Purpose: Sinonasal cancers are malignant neoplasms arising from the epithelial cells of the
nasal cavity and paranasal sinuses, encompassing diverse tumor types such as squamous
cell carcinoma, adenocarcinoma, and undifferentiated carcinoma. Despite their clinical
significance, comprehensive data on their somatic mutational landscape is limited
due to their rarity. Common treatments for sinonasal cancers include surgery, radiation
therapy, and chemotherapy. Current chemotherapies in clinical trials for sinonasal
carcinomas include cetuximab, cisplatin, 5FU, and leucovorin. Additionally, some clinical
trials are investigating the efficacy of novel chemotherapeutic agents targeting DNA
methylation, such as tazemetostat. In this study, we utilized a publicly available
genomic database to profile the somatic mutations in sinonasal cancer patients, aiming
to identify common mutations and genetic alterations. Moreover, we compared the mutational
profiles across different histological subtypes to uncover subtype-specific mutations
and pathways.
Methods: The American Association for Cancer Research (AACR) Project Genomics Evidence Neoplasia
Information Exchange (GENIE) database was accessed from cBioPortal (v16.1-public)
on July 22, 2024 to identify all patients with sinonasal cancer. The most common gene
mutations, gene correlations, and mutual exclusivities were assessed using a two-sided
T-test and nonparametric tests, with Benjamini-Hochberg False Discovery Rate (FDR)
correction.
Results: Of the 2,595 head and neck cancer samples, 122 (4.7%) had sinonasal carcinoma. Of
these 125 samples, 70 (57.4%) had sinonasal squamous cell carcinoma, 31 (25.4%) had
sinonasal undifferentiated carcinoma, and 21 (17.2%) had sinonasal adenocarcinoma.
In this sample, 78 patients were male (66.7%) and 39 were female (33.3%). The majority
of patients in this sample were white (n = 76, 65%). The majority of patients were adult patients (98%). The most common mutations
in the cohort across all different subtypes were: TP53 (n = 49; 40%), PIK3CA (n = 17; 14%), KMT2D (n = 14; 11%), CDKN2A (n = 11; 9%), FANCA (n = 10; 8%), and NOTCH1, IDH2, and PTEN (each n = 9; 8%). Subtype-specific mutations were observed:
• Squamous cell carcinoma (SCC): TP53 (n = 29, 43%), PIK3CA (n = 12, 18%), KMT2D (n = 11, 16%).
• Undifferentiated carcinoma: TP53 (n = 14, 47%), IDH2 (n = 9, 30%), NF1 (n = 5, 17%).
• Adenocarcinoma: TP53 (n = 6, 30%), LRP1B and FAT1 (n = 3, 15% each).
TP53 was the most common mutation across all subtypes. In this cohort, TP53 mutations
tended to co-occur with PRKDC (n = 4, p = 0.020), and KMT2D tended to co-occur with PIK3CA (n = 4, p = 0.018).
Conclusion: TP53, PIK3CA, and KMT2D mutations account for a significant portion of somatic mutations
in sinonasal carcinoma, suggesting potential opportunities for targeted therapies.
For instance, tazemetostat, which targets DNA methylation, in which KMT2D plays a
key role, is currently being tested in clinical trials. Similarly, cetuximab, targeting
EGFR upstream of the commonly mutated PIK3CA signaling cascade, is a first-line chemotherapy
agent in sinonasal cancers. Identifying specific point mutations and secondary drivers
may advance the development of novel preclinical models for testing targeted therapies.