Potential Single Nucleotide Polymorphisms markers for radiation dermatitis in head and neck cancer patients: a meta-analysis.

PURPOSE: To identify potential Single Nucleotide Polymorphisms (SNPs) of susceptibility for the development of acute radiation dermatitis in head and neck cancer patients, and also to verify the association between SNPs and the severity of RD. METHODS: This systematic review was reported according to the PRISMA guideline. The proportion meta-analysis was performed to identify the prevalence of genetic markers by geographical region and radiation dermatitis severity. The meta-analysis was performed to verify the association between genetic markers and RD severity. The certainty of the evidence was assessed by GRADE. RESULTS: Thirteen studies were included. The most prevalent SNPs were XRCC3 (rs861639) (36%), TGFß1 (rs1800469) (35%), and RAD51 (rs1801321) (34%). There are prevalence studies in Europe and Asia, with a similar prevalence for all SNPs (29-40%). The prevalence was higher in patients who developed radiation dermatitis ≤2 for any subtype of genes (75-76%). No SNP showed a statistically significant association with very low certainty of evidence. CONCLUSION: The most prevalent SNPs may be predictors of acute RD. The analysis of SNP before starting radiation therapy may be a promising method to predict the risk of developing radiation dermatitis and allow radiosensitive patients to have a customized treatment. This current review provides new research directions.

Strategies for evidence-based in head and neck cancer: practical examples in developing systematic review questions.

A systematic review (SR) requires several steps to be conducted. A major and initial challenge is to formulate a focused research question that may have high scientific relevance to provide evidence-based results and strategies. This narrative mini-review aims to present different categories of systematic reviews currently applied in Head and Neck Cancers (HNC), focusing on the strategies to provide results for evidence-based decision making. The SRs identified were of intervention, diagnostic testing, prognosis, in vitro and in vivo studies, prevalence, and epidemiological studies, and of association and risk factors. Focused questions that define the type of review, whether it is a therapy question (intervention), a question of prevalence or an outcome (prognosis) of disease, are discussed. Additionally, the importance in building interesting research questions and following all proposed steps to produce quality evidence are highlighted. This narrative mini-review may guide future research by showing how to perform and report relevant evidence in terms of HNC.

Photobiomodulation effects on fibroblasts and keratinocytes after ionizing radiation and bacterial stimulus.

OBJECTIVE: Photobiomodulation therapy (PBMT) has proven to reduce inflammation and pain and increase wound healing. Thus, the aim of this study was to analyze the effects of PBMT parameters on migration, proliferation, and gene expression after ionizing radiation and bacterial-induced stress in an in vitro study. DESIGN: Keratinocytes (HaCaT) and Fibroblasts (HGFs) were grown in DMEM with 10 % fetal bovine serum until stressful condition induction with lipopolysaccharide (LPS) of Escherichia coli (1 µg/mL), Porphyromonas gingivalis protein extract (5 µg/mL) and ionizing radiation (8 Gy). Low-laser irradiation (660 nm, 30 mW) was carried out in four sessions, with 6 h intervals, and energy density of 2, 3, 4, and 5 J/cm². Scratch assays, immunofluorescence, and RT-qPCR were performed. RESULTS: Treated fibroblasts and keratinocytes showed significant response in proliferation and migration after scratch assays (p < 0.05). Higher expressions of α-SMA in fibroblasts and F-actin in keratinocytes were observed in cells subjected to 3 J/cm². PI3K-pathway genes expression tended to enhance in fibroblasts, presenting a higher relative expression when compared to keratinocytes. In keratinocytes, PBMT groups demonstrated deregulated expression for all inflammatory cytokines' genes tested while fibroblasts presented a tendency to enhance those genes expression in a dose dependent way. CONCLUSIONS: The present study showed that delivering 660 nm, 30 mW was effective to stimulate cell migration, proliferation and to accelerate wound healing. PBMT can modulate cytokines and pathways involved in wound repair. The different energy densities delivering distinct responses in vitro highlights that understanding laser parameters is fundamental to improve treatment strategies.

Oligodontia in the Clinical Spectrum of Syndromes: A Systematic Review.

The aim of this systematic review was to describe the clinical and genetic features of syndromes showing oligodontia as a sign. The review was performed according to the PRISMA 2020 checklist guidelines, and the search was conducted using PubMed, Scopus, Lilacs, Web of science, Livivo, and EMBASE and supplemented by a gray literature search on Google Scholar and ProQuest, applying key terms relevant to the research questions. The systematic review identified 47 types of syndromes in 83 studies, and the most common was hypohidrotic ectodermal dysplasia, which was reported in 24 patients in 22 studies. Other common syndromes that reported oligodontia included Axenfeld-Rieger syndrome, Witkop's syndrome, Ellis-van Creveld syndrome, blepharocheilodontic syndrome, and oculofaciocardiodental syndrome. The X-linked mode of inheritance was the most reported (n = 13 studies), followed by the autosomal dominant (n = 13 studies). The review describes the main syndromes that may have oligodontia as a clinical sign and reinforces the need for orodental-facial examining for adequate diagnosis and treatment of the affected patients. Molecular analysis in order to better understand the occurrence of oligodontia is imperative.

Detection of anti-SARS-CoV-2 salivary antibodies in vaccinated adults.

Since the introduction of efficient anti-SARS-CoV-2 vaccines, the detection of antibodies becomes useful for immunological monitoring and COVID-19 control. Therefore, this longitudinal study aimed to evaluate the detection of SARS-CoV-2 antibodies in the serum and saliva of COVID-19-vaccinated adults. The study included 13 not vaccinated and 35 vaccinated participants with two doses of CoronaVac (Sinovac/Butantan) vaccine who subsequently received BNT162b2 (Pfizer-BioNTech) vaccine as a booster dose. Vaccinated participants donated saliva and serum in three different time points. Enzyme-linked immunosorbent assay was used for antibody detection. In our results, the serum neutralizing antibodies (NAb) were detected in 34/35 samples after second dose and in 35/35 samples one and five months after the booster dose. In saliva, NAb were detected in 30/35 samples after second dose and in 35/35 of samples one and five months after the booster dose. IgA was detected in 19/34 saliva samples after second dose, in 18/35 one month after the booster and in 30/35 five months after. IgG in saliva was detected in 1/34 samples after second dose, 33/35 samples one month after the booster dose and in 20/35 five months after. A strong correlation was found between IgG and neutralizing activity in saliva, and salivary IgA would be a sign of recent exposure to the virus. In conclusion, saliva can be suitable for monitoring antibodies anti-SARS-CoV-2 after vaccination. Heterologous vaccination contributed to increase anti-SARS-CoV-2 antibodies in the Brazilian health context. Complementary studies with large groups are mandatory to conclude the interest in following mucosal immunity.

Critical appraisal tools used in systematic reviews of in vitro cell culture studies: A methodological study.

Systematic reviews (SRs) of preclinical studies are marked with poor methodological quality. In vitro studies lack assessment tools to improve the quality of preclinical research. This methodological study aimed to identify, collect, and analyze SRs based on cell culture studies to highlight the current appraisal tools utilized to support the development of a validated critical appraisal tool for cell culture in vitro research. SRs, scoping reviews, and meta-analyses that included cell culture studies and used any type of critical appraisal tool were included. Electronic search, study selection, data collection and methodological quality (MQ) assessment tool were realized. Further, statistical analyses regarding possible associations and correlations between MQ and collected data were performed. After the screening process, 82 studies remained for subsequent analysis. A total of 32 different appraisal tools were identified. Approximately 60% of studies adopted pre-structured tools not designed for cell culture studies. The most frequent instruments were SYRCLE (n = 14), OHAT (n = 9), Cochrane Collaboration's tool (n = 7), GRADE (n = 6), CONSORT (n = 5), and ToxRTool (n = 5). The studies were divided into subgroups to perform statistical analyses. A significant association (OR = 5.00, 95% CI = 1.54-16.20, p = 0.008) was found between low MQ and chronic degenerative disorders as topic of SR. Several challenges in collecting information from the included studies led to some modifications related to the previously registered protocol. These results may serve as a basis for further development of a critical appraisal tool for cell culture studies capable of capturing all the essential factors related to preclinical research, therefore enhancing the practice of evidence-based.

A meta-analysis reveals the protein profile associated with malignant transformation of oral leukoplakia.

The search for biomarkers associated with oral leukoplakia malignant transformation is critical for early diagnosis and improved prognosis of oral cancer patients. This systematic review and meta-analysis aimed to assess protein-based markers potentially associated with malignant transformation of oral leukoplakia. Five database and the grey literature were searched. In total, 142 studies were included for qualitative synthesis, where 173 proteins were investigated due to their potential role in malignant progression from oral leukoplakia (OL) to oral squamous cell carcinoma (OSCC). The abundance of these proteins was analyzed in fixed tissues and/or biofluid samples, mainly by immunohistochemistry and ELISA, and 12 were shared by both samples. Enrichment analysis revealed that the differential abundant proteins are mostly involved with regulation of cell death, regulation of cell proliferation, and regulation of apoptotic process. Also, these proteins are mainly expressed in the extracellular region (55.5%), cell surface (24.8%), and vesicles (49.1%). The meta-analysis revealed that the proteins related to tumor progression, PD-L1, Mdm2, and Mucin-4 were significantly associated with greater abundance in OSCC patients, with an Odds Ratio (OR) of 0.12 (95% CI: 0.04-0.40), 0.44 (95% CI: 0.24-0.81), and 0.18 (95% CI: 0.04-0.86), respectively, with a moderate certainty of evidence. The results indicate a set of proteins that have been investigated across OSCC initiation and progression, and whose transcriptional expression is associated with clinical characteristics relevant to the prognosis and aggressiveness. Further verification and validation of this biomarkers set are strongly recommended for future clinical application.

Effects of oral supplementation to manage radiation dermatitis in cancer patients: a systematic review.

PURPOSE: To evaluate the effectiveness and safety of oral supplementation as a radioprotective intervention in the management of radiation dermatitis (RD). METHODS: Systematic review and meta-analysis. Six databases and the gray literature were searched for randomized controlled clinical trials (RCTs). Meta-analysis was performed only with studies that evaluated the same intervention. Methodology of included studies was evaluated by the Cochrane risk-of-bias tool for randomized trials (RoB 2.0), and the certainty of evidence was assessed by the GRADE instrument. RESULTS: Seventeen RCTs were included in this review. These evaluated different types of oral supplementations. Findings from three meta-analyses demonstrated no significant benefits to the more severe grades of RD, as oral curcuminoids (RR, 0.59; 95% CI, 0.27 to 1.29; P = 0.19; I2 = 88%), glutamine (RR, 0.40; 95% CI, 0.15 to 1.03; P = 0.06; I2 = 78%) or Wobe-Mugos (RR, 0.57; 95% CI, 0.29 to 1.14; P = 0.11; I2 = 72%). Also, the certainty of the evidence of outcomes evaluated was moderate or low. Except for a few gastrointestinal adverse events, oral supplementation was well tolerated. CONCLUSION: Most oral supplements cannot yet be recommended to manage RD due to insufficient or conflicting evidence. However, despite no significant results, glutamine was shown to be a promising substance in terms of the potential radioprotective effect and may be well tolerated. These results suggest that more RCTs with larger samples are needed to evaluate the efficacy, safety, and tolerance of glutamine in the management of RD.

Revisiting the evidence of photodynamic therapy for oral potentially malignant disorders and oral squamous cell carcinoma: An overview of systematic reviews.

BACKGROUND: This study summarized the available evidence about the use of photodynamic therapy (PDT) for the management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC). METHODS: An overview of systematic reviews was undertaken based on the 2020 PRISMA statement. Electronic searches were performed in five databases. Studies published up to November 2022 were included. Risk of bias was assessed with the AMSTAR 2 tool. RESULTS: A total of 30 studies enrolling 9,245 individuals with OPMD (n = 7,487) or OSCC (n = 1,758) met the selection criteria. All studies examined the efficacy and/or safety of PDT. OPMD were investigated individually in 82.8% of the studies, the most common being oral lichen planus and actinic cheilitis. OSCC was addressed separately in 10.3% of the studies, while only 6.9% evaluated both OPMD and OSCC. Fourteen different types of photosensitizers were described. PDT was used according to the following setting parameters: 417-670 nm, 10-500 mW/cm2, 1.5-200 J/cm2, and 0.5-143 min. Regarding OPMD, leukoerythroplakia showed the best response rates, while oral lichen planus presented a partial or no response in nearly 75% of documented cases. A complete response was observed in 85.9% of OSCC cases, while 14.1% had no resolution. CONCLUSION: Overall, the response to PDT depended on the type of OPMD/OSCC and the parameters used. Although PDT is an emerging candidate for the treatment of OPMD and OSCC, there is heterogeneity of the methodologies used and the clinical data obtained, particularly regarding the follow-up period.

Use of histone methyltransferase inhibitors in cancer treatment: A systematic review.

Histone modifications are an epigenetic mechanism, and the dysregulation of these proteins is known to be associated with the initiation and progression of cancer. In the search for the development of new and more effective drugs, histone modifications were identified as possible therapeutic targets. Histone methyltransferase (HMT) inhibitors correspond to the third generation of epigenetic drugs capable of writing or deleting epigenetic information. This systematic review summarized the development and prospect for the use of different HMT inhibitors in cancer therapy. An electronic search was applied across CENTRAL, Clinical Trials, Embase, LILACS, LIVIVO, Open Gray, PubMed, Scopus, and Web of Science. Based on the title and abstracts, two authors independently selected eligible studies. After the complete reading of the articles, based on the eligibility criteria, 11 studies were included in the review. Different inhibitors of HMT have been explored in multiple clinical studies, and have shown considerable anti-tumor effects. However, few phase 2 studies have been completed and/or have available results. The most advanced clinical trials mainly include tazemetostat, an Enhancer of zeste homolog 2 (EZH2) inhibitor approved for follicular lymphoma (FL). The use of HMT inhibitors has presented, so far, concise results in the treatment of hematological cancers, moreover, the adverse effects presented after the use of these medicines (alone or in combination) did not show a high level of risk for the patient. These findings, in addition to ongoing clinical studies, can represent a promising future regarding the use of HMT inhibitors in treating different types of cancer.

Dosimetric parameters and radiotherapy simulation methods used in preclinical studies of radiation damage to the dentition: a systematic review.

OBJECTIVE: This systematic review investigated the dosimetric parameters used in preclinical studies. STUDY DESIGN: Searches were performed in 3 databases (PubMed, Scopus, and Embase) and gray literature to identify studies for review. In vitro and ex vivo studies that examined the effect of radiation on human permanent teeth were included. The modified Consolidated Standards Of Reporting Trials checklist of items for reporting preclinical in vitro studies was used to assess the risk of bias. RESULTS: In total, 32 studies met the inclusion criteria. The average radiation dose of in vitro studies was 53 (±22) Gy and in ex vivo studies was 69 (±1) Gy. Twenty-two studies used 5 different fractionation schemes. Twenty-two of the included studies did not report the radiotherapy modality of those reporting. Twenty studies used linear accelerators, and 7 used Cobalt-60 with the source-surface-distance of radiation ranging from 1.5 to 100 cm. Distilled water was the storage solution for the dental structure used most commonly. Biases were observed, including small sample sizes, lack of randomization, and blinding processes. CONCLUSION: The dosimetric parameters used in the preclinical studies, including radiation dose, radiotherapy modality, fractionation regime, and the storage solutions used did not support the hypothesis of direct effects of radiation on the dental structure.

Dental education profile in COVID-19 pandemic: A scoping review.

INTRODUCTION: This scoping review aimed to determine the frequency of different teaching methodologies, tools and platforms applied in dental education during the COVID-19 pandemic. MATERIALS AND METHODS: The search strategy was performed in six databases and grey literature. A total of 28 questionnaire-based studies were included, without language or time restriction, from 20 different countries. RESULTS: Six thousand five hundred sixty-five participants were assessed: 84% undergraduates, 9% of faculty members, 5% of postgraduate students/residents/trainees and 2% of dental schools/residency programs. The pooled eligible data for teaching methodologies were 62% of a combination of different methods (95% CI, 35.5% to 82.3%), 23% a combination of synchronous and asynchronous formats (95% CI, 8.2% to 50.2%) and 15% for only synchronous lectures (95% CI, 4.3% to 42.2%). The reported tools were laptops (40%), smartphones (40%), tablets (40%), desktops (20%), Blackboard (20%), Respondus Lockdown Browser (20%), eProctor (20%) and PowerPoint (20%). The most used platforms were Zoom (70.6%), Microsoft Teams (23.5%) and Cisco Webex (23.5%). A better time management (17.9%; 95% CI, 7.9% to 35.6%) and the possibility of revision with additional notes (14.3%; 95% CI, 5.7% to 31.5%) was the greatest advantages related to dental e-learning, while the increased levels of anxiety/stress/burnout/exhaustion (35.7%; 95% CI, 21% to 54.2%) and internet connection problems (35.7%; 95% CI, 21% to 54.2%) was the most cited disadvantages. CONCLUSION: This scoping review showed promising blended teaching methodologies, tools and platforms in the dental education profile. The evidence suggests that e-learning technologies can widely contribute to dental education during the COVID-19 pandemic. Therefore, this study makes a major contribution to research by assessing the impact of COVID restrictions on dental education and further studies are needed to identify how restrictions in dental practice will affect future professionals.

Saliva is suitable for SARS-CoV-2 antibodies detection after vaccination: A rapid systematic review.

Since the introduction of efficient vaccines anti-SARS-CoV-2, antibody quantification becomes increasingly useful for immunological monitoring and COVID-19 control. In several situations, saliva samples may be an alternative to the serological test. Thus, this rapid systematic review aimed to evaluate if saliva is suitable for SARS-CoV-2 detection after vaccination. For this purpose, search strategies were applied at EMBASE, PubMed, and Web of Science. Studies were selected by two reviewers in a two-phase process. After selection, 15 studies were eligible and included in data synthesis. In total, salivary samples of approximately 1,080 vaccinated and/or convalescent individuals were analyzed. The applied vaccines were mostly mRNA-based (BioNTech 162b2 mRNA/Pfizer and Spikevax mRNA-1273/Moderna), but recombinant viral-vectored vaccines (Ad26. COV2. S Janssen - Johnson & Johnson and Vaxzevria/Oxford AstraZeneca) were also included. Different techniques were applied for saliva evaluation, such as ELISA assay, Multiplex immunoassay, flow cytometry, neutralizing and electrochemical assays. Although antibody titers are lower in saliva than in serum, the results showed that saliva is suitable for antibody detection. The mean of reported correlations for titers in saliva and serum/plasma were moderate for IgG (0.55, 95% CI 0.38-9.73), and weak for IgA (0.28, 95% CI 0.12-0.44). Additionally, six out of nine studies reported numerical titers for immunoglobulins detection, from which the level in saliva reached their reference value in four (66%). IgG but not IgA are frequently presented in saliva from vaccinated anti-COVID-19. Four studies reported lower IgA salivary titers in vaccinated compared to previously infected individuals, otherwise, two reported higher titers of IgA in vaccinated. Concerning IgG, two studies reported high antibody titers in the saliva of vaccinated individuals compared to those previously infected and one presented similar results for vaccinated and infected. The detection of antibodies anti-SARS-CoV-2 in the saliva is available, which suggests this type of sample is a suitable alternative for monitoring the population. Thus, the results also pointed out the possible lack of mucosal immunity induction after anti-SARS-CoV-2 vaccination. It highlights the importance of new vaccination strategies also focused on mucosal alternatives directly on primary routes of SARS-CoV-2 entrance. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022336968, identifier CRD42022336968.

Use of Chamomile Infusion to Mitigate Radiotherapy-Induced Dry Desquamation in Head and Neck Cancer Patients.

PURPOSE: To evaluate the effect of using a compress with Chamomilla recutita infusion in the regression of dry desquamation and in the prevention of moist desquamation in head and neck cancer patients undergoing radiotherapy. METHODS: A prospective intervention study was carried out from May 2019 to May 2021. In total, 43 participants were included, who were instructed to apply the compress with the infusion 3 times a day, after occurrence of dry desquamation. Skin evaluation took place daily from initiation of the intervention up to the end of radiotherapy. RESULTS: All the participants presented dry desquamation regression, where 65.1% (95% CI 50.1-78.1) had total regression until the end of radiotherapy, with a mean of 9 days of regression. Only 34.9% (95% CI 21.8-49.9) of the participants developed moist desquamation by the end of the radiotherapy sessions, with a mean accumulated dose of ionizing radiation of 50.9 Gy. CONCLUSION: This study highlighted the potential clinical benefits of using Chamomilla recutita in the regression of dry desquamation and in the prevention of moist desquamation.

To extract or not extract teeth prior to head and neck radiotherapy? A systematic review and meta-analysis.

PURPOSE: Teeth with poor prognosis are generally recommended to be extracted prior to head and neck radiotherapy (RT) to reduce the risk of developing osteoradionecrosis (ORN), although controversies have been reported. The present systematic review aimed to determine whether tooth extraction prior to head and neck RT may be associated with a reduced risk of developing ORN compared to dental extraction during or after RT. METHODS: The review protocol was registered in PROSPERO (CRD42021241631). The review was reported according to the PRISMA checklist and involved a comprehensive search of PubMed, Scopus, Embase, Cochrane Library, LILACS, and Web of Science, in addition to the gray literature. The selection of studies was performed in two phases by two reviewers independently. The risk of bias of individual studies was analyzed using the Joanna Briggs Institute checklist for cross-sectional studies, and the certainty of evidence was assessed using the GRADE tool. RESULTS: Twenty-eight observational studies were included in the qualitative synthesis, which showed substantial heterogeneity regarding the association between the timing of tooth extraction and ORN development. Twenty-seven of 28 studies were pooled in a meta-analysis that demonstrated a significant association between an increased risk of ORN and post-RT tooth extraction (odds ratio: 1.98; 95% CI: 1.17-3.35; p = 0.01). CONCLUSION: It was confirmed with moderate certainty that dental extractions should be performed prior to the start of head and neck RT to reduce the risk of ORN.

Effects of medicinal plants and natural compounds in models of prostate cancer related to sex steroids: A systematic review.

Prostate cancer remains a health problem for men. Targeting androgen (AR) and estrogen (ER) receptors improves the outcomes of the disease, and many medicinal plants exert their effects by modulating these pathways. Therefore, a systematic review was conducted to identify medicinal plants and their natural compounds that may modulate the AR and/or ER pathways in cell and animal models. A search was conducted across EMBASE, LILACS, PubMed, Scopus, and Web of Science, with grey literature from Google SCHOLAR and ProQuest. Two authors independently selected eligible studies based on their titles and abstracts, and a third author resolved conflicts. Then, data from the full text of eligible studies were extracted and synthesized. In total, 75 studies were included. Results showed the effects of several different medicinal plants and natural compounds in reduction of AR and/or ER transcription and translation and AR secondary effects: cell growth reduction, induction of apoptosis, and cell cycle arrest. In animal models, tumor size reduction, increase in apoptosis, and downregulation of AR expression in tumors were also observed. No single phytochemical group concentrating molecules with anti-AR and/or ER activity was identified. Nevertheless, several phytochemical compounds showed potential for future clinical studies in the management of the disease.

Single nucleotide polymorphisms to predict acute radiation dermatitis in breast cancer patients: A systematic review and meta-analysis.

PURPOSE: To identify Single Nucleotide Polymorphisms (SNPs) that can predict acute radiation dermatitis (RD) in breast cancer patients (BC), and the association between SNPs and RD severity. METHODS: We performed the search in seven databases and the gray literature, and a meta-analysis to assess SNPs in patients with RD and to evaluate the association between SNPs and severe RD. RESULTS: We included sixteen single-arm cohort studies with 4742 BC. The most prevalent SNPs were the TGFß1 rs1800469 (41%), and the GSTA1 rs3957356 (36%). Seven genotypes were associated with severe RD (PTTG1 rs3811999-CC; PTTG1 rs2961950-AA; MAD2L2 rs2294638-GG; MAT1A rs2282367-GG; GSTA1 rs3957356-CT; CD44 rs8193-CT; SH3GL1 rs243336-GC) and five SNPs were associated with lower RD (PTTG1 rs2961952-GG; CD44 rs8193-CC; PTTG1 rs3811999-CT; MAT1A rs2282367-GA; OGG1 rs2075747-AA). CONCLUSIONS: The genotyping of SNPs more prevalent may be a strategy for predicting RD in BC, and some genotypes (GSTA1 rs3957356-CT; MAT1A rs2282367-GG) are associated with severe RD.

Expression profile of the PI3K-AKT-mTOR pathway in head and neck squamous cell carcinoma: Data from Brazilian population.

OBJECTIVE: The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of the rapamycin (PI3K-AKT-mTOR) signaling pathway is an important regulator of cell proliferation, survival, and motility. The gain or loss of function of proteins related to this pathway results in the neoplastic transformation in several types of cancers. This study aimed to evaluate the expression profile of the PI3K-AKT-mTOR pathway in patients with head and neck squamous cell carcinoma (HNSCC) and HNSCC cell lines. STUDY DESIGN: The study involved 26 formalin-fixed paraffin-embedded tissue samples from patients with HNSCC. The analysis of immunohistochemical expression of PI3K, AKT, p-mTOR, and phosphatase and tensin homolog (PTEN) proteins was performed by a quantitative assessment. The in vitro gene and protein expression evaluation was performed by real-time polymerase chain reaction and Western blot assay, respectively, in the human cell lines SCC-9 and FaDu. RESULTS: High levels of PI3K, AKT, and p-mTOR were found in most HNSCC tumors. Following this result, we observed low amounts or absence of PTEN in most samples. Additionally, the FaDu cells (pharynx) showed higher AKT expression but lower expression of p-mTOR compared with SCC-9 cells (oral cavity), which hints at a loco-anatomical relevance. CONCLUSION: Overall, this study found increased expression of the PI3K-AKT-mTOR pathway along with evident PTEN reduction in head and neck cancer.