Translocations and Gene Fusions in Sinonasal Malignancies.

PURPOSE OF REVIEW: During the past few years there has been an expansion in our understanding of gene fusions and translocations involved in cancer of the sinonasal tract. Here we review the downstream biologic effects, clinical characteristics, and pathologic features of these tumors. The molecular consequences and neo-antigens resulting from these chromosomal aberrations are considered and targets for current and future clinical trials discussed. RECENT FINDINGS: Several new, clinically relevant, chromosomal aberrations have been discovered and evaluated to varying degrees in sinonasal tumors including DEK::AFF2, BRD4::NUT, ADCK4::NUMBL, and ETV6::NTRK3. Sinonasal malignancies demonstrate a diverse genetic landscape and varying clinical courses. Recent studies illustrate that gene fusions and translocations may play a role in carcinogenesis in certain sinonasal tumor subtypes and may be used to develop new biomarker-driven and patient-centered treatments.

Optimal Combination of Neuroendocrine Markers for the Detection of High-Grade Neuroendocrine Tumors of the Sinonasal Tract and Lung.

PURPOSE OF REVIEW: Identification of neuroendocrine (NE) differentiation is critical to the classification of head and neck (HN) and lung tumors. In combination with tumor morphology, immunohistochemical (IHC) documentation of NE differentiation is necessary for the diagnosis of NE tumors. The purpose of this study is to determine the sensitivity and concordance of two novel NE markers (mASH1, INSM1) across a group of high-grade NE tumors of the sinonasal tract and lung, and to compare their expression with the current widespread use of conventional NE markers, synaptophysin (SYN) and chromogranin A (CGA). In addition, expression of PARP1 is examined as a potential novel therapeutic target. RECENT FINDINGS: Thirty-nine high-grade NE tumors, 23 of the HN and 16 of the lung, were reevaluated by two subspecialized HN and thoracic pathologists, and subsequently stained with mASH1, INSM1, and PARP1. Sensitivity and degree of concordance of all possible combinations of markers were assessed. Sensitivities (standard error) were as follows: mASH1 41% (0.08), INSM1 44% (0.08), SYN 56% (0.08), and CGA 42% (0.09); combination of all four NE markers: 73% (0.08). Sensitivity and standard error for PARP1 was 90% and 0.05, respectively. Highest sensitivity to detect NE differentiation in high-grade NE tumors of the HN and thoracic region was achieved with a combination of four NE markers. Moderate concordance was found with combinations of mASH1 and INSM1 and traditional NE markers, respectively. Consistent overexpression of PARP1 in high-grade tumors with NE differentiation in the HN and lung opens eligibility for PARP1 inhibitor trials.

Signaling Pathways mTOR and ERK as Therapeutic Targets in Sinonasal Intestinal-Type Adenocarcinoma.

Despite advances in surgery and radiotherapy, the overall prognosis of sinonasal intestinal-type adenocarcinoma (ITAC) is poor, and new treatment options are needed. Recent studies have indicated alterations in cellular signaling pathways that may serve as targets for modern inhibitors. Our aim was to evaluate the frequency of mTOR and ERK pathway upregulation in a retrospective series of 139 ITAC and to test the efficacy and mechanism of action of candidate targeted inhibitors in cell line ITAC-3. An immunohistochemical analysis on p-AKT, p-mTOR, p-S6, p-4E-BP1, and p-ERK indicated, respectively, a 68% and 57% mTOR and ERK pathway activation. In vitro studies using low doses of mTOR inhibitor everolimus and ERK inhibitor selumetinib showed significant growth inhibition as monotherapy and especially as combined therapy. This effect was accompanied by the downregulation of mTOR and ERK protein expression. Our data open a new and promising possibility for personalized treatment of ITAC patients.

Translational genomics of sinonasal cancers.

The sinonasal cavities harbor a wide variety of histologically distinct cancers, the majority very aggressive with 5-year survival rates between 30-60% and local recurrence as the main cause of death. This is a complex anatomic area, close to structures such the eyes and the brain, which is of special relevance for surgery and postoperative radiotherapy. The low incidence of these rare tumors hampers accumulation of experience with diagnosis and clinical managment as well as knowledge on recurrent genetic aberrations or testing of new treatment strategies. However, recent years have seen a growing number of publications on genetic aberrations providing data that can aid or fine-tune classification and provide molecular targets for treatment with specific inhibitors. In addition, new sinonasal cancer models are created that enable preclinical testing of candidate inhibitor drugs. With more and more novel targeted therapies being developed, options for personalized treatment of sinonasal cancer patients are now opening up.

Prognostic and Therapeutic Implications of Immune Classification by CD8+ Tumor-Infiltrating Lymphocytes and PD-L1 Expression in Sinonasal Squamous Cell Carcinoma.

Sinonasal squamous cell carcinoma (SNSCC) is an aggressive tumor predominantly arising in the maxillary sinus and nasal cavities. Advances in imaging, surgical and radiotherapeutic techniques have reduced complications and morbidity; however, the prognosis generally remains poor, with an overall 5-year survival rate of 30-50%. As immunotherapy may be a new therapeutic option, we analyzed CD8+ tumor-infiltrating lymphocytes (TILs) and the tumor microenvironment immune type (TMIT, combining CD8+ TILs and PD-L1) in a series of 57 SNSCCs. Using immunohistochemistry, tissue samples of 57 SNSCCs were analyzed for expression of CD8 on TILs and of PD-L1 on tumor cells. The results were correlated to the clinical and survival data. In total, 88% (50/57) of the tumors had intratumoral CD8+ TILs; 19% (11/57)-CD8high (>10%); and 39/57 (68%)-CD8low (1-10%). PD-L1 positivity (>5%) was observed in 46% (26/57) of the SNSCCs and significantly co-occurred with CD8+ TILs (p = 0.000). Using univariate analysis, high intratumoral CD8+ TILs and TMIT I (CD8high/PD-L1pos) correlated with a worse survival rate. These results indicate that SNSCCs are immunogenic tumors, similar to head and neck squamous cell carcinomas. Nineteen percent of the cases were both CD8high and PD-L1pos and this subgroup may benefit from therapy with immune checkpoint inhibitors.

Analysis of MYB oncogene in transformed adenoid cystic carcinomas reveals distinct pathways of tumor progression.

Adenoid cystic carcinomas can occasionally undergo dedifferentiation, a phenomenon also referred to as high-grade transformation. However, cases of adenoid cystic carcinomas have been described showing transformation to adenocarcinomas that are not poorly differentiated, indicating that high-grade transformation may not necessarily reflect a more advanced stage of tumor progression, but rather a transformation to another histological form, which may encompass a wide spectrum of carcinomas in terms of aggressiveness. The aim of this study was to gain more insight in the biology of this pathological phenomenon by means of genetic profiling of both histological components. Using microarray comparative genomic hybridization, we compared the genome-wide DNA copy-number changes of the conventional and transformed area of eight adenoid cystic carcinomas with high-grade transformation, comprising four with transformation into moderately differentiated adenocarcinomas and four into poorly differentiated carcinomas. In general, the poorly differentiated carcinoma cases showed a higher total number of copy-number changes than the moderately differentiated adenocarcinoma cases, and this correlated with a worse clinical course. Special attention was given to chromosomal translocation and protein expression of MYB, recently being considered to be an early and major oncogenic event in adenoid cystic carcinomas. Our data showed that the process of high-grade transformation is not always accompanied by an accumulation of genetic alterations; both conventional and transformed components harbored unique genetic alterations, which indicate a parallel progression. Our data further demonstrated that the MYB/NFIB translocation is not necessarily an early event or fundamental for the progression to adenoid cystic carcinoma with high-grade transformation.

Time trends in the prevalence of HPV in oropharyngeal squamous cell carcinomas in northern Spain (1990-2009).

Recent studies support an important role for human papillomavirus (HPV) in oropharyngeal squamous cell carcinomas (OPSCC), although the incidence varies widely depending on the geographic location and time period studied. The aim of this study was to determine the proportion of HPV in a large cohort of OPSCC in northern Spain in the years 1990-2009. Clinical records and paraffin embedded tumor specimens of 248 consecutive patients surgically treated for OPSCC (140 tonsillar and 108 base of tongue) between 1990 and 2009 were retrieved. OPSCC cases were histomorphologically evaluated, and protein expression of p16 and p53 was analyzed by immunohistochemistry. Detection of high-risk HPV DNA was performed by GP5+/6+-PCR and in situ hybridization (ISH). Thirty cases (12%) were positive for p16 immunostaining, of which eight (3.2% of the total series) were found positive for HPV type 16 by genotyping of GP5+6+-PCR products. All HPV GP5+/6+-PCR-positive tumors were p53-immunonegative, seven had a basaloid morphology and seven were also positive by HPV ISH. Presence of HPV correlated inversely with tobacco and alcohol consumption (p < 0.001), but not with age of onset of OPSCC. Overall survival was better in the HPV-positive group, although not statistically significant (p = 0.175). OPSCC patients in northern Spain demonstrated a low involvement of HPV, increasing (although not significantly, p = 0.120) from 1.8% in 1990-1999 to 6.1% of cases in 2000-2009.

Next-generation sequencing reveals remarkable genetic stability in primary and corresponding recurrent intestinal-type sinonasal adenocarcinoma.

BACKGROUND: Recurrent intestinal-type sinonasal adenocarcinoma (ITAC) can occur several years after primary treatment and with different histology. We aimed to clarify if such recurrences could be second primary tumors and to identify actionable mutations as targets for personalized treatment of recurrent ITAC. METHODS: Twelve pairs of primary and recurrent ITAC were histologically examined and analyzed by next-generation sequencing. RESULTS: Histological differences between primary and recurrent tumor pairs were observed in five cases. Frequent mutations included TP53, APC, TSC2, ATM, EPHA2, BRCA2, LRP1B, KRAS, and KMT2B. There was 86% concordance of somatic mutations between the tumor pairs, while four cases carried additional mutations in the recurrence. CONCLUSIONS: We found all cases to be clonal recurrences and not second primary tumors. Moreover, tumor pairs showed a remarkable genomic stability, suggesting that personalized treatment of a recurrence may be based on actionable molecular genetic targets observed in the primary tumor.

Signet-ring cell change in adenoid cystic carcinoma: a clinicopathological and immunohistochemical study of four cases.

AIMS: Signet-ring cell (SRC) change has not been reported in adenoid cystic carcinoma (ACC). The aim of this study was to describe the clinicopathological and immunohistochemical findings in four cases of ACC with SRCs (ACC-SRC), in which the relative proportion of the SRC component ranged from 25% to 50%. METHODS AND RESULTS: The median age was 58 years (range: 48-81 years), and all patients were women. The involved sites were sinonasal, lip, and submandibular. Two patients developed lung metastasis, and one died of disease 63 months after tumour resection. Neither mucinous nor lipid substances were detected in the SRCs. These showed positive staining for AE1/AE3, cytokeratin 14, and epithelial membrane antigen, which highlighted the intracytoplasmic vacuole borders. The SRC nests were surrounded by myoepithelial cells positive for α-smooth muscle actin and p63. The SRCs showed similar p53 positivity but lower Ki67 and mitotic indices than the conventional component. SRCs were c-Myb-negative. Ultrastructural examination revealed that the intracytoplasmic vacuoles were lumina lined by microvilli. CONCLUSIONS: ACC-SRC is a non-mucin-producing and non-lipid-producing phenomenon, possibly related to disturbed differentiation of ductal/luminal cells. This cellular modification in ACC apparently does not change the biological behaviour of the tumour, but it may cause significant diagnostic problems, particularly in incisional biopsies.

From laryngeal epithelial precursor lesions to squamous carcinoma of the larynx: the role of cell cycle proteins and ß-catenin.

Novel markers to accurately predict the risk of malignant transformation in laryngeal epithelial precursor lesions (EPL) are needed. We tried to identify some molecular alterations occurring in laryngeal tumorigenesis. In this study, 60 paraffin-embedded EPL and 17 metachronous invasive carcinomas were immunostained for markers associated with proliferation (Ki67), cell cycle control (p53, p21, p16, p27, cyclin D1), and cell adhesion and invasion (laminin and ß-catenin). Aberrant expression of p16 and p53 and positivity at cytoplasm for ß-catenin and cyclin D1 were detected significantly in EPL with progression to invasive laryngeal carcinoma. All cases with basal and suprabasal reactivity of p53 showed ß-catenin overexpression. We found that ß-catenin protein expression increased significantly with the grade of dysplasia. This is one of the studies with the largest number of laryngeal EPL and invasive carcinoma studied sequentially. Our data confirm the role of some cell cycle regulatory proteins in the development of laryngeal carcinoma. Cytoplasmic retention of ß-catenin in EPL seems to be related with more aggressive biological behavior. Combined increased p53 and cytoplasmic ß-catenin protein expression could be biologically important in laryngeal tumorigenesis. Further research is required to clarify the involvement of ß-catenin in the mechanism associated with malignant transformation in laryngeal tissues.

Sinonasal Cancer: Improving Classification, Stratification and Therapeutic Options.

The nasal cavities and paranasal sinuses are the site of origin of a wide spectrum of histologically and clinically distinct disease entities [...].

EUSICA/COST IMMUNO-model workshop fostering collaboration to advance sinonasal cancer research: A meeting report.

Sinonasal cancer is a clinically and histologically heterogeneous group of rare tumors with generally poor clinical outcomes. Their low incidence hampers the advancement of clinical management as well as translational research, and calls for multicenter and multinational collaboration between physicians and researchers. This report describes the proceedings of a two-day conference organized by the European Network for Sinonasal Cancer Research (EUSICA) and COST Action 'IMMUNO-model', fostering such collaboration and focusing on preclinical tumor and immuno models, surgical and radio-oncological treatments, core facilities for genetic characterization and molecular tumor classification, and cancer registry.

Sox2 and ßIII-Tubulin as Biomarkers of Drug Resistance in Poorly Differentiated Sinonasal Carcinomas.

Poorly differentiated sinonasal carcinomas (PDCs) are tumors that have a poor prognosis despite advances in classical treatment. Predictive and prognostic markers and new personalized treatments could improve the oncological outcomes of patients. In this study, we analyzed SOX2 and ßIII-tubulin as biomarkers that could have prognostic and therapeutic impacts on these tumors. The cohort included 57 cases of PDCs: 36 sinonasal undifferentiated carcinoma (SNUC) cases, 13 olfactory neuroblastoma (ONB) cases, and 8 sinonasal neuroendocrine carcinoma (SNEC) cases. Clinical follow-up data were available for 26 of these cases. Sox2 expression was detected using immunohistochemistry in 6 (75%) SNEC cases, 19 (53%) SNUC cases, and 6 (46%) ONB cases. The absence of Sox2 staining correlated with a higher rate of recurrence (p = 0.015), especially distant recurrence. The majority of cases showed ßIII-tubulin expression, with strong positivity in 85%, 75%, and 64% of SNEC, ONB, and SNUC cases, respectively. Tumors with stronger ßIII-tubulin expression demonstrated longer disease-free survival than those with no expression or low expression (p = 0.049). Sox2 and ßIII-tubulin expression is common in poorly differentiated sinonasal tumors and has prognostic and therapeutic utility.

Characterization of a Preclinical In Vitro Model Derived from a SMARCA4-Mutated Sinonasal Teratocarcinosarcoma.

Sinonasal teratocarcinosarcoma (TCS) is a rare tumor that displays a variable histology with admixtures of epithelial, mesenchymal, neuroendocrine and germ cell elements. Facing a very poor prognosis, patients with TCS are in need of new options for treatment. Recently identified recurrent mutations in SMARCA4 may serve as target for modern therapies with EZH1/2 and CDK4/6 inhibitors. Here, we present the first in vitro cell line TCS627, established from a previously untreated primary TCS originating in the ethmoid sinus with invasion into the brain. The cultured cells expressed immunohistochemical markers, indicating differentiation of epithelial, neuroepithelial, sarcomatous and teratomatous components. Whole-exome sequencing revealed 99 somatic mutations including SMARCA4, ARID2, TET2, CDKN2A, WNT7A, NOTCH3 and STAG2, all present both in the primary tumor and in the cell line. Focusing on mutated SMARCA4 as the therapeutic target, growth inhibition assays showed a strong response to the CDK4/6 inhibitor palbociclib, but much less to the EZH1/2 inhibitor valemetostat. In conclusion, cell line TCS627 carries both histologic and genetic features characteristic of TCS and is a valuable model for both basic research and preclinical testing of new therapeutic options for treatment of TCS patients.

A Novel External Auditory Canal Squamous Cell Carcinoma Cell Line Sensitive to CDK4/6 Inhibition.

OBJECTIVE: To characterize cell line CAE606 derived from a squamous cell carcinoma (SCC) of the external auditory canal (EAC) and to show its usefulness as a model for testing candidate therapeutic agents. STUDY DESIGN: Preclinical translational research. SETTING: Biomedical research institute. METHODS: The cell line was initiated from a moderately differentiated T2N0M0 EAC SCC. We studied its histologic and genetic features as well as growth and invasion parameters. Sensitivity to cell CDK4/6 cell cycle inhibitor palbociclib was analyzed. RESULTS: CAE606 cells expressed heavy molecular weight cytokeratin, p63, and vimentin. The population doubling time was 25.8 hours, and the cells showed fast collective cell migration in a wound-healing assay. Short tandem repeat analysis confirmed it to be derived from the primary tumor of the patient. Next-generation sequencing revealed alterations in cell cycle regulation genes, including inactivating mutations in CDKN2A and TP53 and high-level amplification of CCND1 and EGFR. CAE606 showed a strong decrease of phospo-Rb expression upon exposure to the CDK4/6 inhibitor palbociclib, causing significant growth inhibition with an IC50 of 0.46 µM. CONCLUSION: This is the first report of a stable EAC SCC cell line. Its genetic features make it a useful tool for preclinical testing of new therapeutic agents for EAC SCC, particularly those targeting cell cycle regulation in combination with radio- and chemotherapy or other specific signaling pathway inhibitors.

Gene amplification and protein overexpression of EGFR and ERBB2 in sinonasal squamous cell carcinoma.

BACKGROUND: Sinonasal squamous cell carcinomas (SNSCCs) are rare tumors with no etiologic link to tobacco or alcohol, as opposed to other squamous cell carcinomas of the head and neck. Despite improvements in the field of surgery and radiotherapy, patients with these tumors still face a very unfavorable prognosis, partly because of their localization in a complex anatomic area, which has special relevance for surgery and postoperative treatment. Therefore, there is a need for new therapeutic possibilities for patients with these tumors. METHODS: Gene copy numbers of epidermal growth factor receptor (EGFR) and v-erb-b2 erythroblastic leukemia viral oncogene homolog 2 (ERBB2) were analyzed by fluorescence in situ hybridization and multiplex ligand-dependent probe amplification, and protein expression was evaluated by immunohistochemistry in 54 SNSCC specimens. The results were correlated with clinicopathologic and follow-up data. RESULTS: EGFR gene copy number increases were observed in 20 of 45 tumors (44%), and 21 of 54 tumors (39%) had EGFR protein overexpression. Eight of 38 tumors (21%) had ERBB2 copy number increases, and 4 of 54 tumors (7%) exhibited elevated protein expression levels. Both copy number increases and protein overexpression of EGFR and ERBB2 were mutually exclusive. v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were absent in 37 tumors that were analyzed. CONCLUSIONS: A substantial proportion of SNSCCs carried alterations in EGFR or ERBB2. Together with the absence of KRAS mutations, these findings indicate that therapies targeting these molecules may be promising additions to the therapeutic options for patients with SNSCC.

Levels and patterns of expression of hypoxia-inducible factor-1α, vascular endothelial growth factor, glucose transporter-1 and CD105 in adenoid cystic carcinomas with high-grade transformation.

AIMS: To compare the expression of proteins regulated by hypoxia between adenoid cystic carcinoma (ACC) with and without high-grade transformation (HGT). METHODS AND RESULTS: In eight ACC-HGT and 18 ACC without HGT, expression of hypoxia-inducible factor-1 (HIF-1α), vascular endothelial growth factor (VEGF), glucose transporter-1 (GLUT-1) and microvascular density (MVD) by CD105 (a hypoxia-inducible protein expressed in angiogenic endothelial cells) was determined. Expression levels of HIF-1α and VEGF as well as CD105-MVD did not differ significantly between: (i) transformed and conventional areas (TA and CA, respectively) of ACC-HGT, (ii) CA and ordinary ACC. HIF-1α was detected in 100% of cases and presented a diffuse expression pattern. No significant association was found between levels of HIF-1α expression and tumour size, metastasis and recurrence. GLUT-1 showed a prostromal expression pattern and was observed exclusively in TA (three of six cases) and in only three of 14 ACC. CONCLUSIONS: Both the absence of significant alterations in levels of expression of HIF-1α, VEGF and CD105 and the patterns of expression of HIF-1α and GLUT-1 suggest that hypoxia may not play a key role in the process of high-grade transformation of ACC. Although HIF-1α expression is a common finding in ACC, it cannot be used as a marker of tumour aggressiveness.

EGFR Exon 20 Insertion Mutations in Sinonasal Squamous Cell Carcinoma.

Recurrent epidermal growth factor receptor (EGFR)-activating mutations have been identified in a rare form of head and neck cancer known as sinonasal squamous cell carcinoma (SNSCC), a malignant disease with a 5-year mortality rate of ~40%. Interestingly, the majority of EGFR mutations identified in patients with primary SNSCC are exon 20 insertions (Ex20ins), which is in contrast to non-small-cell lung cancer (NSCLC), where the EGFR exon 19 deletion and L858R mutations predominate. These studies demonstrate that EGFR Ex20ins mutations are not exclusive to lung cancer as previously believed, but are also involved in driving SNSCC pathogenesis. Here we review the landscape of EGFR mutations in SNSCC, with a particular focus on SNSCC associated with inverted sinonasal papilloma (ISP), a benign epithelial neoplasm. Taking lessons from NSCLC, we also discuss potential new treatment options for ISP-associated SNSCC harbouring EGFR Ex20ins in the context of targeted therapies, drug resistance and precision cancer medicine. Moving forward, further basic and translational work is needed to delineate the biology of EGFR Ex20ins in SNSCC in order to develop more effective treatments for patients with this rare disease.

Molecular Basis and Rationale for the Use of Targeted Agents and Immunotherapy in Sinonasal Cancers.

Despite the progress of surgery, radiotherapy, and neoadjuvant chemotherapy, the prognosis for advanced sinonasal cancers (SNCs) remains poor. In the era of precision medicine, more research has been conducted on the molecular pathways and recurrent mutations of SNCs, with the aim of understanding carcinogenesis, helping with diagnosis, identifying prognostic factors, and finding potentially targetable mutations. In the treatment of SNC, immunotherapy is rarely used, and no targeted therapies have been approved, partly because these tumors are usually excluded from major clinical trials. Data on the efficacy of targeted agents and immune checkpoint inhibitors are scarce. Despite those issues, a tumor-agnostic treatment approach based on targeted drugs against a detected genetic mutation is growing in several settings and cancer subtypes, and could also be proposed for SNCs. Our work aims to provide an overview of the main molecular pathways altered in the different epithelial subtypes of sinonasal and skull base tumors, focusing on the possible actionable mutations for which potential target therapies are already approved in other cancer types.