Tumor-Infiltrating Lymphocytes in Head and Neck Cancer: Ready for Prime Time?

Expression of CD4+ and CD8+ Tumor-Infiltrating Lymphocytes in Oral Squamous Cell Carcinoma and Their Relationship With Clinicopathological Parameters: A Cross-Sectional Study

Background Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm of the oral cavity. The tumor microenvironment (TME) is a dynamic ecosystem composed of components contributed by both the tumor and the host. The immune cells of TME, mainly CD4+ and CD8+ tumor-infiltrating lymphocytes (TILs), suppress the proliferation of cancer cells and play a crucial role in the progression of OSCC. The present study aims to analyze the immunohistochemical expression of CD4+ and CD8+ TILs in OSCC and to compare and correlate them with clinicopathological parameters. Methodology A total of 75 formalin-fixed paraffin-embedded samples of cases diagnosed with primary OSCC were immunostained with CD4+ and CD8+ antibodies and their expression was compared with the clinicopathological parameters. Results There was a significant positive correlation between CD4+ and CD8+ expression (r = 0.655, p = 0.001). Both CD4+ (r = -2.37, p = 0.041) and CD8+ (r = -0.348, p = 0.002) expressions negatively correlated with the TNM stage (r = -2.37, p = 0.041) of OSCC. CD8+ expression positively correlated with histopathological grade (r = 0.288, p = 0.012). Conclusions The study findings suggest that CD4+ cells are essential to maintain and sustain CD8+ TIL-mediated anti-tumor response. CD4+ and CD8+ TILs are key players in cell-mediated adaptive immunity and prevent tumor progression and metastasis. Strikingly, the higher grade of tumors despite heavy CD8+ infiltration may possibly be due to cancer immunoediting.

A Retrospective Multicenter Italian Analysis of Epidemiological, Clinical and Histopathological Features in a Sample of Patients with Acinic Cell Carcinoma of the Parotid Gland

BACKGROUND

The acinic cell carcinoma (AciCC) of the parotid gland is a rare tumor with an indolent behavior; however, a subgroup of this tumor presents an aggressive behavior with a tendency to recur. The aim of this multicenter study was to identify and stratify those patients with AciCC at high risk of tumor recurrence.

METHODS

A retrospective study was carried out involving 77 patients treated with surgery between January 2000 and September 2022, in different Italian referral centers. Data about tumor characteristics and its recurrence were collected. The histological specimens and slides were independently reviewed by a senior pathologist coordinator (L.C.) and the institution's local head and neck pathologist.

RESULTS

The patients' age average was 53.6 years, with a female prevalence in the group. The mean follow-up was 67.4 months (1-258, SD 59.39). The five-year overall survival (OS) was 83.2%. The 5-year disease-free survival (DFS) was 60% (95% CI 58.2-61.7). A high incidence of necrosis, extraglandular spread, lymphovascular invasion (LVI), atypical mitosis, and cellular pleomorphism was observed in the high-risk tumors compared to the low-risk ones.

CONCLUSION

AciCC generally had an indolent behavior, optimal OS, DFS with few cervical node metastases, and rare distant relapses. This multicenter retrospective case series provides evidence of the need for clinical-epidemiological-histological stratification for patients at risk of poor outcomes. Our results suggest that the correct definition of high-risk AciCC should include tumor size, the presence of necrosis, extraglandular spread, LVI, atypical mitosis, and cellular pleomorphism.

Using Intratumor Heterogeneity of Immunohistochemistry Biomarkers to Classify Laryngeal and Hypopharyngeal Tumors Based on Histologic Features

Haralick texture features are used to quantify the spatial distribution of signal intensities within an image. In this study, the heterogeneity of proliferation (Ki-67 expression) and immune cells (CD45 expression) within tumors was quantified and used to classify histologic characteristics of larynx and hypopharynx carcinomas. Of 21 laryngectomy specimens, 74 whole-mount tumor slides were scored on histologic characteristics. Ki-67 and CD45 immunohistochemistry was performed, and all sections were digitized. The tumor area was annotated in QuPath. Haralick features independent of the diaminobenzidine intensity were extracted from the isolated diaminobenzidine signal to quantify intratumor heterogeneity. Haralick features from both Ki-67 and CD45 were used as input for a principal component analysis. A linear support vector machine was fitted to the first 4 principal components for classification and validated with a leave-one-patient-out cross-validation method. Significant differences in individual Haralick features were found between cohesive and noncohesive tumors for CD45 (angular second motion: P =.03, inverse difference moment: P =.009, and entropy: P =.02) and between the larynx and hypopharynx tumors for both CD45 (angular second motion: P =.03, inverse difference moment: P =.007, and entropy: P =.005) and Ki-67 (correlation: P =.003). Therefore, these features were used for classification. The linear classifier resulted in a classification accuracy of 85% for site of origin and 81% for growth pattern. A leave-one-patient-out cross-validation resulted in an error rate of 0.27 and 0.35 for both classifiers, respectively. In conclusion, we show a method to quantify intratumor heterogeneity of immunohistochemistry biomarkers using Haralick features. This study also shows the feasibility of using these features to classify tumors by histologic characteristics. The classifiers created in this study are a proof of concept because more data are needed to create robust classifiers, but the method shows potential for automated tumor classification.

The Immune Cells in the Development of Oral Squamous Cell Carcinoma

A still unresolved issue surrounding tumor formation concerns the role that the immune system plays in preventing the formation and progression of neoplasia, including oral squamous cell carcinoma (OSCC). Antitumor immunity has historically been seen as a critical barrier for cancer cells to develop, grow and spread, and this can be modulated using immunotherapies to achieve antitumor clinical responses. However, it has recently become clear that tumor-associated immunity, particularly the inflammatory microenvironment, has the paradoxical effect of enhancing tumorigenesis and progression. In this review, we discuss the multifaceted function of infiltrating immune cells in suppressing or promoting premalignancy and cancer. In particular, we report on the evidence supporting a role for T lymphocytes, dendritic cells, macrophages, and neutrophils in the development and progression of oral potentially malignant disorders (OPMD) and OSCC. We also draw attention to the clinical relevance of immune cell phenotypes and associated molecules for use as biomarkers and to the translatability of current research findings to improve classification systems and precision medicine in patients with OSCC.

Evaluation of Programmed Death - Ligand 1 (Pd-L1) Expression in Head and Neck Squamous Cell Carcinoma

Background & Objective

Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly frequent malignancy worldwide and is also the leading cause of death. The prognosis for individuals with HNSCC remains dismal, with a five-year survival rate of less than 50%. The novel anti-PD-L1 immunotherapy is found to be promising, and immunohistochemistry (IHC) has been established as a reliable method for patient stratification. We intend to evaluate the prognostic significance of the expression of programmed death ligand-1 (PD-L1) in HNSCC and determine its association with clinicopathological variables.

Methods

A total of 50 cases of biopsy-confirmed HNSCC were studied in a tertiary hospital between Dec 2020 and June 2022. The specimens were tested for PD-L1 IHC expression with antibody clone CAL-10 (Biocare) and scored by Combined Positive Score (CPS). The association between PD-L1 expression and clinicopathological variables was evaluated.

Results

PD-L1 was positive in 92% of the cases, and a significant association (P= 0.024) was seen between PD-L1 expression and tumor-infiltrating lymphocytes (TILs). PD-L1 did not show any significant association with patient demographics, tumor site, grade, or stage.

Conclusion

In the present study, evaluation of the immunohistochemical expression of PD-L1 on the tumor cells and TILs in HNSCC revealed a high prevalence of PD-L1 expression. PD-L1 IHC studies for patient selection for immunotherapy would be a promising technique. Frequent PD-L1 expression in tumors with significant TILs may be useful in identifying patients who may benefit from anti-PD-1/PD-L1 therapy.

Prognostic impact of intra- and peritumoral immune cell subpopulations in head and neck squamous cell carcinomas - comprehensive analysis of the TCGA-HNSC cohort and immunohistochemical validation on 101 patients

Background

Due to the expanding role of immune checkpoint inhibition in the treatment of head and neck squamous cell carcinoma, understanding immunological processes in the tumor microevironment (TME) has strong translational importance. Though analytical methods for a comprehensive analysis of the immunological TME have constantly improved and expanded over the past years the prognostic relevance of immune cell composition in head and neck cancer TME largely remains ambiguous with most studies focusing on one or a small subset of immune cells.

Methods

The overall survival (OS) of the TCGA-HNSC patient cohort comprising 513 head and neck cancer patients was correlated with a total of 29 different immune metrics including a wide spectrum of immune cell subpopulations as well as immune checkpoint receptors and cytokines using RNAseq based immune deconvolution analyses. The most significant predictors of survival among these 29 immune metrics were validated on a separate HNSCC patient cohort (n=101) using immunohistochemistry: CD3, CD20+CXCR5, CD4+CXCR5, Foxp3 and CD68.

Results

Overall immune infiltration irrespective of immune cell composition showed no significant correlation with the patients' overall survival in the TCGA-HNSC cohort. However, when focusing on different immune cell subpopulations, naïve B cells (p=0.0006), follicular T-helper cells (p<0.0001), macrophages (p=0.0042), regulatory T cells (p=0.0306), lymphocytes (p=0.0001), and cytotoxic T cells (p=0.0242) were identified as highly significant predictors of improved patient survival. Using immunohistochemical detection of these immune cells in a second independent validation cohort of 101 HNSCC patients, we confirmed the prognostic relevance of follicular T helper cells, cytotoxic T cells and lymphocytes. In multivariable analysis, HPV negativity and advanced UICC stages were identified as additional prognostic biomarkers associated with poor outcome.

Conclusion

Our study highlights the prognostic relevance of the immunological tumor environment in head and neck cancer and demonstrates that a more detailed analysis of immune cell composition and immune cell subtypes is necessary to accurately prognosticate. We observed the highest prognostic relevance for lymphocytes, cytotoxic T cells, and follicular T helper cells, suggesting further investigations focusing on these specific immune cell subpopulations not only as predictors of patient prognosis but also as promising targets of new immunotherapeutic strategies.

Role of Surgical Pathologist for Detection of Immunooncologic Predictive Factors in Head and Neck Cancer

Immunotherapy has shown promising results in the treatment of recurrent and metastatic head and neck cancers. Antiprogrammed cell death (PD)-1 therapies have been recently approved in this setting and they are currently tested also in the treatment of locally advanced diseases and in the neoadjuvant setting. However, the clinical benefits of these treatments have been quite variable, hence the need to select those patients who may obtain the maximal efficacy through the identification of predictive biomarkers. Currently, PD-L1 immunohistochemical expression by tumor and immune cells is the most widely used predictive biomarker for immunotherapy in head and neck squamous cell carcinoma. Nevertheless, patients with PD-L1 - tumors may still respond to treatments, thereby emphasizing the need for the identification of other predictive biomarkers. In this review, we summarize the current data on histologic and molecular parameters that can be used to select patients with head and neck cancers for immunotherapy, with a focus on squamous cell carcinoma and salivary gland carcinomas.

PD-1 and PD-L1 Expression Levels as a Potential Biomarker of Chronic Rhinosinusitis and Head and Neck Cancers

Inflammation is an etiological factor of various chronic diseases contributing to more than 50% of worldwide deaths. In this study, we focus on the immunosuppressive role of the programmed death-1 (PD-1) receptor and its ligand (PD-L1) in inflammatory-related diseases, including chronic rhinosinusitis and head and neck cancers. The study included 304 participants. Of this number, 162 patients had chronic rhinosinusitis with nasal polyps (CRSwNP), 40 patients had head and neck cancer (HNC) and there were 102 healthy subjects. The expression level of the PD-1 and PD-L1 genes in the tissues of the study groups was measured by qPCR and Western blot methods. The associations between the age of the patients and the extent of disease and genes' expression were evaluated. The study showed a significantly higher mRNA expression of PD-1 and PD-L1 in the tissues of both the CRSwNP and HNC patient groups compared to the healthy group. The severity of CRSwNP significantly correlated with the mRNA expression of PD-1 and PD-L1. Similarly, the age of the NHC patients influenced PD-L1 expression. In addition, a significantly higher level of PD-L1 protein was noticed also for both the CRSwNP and HNC patient groups. The increased expression of PD-1 and PD-L1 may be a potential biomarker of inflammatory-related diseases, including chronic rhinosinusitis and head and neck cancers.

Prognostic value of the nodal yield in oral squamous cell carcinoma: a systematic review and meta-analysis

OBJECTIVES

To systematically evaluate the prognostic value of the nodal yield in oral squamous cell carcinoma by meta-analysis.

METHODS

The meta-analysis was adherence to PRISMA. We searched MEDLINE, Embase, and Cochrane for studies published up to 20 April 2022. We collected evidences from observational studies regarding nodal yield in oral squamous cell carcinoma, and investigated its prognostic value by the routine methods of meta-analysis.

RESULTS

From seven studies, there was no significant impact of the lymph node yield on overall survival among patients with oral squamous cell carcinoma cases and <18 lymph nodes (hazard ratio (HR) = 1.019, 95% confidence interval (CI) = 0.786-1.320, p = 0.887), with significant heterogeneity (I² = 80%). The pooled result indicated that a > 18-lymph node yield was a favorable prognostic factor (HR = 0.786, 95%CI = 0.646-0.956, p = 0.016; I² = 39%). The lymph node yield was not associated with disease-specific survival (HR = 1.594, 95%CI = 0.996-2.552, p = 0.052; I² = 81%) or disease-free survival (HR = 1.508, 95%CI = 0.924-2.460, p = 0.100; I² = 41%).

CONCLUSION

A lymph node yield of ≥18 lymph nodes might be a favorable prognostic factor for the overall survival of patients with oral squamous cell carcinoma.

Differential Regulation of Innate Lymphoid Cells in Human and Murine Oral Squamous Cell Carcinoma

Oral squamous cell carcinomas (OSCC) remain a major healthcare burden in Asian countries. In Pakistan alone, it is the most common cancer in males and second only to breast cancer in females. Alarmingly, treatment options for OSCC remain limited. With this context, investigations made to explore the inflammatory milieu of OSCC become highly relevant, with the hope of practicing immunotherapeutic approaches to address this highly prevalent tumor. We investigated the newly identified innate lymphoid cells (ILCs) and associated cytokines in well-defined human oral squamous cell carcinoma (OSCC) as well as in a 7,12-dimethylbenz[a]anthracene (DMBA)-induced murine model of OSCC using flow cytometry and quantitative real-time polymerase chain reaction (qPCR). We further went on to explore molecular circuitry involved in OSCC by developing a murine model of OSCC and using an α-Thy1 antibody to inhibit ILCs. Amongst the ILCs that we found in human OSCC, ILC3 (23%) was the most abundant, followed by ILC2 (17%) and ILC1 (1%). Mice were divided into four groups: DMBA (n = 33), DMBA+antibody (Ab) (n = 30), acetone (n = 5), and control (n = 5). In murine OSCC tissues, ILC1 and ILC3 were down-infiltrated, while ILC2 remained unchanged compared to controls. Interestingly, compared to the controls (DMBA group), mice treated with the α-Thy1 antibody showed fewer numbers of large tumors, and a larger percentage of these mice were tumor-free at this study's end point. We present novel data on the differential expansion/downsizing of ILCs in OSCC, which provides a pivotal basis to dive deeper into molecular circuitry and the OSCC tumor niche to devise novel diagnostic, therapeutic, and prognostic strategies to prevent/treat oral cancers.

A retrospective analysis of tumor infiltrating lymphocytes in head and neck squamous cell carcinoma patients treated with nivolumab

Nivolumab, an immune checkpoint inhibitor is the first-line therapy for platinum-resistant recurrent/metastatic head and neck cancer, and highly effective for some patients. However, no factors have been identified that could predict response or prognosis after nivolumab administration. We retrospectively investigated the association between tumor infiltrating lymphocytes (TILs) of initial pathology and prognosis in patients treated with nivolumab. Twenty-eight patients with human papilloma virus and Epstein-Barr virus unrelated head and neck squamous cell carcinoma were enrolled. CD8⁺cells, FoxP3⁺cells and FoxP3^-CD4⁺cells in the tumoral and peritumoral stromal area and PD-L1 were measured. In result, FoxP3^-CD4⁺TIL, FoxP3⁺TIL, and CD8⁺TIL were not correlated with survival in either intratumoral and stromal area. In univariate analysis, objective response was significant prognostic factor both in progression-free survival and overall survival (p = 0.01, 0.006, respectively). PD-L1 was also significant prognostic factor both in progression-free survival and overall survival (p = 0.01, 0.01, respectively). ECOG Performance status was a significant prognostic factor in overall survival (p = 0.0009). In the combined analysis of stromal CD8⁺TIL and PD-L1, PD-L1 positive with high stromal CD8⁺TIL subgroups had a better prognosis than PD-L1 negative with low stromal CD8⁺TIL subgroups in progression-free survival (p = 0.006). Although these results require a further investigation, PD-L1 and ECOG Performance status and the combination of stromal CD8⁺TIL and PD-L1 positivity have potential as useful prognostic markers in patients of virus unrelated head and neck squamous cell carcinoma treated with nivolumab.

Impaired intratumoral natural killer cell function in head and neck carcinoma

Natural killer (NK) cells are emerging as unique players in the immune response against cancer; however, only limited data are available on tumor infiltrating NK cells in head and neck squamous cell carcinoma (HNSCC), one of the most common cancer. Occurrence of HNSCC is closely related to the immune microenvironment, and immunotherapy is increasingly being applied to this setting. However, the limited success of this type of treatment in this tumor calls for further investigation in the field.

Surgical HNSSC specimens of 32 consecutive patients were mechanically and enzymatically dissociated. Tumor cells were separated from infiltrating cells by short centrifugation and infiltrating NK cells were phenotypically and functionally characterized by multiple antibody staining and flow cytometry. Tumor infiltrating NK cells in HNSCC showed a peculiar phenotype predominantly characterized by increased NKG2A and reduced Siglec-7, NKG2D, NKp30 and CD16 expression. This phenotype was associated with a decreased ability to perform antibody-dependent cellular cytotoxicity (ADCC). However, NK, CD4 and CD8 shared an increment of glucocorticoid-induced tumor necrosis factor-related (GITR) costimulatory receptor which could be exploited for immunotherapy with agonistic anti-GITR antibodies combined with checkpoint inhibitors.