Somatic mutations in tumor and plasma of locoregional recurrent and/or metastatic head and neck cancer using a next‐generation sequencing panel: A preliminary study

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.

Liquid biopsies based on cell-free DNA as a potential biomarker in head and neck cancer

In the era of 'precision medicine', liquid biopsies based on cell-free DNA (cfDNA) have emerged as a promising tool in the oncology field. cfDNA from cancer patients is a mixture of tumoral (ctDNA) and non-tumoral DNA originated from healthy, cancer and tumor microenvironmental cells. Apoptosis, necrosis, and active secretion from extracellular vesicles represent the main mechanisms of cfDNA release into the physiological body fluids. Focused on HNC, two main types of cfDNA can be identified: the circulating cfDNA (ccfDNA) and the salivary cfDNA (scfDNA). Numerous studies have reported on the potential of cfDNA analysis as potential diagnostic, prognostic, and monitoring biomarker for HNC. Thus, ctDNA has emerged as an attractive strategy to detect cancer specific genetic and epigenetic alterations including DNA somatic mutations and DNA methylation patterns. This review aims to provide an overview of the up-to-date studies evaluating the value of the analysis of total cfDNA, cfDNA fragment length, and ctDNA analysis at DNA mutation and methylation level in HNC patients.