Very rare tumour of the palatine tonsil: a molecular approach.

Mucoepidermoid cancer (MEC) is extremely rare in the palatine tonsil with only three adequately described cases in the literature.We describe a woman in her late 70s with vague pharyngeal discomfort who underwent tonsillectomy, lymph node dissection of the neck and radiotherapy for MEC with loco-regional lymph node metastasis of the palatine tonsil. To confirm this extremely rare diagnosis and to gain deeper insight in the molecular oncogenesis, an extensive molecular study including next-generation sequencing and immunohistochemistry was performed. Immunoreactivity for p16 protein and real-time PCR showed high-risk oncogenic human papillomavirus 16 DNA and mutations in the BRAF, BARD and DNMT3A genes. Tumour mutational burden was low. After a follow-up of 7 years the patient is still alive and well without any residual or disseminated disease.

Fanconi-like anemia related to a FANCM mutation.

Fanconi anemia is primarily inherited as an autosomal recessive genetic disorder with common delays in diagnosis and challenging treatments. Fanconi anemia patients have a high risk of developing solid tumors, particularly in the head and neck or anogenital regions. The diagnosis of Fanconi anemia is primarily based on the chromosomal breakage but FA gene sequencing is recommended in all patients with a positive chromosome fragility test. Here, we present a 32-year-old man with advanced tonsil squamous cell carcinoma and fatal toxicity after the first cycle of chemotherapy. No anemia was present. A recent variant mutation if the FANCM gene was detected (c1511_1515delGAGTA (pArg504AsnfsTer29)). Homozygous or double heterozygous pathogenic variants have been reported in FANCM and linked to azoospermia and primary ovarian failure without anemia. Alterations in this gene have also been associated with a genetic predisposition for solid tumors (breast and ovarian cancer) and hematological malignancies (B-cell acute lymphoblastic leukemia). Due to the hypersensitivity of these patients to DNA-damaging agents such as chemotherapy and radiotherapy, surgery is the best treatment option for malignant solid tumors. Dose reductions or alternative regimens of chemotherapy and/or radiotherapy are recommended in FA patients who develop a malignant tumor.

Epidermotropic metastasis of squamous cell carcinoma of the tonsil: A case report with molecular confirmation.

Metastasis of oropharyngeal squamous cell carcinoma (SCC) to skin is uncommon and portends a poor prognosis. Clinical history and histopathology are key to discerning between metastatic disease vs de novo SCC of the skin. We describe a case of an HPV+ tonsillar SCC in a 77-year-old male, with metastasis to the neck skin. This case is unique because of prominent in situ epidermal involvement on skin biopsy specimen, complicating the distinction between primary and secondary disease. The nature of the lesion was resolved using next-generation sequencing of both the primary oropharyngeal SCC and skin lesion biopsy specimens. Both tumors showed identical ATR D1639G somatic mutations, while the skin lesion contained an additional POLE F1366L mutation. Clonal evolution of metastatic lesions is a well-described phenomenon; comparing the genetic profiles of primary and metastatic specimens can be useful in evaluating the tumor origin as well as identifying targetable genetic aberrations.

Lack of Conserved miRNA Deregulation in HPV-Induced Squamous Cell Carcinomas.

Squamous cell carcinomas (SCCs) in the anogenital and head and neck regions are associated with high-risk types of human papillomaviruses (HR-HPV). Deregulation of miRNA expression is an important contributor to carcinogenesis. This study aimed to pinpoint commonly and uniquely deregulated miRNAs in cervical, anal, vulvar, and tonsillar tumors of viral or non-viral etiology, searching for a common set of deregulated miRNAs linked to HPV-induced carcinogenesis. RNA was extracted from tumors and nonmalignant tissues from the same locations. The miRNA expression level was determined by next-generation sequencing. Differential expression of miRNAs was calculated, and the patterns of miRNA deregulation were compared between tumors. The total of deregulated miRNAs varied between tumors of different locations by two orders of magnitude, ranging from 1 to 282. The deregulated miRNA pool was largely tumor-specific. In tumors of the same location, a low proportion of miRNAs were exclusively deregulated and no deregulated miRNA was shared by all four types of HPV-positive tumors. The most significant overlap of deregulated miRNAs was found between tumors which differed in location and HPV status (HPV-positive cervical tumors vs. HPV-negative vulvar tumors). Our results imply that HPV infection does not elicit a conserved miRNA deregulation in SCCs.

High-risk human papillomavirus-mediated adenocarcinoma of palatine tonsil.

We describe the case of a human papillomavirus-mediated adenocarcinoma of palatine tonsil in a 51-year-old male. Histologically, the tumor exhibited a predominantly cribriform and tubular (glandular) growth of cuboidal and columnar cells with moderate amount of pale eosinophilic cytoplasm and oval or spindled nuclei with finely dispersed or coarse chromatin and small to medium-sized nucleoli. Foci of nuclear anaplasia and multinucleation, numerous mitotic figures, and necrosis (individual-cell and confluent) were seen. No squamous differentiation was identified. The tumor cells showed strong expression of CK7, p16 and HPV E6/E7 mRNA transcripts, and were negative for p40, CK5/6, AR, synaptophysin and chromogranin. Next generation sequencing showed 3 variants of unknown significance: FGF3 p.(R44fs); NF1 p.(S749 L) and POLE p. (S1506 L) with variant allele frequencies of 37 %; 20 %, and 17 % respectively. Chromosomal microarray analysis using single nucleotide polymorphism microarray (OncoScan) assay showed whole chromosomal gains of chromosomes 8 and 19, whole chromosomal losses of chromosomes 2 and 16, as well as segmental gains of chromosomes 3q25.31q29 (encompassing the PIK3CA gene), 17q21.31q25.3, 20p13q13.33, Xq28, and segmental losses of chromosomes 1q32.2, 6p25.1p21.1, 11q23.1q24.1, 12p11.22, 12p11.22, 14q24.1q32.33, 17p13.3q21.31 (encompassing the TP53 and NF1 genes). The results highlight the need to consider HPV testing in non-squamous cell carcinomas of the oropharynx.

HIV-Associated "Double-Hit" Lymphoma of the Tonsil: A First Reported Case.

Double-hit lymphoma (DHL) is a unique subtype of non-Hodgkin lymphoma characterized by atleast two rearrangements involving MYC, BLC2, and/or BCL6. These lymphomas are uncommon and aggressive, responding poorly to typical chemotherapy regimens. Lymphomas rarely arise from the oral cavity or tonsils, and those presenting as a neck mass are predominantly diffuse large B-cell lymphoma. To date, primary DHL of the tonsils has yet to be described in the literature. Here, we report a case of a 44 year-old male patient with well-controlled human immunodeficiency virus (HIV) who presented with a sore throat. He subsequently developed acute respiratory compromise due to a rapidly enlarging tonsillar mass. Pathologic and genetic analysis confirmed the presence of BCL6 and MYC rearrangements suggestive of DHL of the tonsils. In a young patient with HIV and a neck mass, it is essential that lymphoma remains on the list of differential diagnoses as prompt diagnosis and treatment may prevent complications from its rapid expansion.

A novel human in vitro papillomavirus type 16 positive tonsil cancer cell line with high sensitivity to radiation and cisplatin.

BACKGROUND: Human papillomavirus (HPV) is an established risk factor for oropharyngeal squamous cell carcinoma (OSCC). The aim was to establish cell lines from HPV-positive tonsil carcinomas to be used for treatment development. METHODS: Fresh samples from 23 HPV-positive tonsil carcinomas were cultivated in vitro. The established cell line was analyzed for viral characteristics, cell karyotype, TP53 status, and growth capabilities in nude mice. In vitro studies of sensitivities to radiation, cisplatin and cetuximab were performed. RESULTS: After 19 months (eight passages), one cell line, LU-HNSCC-26, was established in vitro and also grew as xenografts. The tumor was from a 48 year old non-smoking man with non-keratinizing, p16 positive tonsil OSCC, stage T2N0M0 with HPV16. It contained 19.5 (CV% 3.7) HPV16 copies/cell (passage 8). The complete HPV16 genome sequence was obtained. Episomal HPV16 was present with an E2/E7 ratio of 1.1 (CV% 2.6). In addition, HPV16 mRNA specific for the intact E2 gene was detected. The viral expression manifested 1.0 (CV% 0.1) E7 mRNA copies per HPV16 genome. The karyotype was determined and the cell line demonstrated wild type TP53. The ID50 for radiation was 0.90 Gy and the IC50 for cisplatin was 0.99 µmol/L. The cell line was inhibited to a maximum of 18% by cetuximab. CONCLUSIONS: We established an in vitro tonsil carcinoma cell line containing episomal HPV16. This is an important step towards efficient treatment development.

Overexpression of FGFR3 in HPV-positive Tonsillar and Base of Tongue Cancer Is Correlated to Outcome.

BACKGROUND/AIM: Human papillomavirus-positive (HPV+) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) have better outcome than corresponding HPV- cancers. To better individualize treatment, additional predictive markers are needed. Previously, we have shown that mutated fibroblast growth factor receptor 3 protein (FGFR3) was correlated to poorer prognosis and here FGFR3 expression was further analyzed. PATIENTS AND METHODS: One-hundred-fifteen HPV+TSCC/ BOTSCC biopsies were analyzed for FGFR3 by immunohistochemistry (IHC), and 109/115 were analyzed for FGFR3 mutations by Ion Proton sequencing, or by Competitive Allele-Specific Taqman PCR (CAST-PCR). Disease-free survival (DFS) was then calculated according to FGFR3 IHC expression. RESULTS: CAST-PCR was useful for detecting the three most common FGFR3 mutations. Focusing especially on the 98/115 patients with HPV+TSCC/BOTSCC and wild-type FGFR3, high FGFR3 expression correlated to significantly better 3-year DFS, p=0.043. CONCLUSION: In patients with HPV+TSCC/BOTSCC and wild-type FGFR3, overexpression of FGFR3 was correlated with better DFS.

MicroRNA-155, -185 and -193b as biomarkers in human papillomavirus positive and negative tonsillar and base of tongue squamous cell carcinoma.

OBJECTIVE: Three-year disease-free survival (DFS) is 80% for human papillomavirus (HPV) positive tonsillar and base of tongue cancer (TSCC/BOTSCC) treated with radiotherapy alone, and today's intensified therapy does not improve prognosis. More markers are therefore needed to more accurately identify patients with good prognosis or in need of alternative therapy. Here, microRNAs (miRs) 155, 185 and 193b were examined as potential prognostic markers in TSCC/BOTSCC. MATERIAL AND METHODS: 168 TSCC/BOTSCC patients diagnosed 2000-2013, with known data on HPV-status, CD8+ tumour infiltrating lymphocytes, tumour staging and survival were examined for expression of miR-155, -185 and -193b using Real-Time PCR. Associations between miR expression and patient and tumour characteristics were analysed using univariate testing and multivariate regression. RESULTS: Tumours compared to normal tonsils showed decreased miR-155 and increased miR-193b expression. miR-155 expression was associated with HPV-positivity, low T-stage, high CD8+ TIL counts and improved survival. miR-185 expression was associated with HPV-negativity and a tendency towards decreased survival, while miR-193b expression was associated with higher T-stage, male gender and lower CD8+ TIL counts, but not with outcome. Upon Cox regression, miR-185 was the only miR significantly associated with survival. Combining miR-155 and miR-185 to predict outcome in HPV+ patients yielded an area under curve (AUC) of 71%. CONCLUSION: Increased miR-155 expression was found as a positive predictor of survival, with the effect mainly due to its association with high CD8+ TIL numbers, while miR-185 independently associated with decreased survival. Addition of these miRs to previously validated prognostic biomarkers could improve patient stratification accuracy.

Profiling dendritic cell subsets in head and neck squamous cell tonsillar cancer and benign tonsils.

Dendritic cells (DCs) have a key role in orchestrating immune responses and are considered important targets for immunotherapy against cancer. In order to develop effective cancer vaccines, detailed knowledge of the micromilieu in cancer lesions is warranted. In this study, flow cytometry and human transcriptome arrays were used to characterize subsets of DCs in head and neck squamous cell tonsillar cancer and compare them to their counterparts in benign tonsils to evaluate subset-selective biomarkers associated with tonsillar cancer. We describe, for the first time, four subsets of DCs in tonsillar cancer: CD123+ plasmacytoid DCs (pDC), CD1c+, CD141+, and CD1c-CD141- myeloid DCs (mDC). An increased frequency of DCs and an elevated mDC/pDC ratio were shown in malignant compared to benign tonsillar tissue. The microarray data demonstrates characteristics specific for tonsil cancer DC subsets, including expression of immunosuppressive molecules and lower expression levels of genes involved in development of effector immune responses in DCs in malignant tonsillar tissue, compared to their counterparts in benign tonsillar tissue. Finally, we present target candidates selectively expressed by different DC subsets in malignant tonsils and confirm expression of CD206/MRC1 and CD207/Langerin on CD1c+ DCs at protein level. This study descibes DC characteristics in the context of head and neck cancer and add valuable steps towards future DC-based therapies against tonsillar cancer.

Clinical implication of programmed cell death-1 ligand-1 expression in tonsillar squamous cell carcinoma in association with intratumoral heterogeneity, human papillomavirus, and epithelial-to-mesenchymal transition.

Programmed cell death-1 ligand-1 (PD-L1), essential for immune evasion, is a potential candidate for pathogenesis and therapeutic target of human papillomavirus (HPV)-positive tonsillar squamous cell carcinomas (TSCCs). MET/hepatocyte growth factor signaling and transcription factors involved in epithelial-to-mesenchymal transition (EMT) upregulate PD-L1, which can contribute to clinical outcome. Intratumoral heterogeneity of PD-L1 expression is of clinical importance in selection bias due to false-negative patient enrollment. However, the clinicopathological features, prognostic value, and coexpressed molecules of PD-L1 remain unclear in TSCCs. PD-L1 expression was evaluated via immunohistochemistry using a specific monoclonal antibody (SP142) between whole-tissue and tissue microarray (TMA) sections of 79 tumors (5% cutoff value with weak staining). Expressions of EMT markers (TWIST1, Snail, and SNIP1) and MET/hepatocyte growth factor were also analyzed. Staining of the TMA sections showed 78.5% concordance rate to the whole section. PD-L1 positivity and its intratumoral heterogeneity were 29.1% and 15.2% of TSCCs by whole section, respectively. PD-L1 positivity was prevalent in females, HPV-positive tumors without base of tongue invasion, and SNIP1-overexpressed tumors. SNIP1 overexpression, unmethylated TWIST1, smoking, and poorly differentiated tumors were predictive for PD-L1 overexpression. PD-L1 positivity was a favorable independent prognostic factor. Subgroup analyses according to the coexpression of PD-L1 with HPV, SNIP1, or unmethylated TWIST1 indicated the best clinical outcome than any other subgroups. In conclusion, intratumoral heterogeneity of PD-L1 expression was frequent, warranting a caution in punching TMA cores. A combined analysis of PD-L1 with EMT and HPV may define a characteristic subset of patients and prognostic group.

Association Between Fibroblast Growth Factor Receptor 1 Gene Amplification and Human Papillomavirus Prevalence in Tonsillar Squamous Cell Carcinoma With Clinicopathologic Analysis.

Amplification of fibroblast growth factor receptor 1 ( FGFR1) has been reported in many squamous cell carcinomas, and human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma has been characterized as a distinct subset with favorable prognosis. Here, we investigated the FGFR1 amplification and HPV status in tonsillar squamous cell carcinoma (TSCC) and analyzed the clinical characteristics. HPV in situ hybridization (HPV ISH) and FGFR1 fluorescence in situ hybridization (FISH) were performed using tissue microarray from 89 cases of TSCC. Fourteen of 89 (15.7%) TSCC cases had FGFR1 amplification, and HPV was detected in 59 of 89 (66.3%) cases. FGFR1 amplification status was not associated with HPV positivity ( p=0.765). Outcomes were not significantly different between FGFR1 amplified and non-amplified patients. Although FGFR1 amplified patients ( n=4) in the HPV ISH-negative group ( n=30) had a tendency for poorer overall survival, no statistical significance was identified ( p=0.150, log-rank). FGFR1 protein overexpression showed better disease-free survival ( p=0.031, log-rank) in HPV-negative TSCC. This study suggests FGFR1 amplification may be important in the pathogenesis of TSCC regardless of HPV status.

Base of tongue cancer-is it tongue cancer located at the base of the tongue, or is it a type of lingual tonsil cancer? The perspective from a genomic analysis.

The aim of this study was to determine whether base of tongue (BOT) cancer is tongue cancer located at the base of the tongue or lingual tonsil cancer originating from tonsil tissue. This was a retrospective study using data from The Cancer Genome Atlas (TCGA). The genomic patterns of three primary cancers (BOT, oral tongue, and tonsil) were compared to determine their similarities and differences. Gene expression data (n=193; 26 BOT, 125 oral tongue, and 42 tonsil cases), copy number alteration data (n=142; 19 BOT, 96 oral tongue, and 27 tonsil cases), and somatic mutation data (n=187; 25 BOT, 122 oral tongue, and 40 tonsil cases) were analyzed using the t-test, heatmap analysis, and OncoPrint, respectively. Clinical information for the three tumour groups was included in the analyses. When using multiplatform analysis, BOT cancer showed nearly the same genomic pattern as tonsil cancer, but not oral tongue cancer. The χ2 test and survival analysis revealed that BOT cancer had the same clinical and survival patterns as tonsil cancer. In conclusion, BOT cancer showed a genomic pattern similar to that of tonsil cancer, but different to that of oral tongue cancer. Further prospective studies are warranted before the results of this study can be applied in a clinical setting.

Oral mucosa tissue gene expression profiling before, during, and after radiation therapy for tonsil squamous cell carcinoma.

BACKGROUND: Radiation-therapy (RT) induces mucositis, a clinically challenging condition with limited prophylactic interventions and no predictive tests. In this pilot study, we applied global gene-expression analysis on serial human oral mucosa tissue and blood cells from patients with tonsil squamous cell cancer (TSCC) to identify genes involved in mucositis pathogenesis. METHODS AND FINDINGS: Eight patients with TSCC each provided consecutive buccal biopsies and blood cells before, after 7 days of RT treatment, and 20 days following RT. We monitored clinical mucositis and performed gene-expression analysis on tissue samples. We obtained control tissue from nine healthy individuals. After RT, expression was upregulated in apoptosis inducer and inhibitor genes, EDA2R and MDM2, and in POLH, a DNA-repair polymerase. Expression was downregulated in six members of the histone cluster family, e.g., HIST1H3B. Gene expression related to proliferation and differentiation was altered, including MKI67 (downregulated), which encodes the Ki-67-proliferation marker, and KRT16 (upregulated), which encodes keratin16. These alterations were not associated with the clinical mucositis grade. However, the expression of LY6G6C, which encodes a surface immunoregulatory protein, was upregulated before treatment in three cases of clinical none/mild mucositis, but not in four cases of ulcerative mucositis. CONCLUSION: RT caused molecular changes related to apoptosis, DNA-damage, DNA-repair, and proliferation without a correlation to the severity of clinical mucositis. LY6G6C may be a potential protective biomarker for ulcerative mucositis. Based on these results, our study model of consecutive human biopsies will be useful in designing a prospective clinical validation trial to characterize molecular mucositis and identify predictive biomarkers.

Tonsillar metastasis of nonsmall cell lung cancer with G719S mutation in exon 18: A case report.

RATIONALE: Lung cancer has the highest mortality of all malignant tumors and is becoming the leading cause of death in China. Surgical resection is the best treatment for early non-small-cell lung carcinoma. But postoperative tumor recurrence is very common. Brain, bone and liver are the most common metastatic sites of lung cancer. PATIENT CONCERNS: A 59-year-old woman was admitted to our hospital finding a lung nodule in physical examination. No other obvious symptoms were obsessed in this patient. No remarkable abnormality was detected in preoperative laboratory tests and physical examination. DIAGNOSES: A ground-glass nodule was detected on the left inferior lobe in the imaging examination. No metastases were detected before the surgery and early-stage lung cancer was supposed. INTERVENTION: This patient underwent a radical resection of lung cancer successfully and enjoyed a peaceful postoperative rehabilitation. OUTCOMES: Although pathological diagnosed confirmed early stage lung adenocarcinoma (T1N0M0). The patient had tumor recurrence 7 months after operation. Gene sequencing confirmed the G719S mutation in exon 18 of the EGFR gene and target therapy, chemotherapy and radiotherapy were all given to this patient successively, but they were all unresponsive. The patient died 26 months after surgery. LESSONS: We herein first report G719S mutation in lung adenocarcinoma with tonsillar metastasis. Generally, the tumor responded poorly to treatment and progressed quickly, which didn't achieve the desired effect. G719S mutant is supposed to be the cause of poor responsive to treatment.

miRNA-expression in tonsillar squamous cell carcinomas in relation to HPV infection and expression of the antileukoproteinase SLPI.

The aim of this study was to determine if micro-(mi-)RNAs are involved in the previously reported inverse correlation between the antileukoproteinase SLPI, HPV, and smoking habit of head and neck squamous cells carcinoma (HNSCC) patients. HPV-status and SLPI-protein expression were determined in tonsillar SCC (TSCC; n=126). Differentially expressed miRNAs dependent on HPV-status and SLPI-expression were detected by microarray; possible binding-sites in SLPI- and HPVE6-mRNAs were determined in silico. Survival rates were estimated testing prognostic values of HPV-status, SLPI- and miRNA-expression. miRNA-array identified 24 up-regulated and 10 down-regulated miRNAs in HPV-positive versus HPV-negative TSCC (p<0.01; HPV-positivity: 42.1%). HPV-positivity resulted in two up-regulated miRNAs in SLPI-positive TSCC. Of 16 further miRNAs, eight miRNAs were up- and eight were down-regulated in SLPI-negative TSCC. RT-q-PCR-validation of the four most differentially expressed miRNAs showed that miR-363 is expressed strongest in SLPI-negative/HPV-positive TSSC. In silico-analysis of all differentially expressed miRNAs identified miR-363, miR-210, miR-130a, and miR-181a with possible binding sites in the HPV16-E6-mRNA, but none were predicted in the SLPI-mRNA. HPV-positivity, low SLPI-levels and high miR-363-levels are significantly associated with better survival rates. The data presented here show that miR-363 is associated with HPV-positive/SPLI-negative TSCC. The prognostic value of miR-363 suggests a role in the assumed inverse correlation of smoking and SPLI-expression in the mode of HPV-infections in tonsillar but possibly also other HNSCC.

Human Papillomavirus and Potentially Relevant Biomarkers in Tonsillar and Base of Tongue Squamous Cell Carcinoma.

Human papillomavirus (HPV)-positive tonsillar- and base of tongue cancer is increasing epidemically and has much better outcome than corresponding HPV-negative cancer and most other head and neck cancers with around 80% 3-year disease free survival with conventional radiotherapy and surgery. Consequently, most HPV-positive cancer patients may not require the intensified chemoradiotherapy given to many head and neck cancer patients and would, with tapered treatment, avoid several severe side-effects. Moreover, intensified therapy has not improved survival and treatment alternatives are needed. To identify patients eligible for tapered or targeted therapy, additional biomarkers are required. Several studies have, therefore, focused on finding predictive markers, some of which are also potentially targetable. To conclude, better-tailored therapy, either as tapered or targeted, is important for increasing numbers of patients with HPV-positive tonsillar- and base of tongue cancer. This review deals with some of these issues and presents some promising markers.

Prevalence of high-risk human papillomavirus infection and cancer gene mutations in nonmalignant tonsils.

OBJECTIVES: To analyze the prevalence of high-risk HPV (human papillomavirus) and genetic alterations in nonmalignant tonsils. METHODS: We collected benign fresh tonsillar tissue specimens from 477 patients undergoing tonsillectomy because of chronic tonsillitis or tonsillar hypertrophy in 2012 (Group A, n=237) and in 2015 (Group B, n=240). Luminex xMAP technique served to detect E6/E7 DNA from 16 different high-risk HPV types. Tonsillar DNA and peripheral blood leukocyte DNA from the infected individuals were analyzed using Nimblegen SeqCap EZ Comprehensive Cancer Design panel. The panel targets 578 different genes that are relevant in carcinogenesis. HPV negative tonsillar specimens from age- and gender matched individuals were used as controls. All specimens harboring high-risk HPV were analyzed using fluorescence in situ hybridization (FISH). RESULTS: Five of 477 (1.0%) patients tested positive for the following HPV types: HPV16 (two cases), HPV52 (one case), HPV66 (one case), HPV52 and HPV68 (coinfection, one case). FISH analyses showed that the appearance of HPV in specimens infected with HPV 16 was episomal. Benign tonsils infected with high-risk HPV harbored mutations in EP300, NF1, PIK3CA, and RB1 which are considered relevant in the development of HPV-associated head and neck squamous cell carcinoma (SCC). CONCLUSIONS: The prevalence of high-risk HPV in nonmalignant tonsils is low. High-risk HPV positive tonsils harbored mutations in genes that are commonly altered in HPV-associated head and neck SCC. The role of these mutations in tonsillar carcinogenesis is an interesting target for future research.

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.