Disparities in Head and Neck Cancer: A Case for Chemoprevention with Vitamin D

Racial Disparities in Head and Neck Cancer: It's Not Just About Access

OBJECTIVE

Medical literature identifies stark racial disparities in head and neck cancer (HNC) in the United States, primarily between non-Hispanic white (NHW) and non-Hispanic black (NHB) populations. The etiology of this disparity is often attributed to inequitable access to health care and socioeconomic status (SES). However, other contributors have been reported. We performed a systematic review to better understand the multifactorial landscape driving racial disparities in HNC.

DATA SOURCES

A systematic review was conducted in Covidence following Preferred Reporting Items for Systematic Reviews and Meta-analyses Guidelines. A search of PubMed, SCOPUS, and CINAHL for literature published through November 2022 evaluating racial disparities in HNC identified 2309 publications.

REVIEW METHODS

Full texts were screened by 2 authors independently, and inconsistencies were resolved by consensus. Three hundred forty publications were ultimately selected and categorized into themes including disparities in access/SES, treatment, lifestyle, and biology. Racial groups examined included NHB and NHW patients but also included Hispanic, Native American, and Asian/Pacific Islander patients to a lesser extent.

RESULTS

Of the 340 articles, 192 focused on themes of access/SES, including access to high-quality hospitals, insurance coverage, and transportation contributing to disparate HNC outcomes. Additional themes discussed in 148 articles included incongruities in surgical recommendations, tobacco/alcohol use, human papillomavirus-associated malignancies, and race-informed silencing of tumor suppressor genes.

CONCLUSION

Differential access to care plays a significant role in racial disparities in HNC, disproportionately affecting NHB populations. However, there are other significant themes driving racial disparities. Future studies should focus on providing equitable access to care while also addressing these additional sources of disparities in HNC.

Liquid Biopsy in Head and Neck Cancer: Its Present State and Future Role in Africa

The rising mortality and morbidity rate of head and neck cancer (HNC) in Africa has been attributed to factors such as the poor state of health infrastructures, genetics, and late presentation resulting in the delayed diagnosis of these tumors. If well harnessed, emerging molecular and omics diagnostic technologies such as liquid biopsy can potentially play a major role in optimizing the management of HNC in Africa. However, to successfully apply liquid biopsy technology in the management of HNC in Africa, factors such as genetic, socioeconomic, environmental, and cultural acceptability of the technology must be given due consideration. This review outlines the role of circulating molecules such as tumor cells, tumor DNA, tumor RNA, proteins, and exosomes, in liquid biopsy technology for the management of HNC with a focus on studies conducted in Africa. The present state and the potential opportunities for the future use of liquid biopsy technology in the effective management of HNC in resource-limited settings such as Africa is further discussed.

Role of Vitamin D in Head and Neck Cancer-Immune Function, Anti-Tumour Effect, and Its Impact on Patient Prognosis

Head and neck squamous cell carcinoma (HNSCC) describes a heterogeneous group of human neoplasms of the head and neck with high rates of morbidity and mortality, constituting about 3% of all cancers and ~1.5% of all cancer deaths. HNSCC constituted the seventh most prevalent human malignancy and the most common human cancer in the world in 2020, according to multi-population observations conducted by the GLOBOCAN group. Since approximately 60-70% of patients present with stage III/IV neoplastic disease, HNSCC is still one of the leading causes of death in cancer patients worldwide, with an overall survival rate that is too low, not exceeding 40-60% of these patients. Despite the application of newer surgical techniques and the implementation of modern combined oncological treatment, the disease often follows a fatal course due to frequent nodal metastases and local neoplastic recurrences. The role of micronutrients in the initiation, development, and progression of HNSCC has been the subject of considerable research. Of particular interest has been vitamin D, the pleiotropic biologically active fat-soluble family of secosteroids (vitamin-D-like steroids), which constitutes a key regulator of bone, calcium, and phosphate homeostasis, as well as carcinogenesis and the further development of various neoplasms. Considerable evidence suggests that vitamin D plays a key role in cellular proliferation, angiogenesis, immunity, and cellular metabolism. A number of basic science, clinical, and epidemiological studies indicate that vitamin D has multidirectional biological effects and influences anti-cancer intracellular mechanisms and cancer risk, and that vitamin D dietary supplements have various prophylactic benefits. In the 20th century, it was reported that vitamin D may play various roles in the protection and regulation of normal cellular phenotypes and in cancer prevention and adjunctive therapy in various human neoplasms, including HNSCC, by regulating a number of intracellular mechanisms, including control of tumour cell expansion and differentiation, apoptosis, intercellular interactions, angio- and lymphogenesis, immune function, and tumour invasion. These regulatory properties mainly occur indirectly via epigenetic and transcriptional changes regulating the function of transcription factors, chromatin modifiers, non-coding RNA (ncRNAs), and microRNAs (miRs) through protein-protein interactions and signalling pathways. In this way, calcitriol enhances intercellular communication in cancer biology, restores the connection with the extracellular matrix, and promotes the epithelial phenotype; it thus counteracts the tumour-associated detachment from the extracellular matrix and inhibits the formation of metastases. Furthermore, the confirmation that the vitamin D receptor (VDR) is present in many human tissues confirmed the physiopathological significance of vitamin D in various human tumours. Recent studies indicate quantitative associations between exposure to vitamin D and the incidence of HNC, i.e., cancer risk assessment included circulating calcidiol plasma/serum concentrations, vitamin D intake, the presence of the VDR gene polymorphism, and genes involved in the vitamin D metabolism pathway. Moreover, the chemopreventive efficacy of vitamin D in precancerous lesions of the head and neck and their role as predictors of mortality, survival, and recurrence of head and neck cancer are also widely discussed. As such, it may be considered a promising potential anti-cancer agent for developing innovative methods of targeted therapy. The proposed review discusses in detail the mechanisms regulating the relationship between vitamin D and HNSCC. It also provides an overview of the current literature, including key opinion-forming systematic reviews as well as epidemiological, prospective, longitudinal, cross-sectional, and interventional studies based on in vitro and animal models of HNSCC, all of which are accessible via the PubMed/Medline/EMBASE/Cochrane Library databases. This article presents the data in line with increasing clinical credibility.

Emerging Disparities in Prevention and Survival Outcomes for Patients with Head and Neck Cancer and Recommendations for Health Equity

Purpose of Review

The aim of this review is to describe less known and emerging disparities found in the prevention and survival outcomes for patients with head and neck cancer (HNC) that are likely to play an increasingly important role in HNC outcomes and health inequities.

Recent Findings

The following factors contribute to HNC incidence and outcomes: (1) the effect of rurality on prevention and treatment of HNC, (2) dietary behavior and nutritional factors influencing the development of and survival from HNC, and (3) barriers and benefits of telehealth for patients with HNC.

Summary

Rurality, nutrition and diet, and telehealth usage and access are significant contributors to the existing health disparities associated with HNC. Population and culturally specific interventions are urgently needed as well as more research to further define the issues and develop appropriate population and individual level solutions.

Vitamin D in 2020: An Old Pro-Hormone with Potential Effects beyond Mineral Metabolism

Vitamin D is not a vitamin but a pro-hormone. [...].