Inverted sinonasal papilloma (ISP) is a locally aggressive neoplasm associated with sinonasal squamous cell carcinoma (SNSCC) in 10-25% of cases. To date, no recurrent mutations have been identified in ISP or SNSCC. Using targeted next generation sequencing and Sanger sequencing, we identified activating EGFR mutations in 88% of ISP and 77% of ISP-associated SNSCC. Identical EGFR genotypes were found in matched pairs of ISP and associated SNSCC, providing the first genetic evidence of a biological link between these tumors. EGFR mutations were not identified in exophytic or oncocytic papillomas or non-ISP-associated SNSCC suggesting that the ISP/SNSCC spectrum is biologically distinct among sinonasal squamous tumors. Patients with ISP harboring EGFR mutations also exhibited an increased progression-free survival compared to those with wild-type EGFR. Finally, treatment of ISP-associated carcinoma cells with irreversible EGFR inhibitors resulted in inactivation of EGFR signaling and growth inhibition. These findings implicate a prominent role for activating EGFR mutations in the pathogenesis of ISP and associated SNSCC and rationalize consideration of irreversible EGFR inhibitors in the therapy of these tumors.

Key Points• FL carries mutations in linker histone H1 B, C, D, and E genes in 27% of cases.• FL carries recurrent mutations in OCT2 (POU2F2), IRF8, and ARID1A.Follicular lymphoma (FL) constitutes the second most common non-Hodgkin lymphoma in the western world. FL carries characteristic recurrent structural genomic aberrations. However, information regarding the coding genome in FL is still evolving. Here, we describe the results of massively parallel exome sequencing and single nucleotide polymorphism 6.0 array genomic profiling of 11 highly purified FL cases, and 1 transformed FL case and the validation of selected mutations in 102 FL cases. We report the identification of 15 novel recurrently mutated genes in FL. These include frequent mutations in the linker histone genes HIST1H1 B-E (27%) and mutations in OCT2 (also known as POU2F2; 8%), IRF8 (6%), and ARID1A (11%). A subset of the mutations in HIST1H1 B-E affected binding to DNMT3B, and mutations in HIST1H1 B-E and in EZH2 or ARID1A were largely mutually exclusive, implicating HIST1H1 B-E in epigenetic deregulation in FL. Mutations in OCT2 (POU2F2) affected its transcriptional and functional properties as measured through luciferase assays, the biological analysis of stably transduced cell lines, and global expression profiling. Finally, multiple novel mutated genes located within regions of acquired uniparental disomy in FL are identified. In aggregate, these data substantially broaden our understanding of the genomic pathogenesis of FL.

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A high rate of acute and late mucosa-related DLT and a high rate of complete tumor response were observed in this regimen at the dose levels of 50 to 300 mg/m(2), which also resulted in similar, subcytotoxic intracellular dFdCTP concentrations. These results demonstrate significant tumor and normal tissue radiosensitization by low-dose gemcitabine. Different regimens of combined radiation and gemcitabine should be evaluated, based on newer preclinical data promising an improved therapeutic ratio.