criterion for determining the presence of invasion.

Methods

Eighty-seven(n = 87) cases of invasive squamous cell carcinoma and preinvasive squamous neoplasia were evaluated. In each case, the number of eosinophils per high power field(eosinophils/hpf), and per 10 hpf in the tissue adjacent to the neoplastic epithelium, were counted and tabulated. For statistical purposes, the elevated eosinophils were defined and categorized as: focally and moderately elevated (5–9 eos/hpf), focally and markedly increased(>10/hpf), diffusely and moderately elevated(5–19 eos/10hpf), and diffusely and markedly increased (>20/10hpf).

Results

In the invasive carcinoma, eosinophil counts were elevated focally and /or diffusely, more frequently seen than in non-invasive neoplastic lesions. The increased eosinophil counts, specifically >10hpf, and >20/10hpf, were all statistically significantly associated with stromal invasion. Greater than 10 eosinophils/hpf and/or >20 eosinophils/10hpf had highest predictive power, with a sensitivity, specificity and positive predictive value of 82%, 93%, 96% and 80%, 100% and 100%, respectively. Virtually, greater than 20 eosinophils/10 hpf was diagnostic for tumor invasion in our series.

Conclusion

Our study suggests for the first time that the elevated eosinophil count in squamous neoplasia of the larynx is a morphologic feature associated with tumor invasion. When the number of infiltrating eosinophils exceeds 10/hpf and or >20/10 hpf in a laryngeal biopsy with squamous neoplasia, it represents an indicator for the possibility of tumor invasion. Similarly, the presence of eosinophils meeting these thresholds in an excisional specimen should prompt a thorough evaluation for invasiveness, when evidence of invasion is absent, or when invasion is suspected by conventional criteria in the initial sections.