The neoadjuvant paradigm reinvigorated: a review of pre-surgical immunotherapy in HNSCC

The risk and prognostic factors for lung metastases in oral squamous cell carcinoma: A population-based analysis of the SEER database

PURPOSE

This study aimed to describe the risk and prognostic factors associated with lung metastases among oral squamous cell carcinoma (OSCC) patients, further to establish a nomogram model to predict the risk of lung metastases.

METHODS

Data on OSCC patients was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2019. Univariable and multivariable logistic and Cox regression models were used to explore the risk factors for developing lung metastases, further the predictive nomogram was constructed.

RESULTS

19, 606 OSCC patients meets the inclusion criteria and were enrolled into this study. Of which, 221 cases have lung metastases at initial diagnosis. Multivariate logistic regression analysis indicated race, T stage, N stage as well as bone metastases, liver metastases were independently associated the development of lung metastases. The diagnostic nomogram for developing lung metastases was constructed, the c-index for this model was 0.830 (0.804-0.856). Both the ROC curve and calibration curves revealed accurate predictability. DCA curve displayed the established nomogram model had good clinical applicability for the prediction of lung metastases. The median OS of OSCC patients with lung metastases was 7.0 months (6.0-9.0), and the 6-months, 12-months, 24-month OS rates were 54.5%, 30.9%, 17.7%, respectively. The multivariate Cox analysis showed that chemotherapy and liver metastases were independently associated with both OS and CSS.

CONCLUSION

This study determined the risk and prognostic factors for lung metastases among OSCC patients and the established nomogram had good calibration and discrimination for predicting lung metastases.

Surgical margins in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC), a prevalent and frequently recurring malignancy, often necessitates surgical intervention. The surgical margin (SM) plays a pivotal role in determining the postoperative treatment strategy and prognostic evaluation of HNSCC. Nonetheless, the process of clinical appraisal and assessment of the SMs remains a complex and indeterminate endeavor, thereby leading to potential difficulties for surgeons in defining the extent of resection. In this regard, we undertake a comprehensive review of the suggested surgical distance in varying circumstances, diverse methods of margin evaluation, and the delicate balance that must be maintained between tissue resection and preservation in head and neck surgical procedures. This review is intended to provide surgeons with pragmatic guidance in selecting the most suitable resection techniques, and in improving patients' quality of life by achieving optimal functional and aesthetic restoration.

Lymphatic endothelial cell-mediated accumulation of CD177+Treg cells suppresses antitumor immunity in human esophageal squamous cell carcinoma

Regulatory T (Treg) cells are critical in shaping an immunosuppressive microenvironment to favor tumor progression and resistance to therapies. However, the heterogeneity and function of Treg cells in esophageal squamous cell carcinoma (ESCC) remain underexplored. We identified CD177 as a tumor-infiltrating Treg cell marker in ESCC. Interestingly, expression levels of CD177 and PD-1 were mutually exclusive in tumor Treg cells. CD177+ Treg cells expressed high levels of IL35, in association with CD8+ T cell exhaustion, whereas PD-1+ Treg cells expressed high levels of IL10. Pan-cancer analysis revealed that CD177+ Treg cells display increased clonal expansion compared to PD-1+ and double-negative (DN) Treg cells, and CD177+ and PD-1+ Treg cells develop from the same DN Treg cell origin. Importantly, we found CD177+ Treg cell infiltration to be associated with poor overall survival and poor response to anti-PD-1 immunotherapy plus chemotherapy in ESCC patients. Finally, we found that lymphatic endothelial cells are associated with CD177+ Treg cell accumulation in ESCC tumors, which are also decreased after anti-PD-1 immunotherapy plus chemotherapy. Our work identifies CD177+ Treg cell as a tumor-specific Treg cell subset and highlights their potential value as a prognostic marker of survival and response to immunotherapy and a therapeutic target in ESCC.

An AI-assisted integrated, scalable, single-cell phenomic-transcriptomic platform to elucidate intratumor heterogeneity against immune response

We present a novel framework combining single-cell phenotypic data with single-cell transcriptomic analysis to identify factors underpinning heterogeneity in antitumor immune response. We developed a pairwise, tumor-immune discretized interaction assay between natural killer (NK-92MI) cells and patient-derived head and neck squamous cell carcinoma (HNSCC) cell lines on a microfluidic cell-trapping platform. Furthermore we generated a deep-learning computer vision algorithm that is capable of automating the acquisition and analysis of a large, live-cell imaging data set (>1 million) of paired tumor-immune interactions spanning a time course of 24 h across multiple HNSCC lines (n = 10). Finally, we combined the response data measured by Kaplan-Meier survival analysis against NK-mediated killing with downstream single-cell transcriptomic analysis to interrogate molecular signatures associated with NK-effector response. As proof-of-concept for the proposed framework, we efficiently identified MHC class I-driven cytotoxic resistance as a key mechanism for immune evasion in nonresponders, while enhanced expression of cell adhesion molecules was found to be correlated with sensitivity against NK-mediated cytotoxicity. We conclude that this integrated, data-driven phenotypic approach holds tremendous promise in advancing the rapid identification of new mechanisms and therapeutic targets related to immune evasion and response.

Association between spatial distribution of leukocyte subsets and clinical presentation of head and neck squamous cell carcinoma

Background

Interactions between tumor cells and cells in the microenvironment contribute to tumor development and metastasis. The spatial arrangement of individual cells in relation to each other influences the likelihood of whether and how these cells interact with each other.

Methods

This study investigated the effect of spatial distribution on the function of leukocyte subsets in the microenvironment of human head and neck squamous cell carcinoma (HNSCC) using multiplex immunohistochemistry (IHC). Leukocyte subsets were further classified based on analysis of two previously published HNSCC single-cell RNA datasets and flow cytometry (FC).

Results

IHC revealed distinct distribution patterns of leukocytes differentiated by CD68 and CD163. While CD68hiCD163lo and CD68hiCD163hi cells accumulated near tumor sites, CD68loCD163hi cells were more evenly distributed in the tumor stroma. PD-L1hi and PD-1hi cells accumulated predominantly around tumor sites. High cell density of PD-L1hi CD68hiCD163hi cells or PD-1hi T cells near the tumor site correlated with improved survival. FC and single cell RNA revealed high variability within the CD68/CD163 subsets. CD68hiCD163lo and CD68hiCD163hi cells were predominantly macrophages (MΦ), whereas CD68loCD163hi cells appeared to be predominantly dendritic cells (DCs). Differentiation based on CD64, CD80, CD163, and CD206 revealed that TAM in HNSCC occupy a broad spectrum within the classical M1/M2 polarization. Notably, the MΦ subsets expressed predominantly CD206 and little CD80. The opposite was observed in the DC subsets.

Conclusion

The distribution patterns and their distinct interactions via the PD-L1/PD-1 pathway suggest divergent roles of CD68/CD163 subsets in the HNSCC microenvironment. PD-L1/PD-1 interactions appear to occur primarily between specific cell types close to the tumor site. Whether PD-L1/PD-1 interactions have a positive or negative impact on patient survival appears to depend on both the spatial localization and the entity of the interacting cells. Co-expression of other markers, particularly CD80 and CD206, supports the hypothesis that CD68/CD163 IHC subsets have distinct functions. These results highlight the association between spatial leukocyte distribution patterns and the clinical presentation of HNSCC.

Revisiting the concept of neoadjuvant and induction therapy in head and neck cancer with the advent of immunotherapy

The treatment of locally advanced (LA) Head and Neck Squamous Cell Carcinoma (HNSCC) is based on surgery followed by (chemo)radiation or on curative (chemo)radiation, depending on site and stage. Despite optimal locoregional treatment, about 50% of patients recur, with a huge impact on prognosis and substantial morbidity. The advent of immunotherapy (IT) with immune checkpoint inhibitors (ICIs) changed the paradigm of systemic treatment for recurrent/metastatic (RM) disease, showing activity, efficacy, and safety in both platinum-resistant and platinum-naïve patients. Such data led clinicians to design clinical trials to investigate early administration of IT even in the neoadjuvant or window of opportunity setting. In this review, we examine the published and ongoing trials investigating IT in the neoadjuvant setting for LA HNSCC. We address the current challenges of this treatment modality: optimal patient selection for neoadjuvant IT; choosing the appropriate systemic approach to enhance response without compromising tolerability; determining the ideal study endpoint, with a focus on major pathological response as a potential surrogate for overall survival; evaluating treatment response through imaging, considering the discordance between radiological and pathological assessments; and the influence of neoadjuvant IT response on locoregional treatment de-escalation strategies.

Neoadjuvant use of oncolytic herpes virus G47Δ prevents local recurrence after insufficient resection in tongue cancer models

A complete resection of tongue cancer is often difficult. We investigate the usefulness of administering G47Δ (teserpaturev), a triple-mutated oncolytic herpes simplex virus type 1, prior to resection. G47Δ exhibits good cytopathic effects and replication capabilities in all head and neck cancer cell lines tested. In an orthotopic SCCVII tongue cancer model of C3H/He mice, an intratumoral inoculation with G47Δ significantly prolongs the survival. Further, mice with orthotopic tongue cancer received neoadjuvant G47Δ (or mock) therapy with or without "hemilateral" resection, the maximum extent avoiding surgical deaths. Neoadjuvant G47Δ and resection led to 10/10 survival (120 days), whereas the survivals for G47Δ alone and resection alone were 6/10 and 5/10, respectively: all control animals died by day 11. Furthermore, 100% survival was achieved with neoadjuvant G47Δ therapy even when the resection area was narrowed to "partial," providing insufficient resection margins, whereas hemilateral resection alone caused death by local recurrence in half of the animals. G47Δ therapy caused increased number of tumor-infiltrating CD8+ and CD4+ cells, increased F4/80+ cells within the residual tongues, and increased expression of immune-related genes in and around the tumor. These results imply that neoadjuvant use of G47Δ is useful for preventing local recurrence after tongue cancer surgery.

Comparison of Post-Operative Complications in Oral Cancer Treated with and without Neoadjuvant Chemotherapy

Aim

The aim of the present study was to compare the treatment outcome in oral cancer cases treated with neoadjuvant chemotherapy (NACT) and upfront surgery in localized advance disease.

Materials and Methods

A randomized, prospective study was conducted in 20 cases. Patients were divided into two groups. Group A was taken up for upfront surgery and group B was taken up for surgery after two to three cycles of NACT based on patients' response, performance, and compliance.

Results

Neither group showed statistically significant differences in clinical characteristics. In the present study, satisfactory outcomes were seen in nine patients belonging to NACT group and eight patients of non-NACT group had satisfactory outcomes after surgery, which were found to be statistically significant (P = 0.001).

Conclusion

NACT may be considered as a treatment option for oral squamous cell carcinoma patients, particularly those with locally advanced tumors. Further prospective studies are needed to validate these findings in patients.

Low-dose immunotherapy as a potentiator to increase the response with neo-adjuvant chemotherapy in oral cancers

Neo-adjuvant chemotherapy (NACT) is utilized in locally advanced oral cancers to reduce the tumor burden and downstage the tumor to be amenable for definitive surgical management. Its long-term results compared to upfront surgical resection was not encouraging. Immunotherapy has now been used not only in recurrence and metastatic setting but also in the locally advanced tumor management regimens. The purpose of this concept paper is to bring forward the rationale to use a fixed low-dose immunotherapy agent as a potentiator to the standard NACT regimen and recommend their future investigation in oral cancer management.

Remodeling the tumor microenvironment to overcome treatment resistance in HPV-negative head and neck cancer

Despite intensive efforts and refined techniques, overall survival in HPV-negative head and neck cancer remains poor. Robust immune priming is required to elicit a strong and durable antitumor immune response in immunologically cold and excluded tumors like HPV-negative head and neck cancer. This review highlights how the tumor microenvironment could be affected by different immune and stromal cell types, weighs the need to integrate metabolic regulation of the tumor microenvironment into cancer treatment strategies and summarizes the emerging clinical applicability of personalized immunotherapeutic strategies in HPV-negative head and neck cancer.

A systematic review of neoadjuvant and definitive immunotherapy in locally advanced head and neck squamous cell carcinoma

BACKGROUND

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) require multi-modality treatment. Immune checkpoint inhibitors (ICIs) are now standard of care in management of recurrent/metastatic HNSCC. However, its role in the definitive and neoadjuvant setting remains unclear.

METHODS

A literature search was conducted that included all articles investigating ICI in untreated locally advanced (LA) HNSCC. Data was extracted and summarised and rated for quality using the Cochrane risk of bias tool.

RESULTS

Of 1086 records, 29 met the final inclusion criteria. In both concurrent and neoadjuvant settings, the addition of ICI was safe and did not delay surgery or reduce chemoradiotherapy completion. In the concurrent setting, although ICI use demonstrates objective responses in all published trials, there has not yet been published data to with PFS or OS benefit. In the neoadjuvant setting, combination ICI resulted in superior major pathological response rates compared to ICI monotherapy without a significant increase adverse event profiles, but its value in improving survival is not clear. ICI efficacy appears to be affected by tumour characteristics, in particular PD-L1 combined positive score, HPV status and the tumour microenvironment.

CONCLUSIONS

There is significant heterogeneity of ICI use in untreated LA HNSCC with multiple definitive concurrent and neoadjuvant protocols used. Resultantly, conclusions regarding the survival benefits of adding ICI to standard-of-care regimens cannot be made. Further trials and translational studies are required to elucidate optimal ICI sequencing in the definitive setting as well as better define populations more suited for neoadjuvant protocols.

A photodynamically sensitized dendritic cell vaccine that promotes the anti-tumor effects of anti-PD-L1 monoclonal antibody in a murine model of head and neck squamous cell carcinoma

BACKGROUND

Immune checkpoint inhibitors are promising tools in combating several cancers, including head and neck squamous cell carcinoma (HNSCC). However, a substantial portion of HNSCC patients do not respond to PD-L1 antibody. Here we describe a photodynamic therapeutic (PDT) approach to enhance anti-tumor effects of the anti-PD-L1 antibody.

METHODS

Phototoxicity of PDT was confirmed using fluorescence microscopy, Cell Counting Kit-8 (CCK-8), Enzyme Linked Immunosorbent Assay (ELISA) and flow cytometry analyses. Phenotypic and functional maturation of immature DCs (imDCs) induced by PDT were measured using flow cytometry and ELISA. A mouse model was established using the HNSCC line, SCC7, and was used to evaluate therapeutic effects of PDT-DC vaccine in facilitating anti-tumor immunity of PD-L1 antibody.

RESULTS

Immunogenic cell death (ICD) of SCC7 cells was induced by PDT with 0.5 µM of m-THPC and the 5 J/cm² of light dose. ICD of SCC7 cells stimulated imDCs maturation. In vivo assays suggested that PDT-DC vaccine and anti-PD-L1 mAb synergistically induced anti-tumor immunity and suppressed tumor progression.

CONCLUSION

PDT-DC vaccine enhances therapeutic effects of PD-L1 antibody, which might provide a novel approach for HNSCC immunotherapy.

Clinical Response to Neoadjuvant Immunotherapy Combined with Targeted Therapy and Chemotherapy in Oral Squamous Cell Carcinoma: Experience in Three Patients

Immune checkpoint inhibitors (ICIs) pembrolizumab and nivolumab have been approved for the treatment of head and neck squamous cell carcinoma (HNSCC) and used in neoadjuvant immunotherapy in clinical trials. However, combination of ICIs with targeted therapy and chemotherapy was rarely used in pre-surgical HNSCC patients. Herein, we encountered three cases of patients with oral squamous cell carcinoma (OSCC) who all had good responses to neoadjuvant immunotherapy (anti-PD-1 inhibitors) combined with nimotuzumab (anti-EGFR monoclonal antibody) plus paclitaxel. Both Case 1 and Case 2 underwent the same neoadjuvant therapeutic combination (nivolumab, nimotuzumab and paclitaxel) and exhibited a marked tumor shrinkage even complete disappearance by radiological evaluation. Moreover, pathological response was observed in post-surgical tissues of Case 1. Additionally, Case 3 with tongue squamous cell carcinoma also had satisfactory tumor regression (complete healing of his tongue ulcer upon treatment) after receiving similar neoadjuvant therapy with sintilimab (another PD-1 inhibitor), nimotuzumab and paclitaxel. We characterized their potential causes behind favorable treatment outcomes. While there were differences in driver mutations and tumor mutation burden (TMB) identified in pre-treatment tumor tissues among the three patients, numerous CD68+ (macrophages) infiltrates were common for all the cases. Of note, the majority (>80%) of the total macrophages were molecularly defined as PD-L1-positive macrophages. Given the high expression of PD-L1 in macrophages is associated with better immunotherapy outcomes, we propose that the high proportion of CD68+PD-L1+ cells in total macrophages alone could serve as a promising biomarker for neoadjuvant immunotherapy in combination with other therapies in HNSCC.

Poor treatment tolerance in head and neck cancer patients with low muscle mass

BACKGROUND

We ascertain the role of a low cervical paraspinal skeletal muscle index (CPSMI) as a biomarker for poor treatment tolerance in patients with operable mucosal head and neck squamous cell carcinoma (HNSCC).

METHODS

A prospective cohort of patients with operable HNSCC requiring microvascular reconstruction was evaluated. Low CPSMI was calculated using preoperative CT neck imaging. Poor treatment tolerance, a composite measure of incomplete therapy or severe morbidity/mortality during treatment, was the primary outcome.

RESULTS

One hundred and twenty-seven patients underwent extirpative surgery with a mean age was 60.5. Poor treatment tolerance occurred in 71 (56%) patients with 21 not completing recommended adjuvant therapy and 66 having severe treatment-related morbidity. A low CPSMI was independently associated with poor treatment tolerance (OR 2.49, 95%CI 1.10-5.93) and delay to adjuvant therapy (OR 4.48, 95%CI 1.07-27.6) after adjusting for multiple confounders.

CONCLUSION

Low CPSMI was independently associated with poor treatment tolerance in patients with operable HNSCC.

Antitumor immune effects of preoperative sitravatinib and nivolumab in oral cavity cancer: SNOW window-of-opportunity study

BACKGROUND

Sitravatinib, a tyrosine kinase inhibitor that targets TYRO3, AXL, MERTK and the VEGF receptor family, is predicted to increase the M1 to M2-polarized tumor-associated macrophages ratio in the tumor microenvironment and have synergistic antitumor activity in combination with anti-programmed death-1/ligand-1 agents. SNOW is a window-of-opportunity study designed to evaluate the immune and molecular effects of preoperative sitravatinib and nivolumab in patients with oral cavity squamous cell carcinoma.

METHODS

Patients with newly-diagnosed untreated T2-4a, N0-2 or T1 >1 cm-N2 oral cavity carcinomas were eligible. All patients received sitravatinib 120 mg daily from day 1 up to 48 hours pre-surgery and one dose of nivolumab 240 mg on day 15. Surgery was planned between day 23 and 30. Standard of care adjuvant radiotherapy was given based on clinical stage. Tumor photographs, fresh tumor biopsies and blood samples were collected at baseline, at day 15 after sitravatinib alone, and at surgery after sitravatinib-nivolumab combination. Tumor flow cytometry, multiplex immunofluorescence staining and single-cell RNA sequencing (scRNAseq) were performed on tumor biopsies to study changes in immune-cell populations. Tumor whole-exome sequencing and circulating tumor DNA and cell-free DNA were evaluated at each time point.

RESULTS

Ten patients were included. Grade 3 toxicity occurred in one patient (hypertension); one patient required sitravatinib dose reduction, and one patient required discontinuation and surgery delay due to G2 thrombocytopenia. Nine patients had clinical-to-pathological downstaging, with one complete response. Independent pathological treatment response (PTR) assessment confirmed a complete PTR and two major PTRs. With a median follow-up of 21 months, all patients are alive with no recurrence. Circulating tumor DNA and cell-free DNA dynamics correlated with clinical and pathological response and distinguished two patient groups with different tumor biological behavior after sitravatinib alone (1A) versus sitravatinib-nivolumab (1B). Tumor immunophenotyping and scRNAseq analyses revealed differential changes in the expression of immune cell populations and sitravatinib-targeted and hypoxia-related genes in group 1A vs 1B patients.

CONCLUSIONS

The SNOW study shows sitravatinib plus nivolumab is safe and leads to deep clinical and pathological responses in oral cavity carcinomas. Multi-omic biomarker analyses dissect the differential molecular effects of sitravatinib versus the sitravatinib-nivolumab and revealed patients with distinct tumor biology behavior.

TRIAL REGISTRATION NUMBER

NCT03575598.

Neoadjuvant PD-1/PD-L1 Inhibitors for Resectable Head and Neck Cancer: A Systematic Review and Meta-analysis

Importance

The emerging approach of neoadjuvant immunotherapy for solid cancers has set the ground for the integration of programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) inhibitors into the neoadjuvant setting of head and neck squamous cell carcinoma (HNSCC) treatment.

Objective

To assess the reported efficacy and safety of neoadjuvant immunotherapy for resectable HNSCC.

Data Sources and Study Selection

Electronic databases, including PubMed (MEDLINE), Embase, the Cochrane Library, and ClinicalTrials.gov were systematically searched for published and ongoing cohort studies and randomized clinical trials that evaluate neoadjuvant immunotherapy for resectable HNSCC. The search results generated studies from 2015 to July 2021.

Data Extraction and Synthesis

Two investigators (R.M. and L.K.) independently identified and extracted articles for potential inclusion. Random and fixed models were used to achieve pooled odds ratios. All results are presented with 95% CIs. Data quality was assessed by means of the Cochrane Collaboration's risk of bias tool.

Main Outcomes and Measures

The primary outcomes were reported efficacy, evaluated by major pathological response and pathological complete response in the primary tumors and lymph nodes separately, and safety, assessed by preoperative grade 3 to 4 treatment-related adverse events and surgical delay rate.

Results

A total of 344 patients from 10 studies were included. In 8 studies, neoadjuvant immunotherapy only was administered, and the other 2 studies combined immunotherapy with neoadjuvant chemotherapy and/or radiotherapy. The overall major pathological response rate in the primary tumor sites from studies reporting on neoadjuvant immunotherapy only was 9.7% (95% CI, 3.1%-18.9%) and the pathological complete response rate was 2.9% (95% CI, 0%-9.5%). Preoperative grade 3 to 4 treatment-related adverse events were reported at a rate of 8.4% (95% CI, 0.2%-23.2%) and surgical delay at a rate of 0% (95% CI, 0%-0.9%). There was a favorable association of neoadjuvant immunotherapy with all outcome measures. The subgroup analyses did not find one specific anti-PD-1/PD-L1 agent to be superior to another, and the favorable association was demonstrated by either immunotherapy alone or in combination with anti-CTLA-4.

Conclusions and Relevance

In this systematic review and meta-analysis, neoadjuvant anti-PD-1/PD-L1 immunotherapy for resectable HNSCC was well tolerated and may confer therapeutic advantages implied by histopathological response. Long-term outcomes are awaited.

Immunotherapy for Head and Neck Cancer

Head and neck squamous cell carcinomas (HNSCC) remain an important cause of global cancer morbidity and mortality. Historically, outcomes for patients with recurrent or metastatic disease were poor with limited treatment options. In recent decades, the demographic profile of this disease has evolved with an increase in human papilloma virus-associated oropharyngeal carcinoma and a decrease in tobacco-related disease. The treatment paradigm for HNSCC has rapidly evolved with identification of novel, immune-directed, therapeutic strategies that take advantage of immune dysregulation commonly seen in HNSCC. This review summarizes recent developments in this field and discusses emerging strategies for future therapies.

Preoperative Immunotherapy in the Multidisciplinary Management of Oral Cavity Cancer

Despite advances in multimodal treatment for oral cavity squamous cell carcinoma, recurrence rates remain high, providing an opportunity for new therapeutic modalities that may improve oncologic outcomes. Much recent attention has been paid to the molecular interactions between the tumor cells with the adjacent peritumoral microenvironment, in which immunosuppressive molecular changes create a landscape that promotes tumor progression. The rationale for the introduction of immunotherapy is to reverse the balance of these immune interactions in a way that utilizes the host immune system to attack tumor cells. In the preoperative setting, immunotherapy has the advantage of priming the unresected tumor and the associated native immune infiltration, supercharging the adaptive anti-tumor immune response. It also provides the basis for scientific discovery where the molecular profile of responders can be interrogated to elucidate prognostic markers to aid in future patient selection. Preoperative immunotherapy is not without limitations. The risk of surgical delay due to immune adverse events must be carefully discussed by members of a multidisciplinary treatment team and patient selection will be critical. One day, the discovery of predictive biomarkers may allow for algorithms where pre-surgical immunotherapy decreases the size of surgical defect and impacts the intensity of adjuvant therapy leading to improved patient survival and decreased morbidity. With further study, immunotherapy could become a key component of future treatment algorithm.

Immune deserts in head and neck squamous cell carcinoma: A review of challenges and opportunities for modulating the tumor immune microenvironment

Immunotherapy revolutionized cancer treatment but has yet to elicit durable responses in the majority of patients with head and neck squamous cell carcinoma (HNSCC). HNSCC is generally characterized by a high tumor mutational burden, which has translated to a large neoantigen load that could prime the immune system to recognize and eliminate malignant cells. Studies are increasingly showing, however, that HNSCC is an "immune desert" tumor that can hijack multiple parts of the tumor immunity cycle in order to evade immune recognition and suppress immune system activation. Herein we will review how HNSCC tumors modulate their architecture, cellular composition, and cytokine milieu to maximize immunosuppression; as well as relevant therapeutic opportunities and emerging issues facing the field of HNSCC immuno-oncology.

Explant Modeling of the Immune Environment of Head and Neck Cancer

Patients exhibit distinct responses to immunotherapies that are thought to be linked to their tumor immune environment. However, wide variations in outcomes are also observed in patients with matched baseline tumor environments, indicating that the biological response to treatment is not currently predictable using a snapshot analysis. To investigate the relationship between the immune environment of tumors and the biological response to immunotherapies, we characterized four murine head and neck squamous cell carcinoma (HNSCC) models on two genetic backgrounds. Using tumor explants from those models, we identified correlations between the composition of infiltrating immune cells and baseline cytokine profiles prior to treatment. Following treatment with PD-1 blockade, CTLA-4 blockade, or OX40 stimulation, we observed inter-individual variability in the response to therapy between genetically identical animals bearing the same tumor. These distinct biological responses to treatment were not linked to the initial tumor immune environment, meaning that outcome would not be predictable from a baseline analysis of the tumor infiltrates. We similarly performed the explant assay on patient HNSCC tumors and found significant variability between the baseline environment of the tumors and their response to therapy. We propose that tumor explants provide a rapid biological assay to assess response to candidate immunotherapies that may allow matching therapies to individual patient tumors. Further development of explant approaches may allow screening and monitoring of treatment responses in HNSCC.

Neoadjuvant nivolumab for patients with resectable HPV-positive and HPV-negative squamous cell carcinomas of the head and neck in the CheckMate 358 trial

BACKGROUND

Head and neck squamous cell carcinomas (HNSCCs) are common malignancies caused by carcinogens, including tobacco and alcohol, or infection with human papillomavirus (HPV). Immune checkpoint inhibitors targeting the programmed cell death 1 (PD-1) pathway are effective against unresectable recurrent/metastatic HNSCC. Here, we explored the safety and efficacy of anti-PD-1 therapy in at-risk resectable HPV-positive and HPV-negative HNSCC in the neoadjuvant setting.

METHODS

The phase I/II CheckMate 358 trial in virus-associated cancers assessed neoadjuvant nivolumab in patients with previously untreated, resectable HPV-positive or HPV-negative HNSCC. Patients received nivolumab 240 mg intravenously on days 1 and 15, with surgery planned by day 29. Safety/tolerability (primary endpoint) was assessed by monitoring adverse events (AEs) and surgical delays. Radiographic response was measured before surgery using RECIST v1.1, adapted for a single post-nivolumab evaluation. Pathologic specimens were examined for treatment response using immune-based criteria.

RESULTS

From November 2015 to December 2017, 52 patients with AJCC (seventh edition) stage III-IV resectable HNSCC received neoadjuvant nivolumab (26 HPV-positive, 26 HPV-negative). Any-grade treatment-related AEs (TRAEs) occurred in 19 patients (73.1%) and 14 patients (53.8%) in the HPV-positive and HPV-negative cohorts, respectively; grade 3-4 TRAEs occurred in five (19.2%) and three patients (11.5%), respectively. No patient had a protocol-defined TRAE-related surgical delay (>4 weeks). Thirty-eight patients were reported as undergoing complete surgical resection, 10 had a planned post-nivolumab biopsy instead of definitive surgery due to a protocol misinterpretation, and four did not undergo surgery or biopsy, including two with tumor progression. Radiographic response rates in 49 evaluable patients were 12.0% and 8.3% in the HPV-positive and HPV-negative cohorts, respectively. There were no complete pathologic responses by site or central review in operated patients. Among 17 centrally evaluable HPV-positive tumors, one (5.9%) achieved major pathological response and three (17.6%) achieved partial pathologic response (pPR); among 17 centrally evaluable HPV-negative tumors, one (5.9%) achieved pPR.

CONCLUSIONS

Neoadjuvant nivolumab was generally safe and induced pathologic regressions in HPV-positive (23.5%) and HPV-negative (5.9%) tumors. Combinatorial neoadjuvant treatment regimens, and continued postoperative therapy for high-risk tumors, are warranted in future trials to enhance the efficacy of this approach.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT02488759; https://clinicaltrials.gov/ct2/show/NCT02488759.

The role of pulmonary metastasectomy for pulmonary metastasis from head and neck cancer

The incidence rate of distant metastasis from head and neck (HN) cancers is 4.2-58.8%. The lung is the most common site of distant metastasis, and pulmonary metastasectomy (PM) can be performed in selected patients with pulmonary metastasis originating from HN cancers. However, due to the small number of study objectives, the knowledge on PM treatment of pulmonary metastasis from HN cancers remains insufficient, and the optimal management of pulmonary metastasis from HN cancer is unclear. Patients with pulmonary metastasis from HN cancer who underwent PM have a better prognosis than those who did not, with reported 5-year overall survival rates after PM of 20.9-59.4%. A histology of squamous cell carcinoma, incomplete resection, a short disease-free interval (DFI), and the oral cancer have been identified as factors predicting a worse prognosis after PM in this patient population. As a systemic therapy, longer overall survival has been achieved using immune check point inhibitors compared with standard single-agent therapies. Since the clinical and morphological diagnoses of pulmonary metastasis from HN cancers are often difficult, molecular techniques can provide useful information for the differential diagnosis between pulmonary metastasis from HN cancers and primary lung cancers. In cases of suspected pulmonary metastasis from HN cancer, the surgical strategy should be determined based on the patient's clinical background.

Immune Checkpoints Pathways in Head and Neck Squamous Cell Carcinoma

Simple Summary

During the last decades, scientific advances in immuno-oncology and a better understanding of tumors’ immune profile led to the development of novel immunotherapeutic strategies, especially immune checkpoint inhibitors. The blockade of PD-1 by monoclonal antibodies (mAbs) is the only immunotherapy based on immune checkpoint pathways approved for head and neck squamous cell carcinoma. As only a small fraction of patients perceives clinical benefit, understanding the molecular mechanisms and signaling pathways activated by the immune checkpoints and other tumor intrinsic features that modulate the immune infiltrate is crucial to better select patients for immunotherapy treatment and to develop novel therapeutic strategies. We here review the immune escape mechanisms of head and neck tumors, with a particular focus on the immune checkpoints, their role as therapeutic targets, and the predictive biomarkers of response to anti-PD-1/PD-L1 therapy. We also summarize the ongoing clinical trials testing several combinations of immune checkpoint inhibitors with other therapeutic approaches to improve patient outcomes.

Abstract

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of tumors usually diagnosed at an advanced stage and characterized by a poor prognosis. The main risk factors associated with its development include tobacco and alcohol consumption and Human Papillomavirus (HPV) infections. The immune system has a significant role in the oncogenesis and evolution of this cancer type. Notably, the immunosuppressive tumor microenvironment triggers immune escape through several mechanisms. The improved understanding of the antitumor immune response in solid tumors and the role of the immune checkpoint molecules and other immune regulators have led to the development of novel therapeutic strategies that revolutionized the clinical management of HNSCC. However, the limited overall response rate to immunotherapy urges identifying predictive biomarkers of response and resistance to treatment. Here, we review the role of the immune system and immune checkpoint pathways in HNSCC, the most relevant clinical findings linked to immunotherapeutic strategies and predictive biomarkers of response and future treatment perspectives.

Neoadjuvant chemotherapy prior to fertility-sparing surgery in cervical tumors larger than 2 cm: a systematic review on fertility and oncologic outcomes

BACKGROUND

Management of cervical cancer tumors >2 cm has been a subject of controversy, with management often considered as either up-front radical trachelectomy or neoadjuvant chemotherapy before fertility-sparing surgery.

METHODS

A systematic literature review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) checklist. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO). We searched Medline through PubMed, EMBASE, Cochrane Central Register of Controlled Trials, SCOPUS, and OVID between January 1985 and December 2020. Eligibility criteria for selecting studies were English language, randomized controlled trials, and observational studies including information on fertility and oncologic outcomes. All titles were managed in EndNote X7. Risk of bias was evaluated using the Joanna Briggs Institute (JBI) critical appraisal checklist for observational studies.

RESULTS

Twenty-three studies with 205 patients who received neoadjuvant chemotherapy were included. The majority of patients (92.2%, n=189) had stage IB FIGO 2009 cervical cancer. The preferred regimen used was cisplatin in combination with paclitaxel or ifosfamide (80%, n=164). One hundred and eighty patients (87.8%) underwent fertility-sparing surgery; radical vaginal trachelectomy, abdominal trachelectomy, conization, and simple trachelectomy were performed in 62 (34.4%), 49 (27.2%), 34 (18.9%), and 26 (14.4%) women, respectively. In nine patients (5%) the type of procedure was not specified. The follow-up time reported in all studies ranged between 6 and 69 months. In 112 women who sought a pregnancy after surgery, 84.8% (n=95) achieved a gestation.The global recurrence and death rates were 12.8% and 2.8%, respectively.

CONCLUSION

Neoadjuvant chemotherapy followed by fertility-sparing surgery is a promising strategy that might allow fertility preservation in highly selected patients with cervical cancer with tumors >2 cm while providing acceptable oncologic outcomes. Results of prospective studies are required to validate its oncological safety.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020203789.

Synergies Radiotherapy-Immunotherapy in Head and Neck Cancers. A New Concept for Radiotherapy Target Volumes-"Immunological Dose Painting"

The combination of immune checkpoint inhibitors and definitive radiotherapy is investigated for the multimodal treatment of cisplatin non-eligible locally advanced head and neck cancers (HNC). In the case of recurrent and metastatic HNC, immunotherapy has shown benefit over the EXTREME protocol, being already considered the standard treatment. One of the biggest challenges of multimodal treatment is to establish the optimal therapy sequence so that the synergistic effect is maximal. Thus, superior results were obtained for the administration of anti-CTLA4 immunotherapy followed by hypofractionated radiotherapy, but the anti-PD-L1 therapy demonstrates the maximum potential of radio-sensitization of the tumor in case of concurrent administration. The synergistic effect of radiotherapy–immunotherapy (RT–IT) has been demonstrated in clinical practice, with an overall response rate of about 18% for HNC. Given the demonstrated potential of radiotherapy to activate the immune system through already known mechanisms, it is necessary to identify biomarkers that direct the “nonresponders” of immunotherapy towards a synergistic RT–IT stimulation strategy. Stimulation of the immune system by irradiation can convert “nonresponder” to “responder”. With the development of modern techniques, re-irradiation is becoming an increasingly common option for patients who have previously been treated with higher doses of radiation. In this context, radiotherapy in combination with immunotherapy, both in the advanced local stage and in recurrent/metastatic of HNC radiotherapy, could evolve from the “first level” of knowledge (i.e., ballistic precision, dose conformity and homogeneity) to “level two” of “biological dose painting” (in which the concept of tumor heterogeneity and radio-resistance supports the need for doses escalation based on biological criteria), and finally to the “third level“ ofthe new concept of “immunological dose painting”. The peculiarity of this concept is that the radiotherapy target volumes and tumoricidal dose can be completely reevaluated, taking into account the immune-modulatory effect of irradiation. In this case, the tumor target volume can include even the tumor microenvironment or a partial volume of the primary tumor or metastasis, not all the gross and microscopic disease. Tumoricidal biologically equivalent dose (BED) may be completely different from the currently estimated values, radiotherapy treating the tumor in this case indirectly by boosting the immune response. Thus, the clinical target volume (CTV) can be replaced with a new immunological-clinical target volume (ICTV) for patients who benefit from the RT–IT association (Image 1).

Challenges in Combining Immunotherapy with Radiotherapy in Recurrent/Metastatic Head and Neck Cancer

Immunotherapy with immune checkpoint inhibitors (ICI) has recently become a standard part of the treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), although the response rates are low. Numerous preclinical and clinical studies have now illuminated several mechanisms by which radiotherapy (RT) enhances the effect of ICI. From RT-induced immunogenic cancer cell death to its effect on the tumor microenvironment and vasculature, the involved mechanisms are diverse and intertwined. Moreover, the research of these interactions is challenging because of the thin line between immunostimulatory and the immunosuppressive effect of RT. In the era of active research of immunoradiotherapy combinations, the significance of treatment and host-related factors that were previously seen as being less important is being revealed. The impact of dose and fractionation of RT is now well established, whereas selection of the number and location of the lesions to be irradiated in a multi-metastatic setting is something that is only now beginning to be understood. In addition to spatial factors, the timing of irradiation is as equally important and is heavily dependent on the type of ICI used. Interestingly, using smaller-than-conventional RT fields or even partial tumor volume RT could be beneficial in this setting. Among host-related factors, the role of the microbiome on immunotherapy efficacy must not be overlooked nor can we neglect the role of gut irradiation in a combined RT and ICI setting. In this review we elaborate on synergistic mechanisms of immunoradiotherapy combinations, in addition to important factors to consider in future immunoradiotherapy trial designs in R/M HNSCC.

[Organ preservation in advanced laryngeal/hypopharyngeal carcinoma: lessons from the DeLOS-II trial]

Patients with locoregionally advanced laryngeal and hypopharyngeal squamous cell carcinomas (LHSCC) comprise two broad groups: those who are candidates for functional larynx preservation (LP) with avoidance of ablative surgery and those who are not. Currently, treatment depends on the patient's needs and wishes, the experience and recommendation of the surgeon, the philosophy of the institution, etc. The milestone VA trial established non-surgical LP in advanced LHSCC in the 1990s using induction chemotherapy (IC) with PF (cisplatin, P, plus 5‑fluorouracil, F) followed by irradiation (IC + RT) as an appropriate alternative treatment to total laryngectomy (TL). Even though the findings of the VA trial were verified by the EORTC 24891 trial, a debate persists regarding the best protocol for balancing survival and laryngectomy-free survival (LFS) with acceptable late toxicity and good functional outcome. In advanced LHSCC without surgical options for larynx preservation, only IC + RT or primary concurrent platin-based chemoradiotherapy (CRT) are accepted treatment options aiming to preserve a functional larynx. In the US, cisplatin-based CRT is exclusively recommended as the best curative protocol. With regards to long-term survival with functional organ preservation and persistently high failure rates, there is current discussion on the necessity of improving patient selection based on the current literature and the recently published data of the DeLOS-II trial.