EGFR mutation and HPV infection in sinonasal inverted papilloma and squamous cell carcinoma

BACKGROUND

To evaluate the involvement of EGFR signalling and HPV infection in a cohort of inverted sinonasal papilloma (ISP) and sinonasal squamous cell carcinoma (SNSCC) and their value for prognosis and clinical treatment.

METHODS

We analysed 55 ISP, 14 SNSCC associated with ISP (SNSCC-isp) and and 60 SNSCC not associated with ISP (SNSCC-novo) for EGFR gene mutation and copy number gain, protein expression of EGFR and phosporylated EGFR (pEGFR), and HPV-infection and KRAS mutation. Findings were correlated to clinico-pathological and follow-up data.

RESULTS

We found EGFR exon 20 mutations in 38% (7/18) ISP, in 50% (6/12) SNSCC-isp and in 5% (1/19) SNSCC-novo. EGFR was expressed in 92% of ISP, while pEGFR was observed in 54% (21/39). SNSCC-isp and SNSCC-novo demonstrated comparable expression of EGFR (57% and 33%) and of pEGFR (44% and 38%). We observed an inverse relation between EGFR exon 20 mutation and pEGFR expression. Four of 39 (10%) ISP carried HPV-16. Oncogenic HPV was detected in 3/12 (25%) SNSSC-isp and in 1/8 (13%) SNSCC-novo. KRAS mutations were not detected in any of the samples. HPV infection was inversely correlated with pEGFR expression but not with EGFR mutation. ISP with EGFR activation by mutation or by phosphorylation had longer ISP-free survival, however, neither EGFR exon 20 mutation, pEGFR expression nor HPV infection demonstrated prognostic value in SNSCC.

CONCLUSIONS

EGFR exon 20 mutation is frequent in ISP and SNSCC-isp, while activation of EGFR through phosphorylation also plays an important role. Our data indicate that a large proportion of SNSCC patients could benefit from therapy with modern EGFR inhibitors.

Abstract 2125: Genetic analysis for classification and treatment of poorly differentiated sinonasal cancer

Introduction: The sinonasal cavities harbour a wide variety of rare tumour types, including squamous-cell carcinoma (SNSCC), intestinal-type adenocarcinoma (ITAC), olfactory neuroblastoma (ONB), neuroendocrine carcinoma (SNEC), undifferentiated carcinoma (SNUC) and malignant mucosal melanoma (MMM). Histopathological classification is related to clinical outcome, but correct diagnosis is difficult in cases with poor differentiation. Five-year overall survival ranges from 20% to 60% while therapeutic options are limited. This study aims to identify genetic alterations that may aid diagnosis and indicate targets for modern specific therapies.

Experimental procedures: DNA was extracted from 80 frozen or paraffin-embedded tumor tissues collected from three different hospital centers. Mutations were screened by next generation sequencing of a panel of 120 cancer-related genes using the SureSelect QXT Target Enrichment Kit for Ilumina Multiplexed Sequencing, and recurrent hits were confirmed by Sanger sequencing and by analyzing their effect on protein expression.

Results: Frequently mutated genes were TP53, KRAS, PI3K, NTRK1, ATM and BRCA1 and BRCA2. Several mutations were found exclusive to only one sinonasal tumor-type: APC and B-catenin in ITAC, EGFR exon 20 in SNSCC, IDH2 in SNUC and NF1 in MMM. With exception of ONB, a majority of cases showed a high mutational burden.

Conclusions: A number of tumor-specific mutations were identified that may be used for differential diagnosis. In addition, many gene mutations may serve as targets for specific antibody or small molecule inhibitors. Finally, the finding that sinonasal tumors carry a high mutational burden suggests that therapy with immune checkpoint inhibitors may be effective in clinical management.

Citation Format: Mario Hermsen, Cristina Riobello, Virginia N. Cabal, Rocío García-Marín, Sira Potes-Ares, Laura Suárez-Fernández, Blanca Vivanco, Alessandro Franchi, Reinhard Büttner, Fernando López, José Luis Llorente. Genetic analysis for classification and treatment of poorly differentiated sinonasal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2125.

Abstract 3325: EGFR mutation and protein expression analysis in sinonasal inverted papilloma and squamous cell carcinoma

Introduction Inverted sinonasal papilloma has been demonstrated to be precursor to a subset of sinonasal squamous cell carcinoma and to carry frequent mutations in EGFR exon 20. The aim of this study was to evaluate EGFR mutation and protein expression as risk marker for malignant transformation of inverted papillomas.

Experimental procedures The total number of samples studied was 41 inverted papillomas (ISP) and 32 squamous carcinomas (SCC). We defined patients with one single ISP, with multiple ISP (ISP-ISP) or ISP with malignant transformation (ISP-transformed). In addition, we classified SCC related with ISP (SCC-ISP) and those without relation (SCC de novo). EGFR exon 20 was amplified by PCR and analyzed by Sanger sequencing using the ABI PRISM 3100 and 3730 Genetic Analyzer, (Applied Biosystems, Foster City CA). Immunohistochemistry was performed on an automatic staining workstation (Dako Autostainer Plus; DakoCytomation, Glostrup, Denmark) using the antibody anti-pEGFR clone D7A5 (Cell Signaling Technology, Cambridge, UK). Results were evaluated by two experienced investigators (BV and MM).

Results We found EGFR exon 20 mutations in 62% (8/13) ISP, 58% (7/12) ISP-ISP, 63% (10/16) ISP-transformed, 54% (7/13) SCC-ISP and 5% (1/19) SCC de novo. Protein expression of pEGFR was detected in 56% (5/9) ISP, 75% (6/8) ISP-ISP, 47% (7/15) ISP-transformed, 42% (5/12) SCC-ISP and 71% (10/14) SCC de novo. We observed an inverse correlation between EGFR exon 20 mutation and pEGFR expression (p=0.034). Overall survival was significantly better for SCC-ISP compared with SCC de novo (2-year survival 54% and 29% respectively; p=0.030).

Conclusions EGFR exon 20 mutations occurred in a high frequency, both for cases with single or multiple ISP and for ISP-transformed, making it a characterizing genetic abnormality for ISP in general. This result also means that the presence of a EGFR exon 20 mutations is not of value as a risk marker for malignant progression. Among the SCC, EGFR exon 20 mutations were notably less and pEGFR expression more frequent in SCC de novo compared to SCC-ISP, suggesting that the EGFR signaling pathway is important in both types of SCC, albeit activated in a different manner. Patients with SCC-ISP had a more favorable clinical course, however, neither EGFR exon 20 mutations nor pEGFR expression demonstrated prognostic value. Nevertheless, EGFR exon 20 mutations can be targeted with specific inhibitors and may be of value for adjuvant therapy for SCC as well as ISP that are difficult to manage.

Citation Format: Virginia N. Cabal, Marta Menéndez, Sira Potes-Ares, Blanca Vivanco, Laura Suárez-Fernández, Cristina Riobello, Rocío García-Marín, Fernando López, José Luís Llorente, Mario Hermsen. EGFR mutation and protein expression analysis in sinonasal inverted papilloma and squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3325.

Predictive value of EGFR-PI3K-pAKT-mTOR-pS6 pathway in sinonasal squamous cell carcinomas

BACKGROUND AND OBJECTIVES

We have previously indicated that EGFR has a role in carcinogenesis in a subgroup of sinonasal squamous cell carcinomas (SNSCC). In addition, EGFR activates 2 of the most important intracellular signalling pathways: PI3K/pAKT/mTOR/pS6 and MAP pathway kinases. The objective of this study was to evaluate the involvement of the EGFR/PI3K/pAKT/mTOR/pS6 pathway and its relationship with clinical-pathological parameters and follow-up of sinonasal squamous cell carcinoma.

MATERIAL AND METHODS

The immunohistochemical expression of different components of the PI3K/AKT/mTOR/pS6 pathway and its relationship with various clinical-pathological parameters was studied in a series of 54 patients with SNSCC.

RESULTS

Loss of PTEN expression was observed in 33/54 cases (61%) and pAKT, mTOR and pS6 pre-expression was observed in 19/54 cases (35%), 8/54 cases (15%), and 47/54 cases (87%), respectively. Loss of PTEN expression was related to intracranial invasion and development of regional metastases (p=0.005). Overexpression of pS6 was associated with a decrease in survival (p=0.008), presence of local recurrences (p=0.055), and worsening of overall prognosis (p=0.007). No significant relationships were observed between pAKT and mTOR expression and the clinicopathological parameters studied.

CONCLUSIONS

Alterations in the expression of EGFR/PI3K/pAKT/mTOR/pS6 pathway components are common in a subgroup of SNSCC. This study reveals that the absence of pS6 overexpression is associated with better clinical outcomes. Therefore, pS6 expression could be considered as an unfavourable prognostic marker.

Programmed death ligand-1 expression as immunotherapeutic target in sinonasal cancer

BACKGROUND

Sinonasal cancer carries a poor prognosis, especially in recurrent stages, and it is a disease with very limited treatment options.

METHODS

The expression of programmed death ligand-1 (PD-L1) as a marker for immunotherapy was evaluated in 53 sinonasal squamous cell carcinoma (SCC) and 126 intestinal-type adenocarcinoma (ITAC) samples. Results were correlated to clinicopathological characteristics and follow-up data.

RESULTS

Membranous PD-L1 staining of tumor cells was observed in 34% (18/53) of the sinonasal SCC samples and in 17% (22/126) of the ITAC samples. The PD-L1 positivity on infiltrating immune cells occurred in 45% (24/53) of the sinonasal SCC samples and in 33% (41/126) of the ITAC samples. Expression of PD-L1 showed no correlation to clinicopathological parameters and was not an independent risk factor for survival.

CONCLUSION

The PD-L1 positivity does not seem to have prognostic value. However, a proportion of patients with sinonasal SCC and ITAC may benefit from therapy with immune checkpoint inhibitors that recently have been approved for clinical application in head and neck cancer.

Genomic profiling of intestinal-type sinonasal adenocarcinoma reveals subgroups of patients with distinct clinical outcomes

BACKGROUND

Patients with intestinal-type sinonasal adenocarcinoma (ITAC) have an unfavorable prognosis and new therapeutic approaches are needed to improve clinical management.

METHODS

Genetic analysis of 96 ITACs was performed by microarray comparative genomic hybridization and immunohistochemistry and correlated to previously obtained mutation, methylation, and protein expression data, and with pathological characteristics and clinical outcome.

RESULTS

Seven copy number alterations (CNAs) were significantly associated with unfavorable clinical outcome: gains at 1q22-23, 3q28-29, 6p22, and 13q31-33, and losses at 4p15-16, 4q32-35, and 10q24. Unsupervised cluster analysis resulted in 5 subgroups of ITAC with significantly distinct genetic signatures and clinical outcomes, independently of disease stage or histological subtype.

CONCLUSION

These data may guide studies to identify driver genes and signaling pathways involved in ITAC. In addition, the subclassification of genetic subgroups of patients with distinct clinical behavior can aid therapeutic decision making and may ultimately lead to personalized therapy with targeted inhibitors.