Abstract

4127 Background: HPV is an infectious cause of several malignancies. Neuroendocrine neoplasms (NEN) are highly heterogeneous, ranging from low-grade indolent tumors to high-grade clinically aggressive carcinomas. Aside from cervical NENs, most have not traditionally been associated with HPV, but our initial studies uncovered a subset of NENs that are HPV 16/18 positive. To identify actionable differences between HPV+ NEN and non-NENs, genomic and transcriptomic landscapes were investigated. Methods: 101343 solid tumors were sequenced at Caris Life Sciences (Phoenix, AZ) with NextGen Sequencing of DNA (whole or hybrid exome) and RNA (whole or hybrid transcriptome) and assayed for HPV16/18 positivity (HPV+) via DNA sequencing. Mutation prevalence for pathogenic SNVs/indels (-Mt) and copy number amplification (CNA) were calculated. Expression of Ki-67 mRNA ( MKI67) was used to infer high grade vs low grade NEN. Gene expression profiles were analyzed for a transcriptional signature predictive of response to immunotherapy, interferon 𝛾">γ score (IFN). Differentially regulated pathways were assessed by gene set enrichment analysis (GSEA). Fisher’s exact/χ2 tests were applied as appropriate with p-values adjusted for multiple comparisons ( p < .05). Results: Among all solid tumor types, rates of HPV+ were highest in cervical carcinomas (70%, 1200/1716), followed by vulvar squamous cell carcinoma (31%, 126/410) and head and neck (HN) carcinomas (28%, 668/2413), with HPV+ tumors also found in NENs (6%, 96/1620). Within NENs, the highest HPV+ rates were observed for those with a tumor origin of cervical (76%, 55/58), anorectal (AR, 27%, 29/106), female genitourinary tract (23%, 12/52) and HN (19%, 7/36). Amongst HPV+ NEN, 93% were high grade compared to 54% of HPV- NEN (p < .001). Focusing on AR, cervical and HN primary sites, significant differences in the genomic landscape were observed between non-NEN v NEN tumors (Table 1). Non-NEN tumors had a significantly higher IFN compared to NEN across sites (Cervical: -0.20 v -0.61, AR: -0.33 v -0.58, HN: -0.16 v -0.54 arbitrary units, p < .001 all). Non-NEN tumors at AR, cervical and HN sites were significantly enriched for several genes sets related to immune response (Interferon α/γ, TNFα/NF-κβ, IL6/JAK/STAT3 and inflammatory response). Conclusions: Our data suggest that non-NEN HPV+ tumors are enriched for gene sets related to immunotherapy response, and that HPV+ NENs have alterations that vary by anatomic site. We uncover a category of HPV+ NENs with distinct genomic and transcriptomic landscapes compared to non-NEN tumors. [Table: see text]