ABSTRACT
Patients with head and neck cancer often experience a significant decrease in their quality of life during chemoradiotherapy (CRT) due to treatment-related pain, which is frequently classified as severe. Transcranial direct current stimulation (tDCS) is a method of non-invasive brain stimulation that has been frequently used in experimental and clinical pain studies. In this pilot study, we investigated the clinical impact and central mechanisms of twenty primary motor cortex (M1) stimulation sessions with tDCS during 7 weeks of CRT for head and neck cancer. From 48 patients screened, seven met the inclusion criteria and were enrolled. Electroencephalography (EEG) data were recorded before and after tDCS stimulation as well as across the trial to monitor short and long-term impact on brain function. The compliance rate during the long trial was extremely high (98.4%), and patients mostly reported mild side effects in line with the literature (e.g., tingling). Compared to a large standard of care study from our institution, our initial results indicate that M1-tDCS stimulation has a pain relief effect during the CRT that resulted in a significant attenuation of weight reduction and dysphagia normally observed in these patients. These results translated to our patient cohort not needing feeding tubes or IV fluids. Power spectra analysis of EEG data indicated significant changes in α, ß, and γ bands immediately after tDCS stimulation and, in addition, α, δ, and θ bands over the long term in the seventh stimulation week (p < 0.05). The independent component EEG clustering analysis showed estimated functional brain regions including precuneus and superior frontal gyrus (SFG) in the seventh week of tDCS stimulation. These areas colocalize with our previous positron emission tomography (PET) study where there was activation in the endogenous µ-opioid system during M1-tDCS. This study provides preliminary evidence demonstrating the feasibility and safety of M1-tDCS as a potential adjuvant neuromechanism-driven analgesic therapy for head and neck cancer patients receiving CRT, inducing immediate and long-term changes in the cortical activity and clinical measures, with minimal side-effects.
Subject(s)
Mandibular Diseases/diagnostic imaging , Odontogenic Tumors/diagnostic imaging , Adolescent , Female , Humans , Male , RadiographyABSTRACT
OBJECTIVE: This study aimed to document three new cases of primary small cell carcinoma (SmCC) of the parotid and examine immunohistochemical and quantitative real-time polymerase chain reaction (qPCR) data of the recently developed Merkel cell polyomavirus (MCPyV) within these tumors. STUDY DESIGN: Immunohistochemistry for neuroendocrine markers (chromogranin A, CD56, CD57, neuron-specific enolase [NSE], thyroid transcription factor 1 [TTF-1]), epithelial markers (CK20, CK7, CAM 5.2), and MCPyV large T antigen (LTAg) were examined. qPCR and Sanger sequencing were performed to confirm the presence of the MCPyV LTAg gene. RESULTS: Two males and one female, average age 76 years, presented with left parotid masses. Clinical examinations, histories, and imaging studies were negative for cutaneous Merkel cell carcinoma (MCC), pulmonary and extrapulmonary SmCC, or any other malignancy. Immunohistochemical analysis demonstrated positive immunoreactivity for CK20 in a perinuclear dotlike pattern (3/3), CAM 5.2 (3/3), (2/3), NSE (3/3), CD56 (2/3), and CD57 (3/3). Two cases stained positive for MCPyV, showing moderate to strong, diffuse positivity, confirmed with qPCR. PCR-Sanger sequencing of LTAg exon 2 showed greater than 97% similarity to the MCPyV reference genome in both cases. CONCLUSION: Our findings expand the number of reported cases classified as primary parotid SmCC that harbors MCPyV and underscore the similarity between cutaneous MCC and parotid SmCC. Further investigation is needed to determine whether immune-based therapeutic strategies targeting MCPyV in MCC are also effective in the setting of parotid SmCC harboring MCPyV.
