Alex Farrell

Olfactory neuroblastoma (ONB), sinonasal undifferentiated carcinoma (SNUC), and sinonasal neuroendocrine carcinoma (SNEC) are rare malignancies arising from the sinonasal tract with limited therapeutic options. The expression of the somatostatin receptor 2 gene (SSTR2), which is expressed in other neuroendocrine neoplasms and is therapeutically actionable, has been reported in these tumors. Here, we analyzed SSTR2 gene expression and its associations with genomic features, established biomarkers predicting of immune response, and the tumor immune microenvironment in a cohort of ONB, SNUC, and SNEC tumor samples (26, 13, and 8 samples, respectively) from a real-world database. SSTR2 gene expression was high in neural-type ONB and low in basal-type ONB and in most of the SNUC and SNEC cases; there was no difference in expression between primary and metastatic tumors. The T cell-inflamed (TCI) score analysis classified 38.5% of SNUC cases as T cell-inflamed compared to only 3.9% of ONB and 0% of SNEC cases; 26.9% of ONB cases were classified as intermediate TCI; and SNEC had the lowest relative immune cell infiltration by deconvolution. In high SSTR2-expressing ONB, there was a higher proportion of infiltrating of Natural Killer cells and dendritic cells by deconvolution. Additionally, high SSTR2-expressing ONB was enriched for proliferation pathways, including E2F and Myc targets and G2M checkpoints. In conclusion, our findings delineate significant differences between these three types of sinonasal malignancies that were examined. In ONB, relative to SNUC and SNEC, the SSTR2 expression profile, combined with its immune profiles, indicates potential novel therapeutic strategies and combinations for this unmet clinical need. Conversely, the inflammatory microenvironment of SNUC may be targetable using immuno-oncologic therapies.

Vulvar squamous cell cancer (VSC) accounts for 90% of vulvar cancers. Next-generation sequencing studies of VSC imply human papillomavirus (HPV) and p53 status play separate roles in carcinogenesis and prognosis. We sought to describe the genomic landscape and analyze the immunologic profiles of VSC with respect to HPV and p53 status. A total of 443 VSC tumors underwent tumor profiling. Next-generation sequencing was performed on genomic DNA isolated from formalin-fixed paraffin-embedded tumor samples. PD-L1, microsatellite instability were tested by fragment analysis, IHC, and next-generation sequencing. Tumor mutational burden—high was defined as >10 mutations per MB. HPV 16/18 positive (HPV+) status was determined using whole exome sequencing on 105 samples. Three cohorts were identified from 105 samples with known HPV: HPV+, HPV−/p53wt, and HPV−/p53mt. Where HPV and p53 status were examined, TP53 mutations were exclusive of HPV+ tumors. In all, 37% of samples were HPV+. Among the 66 HPV− tumors, 52 (78.8%) were HPV−/p53mt and 14 (21.2%) were HPV−/p53wt. The HPV−/p53wt cohort had a higher rate of mutations in the PI3KCA gene (42.9% HPV−/p53wt vs 26.3% HPV+ vs. 5.8% HPV−/p53mt, q=0.028) and alterations in the PI3K/AkT/mTOR pathway (57.1% HPV−/p53wt vs. 34.2% HPV+ vs. 7.7% HPV−/p53mt, q=0.0386) than the other 2 cohorts. Ninety-eight VSC tumors with HPV16/18 information underwent transcriptomic analysis and immune deconvolution method. No differences were observed in immune profiles. The HPV−/p53wt VSC tumors had significantly higher rates of mutations in the PI3KCA gene and alterations in the PI3K/AkT/mTOR pathway, a potential target that merits further investigation in this subgroup.