INTRODUCTION: Oral cancer is a major public health concern in India. Both conventional and altered fractionation radiotherapy schedules have been used in curative treatment of oral cancer. This study aimed to retrospectively evaluate the clinical profile and treatment outcomes of patients with carcinoma buccal mucosa who underwent treatment with definitive hypofractionated accelerated radiotherapy. METHODS: A total of 517 patients treated from January 2011 to December 2016 were eligible for the analysis. All patients were treated with definitive hypofractionated accelerated radiotherapy schedule of 5,250 cGy in 15 fractions over 3 weeks. Survival estimates were generated using the Kaplan-Meier method. RESULTS: At a median follow-up of 77.4 months, 473 (91.5%) patients attained complete remission with radiation therapy. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 69% and 80.5%, respectively. The 5-year OS for stage I, II, III and IVa tumours was 80.3%, 84.4%, 81.4% and 73.7%, respectively, and the DFS was 75.7%, 73.2%, 69.6% and 60.2%, respectively. Age >50 years was found to be a significant factor affecting DFS ( P = 0.026) and OS ( P = 0.048) in multivariate analysis. Fifty-three (10.3%) patients developed osteoradionecrosis of the mandible. CONCLUSION Excellent outcome could be achieved in less-aggressive, low-volume carcinoma of the buccal mucosa with radical accelerated hypofractionated radiotherapy. A radiotherapy schedule over a 3-week period is useful in high-volume centres.
Humans ; Retrospective Studies ; Male ; Female ; Middle Aged ; Mouth Neoplasms/mortality* ; Mouth Mucosa/radiation effects* ; Treatment Outcome ; Aged ; Adult ; Radiation Dose Hypofractionation ; Disease-Free Survival ; India ; Kaplan-Meier Estimate ; Dose Fractionation, Radiation ; Aged, 80 and over

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer with a high mortality rate in its late stages. One of the major challenges in OSCC treatment is the resistance to epidermal growth factor receptor (EGFR) inhibitors. Therefore, it is imperative to elucidate the mechanism underlying drug resistance and develop appropriate precision therapy strategies to enhance clinical efficacy. METHODS: To evaluate the efficacy of the combination of the Ca 2+ /calmodulin-dependent protein kinase II (CAMK2) inhibitor KN93 and EGFR inhibitors, we performed in vitro and in vivo experiments using two FAT atypical cadherin 1 ( FAT1 )-deficient (SCC9 and SCC25) and two FAT1 wild-type (SCC47 and HN12) OSCC cell lines. We assessed the effects of EGFR inhibitors (afatinib or cetuximab), KN93, or their combination on the malignant phenotype of OSCC in vivo and in vitro . The alterations in protein expression levels of members of the EGFR signaling pathway and SRY-box transcription factor 2 (SOX2) were analyzed. Changes in the yes-associated protein 1 (YAP1) protein were characterized. Moreover, we analyzed mitochondrial dysfunction. Besides, the effects of combination therapy on mitochondrial dynamics were also evaluated. RESULTS: OSCC with FAT1 mutations exhibited resistance to EGFR inhibitors treatment. The combination of KN93 and EGFR inhibitors significantly inhibited the proliferation, survival, and migration of FAT1 -mutated OSCC cells and suppressed tumor growth in vivo . Mechanistically, combination therapy enhanced the therapeutic sensitivity of FAT1 -mutated OSCC cells to EGFR inhibitors by modulating the EGFR pathway and downregulated tumor stemness-related proteins. Furthermore, combination therapy induced reactive oxygen species (ROS)-mediated mitochondrial dysfunction and disrupted mitochondrial dynamics, ultimately resulting in tumor suppression. CONCLUSION Combination therapy with EGFR inhibitors and KN93 could be a novel precision therapeutic strategy and a potential clinical solution for EGFR-resistant OSCC patients with FAT1 mutations.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/metabolism* ; Cell Line, Tumor ; Animals ; Drug Resistance, Neoplasm/genetics* ; Cadherins/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Mice ; Mutation/genetics* ; Mice, Nude ; Protein Kinase Inhibitors/therapeutic use* ; Cetuximab/pharmacology* ; Afatinib/therapeutic use* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects*

OBJECTIVE: To explore the technical key points and effectiveness of the facial artery perforator myomucosal flap (FAPMF) in repairing oral and perioral tissue defects. METHODS: Between June 2023 and December 2024, 8 patients with oral and perioral tissue defects were repaired with the FAPMF. There were 4 males and 4 females, with an average age of 57.6 years (range, 45-72 years). Among them, 4 cases had floor-of-mouth defects and 3 cases had buccal mucosa defects remaining after squamous cell carcinoma resection, and 1 case had lower lip defect caused by trauma. The size of tissue defects ranged from 4.5 cm×3.0 cm to 6.0 cm×5.0 cm. The preoperative mouth opening was (39.55±1.88) mm, and the preoperative swallowing score of the University of Washington Quality of Life Questionnaire (UW-QOL) was 64.64±8.47. Preoperatively, CT angiography and Doppler ultrasound were used to locate the perforator vessels. A myomucosal flap pedicled with the perioral perforators of the facial artery was designed, with the harvesting size ranging from 4.0 cm×2.5 cm to 6.5 cm×4.0 cm. The length of the vascular pedicle was 4.2-6.8 cm (mean, 5.2 cm). Postoperatively, FAPMF survival, complications, and functional recovery were observed. RESULTS: All 8 surgeries were successfully completed without conversion to other repair methods or complications such as facial nerve injury. The total operation time ranged from 110 to 180 minutes, with an average of 142.5 minutes; among this, the harvesting time of the FAPMF ranged from 35 to 65 minutes, with an average of 48.7 minutes. The intraoperative blood loss was 50-150 mL, with an average of 85.6 mL. All FAPMFs survived completely. One patient developed venous reflux disorder at 24 hours after operation, which relieved after conservative treatment. All patients were followed up 7-16 months (mean, 12.4 months). All FAPMFs achieved complete epithelialization at 3 months after operation, showing a similar soft texture to the surrounding mucosa. At 7 months after operation, the mouth opening was (39.11±1.79) mm, slightly lower than preoperative level, but the difference was not significant (P>0.05). The swallowing score of the UW-QOL was 63.78±8.31, which was significantly lower than preoperative score (P<0.05). The visual analogue scale (VAS) score for patient satisfaction was 7-10, with an average of 8.9. CONCLUSION The FAPMF has advantages such as reliable blood supply, high mucosal matching degree, and concealed donor site, making it an ideal option for repairing small and medium-sized oral and perioral tissue defects.
Humans ; Male ; Middle Aged ; Female ; Perforator Flap/blood supply* ; Aged ; Plastic Surgery Procedures/methods* ; Mouth Neoplasms/surgery* ; Mouth Mucosa/surgery* ; Mouth/surgery* ; Quality of Life ; Face/surgery* ; Treatment Outcome ; Carcinoma, Squamous Cell/surgery* ; Arteries/surgery*

Oral and maxillofacial tumors, due to their complex anatomical structures and vital physiological functions, pose significant risks, not only affecting patients' appearance and function but also potentially endangering their lives. Traditional tumor resection and reconstruction surgeries face challenges such as inadequate precision, long surgical durations, and unsatisfactory postoperative outcomes. In the treatment of oral and maxillofacial tumors, 3D printing technology can be used for preoperative planning, surgical guide plate production, and the design and manufacture of personalized prosthetics, providing new solutions for functional reconstruction after tumor resection. This article reviews the progress of 3D printing technology in the medical field and explores its potential value in the resection and reconstruction of oral and maxillofacial tumors, aiming to provide references for clinical practice and promote the further application and development of this technology in oral and maxillofacial surgery.
Printing, Three-Dimensional ; Humans ; Plastic Surgery Procedures/methods* ; Mouth Neoplasms/surgery*

OBJECTIVES: To analyze the trends of disease burden of lip and oral cancers in East Asia from 1990 to 2021 and its future projections. METHODS: We used the Global Burden of Disease 2021 database to conduct a comprehensive analysis of disease burden data from China (including Taiwan Province of China), Japan, Republic of Korea, Democratic People's Republic of Korea and Mongolia. The data were stratified by age, gender and major risk factors, and a Bayesian age-period-cohort model was employed to predict the future trends. RESULTS: From 1990 to 2021, the burden of lip and oral cancers in East Asian countries exhibited a steady increase. Taiwan Province of China experienced the most significant increases in incidence, prevalence, mortality, and disability-adjusted life years (DALYs), while Mongolia saw a decline in both mortality and DALYs. In 2021, Taiwan Province of China reported the highest rates of lip and oral cancer incidence (27.50 per 100 000), prevalence (137.92 per 100 000), mortality (9.59 per 100 000), and DALYs (292.07 person-years per 100 000), particularly among male and elderly populations. Tobacco use and alcohol consumption significantly exacerbated the disease burden in Taiwan Province of China and Japan. Future projections indicate that the incidence and prevalence of lip and oral cancer in China (excluding Taiwan Province of China) will continue to rise, while their mortality rates are expected to decline in most regions, except for Taiwan Province of China and Democratic People's Republic of Korea. CONCLUSIONS By the year 2035, the disease burden of lip and oral cancers in East Asia is expected to continue to increase, especially in Taiwan Province of China. To address this challenge, it is essential to implement effective measures to control major risk factors, promote early screening, and ensure equitable distribution of healthcare resources.
Humans ; Mouth Neoplasms/epidemiology* ; Incidence ; Lip Neoplasms/epidemiology* ; Asia, Eastern/epidemiology* ; Male ; Disability-Adjusted Life Years ; Prevalence ; Female ; Forecasting ; Risk Factors ; Cost of Illness ; Middle Aged ; Global Burden of Disease ; Aged ; Bayes Theorem

Perineural invasion (PNI) by tumor cells is a key phenotype of highly-invasive oral squamous cell carcinoma (OSCC). Since Schwann cells (SCs) and fibroblasts maintain the physiological homeostasis of the peripheral nervous system, and we have focused on cancer-associated fibroblasts (CAFs) for decades, it's imperative to elucidate the impact of CAFs on SCs in PNI⁺ OSCCs. We describe a disease progression-driven shift of PNI^- towards PNI⁺ during the progression of early-stage OSCC (31%, n = 125) to late-stage OSCC (53%, n = 97), characterized by abundant CAFs and nerve demyelination. CAFs inhibited SC proliferation/migration and reduced neurotrophic factors and myelin in vitro, and this involved up-regulated ER stress and decreased MAPK signals. Moreover, CAFs also aggravated the paralysis of the hind limb and PNI in vivo. Unexpectedly, leukemia inhibitory factor (LIF) was exclusively expressed on CAFs and up-regulated in metastatic OSCC. The LIF inhibitor EC330 restored CAF-induced SC inactivation. Thus, OSCC-derived CAFs inactivate SCs to aggravate nerve injury and PNI development.
Schwann Cells/metabolism* ; Mouth Neoplasms/metabolism* ; Humans ; Cancer-Associated Fibroblasts/metabolism* ; Animals ; Carcinoma, Squamous Cell/metabolism* ; Neoplasm Invasiveness/pathology* ; Male ; Female ; Mice ; Cell Movement/physiology* ; Cell Proliferation/physiology* ; Cell Line, Tumor ; Leukemia Inhibitory Factor/metabolism* ; Middle Aged

Oral squamous cell carcinoma (OSCC) is the most common manifestation of oral cancer. It has been proposed that periodontal pathogens contribute to OSCC progression, mainly by their virulence factors. However, the main periodontal pathogen and its mechanism to modulate OSCC cells remains not fully understood. In this study we investigate the main host-pathogen pathways in OSCC by computational proteomics and the mechanism behind cancer progression by the oral microbiome. The main host-pathogen pathways were analyzed in the secretome of biopsies from patients with OSCC and healthy controls by mass spectrometry. Then, functional assays were performed to evaluate the host-pathogen pathways highlighted in oral cancer. Host proteins associated with LPS response, cell migration/adhesion, and metabolism of amino acids were significantly upregulated in the human cancer proteome, whereas the complement cascade was downregulated in malignant samples. Then, the microbiome analysis revealed large number and variety of peptides from Fusobacterium nucleatum (F. nucleatum) in OSCC samples, from which several enzymes from the L-glutamate degradation pathway were found, indicating that L-glutamate from cancer cells is used as an energy source, and catabolized into butyrate by the bacteria. In fact, we observed that F. nucleatum modulates the cystine/glutamate antiporter in an OSCC cell line by increasing SLC7A11 expression, promoting L-glutamate efflux and favoring bacterial infection. Finally, our results showed that F. nucleatum and its metabolic derivates promote tumor spheroids growth, spheroids-derived cell detachment, epithelial-mesenchymal transition and Galectin-9 upregulation. Altogether, F. nucleatum promotes pro-tumoral mechanism in oral cancer.
Humans ; Fusobacterium nucleatum/metabolism* ; Mouth Neoplasms/metabolism* ; Disease Progression ; Proteomics ; Carcinoma, Squamous Cell/metabolism* ; Host-Pathogen Interactions ; Metabolic Networks and Pathways ; Case-Control Studies ; Mass Spectrometry

Cancer stem cells (CSCs) are widely acknowledged as primary mediators to the initiation and progression of tumors. The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years. Porphyromonas gingivalis (P. gingivalis) is increasingly considered to be closely related to the development of oral squamous cell carcinoma (OSCC). Nevertheless, the role of P. gingivalis in the stemness of OSCC cells remains uncertain. Herein, we showed that P. gingivalis was positively correlated with CSC markers expression in human OSCC specimens, promoted the stemness and tumorigenicity of OSCC cells, and enhanced tumor formation in nude mice. Mechanistically, P. gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1 (SCD1) expression, a key enzyme involved in lipid metabolism, which ultimately resulted in enhanced acquisition of stemness. Moreover, SCD1 suppression attenuated P. gingivalis-induced stemness of OSCC cells, including CSCs markers expression, sphere formation ability, chemoresistance, and tumor growth, in OSCC cells both in vitro and in vivo. Additionally, upregulation of SCD1 in P. gingivalis-infected OSCC cells was associated with the expression of KLF5, and that was modulated by P. gingivalis-activated NOD1 signaling. Taken together, these findings highlight the importance of SCD1-dependent lipid synthesis in P. gingivalis-induced stemness acquisition in OSCC cells, suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.
Porphyromonas gingivalis/pathogenicity* ; Stearoyl-CoA Desaturase/metabolism* ; Humans ; Carcinoma, Squamous Cell/pathology* ; Mouth Neoplasms/metabolism* ; Animals ; Neoplastic Stem Cells/microbiology* ; Mice, Nude ; Mice ; Nod1 Signaling Adaptor Protein/metabolism* ; Kruppel-Like Transcription Factors/metabolism* ; Cell Line, Tumor

Oral squamous cell carcinoma (OSCC) progresses from preneoplastic precursors via genetic and epigenetic alterations. Previous studies have focused on the treatment of terminally developed OSCC. However, the role of epigenetic regulators as therapeutic targets during the transition from preneoplastic precursors to OSCC has not been well studied. Our study identified lysine-specific demethylase 1 (LSD1) as a crucial promoter of OSCC, demonstrating that its knockout or pharmacological inhibition in mice reversed OSCC preneoplasia. LSD1 inhibition by SP2509 disrupted cell cycle, reduced immunosuppression, and enhanced CD4+ and CD8+ T-cell infiltration. In a feline model of spontaneous OSCC, a clinical LSD1 inhibitor (Seclidemstat or SP2577) was found to be safe and effectively inhibit the STAT3 network. Mechanistic studies revealed that LSD1 drives OSCC progression through STAT3 signaling, which is regulated by phosphorylation of the cell cycle mediator CDK7 and immunosuppressive CTLA4. Notably, LSD1 inhibition reduced the phosphorylation of CDK7 at Tyr170 and eIF4B at Ser422, offering insights into a novel mechanism by which LSD1 regulates the preneoplastic-to-OSCC transition. This study provides a deeper understanding of OSCC progression and highlights LSD1 as a potential therapeutic target for controlling OSCC progression from preneoplastic lesions.
STAT3 Transcription Factor/metabolism* ; Animals ; Histone Demethylases/genetics* ; Phosphorylation ; Mouth Neoplasms/immunology* ; Mice ; Carcinoma, Squamous Cell/immunology* ; Disease Progression ; Cyclin-Dependent Kinase-Activating Kinase ; Precancerous Conditions/metabolism* ; Humans ; Cyclin-Dependent Kinases/metabolism* ; Disease Models, Animal

Hypoxia and aberrant activation of epidermal growth factor receptor (EGFR) are considered important features of various malignancies. However, whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear. In this study, we demonstrated that in oral cancer, a typical hypoxic tumor, hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands. Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia. In hypoxic HN4 and HN6 cells, ubiquitination-mediated endocytosis, lysosomal sorting, and degradation lead to low levels of EGFR phosphorylation. However, in CAL-27 and HN30 cells, a novel HIF-1α-induced long noncoding RNA (lncRNA), EUDAL, can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR, stabilizing phosphorylated EGFR (pEGFR) and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling. STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance. A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients. Collectively, hypoxia can induce noncanonical ligand-independent EGFR phosphorylation. High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/pathology* ; RNA, Long Noncoding/genetics* ; Drug Resistance, Neoplasm/genetics* ; Cell Line, Tumor ; Phosphorylation ; Signal Transduction ; STAT3 Transcription Factor/metabolism* ; Cell Hypoxia ; Autophagy ; Proto-Oncogene Proteins c-cbl/metabolism*