Subset Of Squamous Cell Carcinomas Research Articles

Abstract 2508: Clinical significance of PARP7 (TIPARP) gene copy number alterations in human non-small cell and head & neck carcinomas

Abstract Introduction: PARP7, encoded by the TIPARP gene, is a monoART involved in cellular stress responses and with immunomodulatory functions in cancer. The PARP7 gene is amplified in a subset of squamous cell carcinomas and ongoing clinical studies are assessing its role as anti-cancer therapeutic target (NCT04053673, NCT05127590) Here, we analyzed the frequency of PARP7 copy number alterations and its association with tumor immune microenvironment (TIME) features and outcomes in non-small cell lung cancer (NSCLC) and head & neck squamous-cell carcinoma (HNSCC) cohorts. Methods: The PARP7 gene copy number and amplification was analyzed using a dual probe fluorescence in situ hybridization (FISH) assay in two retrospective cohorts of NSCLC (Cohort #1, n=124) and HNSCC (Cohort #2, n=83) represented in tissue microarray format. In a subset of cases, the PARP7 copy number was also studied using whole exome DNA sequencing. The TIME was assessed on consecutive tumor sections using a multiplexed quantitative immunofluorescence panel including the markers DAPI, cytokeratin, CD4, CD8 and PD-L1 coupled to computational pathology analysis. The association between the markers, with clinicopathologic variables and survival was studied. Results: Increased PARP7 copy number (>2 copies/cell) was identified in 55% of NSCLCs (85% of them of squamous-cell histology) and 76% of HNSCCs. A high copy number (>3 copies/cell) was identified in 22% cases from both tumor type cohorts. After adjustment of the PARP7 gene copy number by the chromosome 3 centromeric probe (CEN3) signal, PARP7 amplification (>1.5 PARP7/CEN3 signal) was detected in 22% of NSCLC cases and 34% of HNSCC. A higher number of cases with PARP7 copy number gains were identified using FISH than with whole exome DNA sequencing. No significant associations between the PARP7 gains/losses and major clinicopathologic variables were found. However, higher PARP7 copy number was associated with reduced CD8+ or CD4+ tumor infiltrating lymphocytes (TILs) and a numerically lower tumor PD-L1 protein levels in HNSCC. Elevated PARP7 copy number was associated with shorter overall survival in both studied tumor types. Conclusion: Elevated PARP7 gene copy number identifies a subset of lung and head & neck squamous-cell carcinomas with unfavorable TIME features and adverse prognosis. Detection of PARP7 gene abnormalities using FISH in tumor biopsy samples is sensitive and has potential as a predictive biomarker. Citation Format: Viviana A. Ahumada, Kristen McEachern, Kristy Kuplast-Barr, Kurt Alex Schalper. Clinical significance of PARP7 (TIPARP) gene copy number alterations in human non-small cell and head & neck carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2508.

Distinct regulations driving YAP1 expression loss in poroma, porocarcinoma and RB1-deficient skin carcinoma.

Recently, YAP1 fusion genes have been demonstrated in eccrine poroma and porocarcinoma, and the diagnostic use of YAP1 immunohistochemistry has been highlighted in this setting. In other organs,loss of YAP1 expression can reflect YAP1 rearrangement or transcriptional repression, notably through RB1 inactivation. In this context, our objective was to re-evaluate the performance of YAP1 immunohistochemistry for the diagnosis of poroma and porocarcinoma. The expression of the C-terminal part of the YAP1 protein was evaluated by immunohistochemistry in 543 cutaneous epithelial tumours, including 27 poromas, 14 porocarcinomas and 502 other cutaneous tumours. Tumours that showed a lack of expression of YAP1 were further investigated for Rb by immunohistochemistry and for fusion transcripts by real-time PCR (YAP1::MAML2 and YAP1::NUTM1). The absence of YAP1 expression was observed in 24 cases of poroma (89%), 10 porocarcinoma (72%), 162 Merkel cell carcinoma (98%), 14 squamous cell carcinoma (SCC) (15%), one trichoblastoma and one sebaceoma. Fusions of YAP1 were detected in only 16 cases of poroma (n=66%), 10 porocarcinoma (71%) all lacking YAP1 expression, and in one sebaceoma. The loss of Rb expression was detected in all cases except one of YAP1-deficient SCC (n=14), such tumours showing significant morphological overlap with porocarcinoma. In-vitro experiments in HaCat cells showed that RB1 knockdown resulted in repression of YAP1 protein expression. In addition to gene fusion, we report that transcriptional repression of YAP1 can be observed in skin tumours with RB1 inactivation, including MCC and a subset of SCC.

Towards a Molecular Classification of Sinonasal Carcinomas: Clinical Implications and Opportunities.

Simple SummaryIn recent years, there have been several molecular and immunohistochemical additions to the pathologic diagnosis of sinonasal malignancies that could facilitate the identification of clinically relevant groups of sinonasal malignancies. Molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this article we review the recent literature on molecular analysis and/or subtyping of sinonasal carcinomas and we discuss the possible clinical implications of a classification of sinonasal tumors based on their molecular features.Sinonasal carcinomas are a heterogeneous group of rare tumors, often with high-grade and/or undifferentiated morphology and aggressive clinical course. In recent years, with increasing molecular testing, unique sinonasal tumor subsets have been identified based on specific genetic alterations, including protein expression, chromosomal translocations, specific gene mutations, or infection by oncogenic viruses. These include, among others, the identification of a subset of sinonasal carcinomas associated with HPV infection, the identification of a subset of squamous cell carcinomas with EGFR alterations, and of rare variants with chromosomal translocations (DEK::AFF2, ETV6::NTRK and others). The group of sinonasal adenocarcinomas remains very heterogeneous at the molecular level, but some recurrent and potentially targetable genetic alterations have been identified. Finally, poorly differentiated and undifferentiated sinonasal carcinomas have undergone a significant refinement of their subtyping, with the identification of several new novel molecular subgroups, such as NUT carcinoma, IDH mutated sinonasal undifferentiated carcinoma and SWI/SNF deficient sinonasal malignancies. Thus, molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this review, we summarize the recent developments in the molecular characterization of sinonasal carcinomas and we discuss how these findings are likely to contribute to the classification of this group of rare tumors, with a focus on the potential new opportunities for treatment.

Updates in the cause of sinonasal inverted papilloma and malignant transformation to squamous cell carcinoma.

The purpose of this study was to give an overview of recently published articles investigating the cause of inverted papilloma and possible mechanisms mediating malignant transformation into squamous cell carcinoma (SCCa). Inverted papilloma is a sinonasal tumour that is benign in nature, but has a tendency for local invasion, recurrence and malignant degeneration. Its pathogenesis has not been elucidated and the etiological role for human papillomavirus virus (HPV) has been controversial. Recent reports have varied in detection method (mRNA ISH, DNA ISH and PCR amplification of highly conserved regions of the viral genome), ranging from 0 to 100%. Advances in meta-genomics have permitted detection of HPV viral signatures that were previously cost-prohibitive, and there appears to be a potential role for both low-risk and high-risk in the cause of the disease. Activating EGFR mutations have also been identified to be correlated with malignant transformation, which may be exclusive of HPV infection. Furthermore, more comprehensive approaches in detecting genomic markers have been reported, with HOX-related genes and epithelial-mesenchymal-transition-related gene sets appear to be differentially upregulated. Sinonasal inverted papilloma is a diverse disease that is predominantly benign, but it harbours the potential for malignant degeneration in the SCCa with cause yet to be elucidated. Current evidence supports a potential role for high-risk HPV in a subset of SCCa, with the role of low-risk HPV yet to be defined. Historic studies of individual and small groups of molecular markers have not consistently adequate characterize signalling pathways underpinning the oncogenesis, and comprehensive genomic studies are needed to better understand the disease.

JAAD Game Changers∗: Squamous cell carcinoma with aggressive subclinical extension: 5-year retrospective review of diagnostic predictors

Capsule Summary•A subset of squamous cell carcinomas has aggressive subclinical extension.•Our analysis identified several diagnostic factors associated with this phenomenon, particularly immunosuppression.•Our model can help predict the occurrence of subclinically aggressive squamous cell carcinoma and thereby optimize surgical planning and patient preparedness.How did this article1 change the practice of dermatology?Approximately 2% of patients with cutaneous squamous cell carcinoma (SCCs) die from metastatic disease. SCCs with aggressive subclinical extension (SCC-ASE) are those that appear nonaggressive on clinical examination but are found to be subclinically aggressive during Mohs micrographic surgery. This retrospective study reviewed demographic factors that might be predictors of this outcome. Immunosuppressed patients with a diagnosis of SCC were almost 3 times more likely to have SCC-ASE. Cigarette use was more predominant among the patients with SCC-ASE and was an independent risk factor for the development of SCC-ASE when results were controlled for other confounders.

The first report of molecular characterized BRD4-NUT carcinoma in Brazil: a case report

BackgroundNUT midline carcinoma is a rare and aggressive subset of squamous cell carcinoma, which is characterized by the translocation of nuclear protein in testis gene that is mostly fused with bromodomain and extraterminal family proteins. We describe here the first Brazilian case of NUT midline carcinoma with BRD4-NUT fusion detected in a next-generation sequencing panel and we present the clinical evolution of this patient.Case presentationA 42-year-old Caucasian man was diagnosed with poorly differentiated squamous cell carcinoma of the left maxillary sinus, with negative in situ hybridization for Epstein–Barr encoding region and human papillomavirus genotyping. He received induction therapy, chemoradiotherapy with weekly systemic chemotherapy, and, concurrently, weekly intra-arterial chemotherapy. New imaging evaluation, 1 month after the end of the last treatment, revealed a good partial response in the primary lesion. However, positron emission tomography-computed tomography showed multiple suspicious lesions in his bones and lungs, which were histologically confirmed. He died exactly 2 months after metastatic disease was diagnosed.ConclusionsNUT midline carcinoma is usually very aggressive. Currently, there is no standard of care for treatment of NUT midline carcinoma. The definitive diagnosis must be by demonstration of NUTM1 rearrangement. Immunohistochemical staining of greater than 50% of tumor nuclei on formalin-fixed paraffin-embedded tissue using the monoclonal rabbit antibody to NUT (clone C52B1), has a specificity of 100%, and sensitivity of 87% for the diagnosis of NUT midline carcinoma. Our case is the first Brazilian case of NUT midline carcinoma with BRD4-NUT fusion.

SOX2 and PI3K Cooperate to Induce and Stabilize a Squamous-Committed Stem Cell Injury State during Lung Squamous Cell Carcinoma Pathogenesis.

Although cancers are considered stem cell diseases, mechanisms involving stem cell alterations are poorly understood. Squamous cell carcinoma (SQCC) is the second most common lung cancer, and its pathogenesis appears to hinge on changes in the stem cell behavior of basal cells in the bronchial airways. Basal cells are normally quiescent and differentiate into mucociliary epithelia. Smoking triggers a hyperproliferative response resulting in progressive premalignant epithelial changes ranging from squamous metaplasia to dysplasia. These changes can regress naturally, even with chronic smoking. However, for unknown reasons, dysplasias have higher progression rates than earlier stages. We used primary human tracheobronchial basal cells to investigate how copy number gains in SOX2 and PIK3CA at 3q26-28, which co-occur in dysplasia and are observed in 94% of SQCCs, may promote progression. We find that SOX2 cooperates with PI3K signaling, which is activated by smoking, to initiate the squamous injury response in basal cells. This response involves SOX9 repression, and, accordingly, SOX2 and PI3K signaling levels are high during dysplasia, while SOX9 is not expressed. By contrast, during regeneration of mucociliary epithelia, PI3K signaling is low and basal cells transiently enter a SOX2LoSOX9Hi state, with SOX9 promoting proliferation and preventing squamous differentiation. Transient reduction in SOX2 is necessary for ciliogenesis, although SOX2 expression later rises and drives mucinous differentiation, as SOX9 levels decline. Frequent coamplification of SOX2 and PIK3CA in dysplasia may, thus, promote progression by locking basal cells in a SOX2HiSOX9Lo state with active PI3K signaling, which sustains the squamous injury response while precluding normal mucociliary differentiation. Surprisingly, we find that, although later in invasive carcinoma SOX9 is generally expressed at low levels, its expression is higher in a subset of SQCCs with less squamous identity and worse clinical outcome. We propose that early pathogenesis of most SQCCs involves stabilization of the squamous injury state in stem cells through copy number gains at 3q, with the pro-proliferative activity of SOX9 possibly being exploited in a subset of SQCCs in later stages.

Anticancer activity of drug conjugates in head and neck cancer cells.

Sexually transmitted oral cancer/head and neck cancer is increasing rapidly. Human papilloma virus (HPV) is playing a role in the pathogenesis of a subset of squamous cell carcinoma of head and neck (SCCHN). Paclitaxel is a widely used anticancer drug for breast, ovarian, testicular, cervical, non-small cell lung, head and neck cancer. However, it is water insoluble and orally inactive. We report the synthesis of water soluble nanosize conjugates of paclitaxel, branched PEG, and EGFR-targeting peptide by employing native chemical ligation. We performed a native chemical ligation between the N-hydroxy succinimide (NHS) ester of paclitaxel succinate and cysteine at pH 6.5 to give the cysteine-conjugated paclitaxel derivative. The thiol functionality of cysteine was activated and subsequently conjugated to multiarm thiol-PEG to obtain the paclitaxel branched PEG conjugate. Finally, we conjugated an EGFR-targeting peptide to obtain conjugates of paclitaxel, branched PEG, and EGFR-targeting peptide. These conjugates show anticancer activity against squamous cell carcinoma of head and neck cells (SCCHN, Tu212).

Markers of squamocolumnar junction cells in normal tonsils and oropharyngeal cancer with and without HPV infection.

HPV infection has been identified recently as the causative agent of a subset of squamous cell carcinomas arising in oropharyngeal tonsils. Factors influencing the susceptibility of tonsillar epithelium to HPV-induced oncogenesis are far from being elucidated. A 5-protein signature including cytokeratin (CK)7, anterior gradient (AGR)2, cluster differentiation (CD)63, matrix metalloproteinase (MMP)7, and guanine deaminase (GDA) has recently been found to identify a residual embryonic cell population in the squamocolumnar (SC) junction of the cervix, susceptible to HPV infection, and cancers originating from these cells. The expression of SC junction markers was investigated with immunohistochemistry in normal tonsils and in oropharyngeal carcinomas (OPC) fully characterised for HPV. All markers were constantly expressed in the reticulated epithelial cells of the tonsillar crypts, with variable diffusion and intensity; in OPC, positivity was observed in 36,5%, 29,2%, 39%, 17%, and 25% of cases with respectively AGR2, CK7, GDA, CD63, and MMP7 antibodies. No OPC was positive for all markers; 6 were completely negative. AGR2 and CK7 showed significant association with tumor- and HPV-related parameters. AGR2 expression was associated with tumor origin in the tongue base (p=0.013); CK7 was associated with non-keratinising morphology (p=0.013). p16 tumor cell expression was associated with AGR2 (p=0.021); transcriptionally active HPV infection was associated with AGR2 and CK7 (p=0.024 and 0.043). Expression of SC junction markers in tonsillar crypt cells might be related to the embryological development of tonsillar structures; their partial association with HPV oncogenic infection could help to identify HPV-susceptible cells and related OPC.

Infundibulocystic Squamous Cell Carcinoma

Infundibulocystic squamous cell carcinoma was first reported in 2008 as a subset of squamous cell carcinoma arising from the infundibulum of the hair follicle and exhibiting infundibular differentiation. It has well-differentiated, less-differentiated, and infiltrative forms. It was thoroughly analyzed in a series of cases in 2011 by Misago et al. and has been redefined to include only the infiltrative form owing to its unique clinical and histological characteristics. Here, we report an interesting case of infundibulocystic squamous cell carcinoma in a 72-year-old man presenting with a mass on the left helix of the ear.

Her2 expression and gene amplification is rarely detectable in patients with oral squamous cell carcinomas

Her2 (ErbB2) transforms cells when overexpressed and is an important therapeutic target in breast cancer. Contrary to breast cancer, studies on Her2 overexpression and gene amplification in squamous cell carcinomas of the head and neck region described largely different results. This study was undertaken to learn more on the prevalence and clinical significance of HER2 amplification and overexpression in squamous cell carcinomas of the head and neck. Her2 expression and gene amplification was analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) on two tissue microarrays composed of 427 squamous cell carcinomas of the head and neck region and 222 oral squamous cell carcinomas. Results were compared with clinicopathological features. Her2 expression and gene amplification was rarely detectable in squamous cell carcinomas of the head and neck region and unrelated to tumor phenotype or survival of the patients with oral squamous carcinoma. Our results demonstrate that Her2 protein and gene amplification was only detectable in a small subset of squamous cell carcinomas of the head and neck region as well as oral squamous cell carcinomas. However, it can be speculated that those few patients with Her2 overexpressing and gene amplificated tumors may possibly benefit from an anti-Her2 therapy.

Phase I Study of Oral Rigosertib (ON 01910.Na), a Dual Inhibitor of the PI3K and Plk1 Pathways, in Adult Patients with Advanced Solid Malignancies

To determine the pharmacokinetics (PK), maximum tolerated dose (MTD), safety, and antitumor activity of an oral formulation of rigosertib, a dual phosphoinositide 3-kinase (PI3K) and polo-like kinase 1 (Plk1) pathway inhibitor, in patients with advanced solid malignancies. Patients with advanced solid malignancies received rigosertib twice daily continuously in 21-day cycles. Doses were escalated until intolerable grade ≥2 toxicities, at which point the previous dose level was expanded to define the MTD. All patients were assessed for safety, PK, and response. Urinary PK were performed at the MTD. Archival tumors were assessed for potential molecular biomarkers with multiplex mutation testing. A subset of squamous cell carcinomas (SCC) underwent exome sequencing. Forty-eight patients received a median of 2 cycles of therapy at 5 dose levels. Rigosertib exposure increased with escalating doses. Dose-limiting toxicities were hematuria and dysuria. The most common grade ≥2 drug-related toxicities involved urothelial irritation. The MTD is 560 mg twice daily. Activity was seen in head and neck SCCs (1 complete response, 1 partial response) and stable disease for ≥12 weeks was observed in 8 additional patients. Tumors experiencing ≥partial response had PI3K pathway activation, inactivated p53, and unique variants in ROBO3 and FAT1, two genes interacting with the Wnt/β-catenin pathway. The recommended phase II dose of oral rigosertib is 560 mg twice daily given continuously. Urinary toxicity is the dose-limiting and most common toxicity. Alterations in PI3K, p53, and Wnt/β-catenin pathway signaling should be investigated as potential biomarkers of response in future trials.

Role of human papillomavirus in oropharyngeal squamous cell carcinoma: A review.

Human papillomavirus (HPV) has been implicated in the pathogenesis of a subset of oropharyngeal squamous cell carcinoma. As a result, traditional paradigms in relation to the management of head and neck squamous cell carcinoma have been changing. Research into HPV-related oropharyngeal squamous cell carcinoma is rapidly expanding, however many molecular pathological and clinical aspects of the role of HPV remain uncertain and are the subject of ongoing investigation. A detailed search of the literature pertaining to HPV-related oropharyngeal squamous cell carcinoma was performed and information on the topic was gathered. In this article, we present an extensive review of the current literature on the role of HPV in oropharyngeal squamous cell carcinoma, particularly in relation to epidemiology, risk factors, carcinogenesis, biomarkers and clinical implications. HPV has been established as a causative agent in oropharyngeal squamous cell carcinoma and biologically active HPV can act as a prognosticator with better overall survival than HPV-negative tumours. A distinct group of younger patients with limited tobacco and alcohol exposure have emerged as characteristic of this HPV-related subset of squamous cell carcinoma of the head and neck. However, the exact molecular mechanisms of carcinogenesis are not completely understood and further studies are needed to assist development of optimal prevention and treatment modalities.

Cutaneous squamous cell carcinomas of the lower extremity: A distinct subset of squamous cell carcinomas

Some patients develop a disproportionate number of cutaneous squamous cell carcinomas (SCCs) on their lower extremity (LE). We sought to characterize the clinical features, treatment, and outcome in patients who develop multiple LE SCCs. We identified 22 patients with 4 or more biopsy-diagnosed LE SCCs during a 4.5-year study period. The location, size, treatment, and clinical outcome of each LE SCC were recorded. Of the 22 patients studied, 18 were female. Of the 360 SCCs our patients developed, 260 (72.2%) were on the LE. The incidence of SCCs in these patients was nearly 7 times greater than the incidence of basal cell carcinoma in the same patients. The number of patients is small and limits definitive conclusions about prevalence of SCCs on the LE in the general population. LE SCCs are a distinct subset of cutaneous SCCs and may have distinctive clinical features and biologic behavior requiring additional study.

A Study of Gata3 and Phox2b Expression in Tumors of the Autonomic Nervous System

Autonomic neurons and chromaffin cells, which constitute the autonomic nervous system, are derived from a common progenitor from the neural crest, and its development is controlled by a network of transcription factors, including the master regulator, Phox2b, and its downstream, Gata3. Anti-Phox2b and anti-Gata3 antibodies were applied to a total of 77 autonomic nervous system tumors, including 35 paragangliomas, 21 pheochromocytomas, 9 neuroblastomas, 4 ganglioneuroblastomas, and 8 ganglioneuromas, as well as their potential morphologic mimics, including tumors of the small round cell tumor group, neuroendocrine carcinomas of lung and gastrointestinal tract (carcinoid tumors/neuroendocrine tumors, large cell neuroendocrine carcinomas, and small cell carcinomas), Merkel cell carcinomas, benign and malignant tumors of thyroid, parathyroid, and adrenal cortex, and malignant melanomas. A variety of nonendocrine/neuroendocrine carcinomas were also studied. Gata3 expression was seen in 89% of paragangliomas, 95% of pheochromocytomas, and all neuroblastomas, ganglioneuroblastomas, and ganglioneuromas, as well as in all parathyroid tumors, a majority of urothelial and mammary carcinomas, and a subset of squamous cell carcinomas, but all other tumors were negative. Phox2b expression was seen in all neuroblastomas, ganglioneuroblastomas, and ganglioneuromas and in 40% of paragangliomas, but pheochromocytomas and all other tumors were negative. Gata3 is a highly reliable marker for paragangliomas, pheochromocytomas, and neuroblastic tumors to distinguish from their simulators. This is an additional utility for this marker, which is used for the diagnosis of urothelial and mammary carcinomas. Phox2b is also highly specific, but its low sensitivity to paragangliomas and pheochromocytomas would limit the utility only to neuroblastic tumors.

DDR2 mutations in lung cancer in adenocarcinoma and squamous cell carcinoma and association with MET activation.

8115 Background: The discoidin domain receptor tyrosine kinase 2 (DDR2) gene is mutated in a small subset of squamous cell carcinomas (SQCAs) of the lung. Targeting of DDR2 with the inhibitor dasatinib inhibits DDR2-mutated cell line growth and is being investigated in clinical trials for treatment of DDR2-mutated lung tumors. We investigated the frequency and type of DDR2 mutations and their association with other targetable growth factor pathway alterations in non-small cell lung carcinoma (NSCLC). Methods: DNA was extracted from macro-dissected FFPE sections of 105 advanced stage lung carcinomas. Next-generation sequencing was performed using a 36-amplicon panel including the coding regions of DDR2 and exons 11 and 15 of BRAF. DDR2 mutations were confirmed by bidirectional Sanger sequencing. Lung tumors were classified using a standard immunohistochemistry panel. MET pathway activation was assessed with immunohistochemistry using an activation-specific phospho-antibody (pMET, Try1234/1235). MET amplification and ALK rearrangement were assessed using FISH. Mutational analysis for EGFR (exon 18-21), PIK3CA (exons 9 and 20), and KRAS(exons 1-2) was performed using PCR-based DNA sequencing. Results: Heterozygous DDR2 point mutations were identified in 7/105 (6.7%) NSCLCs, including 3/29 (10.3%) SQCAs and 4/69 (5.8%) ACAs, but not in neuroendocrine/large cell carcinomas (0/7). DDR2 mutations were scattered throughout the gene, with 4 present in the discoidin domain and 3 in the kinase domain. MET pathway activation, seen in 25% of DDR2-unmutated cases, was found in 3/6 (50%) DDR2-mutated cases, including 1 SQCA with high-level MET gene amplification. DDR2 mutations were mutually exclusive with BRAF or EGFR mutation or ALK rearrangement, with 1 KRAS-mutated case. Conclusions: DDR2 mutations occur in lung carcinomas with a range of histologic features and in association with MET activation. Dual targeting of the MET and DDR2 kinases in such cases may warrant further investigation.

Fibroblast growth factor receptor 1 (FGFR1) gene copy number gain in adenocarcinoma and squamous cell carcinoma of the lung.

7552 Background: FGFR-1 is a novel target for therapy in non-small cell lung carcinoma (NSCLC). FGFR1 gene has been shown to be amplified in ~20% of squamous cell carcinomas (SCC) of the lung. The frequency of FGFR1 copy number gain (CNG) and gene amplification (GA) in lung adenocarcinoma (AC) is unknown, and the clinicopathological and molecular characteristics of the NSCLC tumors with FGFR1gene increase have not been fully described. Methods: We examined FGFR1 gene copy number (GCN) by fluorescent in-situ hybridization (FISH) and FGFR1 protein expression by immunohistochemistry in 475 surgically resected NSCLCs (162 SCCs, and 313 ACs) stages I-III in tissue microarrays. Three FGFR1 FISH categories were identified: a) no CNG; b) CNG, defined as ≥4 gene copies in ≥40% of cells; c) GA, defined as ratio of copies of FGFR1:CEP8 ≥2 or presence of tight gene clusters in ≥10% of cells. FGFR1 protein expression in the cytoplasm and membrane of tumor cells was quantified using H score. Results: FGFR1 GA was detected only in SCCs (14 cases, 9%). CNG was detected in both SCC (39 cases, 24%) and AC (80 cases, 26%). In AC, significantly higher frequency of CNG was detected in patients with smoking history (P=0.008) and in tumors with low differentiated histology (P=0.0005). No correlation was detected between FGFR1 CNG and mutation of KRAS and EGFR in AC. In SCC, tumors with FGFR1 CNG/GA had higher cytoplasmic FGFR1 protein expression than those with no copy changes (49±39 vs. 26±21, P<0.001), and the protein expression correlated with GCN (R=0.55; P<0.001). In multivariate analysis, patients with stage I/II SCCs having FGFR1 gene copy ≥6 or GA showed a significantly better overall survival (HR=0.26; 95% CI: 0.08-0.84, P=0.02) than patients with <6 gene copy, after adjusting for smoking, gender and tumor size. An increase on FGFR1copy number was detected in 8/45 (18%) brain metastasis compared with primary tumors. Conclusions: In NSCLC, FGFR1 GA occurs only is a small subset of SCCs (9%), whereas CNG is a relatively frequent phenomenon in both SCC (24%) and ACs (25%). FGFR1 copies ≥6 or GA is associated with better outcome in patients with surgically resected stages I/II SCCs of the lung.

OP196: HPV-16 and CDKN2A hypermethylation in oral squamous cell carcinoma

Purpose Human papillomaviruses have been implicated in the pathogenesis of a subset of squamous cell carcinoma of the head and neck. Some high risk HPV types, especially HPV 16 and 18, and epigenetic silencing of cancer-related genes have been correlated with the genesis of oral squamous cell carcinomas (OSCC). The aim of this work was to investigate the incidence of HPV infection and its correlation with methylation status of CDKN2A in OSCC. Material and methods The samples consisted of 45 paraffin-embedded or fresh specimens of OSCC. Demographic and risk factors exposure information were collected during the patient interview and clinical information was obtained through medical chart reviews. HPV DNA was detected by nested PCR (external primers MY09/MY11 and internal primers GP5/GP6). All reactions included HPV positive and negative controls, as well as a no-template and beta-globin controls. HPV genotype was determined by direct sequencing of PCR fragments and GeneBank BLAST alignment. For methylation assessment, sodium bisulfite modification of DNA (270 ng) was performed using the methylSEQrTM Bisulfite Conversion Kit (Applied Biosystems, Foster City, CA, USA). The modified DNA was used as template for methylation-specific polymerase chain reaction (MSP) using primers specific to methylated and un-methylated sequences. Statistical analyses of associations between variables were performed by the Fisher’s exact test ( p Results HPV (subtype 16) was detected in three out of 45 patients (6%). Promoter hypermethylation of the CDKN2A gene was observed in 24.4% of the cases. Statistical analysis showed an association trend between CDKN2A methylation and nodal involvement ( p = 0.079). Conclusions This study suggesting that methylation of CDKN2A in OSCCs is a potential predictive marker of malignant transformation, independent of HPV infection. Financial Support: CAPES, CNPq and FAPES.

Sex Determining Region Y-Box 2 (SOX2) Amplification Is an Independent Indicator of Disease Recurrence in Sinonasal Cancer

ObjectivesThe transcription factor SOX2 (3q26.3-q27) is an embryonic stem cell factor contributing to the induction of pluripotency in terminally differentiated somatic cells. Recently, amplification of the SOX2 gene locus has been described in squamous cell carcinoma (SCC) of different organ sites. Aim of this study was to investigate amplification and expression status of SOX2 in sinonasal carcinomas and to correlate the results with clinico-pathological data.Materials and MethodsA total of 119 primary tumor samples from the sinonasal region were assessed by fluorescence in-situ hybridization and immunohistochemistry for SOX2 gene amplification and protein expression, respectively. Of these, 59 were SSCs, 18 sinonasal undifferentiated carcinomas (SNUC), 10 carcinomas associated with an inverted papilloma (INVC), 19 adenocarcinomas (AD) and 13 adenoid cystic carcinomas (ACC).Results SOX2 amplifications were found in subsets of SCCs (37.5%), SNUCs (35.3%), INVCs (37.5%) and ADs (8.3%) but not in ACCs. SOX2 amplification resulted in increased protein expression. Patients with SOX2-amplified sinonasal carcinomas showed a significantly higher rate of tumor recurrences than SOX2 non-amplified tumors.ConclusionThis is the first study assessing SOX2 amplification and expression in a large cohort of sinonasal carcinomas. As opposed to AD and ACC, SOX2 amplifications were detected in more than 1/3 of all SCCs, SNUCs and INVCs. We therefore suggest that SNUCs are molecularly closely related to SCCs and INVCs and that these entities represent a subgroup of sinonasal carcinomas relying on SOX2 acquisition during oncogenesis. SOX2 amplification appears to identify sinonasal carcinomas that are more likely to relapse after primary therapy, suggesting that these patients might benefit from a more aggressive therapy regime.

The Importance of Diagnosing NUT Midline Carcinoma

NUT midline carcinoma (NMC) is an aggressive subset of squamous cell carcinoma, genetically defined by rearrangement of the NUT gene. The rearrangements most often take the form of BRD4-NUT fusions, and in a minority of cases, BRD3-NUT or NUT-variant fusions. The simple karyotypes of NMCs, in contrast to the complex ones of typical squamous cell carcinoma, suggest an alternate, genetic shortcut to squamous cancer. Although originally thought to be a disease of the mediastinum, NMC frequently (35%) arises in the head and neck. Diagnosis is made simply by demonstration of nuclear immunoreactivity to NUT protein, and ancillary studies to characterize the fusion oncogene, though not required for diagnosis, are recommended. The prognosis is dismal, with a 6.7month median survival, and treatment with conventional chemotherapeutic regimens is ineffective. The oncogenic mechanism of the dual bromodomains and the p300-binding portion of BRD4-NUT is to sequester p300 to localized regions of chromatin, leading to global transcriptional repression and blockade of differentiation. Two therapies which target this mechanism have emerged, including bromodomain inhibitors (BETi) and histone deacetylase inhibitors (HDACi), both of which induce differentiation and growth arrest of NMC cells, both in vitro and in vivo. BETi is available to adults with NMC through a phase I clinical trial, and clinical response to HDACi has been demonstrated in pediatric patients. The emergence of these promising targeted therapies gives hope that NMC may oneday be effectively treated and provides a strong rationale for diagnostic testing for NMC.