Sinonasal malignancy: presentation and outcomes

Nomenclature of the symptoms of head and neck cancer: a systematic scoping review

Introduction

Evolution of a patient-reported symptom-based risk stratification system to redesign the suspected head and neck cancer (HNC) referral pathway (EVEREST-HN) will use a broad and open approach to the nomenclature and symptomatology. It aims to capture and utilise the patient reported symptoms in a modern way to identify patients' clinical problems more effectively and risk stratify the patient.

Method

The review followed the PRISMA checklist for scoping reviews. A search strategy was carried out using Medline, Embase and Web of Science between January 1st 2012 and October 31st 2023. All titles, abstracts and full paper were screened for eligibility, papers were assessed for inclusion using predetermined criteria. Data was extracted pertaining to the aims, type of study, cancer type, numbers of patients included and symptoms, presenting complaints or signs and symptoms.

Results

There were 9,331 publications identified in the searches, following title screening 350 abstracts were reviewed for inclusion and 120 were considered for eligibility for the review. 48 publications met the eligibility criteria and were included in the final review. Data from almost 11,000 HNC patients was included. Twenty-one of the publications were from the UK, most were retrospective examination of patient records. Data was extracted and charted according to the anatomical area of the head and neck where the symptoms are subjectively and objectively found, and presented according to lay terms for symptoms, clinical terms for symptoms and the language of objective clinical findings.

Discussion

Symptoms of HNC are common presenting complaints, interpreting these along with clinical history, examination and risk factors will inform a clinician's decision to refer as suspected cancer. UK Head and Neck specialists believe a different way of triaging the referrals is needed to assess the clinical risk of an undiagnosed HNC. EVEREST-HN aims to achieve this using the patient history of their symptoms. This review has highlighted issues in terms of what is considered a symptom, a presenting complaint and a clinical finding or sign.

University of Washington Quality of Life subdomain outcomes after treatment of sinonasal malignancy: A prospective, multicenter study

PURPOSE

Sinonasal malignancies (SNMs) adversely impact patients' quality of life (QOL) and are frequently identified at an advanced stage. Because these tumors are rare, there are few studies that examine the specific QOL areas that are impacted. This knowledge would help improve the care of these patients.

METHODS

In this prospective, multi-institutional study, 273 patients with SNMs who underwent definitive treatment with curative intent were evaluated. We used the University of Washington Quality of Life (UWQOL) instrument over 5 years from diagnosis to identify demographic, treatment, and disease-related factors that influence each of the 12 UWQOL subdomains from baseline to 5 -years post-treatment.

RESULTS

Multivariate models found endoscopic resection predicted improved pain (vs. nonsurgical treatment CI 2.4, 19.4, p = 0.01) and appearance versus open (CI 27.0, 35.0, p < 0.001) or combined (CI 10.4, 17.1, p < 0.001). Pterygopalatine fossa involvement predicted worse swallow (CI -10.8, -2.4, p = 0.01) and pain (CI -17.0, -4.0, p < 0.001). Neck dissection predicted worse swallow (CI -14.8, -2.8, p < 0.001), taste (CI -31.7, -1.5, p = 0.02), and salivary symptoms (CI -28.4, -8.6, p < 0.001). Maxillary involvement predicted worse chewing (CI 9.8, 33.2; p < 0.001) and speech (CI -21.8, -5.4, p < 0.001) relative to other sites. Advanced T stage predicted worse anxiety (CI -13.0, -2.0, p = 0.03).

CONCLUSIONS

Surgical approach, management of cervical disease, tumor extent, and site of involvement impacted variable UWQOL symptom areas. Endoscopic resection predicted better pain, appearance, and chewing compared with open. These results may aid in counseling patients regarding potential QOL expectations in their SNM treatment and recovery course.

Imaging of the Sinonasal Cavities

This article describes the various abnormalities that affect the sinonasal cavities and discusses inflammations, tumors, and tumor-like conditions. Specific imaging evaluations that focus on the sinonasal cavities are described in more detail.

Recurrence Patterns and Efficacy of Surveillance Modalities for Sinonasal Malignancies

OBJECTIVE

There is limited information regarding the recurrence patterns and efficacy of surveillance modalities in patients with sinonasal malignancies.

METHODS

A retrospective study was conducted between the years 2001-2018 at a tertiary care center. Included were all patients with sinonasal malignancies treated in our institution. Data regarding recurrence and survival were analyzed.

RESULTS

Eighty-one patients were included. Multimodal treatment was administered to the majority of patients. 24 (35.3%) patients recurred with a median time of 17 months (range, 4-180). Although the majority of recurrences occurred within the first 5 years (83.3%), 4 (16.6%) recurred later on (5-15 years). Recurrences were local in 83.3%, regional in 20.8% and distant in 16.6%. All local recurrences occurred within the radiation treatment field and all patients with distant failure had mucosal melanoma. The majority of recurrences (70.6%) were diagnosed clinically or endoscopically, mainly in patients with SCC during the first 2 years of follow up. MRI or PET-CT were crucial in detecting extra-sinus and distant failures. Salvage surgery was feasible in the majority of patients (58.3%). Overall, 5 years survival (OS) rate was 60.9%.

CONCLUSIONS

Frequent clinic visits with nasal endoscopy combined with frequent imaging studies should be routinely practiced as part of a long-term surveillance plan. Longer follow up duration should be considered in these patients.

Treatment Outcomes of Maxillary Sinus Squamous Cell Carcinoma at a Dedicated Cancer Institute: A Retrospective Study

Introduction

Squamous cell carcinoma arising at the maxillary sinus is a rare neoplasm, characterized by an aggressive growth pattern and glooming prognosis. The proximity of the maxillary sinus with complex anatomical structures such as the eye, skull base, infratemporal fossa, pterygomaxillary fossa, nasal cavities, and ethmoid sinuses makes the surgical treatment of tumors infiltrating into these structures very challenging. The study's objective was to investigate the prognostic factors of survival and maxillary sinus SCC treatment outcomes.

Methods

We did a retrospective analysis of patients treated for maxillary sinus SCC at our institution between 2004 -2018. The study included all the patients with histologically proven maxillary sinus SCC treated with curative intent. The medical record of 43 patients was reviewed and utilized for the analysis. The Kaplan-Meier curve calculated five-year overall survival.

Results

A total of 43 patients were analyzed. At the presentation time, the mean age was 54.56 years (SD ± 11.65). Smoking (n=13, 30.2%) was the common risk factor. 36 (83.7%) patients presented with stage IV disease. Surgery was performed in 16 (37.2%) patients, whereas 27 (62.8%) patients received radiation and chemotherapy. Treatment failure was seen in 35 (81.4%) patients with locoregional recurrence in 30 (85.7%) patients and distant metastases in 5 (14.3%) patients. The five years overall survival in our study was 22%. Loco-regional recurrence and distant metastasis were the significant factors impacting survival (p=0.01).

Conclusion

Maxillary sinus SCC is rare cancer that is more common in males and usually presents at an advanced stage with a poor outcome. These tumors have a higher rate of treatment failure with a poor prognosis. Locoregional recurrence and distant metastasis adversely impact the overall survival.

Recognizing sinonasal cancer in primary care: a matched case-control study using electronic records

BACKGROUND

Cancers of the nasopharynx, nasal cavity, and accessory sinuses ("sinonasal") are rare in England, with around 750 patients diagnosed annually. There are no specific National Institute for Health and Care Excellence (NICE) referral guidelines for these cancers and no primary care research published.

OBJECTIVE

To identify and quantify clinical features of sinonasal cancer in UK primary care patients.

METHODS

This matched case-control study used UK Clinical Practice Research Datalink (CPRD) data. Patients were aged ≥40 years with a diagnosis of sinonasal cancer between January 1, 2000 and December 31, 2009 and had consulted their GP in the year before diagnosis. Clinical features of sinonasal cancer were analysed using conditional logistic regression. Positive predictive values (PPVs) for single and combined features were calculated.

RESULTS

In total, 155 cases and 697 controls were studied. Nine symptoms and one abnormal investigation were significantly associated with the cancer: nasal mass; odds ratio, 95 (95% confidence interval 7.0, 1315, P = 0.001); head and neck lumps, 68 (12, 387, P < 0.001); epistaxis, 17 (3.9, 70, P < 0.001); rhinorrhoea, 14 (4.6, 44, P < 0.001); visual disturbance, 12 (2.2, 67, P = 0.004); sinusitis, 7.3 (2.2, 25, P = 0.001); sore throat, 6.0 (2.0, 18, P = 0.001); otalgia, 5.4 (1.6, 18, P = 0.007); headache, 3.6 (1.4, 9.5, P = 0.01); raised white cell count, 8.5 (2.8, 27, P < 0.001). Combined PPVs for epistaxis/rhinorrhoea, epistaxis/sinusitis, and rhinorrhoea/sinusitis were 0.62%.

CONCLUSION

This is the first primary care study identifying epistaxis, sinusitis, and rhinorrhoea as part of the clinical prodrome of sinonasal cancer. Although no PPVs meet the 3% NICE referral threshold, these results may help clinicians identify who warrants safety-netting and possible specialist referral, potentially reducing the number of advanced-stage diagnoses of sinonasal cancer.

Outcomes of Management of Sinonasal Malignancies at a Dedicated Cancer Institution: A Retrospective Study

Introduction

Sinonasal malignancies (SNMs) are a rare and heterogeneous group of cancers with an incidence of 3%-5% of all head-and-neck tumours. The aim of the present study was to identify the characteristic features of SNMs and to analyze the treatment outcomes and the prognostic factors affecting it.

Materials and Methods

A retrospective review of patients with SNM treated at a dedicated cancer center of Pakistan between 2004 and 2018 was carried out. All patients with histologically proven diagnosis of malignancy arising from nasal cavity or paranasal sinuses and being treated with curative intent were included. The medical records of 184 cases were utilized for final analysis. Chi-square test was applied to identify significant differences. Five-year disease-specific survival (DSS) was calculated using Kaplan-Meier curve via log-rank test and comparison was made between squamous and nonsquamous histologies. P ≤0.05 was considered statistically significant.

Results

Squamous cell carcinoma was the most common histopathology (n = 62, 33.7%). 130 (70.7%) patients presented with stage IV disease. Nodal metastasis was seen in 24 (13%) patients. Treatment failure was seen in 96 (52.2%) patients and was significantly associated with tumour size and the overall stage. DSS of patients with squamous cell carcinoma was 29% as compared to 52% for patients with nonsquamous histologies (P = 0.001).

Discussion

SNM is a diverse group of cancers presenting in late stages. A higher rate of treatment failure associated significantly with stage of the disease was identified in our study.

Utility of 7 Tesla MRI for Preoperative Planning of Endoscopic Endonasal Surgery for Pituitary Adenomas

Objective  There is increasing interest in investigating the utility of 7 Tesla (7 T) magnetic resonance imaging (MRI) for imaging of skull base tumors. The present study quantifies visualization of tumor features and adjacent skull base anatomy in a homogenous cohort of pituitary adenoma patients. Methods  Eighteen pituitary adenoma patients were scanned at 7 T in this prospective study. All patients had reference standard-of-care clinical imaging at either 3 T (7/18, 39%) or 1.5 T (11/18, 61%). Visualization of tumor features and conspicuity of arteries and cranial nerves (CNs) was rated by an expert neuroradiologist on 7 T and clinical field strength MRI. Overall image quality and severity of image artifacts were also characterized and compared. Results  Ability to visualize tumor features did not differ between 7 T and lower field MRI. Cranial nerves III, IV, and VI were better detected at 7 T compared with clinical field strength scans. Cranial nerves III, IV, and VI were also better detected at 7 T compared with only 1.5 T, and CN III was better visualized at 7 T compared with 3 T MRI. The ophthalmic arteries and posterior communicating arteries (PCOM) were better detected at 7 T compared with clinical field strength imaging. The 7 T also provided better visualization of the ophthalmic arteries compared with 1.5 T scans. Conclusion  This study demonstrates that 7 T MRI is feasible at the skull base and identifies various CNs and branches of the internal carotid artery that were better visualized at 7 T. The 7 T MRI may offer important preoperative information that can help to guide resection of pituitary adenoma and reduce operative morbidity.

Surgery with Post-Operative Endoscopy Improves Recurrence Detection in Sinonasal Malignancies

OBJECTIVE

The mainstay of treatment in sinonasal malignancy (SNM) is surgery, and when combined with chemoradiation therapy, often leads to the best overall prognosis. Nasal endoscopy is essential for post-treatment surveillance along with physical exam and radiologic evaluation. The ability to directly visualize the sinus cavities after surgery may also improve early detection of tumor recurrence and is another reason to potentially advocate for surgery in these patients.

METHODS

A retrospective chart review of medical records of patients with pathologically proven SNM was conducted from 2005 to 2019.

RESULTS

The nasal cavity and maxillary sinus were the most common primary tumor sub-sites. The most common pathology was squamous cell carcinoma (42%). The median time to recurrence was 9.8 months. Recurrence was initially detected endoscopically in 34.3% patients, by imaging in 62.7% patients, and by physical exam in 3.0% patients. 67 (29%) total recurrences were detected on follow-up, of which 46 (68.7%) were local. Twenty-three of the local recurrences were identified via nasal endoscopy. Thirteen recurrences were identified via endoscopic surveillance within the surgically patent paranasal sinuses while 13 were identified within the nasal cavity; 5 patients had multiple sites of recurrence.

CONCLUSION

Local recurrence of SNM is the most common site for recurrent disease and nasal endoscopy identified half of these cases. 50% of these recurrences were within the paranasal sinuses and would not have been easily identified if the sinuses were not open for inspection. Thus, open sinus cavities aid in the detection of tumor recurrence and is another advantage of surgery in the management of SNM.

Novel Biomarkers in Sinonasal Cancers: from Bench to Bedside

PURPOSE OF REVIEW

Sinonasal cancers are a heterogenous group of rare cancers for which histopathological diagnosis can be very challenging and treatment options are limited for advanced disease in particular. Here, we review the candidacy of novel diagnostic and prognostic biomarkers, and therapeutic targets for sinonasal cancers.

RECENT FINDINGS

Molecular multidimensional analyses of sinonasal cancers have been lagging behind other major cancers, but there are numerous publications describing the discovery of novel candidate biomarkers, e.g. the methylation classifier, originally developed for brain cancers, and gene expression panels for the prediction of response to induction chemotherapy in sinonasal undifferentiated carcinoma. The most promising biomarkers are summarized and discussed further with regard to their clinical applicability and future potential. Many of the described novel biomarkers for sinonasal cancers will eventually overcome the pitfalls associated with the frequently non-specific immunohistological tests. With comprehensive, multidimensional molecular testing of these tumours in collaborative consortia projects, our better understanding of the molecular mechanisms of sinonasal cancers and their carcinogenesis will determine the most useful diagnostic and prognostic biomarkers, allow stringent multi-institutional validation and guide trials on targeted therapies.

Appropriate timing of surveillance intervals with whole-body 18F-FDG PET/CT following treatment for sinonasal malignancies

PURPOSE

To assess the ideal timing of posttreatment whole-body ¹⁸F-FDG PET/CT examination as routine surveillance to determine local recurrence (R), lymph node metastasis (LM), and distant metastasis (DM) of sinonasal malignancies and to investigate the effect of ¹⁸F-FDG PET/CT on survival.

METHODS

An overall 80 patients who had undergone a total of 197 posttreatment whole-body ¹⁸F-FDG PET/CT examinations for sinonasal malignancy were retrospectively examined after institutional review board approval. Patients were grouped regarding the time intervals (<1 month, 1-3 months, 3-6 months, 6-12 months, 12-18 months and >18 months) after the conclusion of treatment. Differences in diagnostic accuracy due to different follow-up intervals were calculated by receiver operator curves (ROC) and a Cox proportional hazards model was used to assess the prognostic value of surveillance ¹⁸F-FDG PET/CT.

RESULTS

Considering the time intervals of posttreatment ¹⁸F-FDG PET/CT scans, the negative predictive value and positive predictive value of the ¹⁸F-FDG PET/CT examinations to predict overall recurrence in 1-3 months (100 and 100%, respectively) and >18 months (100 and 95%, respectively) were higher than for recurrence detection in <1 month (50 and 100%, respectively), 3-6 months (81 and 93%, respectively), 6-12 months (79 and 87%, respectively), and 12-18 months (75 and 80%, respectively) (p < 0.05). Positive findings on ¹⁸F-FDG PET/CT scans were also independent predictors of poorer overall survival (OS) (p < 0.05).

CONCLUSIONS

Whole-body ¹⁸F-FDG PET/CT is capable of identifying recurrences following treatment, using an optimal time interval for scanning of 1-3 months and >18 months after therapy.

AHNS Series: Do you know your guidelines? Principles for treatment of cancer of the paranasal sinuses: A review of the National Comprehensive Cancer Network guidelines

This article is a continuation of the "Do You Know Your Guidelines" series. This was launched as an initiative of the American Head and Neck Society to increase the awareness of current best practices pertaining to head and neck cancer. The National Comprehensive Cancer Network (NCCN) guidelines for managing cancer of the paranasal sinuses are reviewed in a systematic fashion. These guidelines outline the workup, treatment, and surveillance of patients with cancer of the maxillary and ethmoid sinuses.

Locally advanced paranasal sinus carcinoma: A study of 30 patients

Sinonasal carcinomas (SNcs) are rare neoplasms arising from the paranasal sinuses and nasal cavity. Although these tumours have a heterogeneous histology, they are commonly diagnosed as a locally advanced disease and are associated with a poor prognosis. The present retrospective study reviewed 30 patients with locally advanced SNc, who were treated with surgery followed by chemoradiotherapy or radiotherapy, or radiotherapy with or without concomitant chemotherapy between January 1999 and January 2013 at the Department of Radiation Therapy, University of Naples 'Federico II' (Naples, Italy). A total of 19 patients were treated with upfront surgery followed by adjuvant radio- or chemoradiotherapy (group A), while the remaining 11 patients received exclusive radiotherapy with or without concomitant chemotherapy (group B). Concurrent cisplatin-based chemotherapy (100 mg/m2, days 1, 22 and 43 for 3 cycles) was administered to 34% of patients in group A and 55% of patients in group B. At a median follow-up of 31 months, 33.3% of patients were alive. Cause-specific survival (CSS) and progression-free survival (PFS) times were 32 and 12 months, respectively. No difference in CSS rate was observed between the two treatment groups. Univariate analysis determined that disease stage was the only factor that significantly affected CSS (P=0.002) and PFS (P=0.0001) rates. Acute and chronic toxicities were mild, with only 23.3% of patients reporting G1-2 side effects and no treatment-related blindness. The present study reported moderate activity and efficacy of surgery followed by adjuvant radio- or chemoradiotherapy, and exclusive radiotherapy with or without chemotherapy in this poor prognosis category of patients.

Sinonasal squamous cell carcinoma without clinical lymph node involvement : Which neck management is best?

OBJECTIVES

The purpose of this work was to report outcomes of patients with nonmetastatic sinonasal squamous cell carcinoma (SNSCC) and to discuss the impact of elective neck irradiation (ENI) and selective neck dissection (SND) in clinically negative lymph node (N0) patients.

METHODS

Data from 104 nonmetastatic SNSCC patients treated with curative intent were retrospectively analysed. Uni- and multivariate analyses were used to assess prognostic factors of overall survival (OS) and locoregional control (LRC).

RESULTS

Median follow-up was 4.5 years. Eighty-five percent of tumours were stage III-IV. Treatments included induction chemotherapy (52.9 %), surgery (72 %) and radiotherapy (RT; 87 %). The 5‑year OS, progression-free survival, and LRC rates were 48, 44 and 57 %, respectively. Absence of surgery predicted a decrease of OS (hazard ratio [HR] 2.6; 95 % confidence interval [CI] 1.4-4.7), and LRC (HR 3.5; 95 % CI 1.8-6.8). Regional relapse was observed in 13/104 (13 %) patients and most common sites were level II (n = 12; 70.6 %), level III (n = 5; 29.4 %) and level Ib (n = 4; 23.5 %). Management of the neck in N0 patients (n = 87) included 11 % SND alone, 32 % ENI alone, 20 % SND + ENI and 37 % no neck treatment. In this population, a better LRC was found according to the management of the neck in favour of SND (94 % vs. 47 %; p = 0.002) but not ENI.

CONCLUSION

SND may detect occult cervical positive nodes, allowing selective postoperative RT. ENI (ipsilateral level II, ±Ib and III or bilateral) needs to be proposed in selected patients, especially when SND has not been performed.

Endoscopy versus imaging: Analysis of surveillance methods in sinonasal malignancy

BACKGROUND

The purpose of this study was to assess the utility of imaging and endoscopy in posttreatment surveillance of sinonasal malignancies.

METHODS

We conducted a retrospective analysis of primary sinonasal malignancies diagnosed between 2000 and 2014. Posttreatment surveillance included nasal endoscopy and imaging (MRI, CT, and positron emission tomography [PET]/CT). Positive predictive value (PPV), negative predictive value (NPV), specificity, and sensitivity were calculated for each modality and compared.

RESULTS

One hundred nine sinonasal malignancies were identified with 30 recurrences. Endoscopy showed a sensitivity and specificity of 24% and 89%, respectively, whereas imaging was 76% and 90%, respectively. Identifying suspicious symptoms significantly improved the PPV of both endoscopy and imaging. MRI demonstrates the highest PPV when compared with other imaging modalities.

CONCLUSION

Both modalities are necessary in posttreatment surveillance. MRI shows the highest PPV, whereas endoscopy trends toward a higher specificity. PET/CT scans have a high false-positive rate and should be reserved for tumors with a high propensity for distant metastases. © 2016 Wiley Periodicals, Inc. Head Neck 38:1229-1233, 2016.

Optimized imaging of the midface and orbits

A variety of imaging techniques are available for imaging the midface and orbits. This review article describes the different imaging techniques based on the recent literature and discusses their impact on clinical routine imaging. Imaging protocols are presented for different diseases and the different imaging modalities.

Flattening Filter-Free Beams in Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy for Sinonasal Cancer

PURPOSE

To evaluate the dosimetric impacts of flattening filter-free (FFF) beams in intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for sinonasal cancer.

METHODS

For fourteen cases, IMRT and VMAT planning was performed using 6-MV photon beams with both conventional flattened and FFF modes. The four types of plans were compared in terms of target dose homogeneity and conformity, organ-at-risk (OAR) sparing, number of monitor units (MUs) per fraction, treatment time and pure beam-on time.

RESULTS

FFF beams led to comparable target dose homogeneity, conformity, increased number of MUs and lower doses to the spinal cord, brainstem and normal tissue, compared with flattened beams in both IMRT and VMAT. FFF beams in IMRT resulted in improvements by up to 5.4% for sparing of the contralateral optic structures, with shortened treatment time by 9.5%. However, FFF beams provided comparable overall OAR sparing and treatment time in VMAT. With FFF mode, VMAT yielded inferior homogeneity and superior conformity compared with IMRT, with comparable overall OAR sparing and significantly shorter treatment time.

CONCLUSIONS

Using FFF beams in IMRT and VMAT is feasible for the treatment of sinonasal cancer. Our results suggest that the delivery mode of FFF beams may play an encouraging role with better sparing of contralateral optic OARs and treatment efficiency in IMRT, but yield comparable results in VMAT.

A simple optimization approach for improving target dose homogeneity in intensity-modulated radiotherapy for sinonasal cancer

Homogeneous target dose distribution in intensity-modulated radiotherapy (IMRT) for sinonasal cancer (SNC) is challenging to achieve. To solve this problem, we established and evaluated a basal-dose-compensation (BDC) optimization approach, in which the treatment plan is further optimized based on the initial plans. Generally acceptable initial IMRT plans for thirteen patients were created and further optimized individually by (1) the BDC approach and (2) a local-dose-control (LDC) approach, in which the initial plan is further optimized by addressing hot and cold spots. We compared the plan qualities, total planning time and monitor units (MUs) among the initial, BDC, LDC IMRT plans and volumetric modulated arc therapy (VMAT) plans. The BDC approach provided significantly superior dose homogeneity/conformity by 23%-48%/6%-9% compared with both the initial and LDC IMRT plans, as well as reduced doses to the organs at risk (OARs) by up to 18%, with acceptable MU numbers. Compared with VMAT, BDC IMRT yielded superior homogeneity, inferior conformity and comparable overall OAR sparing. The planning of BDC, LDC IMRT and VMAT required 30, 59 and 58 minutes on average, respectively. Our results indicated that the BDC optimization approach can achieve significantly better dose distributions with shorter planning time in the IMRT for SNC.

Inhibition of squamous cancer growth in a mouse model by Staphylococcal enterotoxin B-triggered Th9 cell expansion

Currently, therapy for squamous cancer (SqC) is unsatisfactory. Staphylococcal enterotoxin B (SEB) has strong immune regulatory activity. This study tests the hypothesis that SEB enforces the effect of immunotherapy on SqC growth in a mouse model. C3H/HeN mice and the SqC cell line squamous cell carcinoma VII were used to create an SqC mouse model. Immune cell assessment was performed by flow cytometry. Real-time RT-PCR and western blotting were used to evaluate target molecule expression. An apoptosis assay was used to assess the suppressive effect of T helper-9 (Th9) cells on the SqC cells. The results showed that immunotherapy consisting of SEB plus SqC antigen significantly inhibited SqC growth in the mice. The frequency of Th9 cells was markedly increased in the SqC tissue and mouse spleens after treatment. SEB markedly increased the levels of signal transducer and activator of transcription 5 phosphorylation and the expression of histone deacetylase-1 (HDAC1) and PU.1 (the transcription factor of the interleukin 9 (IL-9) gene) in CD4⁺ T cells. Exposure to SqC-specific Th9 cells markedly induced SqC cell apoptosis both in vitro and in vivo. In conclusion, the administration of SEB induces Th9 cells in SqC-bearing mice, and theseTh9 cells inhibit SqC growth.