Viral and Clinical Oncology of Head and Neck Cancers

The Role of Estrogen and Estrogen Receptors in Head and Neck Tumors

Head and neck squamous cell carcinoma (HNSCC) is the most common histological form of head and neck tumors (HNTs), which originate from the epithelium of the lips and oral cavity, pharynx, larynx, salivary glands, nasal cavity, and sinuses. The main risk factors include consumption of tobacco in all forms and alcohol, as well as infections with high-risk human papillomaviruses or the Epstein-Barr virus. Regardless of the etiological agent, the risk of developing different types of HNTs is from two to more than six times higher in males than in females. The reason for such disparities probably lies in a combination of both biological and psychosocial factors. Therefore, it is hypothesized that exposure to female sex hormones, primarily estrogen, provides women with protection against the formation and metastasis of HNTs. In this review, we synthesized available knowledge on the role of estrogen and estrogen receptors (ERs) in the development and progression of HNTs, with special emphasis on membrane ERs, which are much less studied. We can summarize that in addition to epidemiologic studies unequivocally pointing to the protective effect of estrogen in women, an increased expression of both nuclear ERs, ERα, and ERβ, and membrane ERs, ERα36, GPER1, and NaV1.2, was present in different types of HNSCC, for which anti-estrogens could be used as an effective therapeutic approach.

Single cell analysis unveils the commonality and heterogeneity between nasopharyngeal and oropharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) and oropharyngeal carcinoma (OPC) are subtypes of head and neck cancer with different treatment effects due to the heterogeneity of tumor microenvironments. This study was to investigate the distinctive tumor microenvironments of NPC and OPC. Analyzing single-cell data from 10 cases of each subtype, we reveal significant differences in cellular composition, with NPC microenvironment dominated by T/NK and B cells, and OPC characterized by prevalent epithelial cells and fibroblasts. Dynamic transitions of CD8 T cells are observed in both tumor types, involving shifts from naivety to cytotoxicity, proliferation, and eventual exhaustion/exhausted states. Additionally, Tregs exhibit heightened proliferative abilities in later developmental stages, concomitant with exhaustion. These highly proliferative T cells and Tregs manifest elevated glycolysis and lactate metabolism activities. Furthermore, we explore intercellular communication between glycolytic malignant epithelial cells and these proliferative T cells. These findings offer comprehensive insights into the heterogeneity of tumor microenvironments and provide a solid foundation for future therapeutic strategies and targeted interventions.

Implications of oral dysbiosis and HPV infection in head and neck cancer: from molecular and cellular mechanisms to early diagnosis and therapy

Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis and HPV infection in HNCs, presenting the involved taxons, molecular effectors and pathways, as well as the HPV-associated particularities of genetic and epigenetic changes and of the tumor microenvironment occurred in different stages of tumor development. Oral dysbiosis is associated with the evolution of HNCs, through multiple mechanisms such as inflammation, genotoxins release, modulation of the innate and acquired immune response, carcinogens and anticarcinogens production, generation of oxidative stress, induction of mutations. Thus, novel microbiome-derived biomarkers and interventions could significantly contribute to achieving the desideratum of personalized management of oncologic patients, regarding both early diagnosis and treatment. The results reported by different studies are not always congruent regarding the variations in the abundance of different taxons in HNCs. However, there is a consistent reporting of a higher abundance of Gram-negative species such as Fusobacterium, Leptotrichia, Treponema, Porphyromonas gingivalis, Prevotella, Bacteroidetes, Haemophilus, Veillonella, Pseudomonas, Enterobacterales, which are probably responsible of chronic inflammation and modulation of tumor microenvironment. Candida albicans is the dominant fungi found in oral carcinoma being also associated with shorter survival rate. Specific microbial signatures (e.g., F. nucleatum, Bacteroidetes and Peptostreptococcus) have been associated with later stages and larger tumor, suggesting their potential to be used as biomarkers for tumor stratification and prognosis. On the other hand, increased abundance of Corynebacterium, Kingella, Abiotrophia is associated with a reduced risk of HNC. Microbiome could also provide biomarkers for differentiating between oropharyngeal and hypopharyngeal cancers as well as between HPV-positive and HPV-negative tumors. Ongoing clinical trials aim to validate non-invasive tests for microbiome-derived biomarkers detection in oral and throat cancers, especially within high-risk populations. Oro-pharyngeal dysbiosis could also impact the HNCs therapy and associated side-effects of radiotherapy, chemotherapy, and immunotherapy. HPV-positive tumors harbor fewer mutations, as well as different DNA methylation pattern and tumor microenvironment. Therefore, elucidation of the molecular mechanisms by which oral microbiota and HPV infection influence the HNC initiation and progression, screening for HPV infection and vaccination against HPV, adopting a good oral hygiene, and preventing oral dysbiosis are important tools for advancing in the battle with this public health global challenge.

Clinical course of longer than five years after definitive radiotherapy for nasopharyngeal carcinoma

BACKGROUND

This study aimed to reveal the long-term outcomes and late toxicities (> 5 years) after definitive intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC).

METHODS

Data from 43 patients (median age, 55 years; range, 17-72 years) with NPC who underwent definitive IMRT between 2001 and 2018 were analyzed. All patients were alive and disease-free 5 years after IMRT. A total dose of 70 (range, 66-70) Gy was delivered in 35 (33-35) fractions with concurrent cisplatin chemotherapy.

RESULTS

The median follow-up duration was 119 (range, 61.5-242.1) months. Three patients developed locoregional failure at 79, 92, and 149 months after IMRT, respectively. Of these, 2 patients died of disease progression at 136 and 153 months after IMRT. One patient died of aspiration pneumonia 141 months after IMRT, despite salvage of the recurrent tumor by re-irradiation. In addition, one patient died of aspiration pneumonia 62 months after the IMRT. Thus, the 10-year overall survival, progression-free survival, and locoregional control rates were 98%, 92%, and 94%, respectively. Grade ≥ 2 and ≥ 3 late toxicities were observed in 28 (65%) and 9 (21%) patients, respectively. Nine second primary cancers, including five tongue cancers and two external auditory canal carcinomas, were observed in seven (16%) patients.

CONCLUSION

Late recurrences, severe late toxicities, and second primary cancers were observed > 5 years after IMRT. A long-term follow-up of > 5 years is needed in patients with NPC.

Associations of Head and Neck Cancer with Hepatitis B Virus and Hepatitis C Virus Infection

This case-control study investigates the associations between head and neck cancer (HNC), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection. We included 5603 patients who had received a diagnosis of HNC as cases and 16,809 propensity score matching controls. We employed multivariate logistic regression models to evaluate the association of HNC with HBV and HCV infection after taking sociodemographic characteristics and diabetes, hypertension, hyperlipidemia, HPV infection, tobacco use disorder, and alcohol abuse/alcohol dependence syndrome into considerations. Results show that 7.9% of the total sample had been previously diagnosed with HBV infection, with 9.0% prevalence among cases and 7.6% among controls (p < 0.001). The chi-squared test suggests a significant difference in the prevalence of HCV infection between cases and controls (3.3% vs. 2.7%, p = 0.019). The covariate-adjusted odds ratio (OR) of HBV infection in patients with HNC relative to controls was 1.219 (95% CI = 1.093~1.359). Additionally, the adjusted OR of HCV infection in patients with HNC was 1.221 (95% CI = 1.023~1.457) compared to controls. Furthermore, patients with oropharyngeal cancer were more likely to have HCV infection than controls (adjusted OR = 2.142, 95% CI = 1.171~3.918). Our study provides evidence that suggests a potential association between HBV and HCV infections and the risk of HNC.

Insight into Oncogenic Viral Pathways as Drivers of Viral Cancers: Implication for Effective Therapy

As per a recent study conducted by the WHO, 15.4% of all cancers are caused by infectious agents of various categories, and more than 10% of them are attributed to viruses. The emergence of COVID-19 has once again diverted the scientific community's attention toward viral diseases. Some researchers have postulated that SARS-CoV-2 will add its name to the growing list of oncogenic viruses in the long run. However, owing to the complexities in carcinogenesis of viral origin, researchers across the world are struggling to identify the common thread that runs across different oncogenic viruses. Classical pathways of viral oncogenesis have identified oncogenic mediators in oncogenic viruses, but these mediators have been reported to act on diverse cellular and multiple omics pathways. In addition to viral mediators of carcinogenesis, researchers have identified various host factors responsible for viral carcinogenesis. Henceforth owing to viral and host complexities in viral carcinogenesis, a singular mechanistic pathway remains yet to be established; hence there is an urgent need to integrate concepts from system biology, cancer microenvironment, evolutionary perspective, and thermodynamics to understand the role of viruses as drivers of cancer. In the present manuscript, we provide a holistic view of the pathogenic pathways involved in viral oncogenesis with special emphasis on alteration in the tumor microenvironment, genomic alteration, biological entropy, evolutionary selection, and host determinants involved in the pathogenesis of viral tumor genesis. These concepts can provide important insight into viral cancers, which can have an important implication for developing novel, effective, and personalized therapeutic options for treating viral cancers.

Tumor associated macrophage in HPV+ tumors: Between immunosuppression and inflammation

Over the past few decades, with the rise of immunotherapies, tumor infiltrating immune cells were increasingly investigated. Indeed, they may represent biomarkers for patient outcome prediction, they may bear immune checkpoint markers that can be targeted by therapeutic antibodies and mechanistic studies may reveal how to tweak their activation profile so that we can re-direct them towards tumor cells. Macrophages possess a central place in tissue homeostasis for tissue remodeling and cleaning, transformed cell elimination, phagocytosis and regulation of inflammation via cytokine production. All these functions allow the discovery of approaches to target Tumor Associated Macrophages (TAMs) using immunotherapies. Indeed, TAMs express known immune checkpoint markers such as PD-L1, CD40, Sirp-α and markers such as CD163, CD204, TREM2, TREM1 associated with prognosis. In the context of therapies TAM may participate to antibody dependent cell phagocytosis (ADCP) thanks to FCγ-Receptors. Here, we will review the recent literature on TAMs in the specific context of HPV⁺ tumors. Indeed, HPV infection of mucosal tissue may lead to head and neck, cervical, penile, anal and vaginal cancers. HPV⁺ tumors exhibit a higher immune cell infiltrate, which relies on inflammation, immunosuppression and anti-viral response. In this context, and considering the many functions on macrophages, we will show the versatility of TAMs in a tumor microenvironment with viral infection features.

Hit and run oncogeneses in head and neck cancers requires greater investigation

Head and neck cancers are unique in so far that two major oncogenic viruses, Epstein Barr virus (EBV) and Human papillomavirus (HPV) infect adjacent anatomy and cause nasopharyngeal and oropharyngeal cancers, respectively. Dominant recognized carcinogens are alcohol and tobacco but some head and neck cancers have been found to have mixed carcinogens (including betel leaf, areca nuts, slaked lime, viruses, etc.) involved in their oncogenesis and conversely, groups of patients with unknown or less dominant carcinogens involved in their development. These cancers may have had viral involvement in the past but then lost most of their viral nucleic acids (be they DNA and/or RNA) below a detection threshold, thus rendering them virus-negative. Some of these virus-negative tumors appear to have mutagenic signatures associated with virus-positive cancers,  for example, from the APOBEC defense mechanism which is known to mutate viral nucleic acids as well as cause collateral damage to host DNA, with subsequent development of strongly viral prejudiced mutational signatures. These mechanisms are likely to be less efficient at oncogenesis than traditional EBV and HPV oncogenes directly driving mutagenesis, thus accounting for the smaller frequencies of these cancers found. More profound investigations of these unusual tumors are warranted to dissect out these mechanistic pathways.

Predictive Risk Factors Associated with Severe Radiation-Induced Mucositis in Nasopharyngeal or Oropharyngeal Cancer Patients: A Retrospective Study

Radiation-induced mucositis in head and neck cancer patients generates difficulties in eating and swallowing, and may influence treatment tolerance, compliance, and quality of life. However, predictive factors have not been studied in detail. Thus, the aim of this study was to describe the association between pre-radiotherapy clinical factors and the incidence of severe radiation-induced mucositis in nasopharyngeal or oropharyngeal cancer patients. This retrospective study included all patients with definitive radiotherapy or chemoradiotherapy for nasopharyngeal or oropharyngeal cancer between July 2011 and June 2021 in a single center. The eligibility criteria included patients who received oral management during radiotherapy. Exclusion criteria was patients who received postoperative radiotherapy. The data were acquired from the medical records of patients. One hundred patients were included in this retrospective study. Grade 3 radiation-induced mucositis occurred in 47 patients (47%). Lymphocyte count was significantly associated with grade 3 mucositis (OR = 0.40; 95% CI = 0.19–0.86; p = 0.018). It is suggested that pre-radiation lower lymphocyte counts are a predictive risk factor for severe mucositis in patients who undergo definitive radiotherapy or chemoradiotherapy for nasopharyngeal or oropharyngeal cancer