Low PD-L1 expression, MAP2K2 alterations, and enriched HPV gene signatures characterize brain metastases in head and neck squamous cell carcinoma.
Publication Title
Journal of translational medicine [electronic resource]
Document Type
Article
Publication Date
10-22-2024
Keywords
california; santa monica; pni; Humans; Male; Middle Aged; Female; B7-H1 Antigen; Squamous Cell Carcinoma of Head and Neck; Brain Neoplasms; Aged; Head and Neck Neoplasms; Papillomaviridae; Adult; Gene Expression Regulation, Neoplastic; Mutation
Abstract
BACKGROUND: Brain metastasis (BM) is a rare but severe complication of head and neck squamous cell carcinoma (HNSCC), with limited knowledge of molecular characteristics and immunogenicity.
METHODS: We analyzed 61 cases of HNSCC-BM from three academic institutions (n = 24) and Foundation Medicine Inc (FMI, n = 37). A subset of cases underwent next-generation sequencing, multiple immunofluorescence, and proximity ligation sequencing. Gene enrichment analysis compared alterations in FMI BM samples (n = 37) with local samples (n = 4082).
RESULTS: Demographics included: median age of 59 years, 75% male, 55% current/former smokers, 75% oropharyngeal primary, and 67% human papillomavirus (HPV) +. ATM (54%), KMT2A (54%), PTEN (46%), RB1 (46%), and TP53 (46%) were frequently altered in BM samples from academic centers (62% HPV/p16+). Structural rearrangements ranged from 9 to 90 variants by proximity ligation sequencing. BMs had low densities of CD8+, PD-1+, PD-L1+, and FOXP3 + cells, and 92% had PD-L1 combined positive scores < 1%. CDKN2A (40.5%), TP53 (37.8%), and PIK3CA (27.0%) alterations were common in the FMI BMs (51% HPV+). MAP2K2 alterations and HPV + signature were enriched in FMI BMs compared to local tumors (11.8% vs. 6.4%, P = 0.005 and 51.25% vs. 26.11%, P = 0.001 respectively), and pathogenic TSC1 inactivating mutations were enriched in local tumors (67.3% vs. 37.8%, P = 0.008). Median overall survival from BM diagnosis was 9 months (range 0-27).
CONCLUSIONS: HNSCC patients with BM frequently have oropharyngeal primary sites and are HPV+. Common molecular alterations in BM samples, including targetable PIK3CA and ATM, were identified. MAP2K2 alterations were enriched and densities of immune cells were low, highlighting potential targets for further research and immunotherapy considerations.
Area of Special Interest
Cancer
Area of Special Interest
Neurosciences (Brain & Spine)
Specialty/Research Institute
Neurosciences
Specialty/Research Institute
Oncology
Specialty/Research Institute
Pathology & Laboratory Medicine
DOI
10.1186/s12967-024-05761-z
