New perspectives on biology,disease progression,and therapy response of head and neck cancer gained from single cell RNA sequencing and spatial transcriptomics

Head and neck squamous cell carcinoma(HNSCC)is one of the most frequent cancers worldwide.The main risk factors are consumption of tobacco products and alcohol,as well as infection with human papilloma virus.Approved therapeutic options comprise surgery,radiation,chemotherapy,targeted therapy through epidermal growth factor receptor inhibition,and immunotherapy,but outcome has remained unsatisfactory due to recurrence rates of~50%and the frequent occurrence of second primaries.The availability of the human genome sequence at the beginning of the millennium heralded the omics era,in which rapid technological progress has advanced our knowledge of the molecular biology of malignant diseases,including HNSCC,at an unprecedented pace.Initially,microarray-based methods,followed by approaches based on next-generation sequencing,were applied to study the genetics,epigenetics,and gene expression patterns of bulk tumors.More recently,the advent of single-cell RNA sequencing(scRNAseq)and spatial transcriptomics methods has facilitated the investigation of the heterogeneity between and within different cell populations in the tumor microenvironment(e.g.,cancer cells,fibroblasts,immune cells,endothelial cells),led to the discovery of novel cell types,and advanced the discovery of cell-cell communication within tumors.This review provides an overview of scRNAseq,spatial transcriptomics,and the associated bioinformatics methods,and summarizes how their application has promoted our understanding of the emergence,composition,progression,and therapy responsiveness of,and intercellular signaling within,HNSCC.

Classificatory updates in verrucous and cuniculatum carcinomas:Insights from the 5^(th) edition of WHO-IARC head and neck tumor classification

The International Agency for Research on Cancer(IARC)and World Health Organization(WHO)collaboratively produce the'WHO Blue Books'essential tools standardizing the diagnostic process for human cancers.Regular updates in this classification accommodate emerging molecular discoveries,advances in immunohistochemical techniques,and evolving clinical insights.The 5th edition of the WHO/IARC classification of head and neck tumors refines the'Oral Cavity and Mobile Tongue'chapter,including sections for non-neoplastic lesions,epithelial tumors,and tumors of uncertain histogenesis.Notably,the epithelial tumors section is rearranged by tumor behavior,starting with benign squamous papillomas and progressing through potentially malignant oral disorders to oral squamous cell carcinoma(OSCC).The section on OSCC reflects recent information on epidemiology,pathogenesis,and histological prognostic factors.Noteworthy is the specific categorization of verrucous carcinoma(VC)and carcinoma cuniculatum(CC),both associated with the oral cavity and distinct in clinical and histologic characteristics.This classification adjustment emphasizes the oral cavity as their predominant site in the head and neck.Designating specific sections for VC and CC aims to provide comprehensive insights into these unique subtypes,elucidating their clinical features,distinct histological characteristics,prevalence,significance,and clinical relevance.By categorizing these subtypes into specific sections,the 5th edition of the WHO classification aims to provide a more nuanced and detailed account,enhancing our understanding of these specific variants within the broader spectrum of head and neck tumors.

Application of single-cell RNA sequencing in head and neck squamous cell carcinoma

Single-cell RNA sequencing has been broadly applied to head and neck squamous cell carcinoma(HNSCC) for characterizing the heterogeneity and genomic mutations of HNSCC benefiting from the advantage of single-cell resolution. We summarized most of the current studies and aimed to explore their research methods and ideas, as well as how to transform them into clinical applications. Through single-cell RNA sequencing, we found the differences in tumor cells’ expression programs and differentiation tracks. The studies of immune microenvironment allowed us to distinguish immune cell subpopulations, the extensive expression of immune checkpoints, and the complex crosstalk network between immune cells and non-immune cells. For cancerassociated fibroblasts(CAFs), single-cell RNA sequencing had made an irreplaceable contribution to the exploration of their differentiation status, specific CAFs markers, and the interaction with tumor cells and immune cells. In addition, we demonstrated in detail how single-cell RNA sequencing explored the HNSCC epithelial-tomesenchymal transition(EMT) model and the mechanism of drug resistance, as well as its clinical value.

Glucocorticoid reduces the efficacy of afatinib on the head and neck squamous cell carcinoma

Glucocorticoids(GC)are widely used to counter the adverse events during cancer therapy;nonetheless,previous studies pointed out that GC may reduce the efficacy of chemotherapy on cancer cells,especially in epidermal growth factor receptor(EGFR)-targeted therapy of head and neck squamous cell carcinoma(HNSCC)remaining to be elucidated.The primary aim of the present study was to probe into the GC-induced resistance of EGFR-targeted drug afatinib and the underlying mechanism.HNSCC cell lines(HSC-3,SCC-25,SCC-9,and H-400)and the human oral keratinocyte(HOK)cell lines were assessed for GC receptor(GR)expression.The promoting tumor growth effect of GC was evaluated by the CCK-8 assay and flow cytometry.Levels of signaling pathways participants GR,mTOR,and EGFR were determined by quantitative polymerase chain reaction and western blotting.GC increased the proliferation of HNSCC cells in a GR-dependent manner and promoted AKT/mTOR signaling.But GC failed in counteracting the inhibition of rapamycin in the mTOR signaling pathway.Besides,GC also induced resistance to EGFR-targeted drug afatinib through AKT/mTOR instead of the EGFR/ERK signaling pathway.Thus,GCs reduce the efficacy of afatinib on HNSCC,implicating a cautious use of glucocorticoids in clinical practice.

Comprehensive bioinformatics analysis and experimental validation:An anoikis-related gene prognostic model for targeted drug development in head and neck squamous cell carcinoma

We analyzed RNA-sequencing(RNA-seq)and clinical data from head and neck squamous cell carcinoma(HNSCC)patients in The Cancer Genome Atlas(TCGA)Genomic Data Commons(GDC)portal to investigate the prognostic value of anoikis-related genes(ARGs)in HNSCC and develop new targeted drugs.Differentially expressed ARGs were screened using bioinformatics methods;subsequently,a prognostic model including three ARGs(CDKN2A,BIRC5,and PLAU)was constructed.Our results showed that the model-based risk score was a good prognostic indicator,and the potential of the three ARGs in HNSCC prognosis was validated by the TISCH database,the model’s accuracy was validated in two independent cohorts of the Gene Expression Omnibus database.Immune correlation analysis and half-maximal inhibitory concentration were also performed to reveal the different landscapes of TIME between risk groups and to predict immuno-and chemo-therapeutic responses.Potential small-molecule drugs for HNSCC were subsequently predicted using the L1000FWD database.Finally,in vitro experiments were used to verify the database findings.The relative ARG mRNA expression levels in HNSCC and surrounding normal tissues remained consistent with the model results.BIRC5 knockdown inhibited anoikis resistance in WSU-HN6 and CAL-27 cells.Molecular docking,real-time PCR,cell counting kit-8(CCK-8),plate clone,and flow cytometry analyses showed that small-molecule drugs predicted by the database may target the ARGs in the prognostic model,inhibit HNSCC cells survival rate,and promote anoikis in vitro.Therefore,we constructed a new ARG model for HNSCC patients that can predict prognosis and immune activity and identify a potential small-molecule drug for HNSCC,paving the way for clinically targeting anoikis in HNSCC.

Neoadjuvant Immunotherapy for Head and Neck Squamous Cell Carcinoma:Expecting Its Application in Temporal Bone Squamous Cell Carcinoma

Temporal bone malignant tumors are characterized by atypical clinical symptoms,and easy recurrence and metastasis.They account for 0.2%of head and neck tumors,and the most common pathological type is squamous cell carcinoma.Patients with squamous cell carcinoma of the temporal bone are often at advanced stages when diagnosed,and lose the chance for surgery.Neoadjuvant immunotherapy has recently been approved as the first-line treatment for refractory recurrent/metastatic squamous cell carcinoma of the head and neck.However,it remains to be determined whether neoadjuvant immunotherapy can be used as the first-line treatment for temporal bone squamous cell carcinoma to reduce the tumor stage before surgery,or as a palliative treatment for patients with unresectable advanced stage carcinoma.The present study reviews the development of immunotherapy and its clinical application in head and neck squamous cell carcinoma,summarizes the treatment of temporal bone squamous cell carcinoma,and prospects the neoadjuvant immunotherapy as the first-line treatment for temporal bone squamous cell carcinoma.

Regulation of RNA methylation and immune infiltration patterns by m5C regulators in head and neck squamous cell carcinoma

5-Methylcytosine(m5C)methylation contributes to the development and progression of various malignant tumors.This study aimed to explore the potential role of m5C methylation regulators(m5CMRs)in head and neck squamous cell carcinoma(HNSCC).Methods:The transcription data of HNSCC samples were obtained from The Cancer Genome Atlas(TCGA)and the Gene Expression Omnibus(GEO)databases.Subsequently,the m5C patterns in HNSCC were evaluated based on 14 m5CMRs.Then,the m5Cscore was developed to quantify m5C patterns by using principal component analysis(PCA)algorithms.Two single-cell RNA sequencing datasets and various methods were employed to assess the prognostic value and sensitivity to immunotherapy.Finally,key prognostic m5CMRs were identified using univariate COX regression analysis,and their clinical significance was validated based on the Human Protein Atlas(HPA)database and by using immunohistochemistry.Results:Two distinct m5C clusters were identified.m5C cluster A is characterized by an immune-activated microenvironment and is associated with a favorable prognosis.Notable differences were observed in prognosis,immune infiltration,and immunotherapy response between the high-and low-m5Cscore groups.Patients in the high-m5Cscore group exhibited high TMB,which is correlated with poor prognosis.The m5Cscore of epithelial cells in HNSCC was higher than that in other cells.Key prognostic m5CMRs,including NSUN2,DNMT3B,ALKBH1,and Y-Box Binding Protein 1(YBX1),were associated with poor prognosis.Conclusion:Our research indicates that in head and neck squamous cell carcinoma,the m5C modification profoundly affects the TME’s diversity and complexity,influencing prognosis and the success of immunotherapy.Targeting m5C regulatory elements may be a new method for enhancing the efficacy of immunotherapy in HNSCC.

Optimization of Culture Medium and Transfection Method for Head and Neck Squamous Cell Carcinoma Organoids

[Objectives] To optimize the culture medium for head and neck squamous cell carcinoma patient-derived organoid and screen suitable cytokines;compare the transfection efficiency of direct transfection and short-term suspension transfection for organoid in matrigel. [Methods] Advanced DMEM/F12 medium, GlutaMax and HEPES buffer, nicotinamide, N-acetylcysteine, B27, A83-01, EGF, Y-27632 and Primocin primary cell antibiotics were prepared. On this basis, fibroblast growth factor 10(FGF10), Neuregulin 1, Noggin and R-spondin-1 were added in turn to prepare the selection medium, and the organoid diameter was used as the evaluation index to evaluate the effect of organoid medium. Using lentivirus, mCherry red fluorescent protein was transfected into HNSCC—PDO in different ways, and the transfection effect was evaluated by the fluorescence intensity of organoid sphere. [Results] Nrg1 Noggin and R-Spondin-1 promoted the growth of head and neck squamous cell carcinoma sphere(P<0.05) while FGF10 did not significantly promote the growth of head and neck squamous cell carcinoma sphere(P>0.05). Compared with direct transfection, short-term suspension transfection had higher transfection efficiency for HNSCC—PDO in matrigel. [Conclusions] R-Spondin-1 Nrg1 and Noggin may be the key cytokines in culture of HNSCC—PDO whereas FGF10 played an insignificant role in this study. Short-term suspension transfection could improve the transfection efficiency of lentivirus to HNSCC—PDO.

Towards system genetics analysis of head and neck squamous cell carcinoma using the mouse model,cellular platform,and clinical human data

Head and neck squamous cell cancer(HNSCC)is a leading global malignancy.Every year,More than 830000 people are diagnosed with HNSCC globally,with more than 430000 fatalities.HNSCC is a deadly diverse malignancy with many tumor locations and biological characteristics.It originates from the squamous epithelium of the oral cavity,oropharynx,nasopharynx,larynx,and hypopharynx.The most frequently impacted regions are the tongue and larynx.Previous investigations have demonstrated the critical role of host genetic susceptibility in the progression of HNSCC.Despite the advances in our knowledge,the improved survival rate of HNSCC patients over the last 40 years has been limited.Failure to identify the molecular origins of development of HNSCC and the genetic basis of the disease and its biological heterogeneity impedes the development of new therapeutic methods.These results indicate a need to identify more genetic factors underlying this complex disease,which can be better used in early detection and prevention strategies.The lack of reliable animal models to investigate the underlying molecular processes is one of the most significant barriers to understanding HNSCC tumors.In this report,we explore and discuss potential research prospects utilizing the Collaborative Cross mouse model and crossing it to mice carrying single or double knockout genes(e.g.Smad 4 and P53 genes)to identify genetic factors affecting the development of this complex disease using genome-wide association studies,epigenetics,micro RNA,long noncoding RNA,lnc RNA,histone modifications,methylation,phosphorylation,and proteomics.

A pilot study of the relative number of circulating tumor cells and leukocytes containing actin-binding proteins in head and neck cancer patients

Circulating tumor cells(CTCs)play an important role in tumor metastases,which is positively correlated with an increased risk of death.Actin-binding proteins,including cofilin(CFL1),profilin 1(PFN1),and adenylate cyclase-associated protein 1(CAP1),are thought to be involved in tumor cell motility and metastasis,specifically in head and neck squamous cell carcinoma(HNSCC).However,currently,there are no published studies on CFL1,PFN1,and CAP1 in CTCs and leukocytes in HNSCC patients.We assessed serum levels of CFL1,PFN1,and CAP1 and the number of CTCs and leukocytes containing these proteins in blood from 31 HNSCC patients(T1-4N0-2M0).The analysis used flow cytometry and an enzyme-linked immunosorbent assay kit.We found that CAP1+CTCs and CAP1+leukocyte subpopulations were prevalent in these HNSCC patient samples,while the prevalence rates of CFL1+and PFN1+CTCs were relatively low.Patients with stage T2-4N1-2M0 had CFL1+and PFN1+CTCs with an elevated PFN1 serum level,compared with the T1-3N0M0 group.In summary,the PFN1 serum level and the relative number of PFN1+CD326+CTCs could be valuable prognostic markers for HNSCC metastases.The current study is the first to obtain data regarding the contents of actin-binding proteins(ABPs)in CTCs,and leukocytes in blood from HNSCC patients.This is also the first to assess the relationship between the number of CTCs subgroups and disease characteristics.

Re-expression of DIRAS3 and P53 induces apoptosis and impaired autophagy in head and neck squamous cell carcinoma

Background:p53 and DIRAS3 are tumor suppressors that are frequently silenced in tumors.In this study,we sought to determine whether the concurrent re-expression of p53 and DIRAS3 could effectively induce head and neck squamous cell carcinoma(HNSCC)cell death.Methods:CAL-27 and SCC-25 cells were treated with Ad-DIRAS3 and rAd-p53 to induce re-expression of DIRAS3 and p53 respectively.The effects of DIRAS3 and p53 re-expression on the growth and apoptosis of HNSCC cells were examined by TUNEL assay,flow cytometric analysis and MTT.The effects of DIRAS3 and p53 re-expression on Akt phosphorylation,oncogene expression,and the interaction of 4 E-BP1 with eIF4 E were determined by real-time PCR,Western blotting and immunoprecipitation analysis.The ability of DIRAS3 and p53 re-expression to induce autophagy was evaluated by transmission electron microscopy,LC3 fluorescence microscopy and Western blotting.The effects of DIRAS3 and p53 re-expression on HNSCC growth were evaluated by using an orthotopic xenograft mouse model.Results:TUNEL assay and flow cytometric analysis showed that the concurrent re-expression of DIRAS3 and p53 significantly induced apoptosis(P<0.001).MTT and flow cytometric analysis revealed that DIRAS3 and p53 reexpression significantly inhibited proliferation and induced cell cycle arrest(P<0.001).Mechanistically,the concurrent re-expression of DIRAS3 and p53 down-regulated signal transducer and activation of transcription 3(STAT3)and upregulated p21WAF1/CIP1 and Bax(P<0.001).DIRAS3 and p53 re-expression also inhibited Akt phosphorylation,increased the interaction of eIF4 E with 4 E-BP1,and reduced the expression of c-Myc,cyclin D1,vascular endothelial growth factor(VEGF),fibroblast growth factor(FGF),epidermal growth factor receptor(EGFR)and Bcl-2(P<0.001).Moreover,the concurrent re-expression of DIRAS3 and p53 increased the percentage of cells with GFP-LC3 puncta compared with that in cells treated with control adenovirus(50.00%±4.55%vs.4.67%±1.25%,P<0.001).LC3 fluorescence microscopy and Western blotting further showed that DIRAS3 and p53 re-expression significantly promoted autophagic activity but also inhibited autophagic flux,resulting in overall impaired autophagy.Finally,the concurrent re-expression of DIRAS3 and p53 significantly decreased the tumor volume compared with the control group in a HNSCC xenograft mouse model[(3.12±0.75)mm^(3) vs.(189.02±17.54)mm^(3),P<0.001].Conclusions:The concurrent re-expression of DIRAS3 and p53 is a more effective approach to HNSCC treatment than current treatment strategies.

The prognostic value of Tiaml proteinexpression in head and neck squamous cellcarcinoma： a retrospective study

Introduction Head and neck squamous cell carcinoma （HNSCC） is a common cancer worldwide and has a poorprognosis. A biomarker predicting the clinical outcome of HNSCC patients could be useful in guiding treatment planning.Overexpression of theT lymphoma invasion and metastasis 1 （Tiaml） protein has been implicated in the migrationand invasion of neoplasms. However, its role in HNSCC progression needs to be further validated. We detectedthe expression of Tiaml in normal and tumor tissues and determined its association with clinical outcomes in patientswith HNSCCMethods： We measured the expression of Tiaml in normal and cancerous tissue samples from the patients withHNSCC treated at Sun Yat-sen University Cancer Center between 2001 and 2008. The Tiaml expression was scoredfrom 0 to 12 based on the percentage of positively stained cells and the staining intensity. We then determined thediagnostic performance of this score in predicting overall survival （OS） and disease-free survival （DFS）.Results： Of the 194 evaluable patients, those with advanced disease, lymph node metastasis at diagnosis, and recurrenceor metastasis during follow-up had a highertendency of having high Tiaml expression as compared with theircounterparts （P 〈 0.05）. The proportion of samples with high Tiaml expression was also higher in cancerous tissuesthan in non-cancerous tissues （57.7% vs. 13.9%, P 〈 0.001）. Cox proportional hazards regression analysis revealed thatTiaml expression scores of 5 and greater independently predicted short OS and DFS.Conclusion： TheTiaml expression is shown as a promising biomarker of clinical outcomes in patients with HNSCCand should be evaluated in prospective trials.

Clinical impact of surveillance for head and neck cancer in patients with esophageal squamous cell carcinoma

AIM To evaluate the clinical impact of surveillance for head and neck(HN) region with narrow band imaging(NBI) in patients with esophageal squamous cell carcinoma(ESCC).METHODS Since 2006, we introduced the surveillance for HN region using NBI for all patients with ESCC beforetreatment, and each follow-up. The patients with newly diagnosed stage Ⅰ to Ⅲ ESCC were enrolled and classified into two groups as follows: Group A(no surveillance for HN region); between 1992 and 2000), and Group B (surveillance for HN region with NBI; between 2006 and 2008). We comparatively evaluated the detection rate of superficial head and neck squamous cell carcinoma (HNSCC), and the serious events due to metachronous advanced HNSCC during the follow-up.RESULTS A total 561 patients(group A: 254, group B: 307) were enrolled. Synchronous superficial HNSCC was detected in 1 patient (0.3%) in group A, and in 12 (3.9%) in group B (P=0.008). During the follow up period, metachronous HNSCC were detected in 10 patients(3.9%) in group A and in 30 patients(9.8%) in group B(P = 0.008). All metachronous lesions in group B were early stage, and 26 patients underwent local resection, however, 6 of 10 patients (60%) in group A lost their laryngeal function and died with metachronous HNSCC.CONCLUSION Surveillance for the HN region by using NBI endoscopy increase the detection rate of early HNSCC in patients with ESCC, and led to decrease serious events related to advanced metachronous HNSCC.

Boron neutron capture therapy: moving towards targeted therapy for locally recurrent head and neck squamous cell carcinoma

Locally recurrent head and neck squamous cell carcinoma(HNSCC)is often unresectable,and a repeat course of radiotherapy is associated with incremental toxicities.Boron neutron capture therapy(BNCT)is a novel targeted radiotherapy modality that can achieve a high dose gradient between cancerous and adjacent normal tissues.However,the relationships among the dose resulting from BNCT,tumor response to BNCT,and survival are not completely understood.Recently,a study published in Radiotherapy and Oncology investigated the efficacy of BNCT in the treatment of patients with locally recurrent HNSCC and the factors associated with favorable treatment response and survival.In this article,the findings,strengths and limitations of this study are discussed in depth,and the significance of the study and motivations for future research are highlighted.

Association of microRNA polymorphisms with the risk of head and neck squamous cell carcinoma in a Chinese population:a case-control study

Background:MicroRNA(miRNA) polymorphisms may alter miRNA-related processes,and they likely contribute to cancer susceptibility.Various studies have investigated the associations between genetic variants in several key miRNAs and the risk of human cancers;however,few studies have focused on head and neck squamous cell carcinoma(HNSCC) risk.This study aimed to evaluate the associations between several key miRNA polymorphisms and HNSCC risk in a Chinese population.Methods:In this study,we genotyped five common single-nucleotide polymorphisms(SNPs) in several key miRNAs(miR-149 rs2292832,miR-146 a rs2910164,miR-605 rs2043556,miR-608 rs4919510,and miR-196a2 rs11614913) and evaluated the associations between these SNPs and HNSCC risk according to cancer site with a case-control study including 576 cases and 1552 controls,which were matched by age and sex in a Chinese population.Results:The results revealed that miR-605 rs2043556[dominant model:adjusted odds ratio(OR) 0.71,95%confidence interval(CI) 0.58-0.88;additive model:adjusted OR 0.74,95%CI 0.62-0.89]and miR-196a2 rs11614913(dominant model:adjusted OR 1.36,95%C11.08-1.72;additive model:adjusted OR 1.28,95%C11.10-1.48) were significantly associated with the risk of oral squamous cell carcinoma(OSCC).Furthermore,when these two loci were evaluated together based on the number of putative risk alleles(rs2043556 A and rs11614913 G),a significant locus-dosage effect was noted on the risk of OSCC(P_(trend) < 0.001).However,no significant association was detected between the other three SNPs(miR-149 rs2292832,miR- 146 a rs2910164,and miR-608 rs4919510) and HNSCC risk.Conclusion:Our study provided the evidence that miR-605 rs2043556 and miR-196a2 rs11614913 may have an impact on genetic susceptibility to OSCC in Chinese population.

Biomarkers of cetuximab resistance in patients with head and neck squamous cell carcinoma

Objective:In patients with head and neck squamous cell carcinoma(HNSCC),cetuximab[a monoclonal antibody targeting epidermal growth factor receptor(EGFR)]has been shown to improve overall survival when combined with radiotherapy in the locally advanced setting or with chemotherapy in first-line recurrent and/or metastatic(R/M)setting,respectively.While biomarkers of resistance to cetuximab have been identified in metastatic colorectal cancer,no biomarkers of efficacy have been identified in HNSCC.Here,we aimed to identify biomarkers of cetuximab sensitivity/resistance in HNSCC.Methods:HNSCC patients treated with cetuximab at the Curie Institute,for whom complete clinicopathological data and formalin-fixed paraffin-embedded(FFPE)tumor tissue collected before cetuximab treatment were available,were included.Immunohistochemistry analyses of PTEN and EGFR were performed to assess protein expression levels.PIK3 CA and H/N/KRAS mutations were analyzed using high-resolution melting(HRM)and Sanger sequencing.We evaluated the predictive value of these alterations in terms of progression-free survival(PFS).Results:Hot spot activating PIK3 CA and KRAS/HRAS mutations were associated with poor PFS among HNSCC patients treated with cetuximab in the first-line R/M setting,but not among HNSCC patients treated with cetuximab in combination with radiotherapy.Loss of PTEN protein expression had a negative predictive value among HNSCC patients treated with cetuximab and radiotherapy.High EGFR expression did not predict cetuximab sensitivity in our patient population.Conclusions:Hot spot activating PIK3 CA and RAS mutations predicted cetuximab resistance among HNSCC patients in the firstline R/M setting,whereas loss of PTEN protein expression predicted resistance to cetuximab when combined to radiotherapy.

Sustained complete response to erlotinib in squamous cell carcinoma of the head and neck:A case report

BACKGROUND Squamous cell carcinoma of head and neck(SCCHN) is the fifth most common cancer worldwide. Inhibition of epidermal growth factor receptor signaling has been shown to be a critical component of therapeutic option. Herein, we report a case of durable complete response to erlotinib.CASE SUMMARY An 81-year-old Caucasian male who presented with metastatic poorly differentiated squamous cell carcinoma of right cervical lymph nodes(levels 2 and 3). Imaging studies including(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(CT) and contrast-enhanced CT scan of neck and chest did not reveal any other disease elsewhere. Panendoscopic examination with random biopsy did not reveal malignant lesion in nasopharynx,oropharynx, and larynx. He underwent modified neck dissection and postoperative radiation. Within 2 mo after completion of radiation, he developed local recurrence at right neck, which was surgically removed. Two mo after the salvage surgery, he developed a second recurrence at right neck. Due to suboptimal performance status and his preference, he started erlotinib treatment.He achieved partial response after first 2 mo of erlotinib treatment, then complete response after total 6 mo of erlotinib treatment. He developed sever skin rash and diarrhea including Clostridium difficile infection during the course of erlotinib treatment requiring dose reduction and eventual discontinuation. He remained in complete remission for more than two years after discontinuation of erlotinib.CONCLUSION We report a case of metastatic SCCHN achieving durable complete response from erlotinib. Patient experienced skin rash and diarrhea toxicities which were likely predictors of his treatment response.

Long-term survivor of metastatic squamous-cell head and neck carcinoma with occult primary after cetuximab-based chemotherapy:A case report

BACKGROUND Cancer of unknown primary(CUP)is a histological proven malignant tumor whose origin cannot be detected despite careful examination.Most cervical lymph node metastases in CUP(80%)will originate from head and neck sites,and 15%show infiltration of squamous carcinoma cells.The survival rates of CUP are poor:The 5-year-survival rate ranges from 10%to 15%.First-line treatment recommendation for advanced,inoperable squamous cell carcinoma of head/neck(HNSCC)was cetuximab plus platinum-fluorouracil chemotherapy until recently,when checkpoint inhibitors proved clinically beneficial therapies.CASE SUMMARY Here,we report a case of a 42-year-old female patient with cervical and abdominal lymph node and distant bone metastases of an occult primary of the head and neck(squamous cell carcinoma,human papillomavirus positive).The cancer was diagnosed during pregnancy 10 years ago,and after giving birth,the patient was treated with cetuximab plus platinum-fluorouracil chemotherapy achieving complete remission(CR).CR lasted 26 mo when new metastases(abdominal lymph node,lumbar vertebral body)emerged.Both manifestations were irradiated.From then on,the patient has not received any further treatment,and her disease has remained controlled.Ten years after the initial cancer diagnosis,the patient is still alive and in good health,representing an exceptional case of HNSCC.CONCLUSION This case illustrates the exceptional clinical course and benefits of combined therapy approaches in advanced metastatic HNSCC with occult primary.

Collision tumor of squamous cell carcinoma and neuroendocrine carcinoma in the head and neck:A case report

BACKGROUND There are many disputes about the definition,diagnosis,therapy,and prognosis of collision tumors.CASE SUMMARY We describe a rare patient with a collision tumor consisting of neuroendocrine carcinoma(NEC)and squamous cell carcinoma(SCC)in the nasal cavity and paranasal sinus.She received operation,concurrent chemoradiotherapy,and then two cycles of palliative chemotherapy.Follow-up at 12 mo after diagnosis showed that this patient experienced a complete response with no signs of recurrence or metastasis.A literature review of previous 26 cases diagnosed with collision tumor of NEC and SCC in the head and neck was also undertaken.CONCLUSION It is challenging to manage collision tumors because there are two morphologically and etiologically distinct tumors.Well-designed multimodality therapy including surgery and chemoradiotherapy might lead to a long survival in these patients.

Nimotuzumab with Concurrent Chemoradiation in Inoperable Locally Advanced Squamous Cell Carcinoma of Head and Neck: An Indian Experience

Background: The prognosis of patients with Epidermal Growth Factor Receptor (EGFR) overexpression in inoperable Locally Advanced Squamous Cell Carcinoma of Head and Neck (LASCCHN) remains poor. Nimotuzumab is an Anti EGFR humanized monoclonal antibody approved for treatment of LASCCHN, with concurrent chemoradiation. Objective: To assess the efficacy and safety of nimotuzumab with concurrent chemoradiation in inoperable LASCCHN patients. Methodology: This is a single-centre, single arm, retrospective study evaluating 35 patients with histologically confirmed inoperable LASCCHN (stages III-IV). The patients were administered IV cisplatin 50 mg/m2 and IV nimotuzumab 200 mg for 6 - 7 weeks, along with radiotherapy of 6600 - 7000 cGy over 35 fractions. Patients were evaluated over response evaluation criteria in solid tumors (RECIST) criteria 12 weeks after the last cycle of chemotherapy. They were also followed up for overall survival and relapse free survival. Results: The median duration of follow-up was 20 months. The most common site of cancer was oropharynx (68.6%). One patient was lost to follow up. Objective Response Rate (ORR) was observed in 97% of the patients with 17 patients (48.6%) achieving complete response (CR) and 17 patients (48.6%) achieving partial response (PR). The median overall survival was 22.7 months (95% CI: 21.30, 34.27). The median relapse free survival was 16.7 months (95% CI: 9.80, 24.50). Nimotuzumab was safe and well tolerated with few mild, self-limiting adverse events. Conclusion: Nimotuzumab with chemoradiation is a safe and efficacious option in patients with LASCCHN. Larger studies are needed to verify the same.