Tonsillar Squamous Cell Carcinoma Research Articles

Genome-wide Expression Profiling (with Focus on the Galectin Network) in Tumor, Transition Zone and Normal Tissue of Head and Neck Cancer: Marked Differences Between Individual Patients and the Site of Specimen Origin.

Expression profiling was performed to delineate and characterize the impact of malignancy by comparing tissues from three sites of head and neck cancer of each patient, also determining interindividual variability. Genome-wide analysis was carried out covering the expression of 25,832 genes with quantification for each site of seven patients with tonsillar or oropharyngeal squamous cell carcinoma. Immunohistochemical analysis was performed for adhesion/growth-regulatory galectins, three pro-inflammatory chemo- and cytokines and keratins. Up- and down-regulation was found for 281 (tumor vs. normal) and 276 genes (transition zone vs. normal), respectively. The profile of the transition zone had its own features, with similarity to the tumor. Galectins were affected in a network manner, with differential regulation and interindividual variability between patients, also true for keratins and the chemo- and cytokines. These results underline special features at each site of specimen origin as well as the importance of analyzing galectins as a network and of defining the expression status of the individual patient prior to reaching clinically relevant conclusions.

Human papillomavirus prevalence in mouthwashes of patients undergoing tonsillectomy shows dominance of HPV69, without the corresponding finding in the tonsils

Background: The role of human papillomavirus (HPV) in tonsillar squamous cell carcinomas (TSCC) is of interest, since a considerable proportion of TSCC in Sweden and other Western countries is HPV positive. Nevertheless, the natural history of HPV in normal tonsils, and the progression from localized infection to pre-malignant lesion to cancer are poorly understood. The aim of this study was to investigate whether HPV types found in mouthwash samples correlated to those in tonsillar tissue from the same individuals undergoing tonsillectomy.Methods: Mouthwash samples from 232 patients, aged 3–56 years, undergoing tonsillectomy, the majority with chronic tonsillitis, were collected at the time of surgery and analysed for the presence of 27 HPV types by a bead based multiplex assay.Results: An HPV prevalence of 10.3% (24/232) was observed in mouthwash samples, with HPV 69 being the dominant type (10/24). Ten patients were positive for high risk HPV (HPV 16, 33, 35, 45, 56, 59). None of the tonsils resected from patients with HPV-positive mouthwash samples were positive for HPV.Conclusions: Despite an oral HPV prevalence of 10.3% in mouthwash samples from tonsillectomized patients, with dominance of HPV 69, none of the corresponding tonsillar samples exhibited the presence of HPV.

Comparison of the Clinical Outcomes of Patients with Squamous Cell Carcinoma of the Tonsil Receiving Postoperative Ipsilateral Versus Bilateral Neck Radiotherapy: A Propensity Score Matching Analysis (KROG 11-07).

PurposeThe impact of postoperative ipsilateral neck radiotherapy (INRT) versus bilateral neck radiotherapy (BNRT) on the clinical outcomes of patients with tonsillar squamous cell carcinoma was analyzed retrospectively.Materials and MethodsBetween October 2001 and June 2012, 241 patients with T1-2 and N0-N2b tonsillar carcinoma from 16 institutes underwent postoperative INRT (n=84) or BNRT (n=157) following a tonsillectomy. Seventy patients were identified from each group by propensity score matching and compared in terms of the overall survival (OS), disease-free survival (DFS), locoregional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates calculated using the Kaplan-Meier method with a log-rank test.ResultsThe median follow-up was 55 months (range, 3 to 133 months). The survival outcomes in the INRT and BNRT groups were similar: 5-year OS (92.8% vs. 94.0%, p=0.985), DFS (80.5% vs. 94.2%. p=0.085), LRRFS (88.1% vs. 97.1%, p=0.083), and DMFS (92.7% vs. 97.0%, p=0.370). Subgroup analysis revealed no contralateral neck recurrence in 61 patients with T1-2N0-2a regardless of the treatment groups. For 79 patients with N2b, contralateral neck recurrence was more common in the INRT group than in the BNRT group (7.9% vs. 0.0%), but the difference was not significant (p=0.107). The overall grade ≥ 2 toxicities were lower in the INRT group: acute (45.7% vs. 74.3%, p=0.001) and late (4.3% vs. 31.4%, p < 0.001), respectively.ConclusionINRT is an attractive strategy for patients with T1-2N0-2a tonsillar carcinoma compared to BNRT. For patients with N2b, there was a small risk of contralateral neck recurrence when treated with INRT, but its impact on the OS was limited with successful salvage treatment.

HIPK2 Overexpression and Its Prognostic Role in Human Papillomavirus-Positive Tonsillar Squamous Cell Carcinoma.

Tonsillar squamous cell carcinomas (TSCCs) are the most common human papillomavirus- (HPV-) associated oropharyngeal cancers with poor prognosis. Homeodomain-interacting protein kinase 2 (HIPK2) is a central regulator of p53, which participates in apoptosis during the DNA damage response. HIPK2 is involved in HPV-associated uterine cervical and cutaneous carcinogenesis through its binding of HPV E6, thereby preventing apoptosis and contributing to tumor progression. However, its clinical and prognostic significance in TSCC remains unclear. HIPK2 mRNA levels were analyzed in 20 normal tonsils and 20 TSCC specimens using real-time reverse transcription polymerase chain reaction. Immunohistochemistry of HIPK2 was performed in 79 resected specimens. HIPK2 was expressed in 57% of the TSCCs, and HIPK2 protein expression and HIPK2 mRNA levels were higher in TSCCs than in normal tonsils. HIPK2 overexpression was associated with poorly differentiated carcinoma and low alcohol consumption and was an independent prognostic factor for overall survival and disease-free survival (DFS) in TSCC and a negative independent prognostic factor for DFS in patients receiving postoperative radiotherapy. HIPK2 overexpression had a significant association with poorer DFS in HPV-positive TSCCs, but not in HPV-negative tumors. HIPK2 overexpression may be a potential prognostic marker for predicting prognoses and a high risk of recurrence, particularly in patients with HPV-positive TSCC.

Continuing rise in oropharyngeal cancer in a high HPV prevalence area: A Danish population-based study from 2011 to 2014

BackgroundHuman papillomavirus (HPV) is a critical element in the rising incidence of oropharyngeal squamous cell carcinoma (OPSCC), although whether this trend will continue, and the types of HPV responsible, are currently unknown. We previously demonstrated an increased incidence of HPV-related OPSCC in the high HPV prevalence area of Eastern Denmark from 2000 to 2010. Therefore, we investigated if the incidence for OPSCC continued to rise, the association to HPV and putative HPV-types in Eastern Denmark from 2011 to 14. We then projected the expected incidence of OPSCC versus cervical cancer through to 2020. Patients and methodsPatients with OPSCC (tonsillar squamous cell carcinoma [TSCC] and base of tongue squamous cell carcinoma [BSCC]) were identified via the Danish Head and Neck Cancer Group and the Danish Pathology Databank (n = 700). Tumours were re-reviewed and assessed using p16 immunohistochemistry, HPV DNA polymerase chain reaction (PCR), with genotyping by next generation sequencing. ResultsSixty-two percent (432/700) of tumours were HPV-positive (HPV+). The total incidence rate (per 100.000) for OPSCC increased from 4.0 in 2011 to 4.5 in 2014, primarily due to a rise in HPV+ TSCCs and HPV+ BSCCs, although numbers of HPV-negative (HPV–) OPSCC also increased during the study period. The majority of HPV+ tumours were HPV16 DNA positive (86%), but we also identified HPV33 DNA (6%), HPV35 DNA (4%) and others (3%), including HPV18, 26, 31, 45, 56, 58, 59 and HPV67. ConclusionAn increasing incidence of OPSCC is driven primarily by HPV+ OPSCC. Sixty-two percent of tumours were HPV+, which is a high-prevalence, although the lower number of HPV– cases has yet to stabilise. HPV16 was the predominant genotype, although a significant proportion (14%) was of another genotype. Our projections suggest that the number of HPV+ OPSCC will exceed that of cervical cancer in 2016 in Eastern Denmark.

Human polyomavirus and human papillomavirus prevalence and viral load in non-malignant tonsillar tissue and tonsillar carcinoma.

Human papillomaviruses (HPVs) are an acknowledged cause of a subset of oropharyngeal cancers, especially of tonsillar cancer. Similar to HPV, some human polyomaviruses (HPyVs), such as Merkel cell polyomavirus (MCPyV), have an oncogenic potential. Recently, several novel HPyVs have been discovered. The aim of our study was to determine viral DNA prevalence and viral DNA load of 13 different HPyVs in benign and malignant tonsillar tissue and to compare the data with those found for HPV. A total of 78 biopsies of palatine tonsils with a histologic diagnosis of non-malignant disease (chronic tonsillitis, tonsillar hyperplasia, n=40) or tonsillar squamous cell carcinoma (n=38) were included in the study. HPyV DNA prevalence and viral load were determined by virus-specific quantitative real-time PCRs. JCPyV (1/40, 2.5%) and WUPyV (3/40, 7.5%) were only found in non-malignant tonsillar tissue. HPyV7 and HPyV10 were only detected in one (2.6%) and seven (18.4%) of the 38 cancer biopsies, respectively. Both MCPyV (8/38, 21.1 vs. 4/40, 10.0%) and HPyV6 (2/38, 5.3 vs. 1/40, 2.5%) were found more frequently in cancer samples than in non-malignant tissue, but the differences were not significant. BKPyV, KIPyV, TSPyV, HPyV9, STLPyV, HPyV12 and NJPyV were not discovered in any of the samples. HPyV loads found in HPyV DNA-positive biopsies were very low with no difference between non-malignant and malignant samples (median load <0.0001 HPyV DNA copies per beta-globin gene copy, respectively). In contrast to HPyV, high-risk HPV types (HPV16/HPV18) were found significantly more frequently in tonsillar cancers than in non-malignant tonsillar tissue (17/38, 44.7 vs. 2/40, 5.0%, p<0.001). Furthermore, high-risk HPV DNA loads were significantly higher in the cancer compared to the non-malignant samples (median load 11.861 vs. 7×10-6 HPV DNA copies per beta-globin gene copy, p=0.012). While both HPV and HPyV may persist in tonsillar tissue, our data on HPyV DNA prevalence and load do not support a role of HPyV in tonsillar carcinogenesis, neither alone nor as co-infecting agents of HPV.

Subsite variation in survival of oropharyngeal squamous cell carcinomas 2004 to 2011.

To evaluate subsite-specific differences in survival between squamous cell carcinomas of the base of tongue and tonsillar fossa in a modern cohort likely to have been treated with intensity-modulated radiation therapy, chemotherapy for stage III and IV, and have had a high incidence of human papillomavirus-associated tumors. Retrospective cohort analysis utilizing data from the Surveillance, Epidemiology, and End Results program of patients with base of tongue and tonsillar fossa squamous cell carcinoma from 2004 to 2011. The cohort included 15,299 primary base of tongue and tonsillar fossa squamous cell carcinoma patients without distant metastases treated between 2004 and 2011. Subsite differences in overall survival and disease-specific survival were examined with Kaplan-Meier curves. Multivariate cox proportional hazard ratios were estimated for overall and disease-specific survival. The cohort included 7,220 (47.2%) base of tongue and 8,079 (52.8%) tonsillar fossa squamous cell carcinoma patients. Overall survival with all stages combined favored tonsillar fossa (P < .001) and remained superior when stratified by stage. In multivariate analyses adjusted for age, gender, race, and treatment, the hazard ratio for overall survival was superior for tonsillar fossa tumors compared to base of tongue tumors for all stages (stage 1, P = .041; stage 2, P = .006; stages 3 and 4, P < .001). Disease-specific survival also favored improved outcomes for tonsillar fossa. In this large modern cohort, overall and disease-specific survival favored outcomes in tonsillar fossa compared with base of tongue. Further study is required to evaluate factors that influence survival differences between tonsillar fossa and base of tongue despite modern therapy. 4 Laryngoscope, 127:1087-1092, 2017.

Double positivity for HPV DNA/p16 in tonsillar and base of tongue cancer improves prognostication: Insights from a large population-based study.

The aim was to explore the overall survival (OS) for palatine tonsillar squamous cell carcinoma (TSCC), subdivided, according to certainty of tonsillar tumour origin, into specified tonsillar squamous cell carcinomas (STSCCs) and nonspecified tonsillar squamous cell carcinomas (NSTSCCs), and base of tongue squamous cell carcinoma (BSCC) when stratifying for HPV DNA status, p16 expression and combined HPV/p16 status. We included all patients (n = 797) diagnosed with TSCCs and BSCCs in Eastern Denmark as registered in the Danish Head and Neck Cancer Group (DAHANCA) database and the Danish Pathology Databank, 2000-2010. Patients were treated according to national guidelines (radiotherapy +/- concomitant cisplatin). All specimens were analysed using HPV DNA PCR and p16 immunohistochemistry. Clinical information was retrieved from the DAHANCA database and the Danish National Patient Registry. Information on vital status was obtained from the Danish Civil Registration System. We observed improved OS for HPV+/p16+ BSCCs compared to HPV-/p16- (hazard ratio for death [HR], 0.15; 95% CI, 0.09-0.24). Among STSCCs, HPV+/p16+ showed the lowest HR (0.19, 95% CI, 0.13-0.29); whereas, HPV-/p16+ showed an intermediate HR (0.39; 95% CI, 0.22-0.70). For NSTSCCs, HPV+/p16+ and HPV-/p16+ showed similar OS (HRs, 0.39; 95% CI, 0.26-0.59; and 0.48; 95% CI, 0.24-0.95, respectively). Combined HPV+/p16+ was a significantly better prognostic marker in BSCCs and STSCCs than HPV DNA and p16, alone (all p-values < 0.05). Whereas, combined testing in NSTSCC was not better than p16 (p = 0.53), alone. In conclusion, double positivity for HPV/p16 in conjunction with the certainty of tumour site improved prognosis.

Epigenetic regulation of OAS2 shows disease-specific DNA methylation profiles at individual CpG sites.

Epigenetic modifications are essential regulators of biological processes. Decreased DNA methylation of OAS2 (2′-5′-Oligoadenylate Synthetase 2), encoding an antiviral protein, has been seen in psoriasis. To provide further insight into the epigenetic regulation of OAS2, we performed pyrosequencing to detect OAS2 DNA methylation status at 11 promoter and first exon located CpG sites in psoriasis (n = 12) and two common subtypes of squamous cell carcinoma (SCC) of the head and neck: tongue (n = 12) and tonsillar (n = 11). Compared to corresponding controls, a general hypomethylation was seen in psoriasis. In tongue and tonsillar SCC, hypomethylation was found at only two CpG sites, the same two sites that were least demethylated in psoriasis. Despite differences in the specific residues targeted for methylation/demethylation, OAS2 expression was upregulated in all conditions and correlations between methylation and expression were seen in psoriasis and tongue SCC. Distinctive methylation status at four successively located CpG sites within a genomic area of 63 bp reveals a delicately integrated epigenetic program and indicates that detailed analysis of individual CpGs provides additional information into the mechanisms of epigenetic regulation in specific disease states. Methylation analyses as clinical biomarkers need to be tailored according to disease-specific sites.

Adjuvant radiation in the TORS era: Is there a benefit to omitting the tumor bed?

PurposeTrans-oral robotic surgery (TORS) followed by adjuvant radiation therapy (RT) is becoming popular in treating node-positive tonsillar squamous cell carcinoma (SCC). One potential benefit is eliminating irradiation of the primary site when the tumor is widely resected, and targeting the neck only. This study assessed whether omitting the tumor bed provides any dosimetric or clinical advantage. Methods and materialsWe identified 21 patients with primary tonsillar SCC that were treated with TORS followed by RT to the ipsilateral neck and primary (N+P) site. We subsequently replanned each case to allow target coverage to the neck only, excluding the tumor bed. For each case, we created 2 plans: neck only (NO) and N+P. Additionally, we identified patients (n = 7) with primary SCC tonsil who did receive NO irradiation to compare their dosimetry and toxicity profile with those treated to both the primary site and ipsilateral neck. Contralateral neck radiation was not administered in any of these cases. ResultsDespite excluding the primary site in the NO plans, the mean dose to the tumor bed was high: 53.9 Gy. The only significant differences in omitting the primary site were lower doses to the oral cavity, 29.8 Gy in NO plan versus 34.6 Gy in N+P plan, P = .002, and superior constrictors, 42.9 Gy in NO plan versus 46.1 Gy in N+P plan, P = .01. No appreciable differences in toxicities were noted in the limited cohort treated with NO irradiation. ConclusionsSparing the primary site after TORS in node-positive tonsillar SCC does not appear to provide any significant dosimetric or clinical advantage. Furthermore, the tumor bed receives a significant but potentially subtherapeutic dose, limiting options for irradiation in a salvage setting. At this time, we do not recommend omitting the tumor bed from the radiation target volume following TORS.

P16 Immunostaining of Canine Squamous Cell Carcinomas Is Not Associated with Papillomaviral DNA

While papillomavirus (PVs) are an established cause of human cancer, few reports have supported a relationship between PV and canine squamous cell carcinomas (SCCs). Human oncogenic PVs lead to an increased expression of the p16 tumor suppressor protein, and the latter can be demonstrated immunohistochemically to support a likely causal relationship between tumor and PV infection. In the present study, archive samples of canine SCC from different anatomical locations were tested by polymerase chain reaction for the presence of PV DNA and by p16 immunohistochemistry. The aims were to investigate the relationship between p16 expression and presence of PV DNA, in order to assess the utility of p16 overexpression as a biomarker of PV infection in canine SCC. A total of 52 SCCs were included. Nine cases (17.3%) showed moderate p16 immunoreactivity, with no association with tumor degree of differentiation, histotype or mitotic activity. The canPVf/FAP64 primers amplified Canis familiaris PV-1 DNA from 3 out of 52 tumors (5.8%), one cutaneous, one oral and one tonsillar SCC. There was no association between PV presence and p16 immunostaining. These results do not support a significant role of PVs in the development of canine SCCs. Additionally, PV infection was apparently not the cause of the p16 immunostaining observed in a subset of canine SCCs. A better awareness of p16 level of expression and cellular function in canine cancer may help to define its diagnostic and prognostic role.

Minimal benefit of tonsillectomy in T1-T2 tonsillar squamous cell carcinoma treated with chemoradiotherapy

BackgroundChemoradiotherapy (CRT) has become the mainstay of treatment for tonsillar squamous cell carcinoma (SCC). Pre-CRT tonsillectomy is frequently performed, mostly for small primary tumors (T1-T2). However, the benefits of pre-CRT tonsillectomy remain unclear. MethodsA retrospective review was performed in 66 patients with T1-T2 tonsillar SCCs treated by CRT from 1997 to 2009. The efficacy of pre-CRT tonsillectomy was analyzed with regard to oncological and functional outcomes. ResultsThirty patients (45.5%) received tonsillectomy (pre-CRT tonsillectomy group), and 36 patients (54.5%) did not (CRT group). Except for a trend toward more T1 cases (33.3% vs. 13.9%, p = 0.061) and significantly less chemotherapy use (60% vs. 86.1%, p = 0.016) in the pre-CRT tonsillectomy group, there were no differences between the two groups in terms of age, gender, N classification (nodal status), overall stage, radiation dose, duration, or technique. In the pre-CRT tonsillectomy group, eight cases (26.7%) achieved an adequate operative margin judged by the surgeon, and only one (12.5%) had a negative pathological margin. In long-term follow-up, there were no statistically significant differences between the two groups regarding local (93.3% vs. 91.7%, p = 0.82) or regional control (93.3% vs. 94.4%, p = 0.84). The pre-CRT tonsillectomy group did not have a better 5-year disease-specific survival rate (83.3% vs. 94.4%, p = 0.177) or 5-year overall survival rate (70% vs. 94.4%, p = 0.017). There were no differences in complications or functional results (feeding tube and tracheostomy dependence), and quality of life demonstrated no significant difference. ConclusionPre-CRT tonsillectomy contributes little to oncological and functional outcomes in patients with T1-T2 tonsillar SCC.

Evaluation of the factors contributing to long-term survival in canine tonsillar squamous cell carcinoma.

To identify any prognostic factors that may be associated with the long-term survival of dogs diagnosed with tonsillar squamous cell carcinoma (TSCC). The medical records of 15 dogs treated for TSCC were reviewed retrospectively. The signalment, presenting signs, clinical stage, treatments and outcome were documented. The overall median survival time (MST) of the dogs in the study was 243 days. There was a 1-and 2-year survival of 40% and 20%, respectively. The results of initial staging had a significant effect on survival, as dogs with only one tonsil affected and no evidence of metastatic disease had a longer MST (637.5 days) than the dogs with local (MST: 134 days) or distant (MST: 75 days) metastatic disease or bilateral tonsillar involvement at the time of initial presentation. Prolonged survival times were reported for dogs undergoing surgery and adjunctive chemotherapy (MST: 464.5 days) for treatment of their TSCC. This is the first veterinary study demonstrating an association between prognosis of patients with TSCC and stage at the time of presentation, with long survival times demonstrated for dogs with early-stage disease following an initial treatment protocol that included surgery and chemotherapy. There was no clear association between long survival and additional surgeries for progressive disease; however; further investigation is warranted.

Radiotherapy alone or combined with chemotherapy as definitive treatment for squamous cell carcinoma of the tonsil.

This study is aimed at updating our institution's experience with definitive radiotherapy (RT) for squamous cell carcinoma of the tonsil. We reviewed 531 patients treated between 1983 and 2012 with definitive RT for squamous cell carcinoma of the tonsil. Of these, 179 patients were treated with either induction (n=19) or concomitant (n=160) chemotherapy. Planned neck dissection was performed on 217 patients: unilaterally in 199 and bilaterally in 18 patients. Median follow-up was 5.2years for all patients (range 0.1-31.6years) and 8.2years for living patients (range 1.9-31.6years). The 5-year local control rates by T stage were as follows: T1, 94%; T2, 87%; T3 79%; T4, 70%; and overall, 83%. Multivariate analysis revealed that local control was significantly influenced by T stage and neck dissection. The 5-year cause-specific survival rates by overall stage were as follows: I, 94%; II, 88%; III, 87%; IVA, 75%; IVB, 52%; and overall, 78%. Multivariate analysis revealed that cause-specific survival was significantly influenced by T stage, N stage, overall stage, fractionation, neck dissection, sex, and ethnicity. Of 77 patients treated with ipsilateral fields only, contralateral neck failure occurred in 1%. The rate of severe complications was 12%. Definitive RT for patients with tonsillar squamous cell carcinoma provides control rates equivalent to other modalities with a comparatively low incidence of late complications. Patients with anterior tonsillar pillar or tonsillar fossa primaries that are well lateralized with no base of tongue or soft palate extension may be treated with ipsilateral fields.

Trends in the Incidence of Oropharyngeal Cancers in the United States.

The incidence of oropharyngeal squamous cell carcinoma (SCCa) has increased in the United States despite a decrease in tobacco usage, and it may be driven by an increase in oral human papilloma virus (HPV) infection. We studied the incidence of tongue base and tonsillar SCCa over time to understand the changing epidemiology of oropharyngeal SCCa. Large national tumor registry. We studied patients diagnosed with oropharyngeal SCCa in SEER data (Surveillance, Epidemiology, and End Results) from 1973 to 2009. Age-adjusted incidence rates standardized to the 2000 US population were computed, with stratifications for age, sex, race, and stage. The sample included 10,061 tongue base and 11,515 tonsillar oropharyngeal cancers. When stratified by age, the incidence of oropharyngeal SCCa in patients ≤55 years of age more than doubled over 30 years. While the incidence rate in females remained stable, the rate in males more than doubled, from 2 per 100,000 persons in 1973 to >4 per 100,000 persons in 2009. The age-adjusted incidence of oropharyngeal SCCa in patients of black race/ethnicity remained consistently elevated, but the incidence in patients of white race/ethnicity rose from 1.3 per 100,000 persons to >2.5 per 100,000 persons, surpassing the incidence in black patients starting in 2002. The observation that the incidence of oropharyngeal SCCa is increasing among younger white males, despite a reduction in tobacco usage in the United States, is consistent with HPV as the source. Primary and secondary prevention strategies may be warranted in this population.

Human papillomavirus in tonsillar squamous cell carcinomas from Guatemala and Brazil

A subgroup of tonsillar squamous cell carcinoma (SCC) is associated with human papillomavirus (HPV). Nevertheless, the prevalence of HPV seems to be variable in different regions and ethnic groups. There are no reports of HPV in tonsillar carcinomas in Guatemala, and data from Brazil are scarce. The aim of this study is to analyze and compare HPV presence in samples of tonsillar SCC from these countries. This study describes the histologic features, expression of p16 by immunohistochemistry (IHC), and HPV by in situ hybridization (ISH) in 13 Guatemalan and 13 Brazilian patients. All cases of tonsillar SCC from Guatemala were positive for p16, 92% expressed HPV by ISH, and 75% corresponded to the high-risk genotype 16/18. From the Brazilian patients, only four expressed p16, and all were negative for HPV. Cases from Guatemala, which were mostly nonkeratinizing SCC and originated from the crypt/reticular epithelium of the tonsil, had high-risk integrated HPV, whereas in Brazilian cases, which were mostly keratinizing SCC that originated from the surface epithelium, there was no association with HPV.

De-escalation of radiation dose for human papillomavirus-positive oropharyngeal head and neck squamous cell carcinoma: A case report and preclinical and clinical literature review.

Traditionally, head and neck squamous cell carcinoma (HNSCC) has been considered to be a relatively homogeneous disease. However, recent data have demonstrated that human papillomavirus (HPV)-positive and HPV-negative disease are two different clinical entities associated with different outcomes. Preclinical and clinical studies have reported a divergence in treatment strategies as well as prognostic outcomes for HNSCCs that are HPV-positive versus HPV-negative. The present study describes the case of a 52-year-old man who presented with stage IVB cT2N3M0 right tonsillar HPV-positive squamous cell carcinoma. Induction chemotherapy with docetaxel, cisplatin and 5-fluorouracil (TPF), followed by chemoradiation therapy with carboplatin and 70 Gray (Gy) radiation in daily fractions was recommended. The patient completed the TPF and carboplatin treatment; however, he was unable to tolerate the radiation course, receiving a final dose of 46 Gy. A 60-day follow-up right neck salvage dissection was subsequently performed. Despite having received a partial radiation treatment of 46 Gy, the patient had no pathological evidence of disease at 60 days post radiation treatment. Repeat positron emission tomography-computed tomography at 32 months after the right neck dissection revealed no evidence of disease. The present study also discusses the current preclinical in vitro and in vivo targets for HPV-positive HNSCC and the obstacles presented in advancing clinical treatment modalities. Previous preclinical models investigating radiation sensitivity have yielded mixed results. Thus, it is important to understand and establish representative preclinical models for studying HPV and HNSCC to improve clinical research and therapeutic development. This review may guide future understanding of the role of HPV in HNSCC.

Problematic PEG: A Case of Enteral Feeding Tube Seeding Malignancy to the Abdominal Wall

The patient is a 57yo African American male with a history of tonsillar squamous cell carcinoma who presented with abdominal pain, distention and leakage from his enteral feeding tube site. He underwent uncomplicated percutaneous gastrostomy and tracheostomy placement following cancer resection surgery 3 years prior. The tracheostomy was removed shortly afterward, but gastrostomy tube was retained for medications and nutrition. Over the next several months, the patient developed worsening pain and drainage at the gastrostomy tube site. He then developed an exophytic mass that grew rapidly to surround the gastrostomy tube and tract. A CT scan of the abdomen described a 5.5 x 4.0cm solid, left anterior abdominal wall mass along the percutaneous gastrostomy tube tract. The patient underwent biopsy of the mass, which showed metastatic invasive tonsillar squamous cell carcinoma. Upon identification of metastatic cancer, the patient was tried on several systemic chemotherapeutic treatments without improvement. The treatment regimen was supplemented with palliative local radiation to the abdominal wall metastasis. For over 6 months following the addition of palliative radiation, the metastatic mass remained quiescent and the patient was symptom free. He was able to use the enteral feeding tube for nutrition and medications without complication. Despite thorough treatment, the mass enlarged and gastrostomy leakage returned. A gastrostomy-jejunostomy tube was placed, which temporarily helped control the leakage and improved delivery of medications and nutrition. During the last two months of the patient's life, he was transitioned to parenteral nutrition supplementation. He was eventually started on a patientcontrolled anesthesia regimen for pain control and discharged to inpatient hospice. Following surgical intervention for many head and neck cancers, patients typically require tracheostomy and enteral feeding tube placement to allow for adequate healing. Seeding of an enteral feeding tube site with oral, head and neck cancers is a rare occurrence. Two theories for seeding currently exist: hematogenous spread versus direct tumor transplantation during endoscopic placement usually seen with traumatic PEG placement or multiple passes of the endoscope during placement of the enteral feeding device. In the setting of development of metastasis to the abdominal wall, local chemoradiation can be used to improve quality at the end of life. This case highlights the importance of utilizing local chemoradiation as a palliative measure for certain patients. Palliative care in this situation should be personalized to the patient, and should include discussion of enteral or parenteral feeding options if indicated in the end of life.Figure 1Figure 2Figure 3

Abstract 1396: Unraveling the cellular hierarchywithin human tonsillar crypt epithelium and oropharyngeal squamous cellcarcinoma tumors

Abstract OPSCCs commonly arise from the epithelium lining the lingual and palatine tonsillar crypts. The stratified epithelium at the surface gives way to complex reticulated epithelium in the crypts which contain a diverse cell population with varying cytokeratin expression patterns. How such a diverse cell population is maintained has not yet been explored. It has been observed that HPV+ HNSCC consistently arise from the tonsillar crypts. In addition, somatic stem and progenitor cells have been identified as the likely targets of tumorigenesis in many tissues. To further evaluate whether tonsillar crypts contain unique multi-potent stem cells that are targets of tumorigenesis, and similar stem cells are maintained in OPSCC tumors of tonsillar origin, we propose the following studies: Aim 1: Characterize the cellular populations of crypt epithelium and compare to oral cavity epithelium. Human tissue obtained from the IRB approved EVMS Biorepository will be evaluated. We will stain for purported markers of stem cell activity including LGR5/6, CD34, p63, Bmi-1, cytokeratins 15, 19, and hTert using tyramide signal amplification when necessary. Cytokeratins 5, 8, 14 and 17 (previously identified in subsets of crypt epithelium) will be evaluated and co-stained with the above markers. Ki67 will be used to identify proliferative regions within the crypt epithelium. Aim 2: Characterize the cellular population of oropharyngeal squamous cell carcinoma and compare to normal tonsillar crypt epithelium. Human tumor obtained from above biorepository will be evaluated. HPV+/- OPSCC cell lines will be quantified for the markers of stem cell activity listed in Aim 1. Similarly, the same markers will be evaluated in HPV+/- human OPSCC tumors and compared to normal tonsil. The cell cycle regulator, p16, which is up-regulated in HPV-induced OPSCC and has previously been identified in a subset of normal tonsillar crypt epithelial cells will also be co-stained with any identified stem cell markers to determine if it is associated with any stem/progenitor cell function. Patient data will be correlated to identify prognostic value of these markers. Aim 3: Evaluate clonal expansions of cells in tonsillar crypts and OPSCC tumors by mitochondrial lineage tracing. Acquired deficiencies in the mitochondrial gene for the respiratory chain enzyme cytochrome c oxidase (CCO) can be exploited to identify cellular lineages within human tissues and tumors. This aim will evaluate if such CCO deficient (CCO-) clones exist within normal tonsillar crypts and OPSCC tumors, which will allow for careful lineage tracing in future experiments to fully understand the cellular hierarchy underlying tonsillar crypt and OPSCC tumor morphology. Elucidating the cellular hierarchy within tonsillar crypts, and identifying whether multi-potent stem cells exist within the tissue is imperative to understanding OPSCC, including those that are HPV-induced. Citation Format: Vivian F. Wu, Tennison Yu, Brette Harding, Robert Bruno. Unraveling the cellular hierarchywithin human tonsillar crypt epithelium and oropharyngeal squamous cellcarcinoma tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1396. doi:10.1158/1538-7445.AM2015-1396

Cell cannibalism by malignant neoplastic cells: three cases in dogs and a literature review.

Cell cannibalism refers to the engulfment of cells by nonprofessional phagocytic cells. Studies in human medicine have demonstrated a relationship between the presence of cell cannibalism by neoplastic cells and a poor outcome, and have shown a positive correlation with the presence of metastasis at the time of diagnosis. The biologic significance of cell cannibalism is unknown, but it is proposed that it may represent a novel mechanism of tumor immune evasion as a survival strategy in cases of unfavorable microenvironmental conditions. This report describes clinical and morphologic features of 3 cases of dogs with malignant neoplasia in which the presence of cellular cannibalism was observed in cytologic and histologic specimens. In the 1(st) case, a dog with a primary tonsillar squamous cell carcinoma with metastasis to retropharyngeal lymph nodes had neoplastic epithelial cells engulfing neutrophils noted in cytologic examination of the lymph nodes. In the 2(nd) case, neoplastic epithelial cells were seen engulfing each other in fine-needle aspirates from a primary mammary carcinoma with lung metastasis. In the 3(rd) case, poorly differentiated neoplastic mast cells from a recurrent, metastatic grade III mast cell tumor were observed cannibalizing eosinophils. A brief review of the literature describing known cell-into-cell relationships and the possible biologic significance and mechanisms involved in this phenomenon is provided. The relationship between cell cannibalism and distant metastasis should be explored in further studies, as it may prove to be a criterion of malignancy, as it is proposed in human medicine.