Tonsillar Squamous Cell Carcinoma Research Articles

A Case of Cutaneous Metastatic Tonsillar Squamous Cell Carcinoma in a Female

Cutaneous metastatic tonsillar squamous cell carcinoma (SCC) is extremely rare and indicates a poor prognosis. To our knowledge, only 8 cases of cutaneous metastatic tonsillar SCC previously have been reported in the English literature. Here, we present the third case of a female with cutaneous metastatic tonsillar SCC.

Prophylactic contralateral neck dissection has no advantage in patients with early stage HPV-positive tonsil cancer

ABSTRACT Background Patients with locally advanced HPV-positive tonsil cancer would benefit from prophylactic contralateral neck dissection (pCND). Aims/Objectives The aim of this study was to analyze rates of contralateral lymph node metastases (LNM) and their prognostic effects on locally advanced HPV-positive tonsillar squamous cell carcinoma. Materials and methods Medical records of 54 patients who underwent upfront primary surgery and pCND were retrospectively reviewed. Results Six (11.1%) patients had contralateral LNM in 54 locally advanced HPV-positive tonsil cancer. Of these, five patients had contralateral level II LNM and one patient had contralateral level II and III LNM. Contralateral LNM showed significant positive correlations with advanced T stage (p = .017) and the presence of extracapsular spread (p = .007). Contralateral lymph node metastasis had no significant association with five-year disease-specific survival. Conclusions and significance This study demonstrated no advantage in performing pCND in early stage HPV-positive tonsil cancer.

Tonsillar swabs and sputum predict SLPI- and AnxA2 expression in tonsils: A prospective study on smoking dependent SLPI- and AnxA2-expression, and tonsillar HPV infection.

Previous retrospective studies have elucidated a correlation between secretory leucocyte protease inhibitor (SLPI) and Annexin A2 (AnxA2), patient smoking status and tonsillar human papilloma virus (HPV) status. The current study assessed these parameters prospectively and to the best of our knowledge, analyzed SLPI-/AnxA2-expression for the first time in tonsillar swabs and sputum. Samples were obtained from 52 patients with tonsillar squamous cell carcinoma and 163 patients with tonsillar hyperplasia (H; n=56) and chronic or recurrent tonsillitis (CRT; n=107). HPV-DNA, SLPI and AnxA2 gene expression was analyzed in sputum, tonsillar swabs and tissue by performing reverse transcription-quantitative PCR. Results were compared with smoking status, revealing that smoking resulted in significantly increased SLPI gene expression in all biomaterials of all cases. SLPI-gene expression was significantly decreased in all HPV-DNA-positive samples (tissue/swab/sputum), while AnxA2 was significantly increased in all HPV-DNA-positive samples. Results from swabs and sputum were able to predict SLPI- and AnxA2 gene expression of the corresponding tonsil. The current prospective study confirmed previous retrospective results underlining this hypothesis: Smoking enhances SLPI-expression, preventing HPV-binding to AnxA2. HPV-binding to AnxA2 appears essential for successful cell-entry. SLPI/AnxA2-gene expression in swabs and sputum reflect their expression in tonsillar tissue. Accordingly, a positive AnxA2/SLPI-ratio in sputum/swabs could possibly be used to reduce HPV-associated carcinogenesis, by performing tonsillectomy or HPV-vaccination in patients with positive AnxA2/SLPI-ratios.

Association of Human Papillomavirus and Epstein-Barr Virus Infection with Tonsil Cancer in Northeastern Thailand.

Background:Human papillomavirus (HPV) and Epstein-Barr virus (EBV) are associated with head and neck cancer, including tonsil cancer (TC) in the oropharyngeal area. Increasing incidence of HPV and EBV infection in different cancer tissues of oropharynx in both epithelial and lymphoid tissues, have been reported. However, little is known about association of these tumor viruses with TC in the Thai population. Here, we investigated the prevalence of HPV and EBV infection in different histology of TC and their association with TC from Thai patients. Methods:Eighty-three exfoliated tonsil cells from non-cancer controls (NCC) and 65 formalin-fixed paraffin-embedded TC tissues (TC) that were histologically classified as tonsillar squamous-cell carcinoma (TSCC) or diffuse large B-cell lymphoma (DLBCL) were studied. Prevalence of HPV and EBV infection was determined by real-time PCR. HPV genotyping was performed by reverse line blot hybridization and HPV genome status was investigated by multiplex qPCR. Localization of EBV infection was determined by EBER in situ hybridization. Results:Infection of HPV and EBV in TC cases was 16.9% and 30.8%, whereas in exfoliated tonsil cells was 1.2% and 66.3% respectively. HPV infection was significantly higher in TSCC (30.6%) than DLBCL samples (13.8%). HPV58 was commonly detected and presented as an integrated form in TSCC, whereas only episomal form was found in DLBCL. EBV infection was significantly higher in DLBCL (44.8%) than TSCC samples (19.4%), and detected in both lower than among exfoliated tonsil cell samples (66.3%). By EBER in situ hybridization in TSCC, EBV infection localized both in epithelial cells and infiltrating lymphocytes. The co-occurrence of HPV and EBV infection was 11.11% and 13.79% of TSCC and DLBCL, respectively, was associated with well-differentiated TSCC. Conclusion:HPV and EBV infection was significantly involved in a specific TC tissue, and associated with a good clinical outcome in TSCC.

Effect evaluation of surgical plus radio(chemo)therapy and non-surgery chemoradiotherapy treatment strategies for advanced tonsillar squamous cell carcinoma

Objective: Using propensity score matching method(PSM) to investigate the clinical effect of surgical plus radio(chemo)therapy and non-surgery chemoradiotherapy treatment strategies for advanced tonsillar squamous cell carcinoma. Methods: A retrospective analysis was conducted on the clinical data of 324 patients diagnosed with advanced tonsillar squamous cell carcinoma and treated in Peking Union Medical College Hospital from 2000 to 2018, confirmed by pathology and without distant metastasis. Survival analysis was performed using Kaplan-Meier estimates, the Cox proportional hazards model, and propensity score matching(PSM). Results: Of the 324 patients, 102 were treated with non-surgery chemoradiotherapy treatment strategies and 222 with surgical plus radio(chemo)therapy treatment. Cox multivariate analysis showed that the non-surgery treatment group had a favorable prognosis than the surgical treatment group, however, these outcomes were not significantly different [overall survival(OS): adjusted Hazard Ratios(aHR): 0.92, 95% confidence interval(CI): 0.60-1.42; disease-specific survival(DSS): aHR: 0.71, 95%CI: 0.43-1.20; disease-free survival(DFS): aHR: 0.82, 95%CI: 0.53-1.28]. The new patient cohort consisted of 102 subpairs after PSM. There were no significant differences between two groups(OS: aHR: 0.85, 95%CI: 0.51-1.40; DSS: aHR: 0.62, 95%CI: 0.35-1.11; DFS: aHR: 0.80, 95%CI: 0.49-1.33). Conclusion: Our findings indicate that patients with non-surgical treatment do not have significantly better survival outcomes compared to surgical treatment group, while non-surgical treatment has advantages in improving the quality of life of patients, so comprehensive treatment based on radiotherapy and chemotherapy may be recommended for advanced tonsillar squamous cell carcinoma.

Decreased CD1a + and CD83 + cells in tonsillar squamous cell carcinoma regardless of HPV status.

Dendritic cells (DCs) are specialized antigen-presenting cells that play a critical role in the immune response against human papillomavirus (HPV) infection, and represent a therapeutic target in cancer.Objective:To identify and quantify DCs in tonsillar squamous cell carcinoma (TSCC) under the influence of HPV infection.Methodology:CD1a and CD83 antibodies were used to identify immature dendritic cells and mature dendritic cells by immunohistochemistry in 33 primary TSCC and 10 normal tonsils (NTs), respectively. For the TSCC samples, the number of DCs per area was evaluated in the intra- and peritumoral compartments. For the NTs, the quantification of DCs was evaluated in the intra- and peritonsillar compartments. HPV detection methods were determined according to the ASCO Clinical Practice Guidelines from the College of American Pathologists Guideline (2018).Results:There were fewer intratumoral CD1a+ DCs in the HPV-positive and HPV-negative TSCC groups than in the NT group (p<0.05). In the peritumoral compartment, there were fewer CD83+ DCs in the HPV-positive and HPV-negative TSCC groups than in the NT group (p<0.001). The quantification of DCs subtypes showed no statistical differences between HPV-positive and HPV-negative TSCC groups (p>0.137). Patients with HPV-positive TSCC had significantly better overall survival rate than those with HPV-negative TSCC (p=0.004).Conclusion:Tumor activity contributes to DC depletion regardless of intralesional HPV positivity. An improved prognosis has been reported in patients with HPV-positive TSCC.

A Rare Finding of Gastric Metastasis From Tonsillar Squamous Cell Carcinoma.

A 61-year-old Caucasian man with tonsillar squamous cell carcinoma (SCC, stage T2N1, diagnosed 1 year ago) underwent an endoscopic percutaneous gastrostomy tube (PEG) placement for oropharyngeal dysphagia at the time of diagnosis. Given pulmonary metastases, he was begun on immunotherapy. Upper endoscopy was scheduled for PEG tube replacement. He denied abdominal pain, melena, and hematochezia. Hemoglobin was 11.6 g/dL. The upper endoscopy found a 3-cm ulcerated mass along the greater curvature of the gastric body (Figure A and Figure B). This was located 2 cm away from the internal PEG bumper. He underwent an uneventful PEG replacement. Biopsies demonstrated SCC (Figure C), with staining positive for p40 (Figure D). This established the diagnosis of gastric metastasis of tonsillar SCC. He was continued on immunotherapy. Head and neck SCC metastasize to the lung, bone, and liver. We demonstrate here one of the few reported cases of tonsillar metastases to the stomach, which is one of the least common primary malignancies that result in gastric metastases. Although our patient did not have metastases at the gastric stoma, PEG tubes have been suggested as a risk factor for distal seeding of metastases. Gastroenterologists should consider direct PEG placement instead of pull-through placement in such patients.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)

1168 Radiotherapy Dose for HPV Driven Oropharyngeal Cancer: What Is Enough?

Abstract Aim Squamous cell carcinoma of the oropharynx is associated with high-risk Human Papilloma Virus (HPV) infection. HPV positive oropharyngeal cancer is often more radiosensitive and first line treatment includes either radiotherapy or surgical resection. Trials are ongoing to establish situations in which radiation doses can be reduced with the aim of reducing late tissue toxicity (“de-escalation trials”) . We report a case in which a patient failed to complete his prescribed radiotherapy treatment, describe his clinical outcomes and the potential questions this situation raises. Method In 2009 a male patient presented with a right T2N0MO P16 positive tonsillar squamous cell carcinoma. He was scheduled to complete a course of chemoradiotherapy. However, he was only able to complete a third of the radiotherapy course. Due to unresolved symptoms, he underwent a right transoral laser extended tonsillectomy, however this showed only fibrous tissue. Results Despite not completing the radiotherapy course he has not experienced local recurrence of the tonsillar OPSCC 11 years post initial treatment. Conclusions This case illustrates that some patients with HPV driven oropharyngeal cancer can have a clinically significant tumour response to markedly lower doses of radiotherapy than is currently recommended. Further randomized controlled trials are required to establish the optimum dose in the management of HPV driven oropharyngeal squamous cell cancer.

S1709 A Rare Case of Tonsillar Squamous Cell Carcinoma With Metastases to the Colon

Introduction: Head and neck squamous cell carcinoma (HNSCC) is associated with tobacco and alcohol use. The incidence of HNSCC in association with human papillomavirus (HPV) has also been increasing in recent years. The most common sites of metastases of HNSCC include the lung and bones. While there have been some reports of esophageal SCC metastasizing to the colon, HNSCC metastasizing to the colon is an even rarer occurrence. Here, we report a case of primary right tonsillar SCC with metastases to the colon. Case Description/Methods: A 59-year-old male with a history of right tonsillar squamous cell carcinoma with metastases to the neck and chest status-post concurrent chemoradiation presented to our hospital due to worsening right upper quadrant abdominal pain. The patient was originally diagnosed with cancer roughly 2 years prior and had been receiving treatment with Oncology. He reported a 7-week history of abdominal pain which had greatly worsened a few days prior to presentation. On evaluation, he was afebrile and hemodynamically stable. Physical examination was notable for RUQ abdominal tenderness. CT of the abdomen demonstrated a circumferential mass of the cecum and ascending colon extending ∼ 7 cm, right lower quadrant lymphadenopathy, and liver metastases. The patient underwent colonoscopy for further evaluation which showed a malignant-appearing, nearly-obstructive ascending colon mass. Pathology from biopsies of the mass showed metastatic squamous cell carcinoma. The patient subsequently underwent open right hemicolectomy with ileocolostomy. Unfortunately, his course was complicated by infection of his wound and pneumonia and he ultimately succumbed to his disease. Discussion: Oropharyngeal SCC is associated with tobacco use and human papillomavirus. The most common sites of metastasis from head and neck cancers are the lung and bones. While it occasionally spreads to the liver or brain, metastatic spread to the colon is rarely reported. To the best of our knowledge, there have been two reports of metastatic SCC to the colon. One case illustrates metastatic spread of SCC to the colon and cervical lymph nodes from an unknown primary malignancy, while the other describes a case of primary submandibular SCC that spread to the colon. There have been a select number of cases describing head and neck SCC metastasizing to the small bowel, but spread to the colon is even rarer. This case illustrates a very rare presentation of SCC of the colon in the setting of a primary tonsillar malignancy.Figure 1.: Malignant-appearing ascending colon mass.

Diagnostic value of tonsillectomy in positron emission tomography and computerised tomography negative carcinoma of unknown primary

&lt;p class="abstract"&gt;Carcinoma of unknown primary (CUP) represents a heterogeneous group of malignancy metastasis unique biology of which remains poorly understood. Even after a complete diagnostic workup including positron emission tomography and computerised tomography (PET-CT) scans the primary site of origin may remain unclear. This case series analysed the diagnostic value of bilateral palatine tonsillectomy in evaluating PET-CT negative head and neck squamous cell CUP. From retrospective analysis of cluster of 68 cases with metastatic cervical nodes with no obvious primary referred for ENT evaluation during a period of 20 months, we identified 5 cases where pan endoscopy and radiological evaluation including PET-CT were negative in detecting the primary. All 5 patients underwent bilateral palatine tonsillectomy along with biopsies from base of tongue and nasopharynx as a part of completion of diagnostic work-up. Tonsillar squamous cell carcinoma was revealed by subsequent histopathology examination in 4 out of 5 patients despite negative PET-CT evaluation. Blind biopsies from other sites like nasopharynx and base of tongue were unfruitful. Our experience strongly emphasises the fact that bilateral palatine tonsillectomy has a high yield in detecting primary even in PET negative CUP, though it needs a larger evidence base.&lt;/p&gt;

Sclerosing microcystic adenocarcinoma of the parotid gland – The first recorded case with histo-cytopathologic correlation and a brief review of the literature

We present a case of a 1.0 cm primary tumor of the left parotid gland that meets the histological criteria for the recently described entity sclerosing microcystic adenocarcinoma. The patient was a 73-year-old man with a concurrent tonsillar squamous cell carcinoma, and a history of nasopharyngeal carcinoma treated with radiotherapy 23 years prior. Fine needle aspiration cytology demonstrated low-grade biphasic basaloid neoplastic cells arranged in branching sheets and clusters with minimal nuclear pleomorphism. A biphasic appearance was apparent and some of the cell clusters were bordered by a layer of flattened cells with ovoid bland nuclei. On histology, the tumor comprised small bilayered infiltrative tubules, nests, cords, and microcysts. On immunohistochemistry, EMA, SOX-10, P63, and S-100 protein highlighted a dual cell population of luminal and abluminal cells. The cells were negative for CD117, and the Ki-67 proliferation index was low (<5%).

SLUG is upregulated and induces epithelial mesenchymal transition in canine oral squamous cell carcinoma.

SLUG, encoded by the Snai2 gene, is known to play a role in epithelial-mesenchymal transition (EMT), which contributes to cell invasion and metastasis in some types of human carcinomas. However, the mechanisms and roles of EMT in canine squamous cell carcinoma (SCC) have not yet been elucidated. We have previously established canine oral SCC cell lines, including tonsillar SCC, and in this study, we evaluated the effects of SLUG on the phenotypes regarding EMT of canine SCC cells. First, immunohistochemical analysis revealed that SLUG is upregulated in canine oral SCC tissues compared to that in non-tumoural oral mucosa. Furthermore, gain-of-function and loss-of-function of SLUG revealed that SLUG partly contributed to migration and invasion of cells, as well as the upregulation of EMT markers such as vimentin and SNAIL. Thus, the current study suggests that SLUG promotes cell migration and invasion through EMT induction in canine oral SCC, as well as human cancers.

Second Primary Tumors in Patients Presenting With Unilateral HPV-Associated Tonsillar Squamous Cell Carcinoma.

To describe and compare rates of metachronous and synchronous second primaries of the contralateral tonsil in patients with primary HPV(+) tonsillar squamous cell carcinoma (SCC). Retrospective cohort study. This is a single tertiary care center retrospective case series, from 2006 to 2019, of HPV(+) tonsillar SCC patients who underwent primary surgical resection with unilateral wide-field tonsillectomy or bilateral tonsillectomy for diagnostic or therapeutic purposes. A metachronous second primary is one diagnosed >6 months after completion of surgical treatment. A synchronous second primary is one diagnosed during bilateral tonsillectomy for unilateral HPV(+) tonsillar SCC. Rates of second primary and patient characteristics were compared using chi-square tests. About 303 patients underwent unilateral surgical resection +/- adjuvant therapy for HPV(+) tonsillar SCC. One (0.3%) developed a metachronous second primary in the contralateral tonsil 11.9 years following treatment. Fifty-seven patients with HPV(+) tonsillar SCC underwent bilateral tonsillectomy, and 37/57 (65%) had no clinical signs for contralateral disease. Of these, only 1/37 (2.7%) was incidentally found to have a synchronous second primary. Twenty patients underwent bilateral tonsillectomy due to clinical concern for contralateral disease. Of these, 3/20 (15%) were found to have a synchronous HPV(+) SCC in the contralateral tonsil. The prevalence of metachronous second primary after appropriate treatment of HPV(+) tonsillar SCC is very low (0.3%) and so is the chance of incidentally discovering a synchronous second primary during bilateral tonsillectomy (2.7%). We do not recommend bilateral tonsillectomy as a part of the routine algorithm in the surgical management of these patients. 3 Laryngoscope, 132:332-338, 2022.

The treatment of tonsillar squamous cell carcinoma at Hue Central Hospital

Objective: To explore some clinical features, treatment selection and middle-term outcomes of patients with tonsillar squamous cell carcinoma at Hue Central Hospital. Methods: A prospective study was conducted in a total of 29 patients with squamous cell carcinoma of the tonsil who had been diagnosed and treated at Hue Central Hospital from 1/2018 to 6/2020. Results: Patients aged over 50 years old were the most seen (accounted for 69%). The mean of age was 57.1 ± 12.8, the ratio of male and female was 1.4/1. The major reason was odynophagia (accounted for 69%). Patients in advanced stage were most often. The cumulative survival rate at 24 months and advanced-stage were 85,7%, 63,6% respectively. All patients with primary surgery followed by adjuvant radiotherapy were still alive in follow-up period, 30 months. The cumulative survival rate of the palliative treatment group at 12 months was 21.9%. Conclusion: Primary surgery followed by adjuvant radiotherapy is an effective treatment of squamous cell carcinoma of the tonsil.

Synchronous HPV positive bilateral palatine tonsillar squamous cell carcinoma – Brief review of current literature on the role of magnetic resonance imaging

Synchronous bilateral palatine tonsillar Squamous Cell Carcinoma (SCC) is a rare presentation and less than 10 cases of Human Papillomavirus (HPV) mediated synchronous bilateral palatine tonsillar SCC has been reported. We report case of a patient who presents with a painless left sided neck swelling and was subsequently diagnosed by imaging and histopathology with bilateral Squamous Cell Carcinoma (SCC) of the palatine tonsil and cervical nodal metastasis. Due to its excellent soft tissue/tumor contrast resolution, Magnetic Resonance Imaging (MRI) is the preferred imaging modality for initial staging. Improved sensitivity for the detection of synchronous tumors can be achieved by Positron Emission Tomography (PET)/ Computed Tomography (CT) examination. Due to the rare nature of this pathology, no specific treatment guideline has been provided by National Comprehensive Cancer Network (NCCN). Treatment options available include bilateral Transoral Robotic Surgery (TORS) radical tonsillectomy combined with bilateral neck dissection with adjuvant radiotherapy or chemoradiotherapy and/or upfront concurrent chemoradiotherapy.

A Case of Streptococcus intermedius Abscess Within a Malignant Neck Mass and Review of the Literature

Abstract Streptococcus intermedius is an organism found commensally in various mucosal sites. Over the past couple decades, it has been recognized as a cause of severe pyogenic infections in sites including the brain, liver, lung, head and neck. Here, we describe an uncommon case of S. intermedius infection in a patient with tonsillar squamous cell carcinoma and a metastatic neck mass with overlying postradiation skin changes. We also review the literature on this pathogen in cancer patients because it remains understudied despite its pathogenicity.

Heterogeneous Response to Immunotherapy in a Patient with Tonsillar Squamous Cell Carcinoma Assessed by 18F-FDG PET/CT.

Tonsillar carcinoma is the second most common malignancy of the head and neck region, with Squamous Cell Carcinoma (TSCC) as the most common histological type (>90%). For the advanced stage of TSCC, radiotherapy with or without platinum-based chemotherapy is the only therapeutic option. Immuno-checkpoint inhibitors (ICIs), in particular Nivolumab, considerably improves clinical management of these patients, but the response can be unpredictable. Difficulties can be encountered in evaluating response to immunotherapy, especially with morphological imaging, which can show an atypical response, such as pseudo-progression, leading to a premature discontinuation. Conversely, metabolic imaging can guide a more properly therapeutic decision. We present a case of a 71-year-old man affected by TSCC, treated with chemotherapy, radiotherapy, and Nivolumab as the last line of treatment. Pre- and post-immunotherapy 18F-FDG PET/CT showed an impressive response, avoiding early drug discontinuation and ensuring better management of this patient.

Clostridium difficile appendicitis in an immunocompromised patient: a case report and review of the literature

BackgroundClostridium difficile (C. difficile) is a common cause of infectious colitis in individuals with prior antibiotic or hospital exposure. Extraintestinal manifestations of C. difficile infections, however, are rare. Here we present a case of C. difficile appendicitis in an immunocompromised patient.Case presentationA 53-year-old Caucasian male presented to the emergency room for two days of lower abdominal pain associated with nausea and subjective fevers. He otherwise denied having diarrhea or hematochezia. He did not have any recent hospitalizations, nursing home stays, or antibiotic exposure. His past medical history was notable for stage III tonsillar squamous cell carcinoma for which he was status post tonsillectomy, radiation therapy, and chemotherapy (cisplatin 4 days prior to presentation). He was afebrile with tenderness to palpation in the bilateral lower quadrants, right greater than left. His white blood cell (WBC) count was 15.6 × 103 cells/μL. Computed tomography (CT) of the abdomen and pelvis showed marked edema and inflammation of the cecum and ascending colon as well as an enlarged appendix with surrounding inflammatory changes with a small amount of free fluid in the right paracolic gutter. He was treated non-surgically with antibiotics. He did not clinically improve and on hospital day 3, he developed diarrhea for which C. difficile stool polymerase chain reaction was sent. Repeat CT of the abdomen and pelvis was performed which showed progression to pan-colitis and persistent appendicitis. C. difficile testing later resulted positive, for which oral vancomycin was started. The patient markedly improved with medical management alone and was subsequently discharged on oral vancomycin.ConclusionsOur case highlights the importance of maintaining a high index of suspicion for C. difficile in a patient presenting with both appendicitis and colitis, with prompt diagnosis and treatment being essential.

Treatment of Early Stage Tonsil Cancer in the Age of Human Papillomavirus-Associated Malignancies.

To investigate the patterns of care and outcomes of treatment of early stage tonsil cancers, controlling for human papillomavirus (HPV) status. Historical cohort study. National Cancer Database (NCDB). Review of the NCDB between 2010 and 2017 for all T1-2N0M0 tonsillar squamous cell carcinoma (SCC). Demographics, clinical characteristics, HPV status, treatment regimens, and survival were analyzed. A total of 4720 patients were identified with early stage SCC of the tonsil. Most were tested for HPV (2759 [58.5%]). Among tested patients, 1758 (63.7%) were positive for HPV and 1001 (36.3%) were negative for HPV. HPV-positive patients had higher 3-year survival compared to HPV-negative patients (93.2% vs 77.8%, P < .001). Among HPV-positive patients, there was no significant difference in survival between treatment cohorts. However, in the HPV-negative cohort, 3-year survival was higher in both bimodality surgical-based settings (tonsillectomy + neck dissection + radiotherapy, 86.0% vs chemoradiotherapy, 69.6%, P = .01) and for all surgical-based treatments when compared to nonsurgical management (84.6% vs 69.3%, P < .001). This difference was maintained in multivariable regression controlling for age, sex, comorbidities, clinical T stage, and treatments. In a subpopulation of HPV-negative patients propensity score matched by all factors significant in multivariable analysis, 3-year survival remained higher in the surgically treated group compared to the nonsurgically treated cohort (84.9% vs 67.1%, P < .001). Surgical- or radiation-based treatment resulted in similar survival in early stage HPV-positive tonsil cancer. Surgical-based treatments were associated with longer survival in HPV-negative cancers. These findings should be further investigated in a randomized prospective trial.

Ipsilateral versus Bilateral Neck Radiation Therapy for Tonsillar Squamous Cell Carcinoma

Ipsilateral neck radiation (I-RT) has been adopted for patients with early stage, well lateralized tonsillar squamous cell carcinoma (SCC), however there are limited data on outcomes of this approach in those with N2b disease. We report locoregional disease free survival (LR-DFS) for patients with tonsillar SCC who received I-RT or bilateral neck radiation (B-RT). Patients with tonsillar SCC who underwent definitive radiation, with or without chemotherapy, at a single academic institution between 3/1/90 and 10/15/18 were identified. Patient, tumor, and treatment characteristics were recorded. Stage was assigned per AJCC 7th ed. Wilcoxon Rank Sum and Chi-Square tests were used to compare patients who underwent either B-RT or I-RT. The primary outcome was locoregional disease-free survival (LR-DFS). Secondary outcomes were freedom from distant recurrence (FFDR) and overall survival (OS). Outcomes were estimated with Kaplan Meier method and compared via log rank test. Multivariate cox proportional hazards were used to estimate the effect of variables on endpoints. 216 patients with tonsillar SCC were treated with B-RT (n = 159) or I-RT (n = 57). Median age was 56 (IQR 51 – 64). Patients who underwent I-RT had T1 (45.6%) or T2 (54.4%) disease. Those who underwent B-RT had a higher proportion of T3/T4 disease: 8.2% T1, 25.8% T2, 42.8% T3, and 23.2% T4 disease (p<0.01). Most patients had nodal disease, I-RT: 3.5% N0, 19.3% N1, 14.0% N2a, 63.2% N2b and B-RT: 15.1% N0, 13.8% N1, 7.6% N2a, 36.5% N2b, 13.2% N2c, and 13.8% N3. HPV/p16 status for patients with B-RT was positive in 31.0%, negative in 2.0%, and unknown in 67.3%; for I-RT, HPV/p16 was positive in 59.6%, negative in 3.5%, and unknown in 36.8%. Median total dose to both groups was 70 Gy at 2 Gy/fraction. Concurrent chemotherapy was used in 94% of patients with B-RT and 77% with I-RT (p<0.01). 5-year estimates for survival endpoints are given below. On multivariate analysis controlling for T/N stage, use of chemotherapy, and HPV status, LR-DFS did not differ significantly for patients receiving B-RT versus I-RT (HR 0.67, 95% CI 0.40 – 4.10, p = 0.67). Among those treated with I-RT, 2 developed local recurrence at the primary tumor site. There were no ipsilateral or contralateral neck recurrences. Of 94 patients with N2b disease, 36 received I-RT. For those with N2b disease, 5-year LR-DFS was 93% (95% CI 73% – 98%) after I-RT versus 85% (95% CI 72% – 92%) after B-RT (p = 0.18). High rates of LR-DFS were achieved with I-RT for T1-T2 N0-2b tonsillar SCC, with no ipsilateral or contralateral neck recurrences. Use of I-RT did not compromise LR-DFS compared to B-RT. For patients with N2b disease, I-RT also resulted in high rates of LR-DFS. To our knowledge, this series represents the largest single institution cohort incorporating patients with tonsillar SCC and N2b disease treated with I-RT.Abstract 3868; TableB-RTI-RTLR-DFS (95% CI)78% (70-84%)91% (78-97%)FFDR (95% CI)89% (82-93%)96% (85-99%)OS (95% CI)71% (63-78%)91% (78-97%) Open table in a new tab