Sinonasal inverted papillomata (SIP) are benign, locally destructive tumours. They have the potential to recur locally and for malignant transformation. Little is known about the genomic alterations under lying this tumour. There is also debate over the role of human papillomavirus (HPV) in its development. The aim of this study was to use next generation sequencing (NGS) to perform genome-wide copy number analysis of SIP and also determine the HPV viral load.
After obtaining ethical approval, patients who had undergone excision of SIP were identified Leeds Pathology Archive. Tissue blocks were obtained and DNA extracted from tumour samples. This was then processed to sequencing libraries and run on the Illumina HiSeq 3000 and the subsequent data analysed for viral load and converted to digital karyograms for analysis.
A low number of copy number alterations (CNA) were found in the SIPs, with no similarity found to a group of HNSCC samples previously studied. Barely detectable viral load of HPV were found in the samples with no predominant subtype.
This study uses a low-cost form of NGS to provide the first genome-wide analyses of SIPs. It suggests HPV is not a key aetiological factor in its development. A larger study with patients who developed sinonasal dysplasia/malignancy could reveal genomic markers of translational benefit.