Base of tongue cancer—is it tongue cancer located at the base of the tongue, or is it a type of lingual tonsil cancer? The perspective from a genomic analysis

Abstract

The aim of this study was to determine whether base of tongue (BOT) cancer is tongue cancer located at the base of the tongue or lingual tonsil cancer originating from tonsil tissue. This was a retrospective study using data from The Cancer Genome Atlas (TCGA). The genomic patterns of three primary cancers (BOT, oral tongue, and tonsil) were compared to determine their similarities and differences. Gene expression data (n=193; 26 BOT, 125 oral tongue, and 42 tonsil cases), copy number alteration data (n=142; 19 BOT, 96 oral tongue, and 27 tonsil cases), and somatic mutation data (n=187; 25 BOT, 122 oral tongue, and 40 tonsil cases) were analyzed using the t-test, heatmap analysis, and OncoPrint, respectively. Clinical information for the three tumour groups was included in the analyses. When using multiplatform analysis, BOT cancer showed nearly the same genomic pattern as tonsil cancer, but not oral tongue cancer. The χ test and survival analysis revealed that BOT cancer had the same clinical and survival patterns as tonsil cancer. In conclusion, BOT cancer showed a genomic pattern similar to that of tonsil cancer, but different to that of oral tongue cancer. Further prospective studies are warranted before the results of this study can be applied in a clinical setting.

Squamous–columnar junction of Von Ebner’s glands may be a significant origin of squamous cell carcinomas in the base of the tongue

“…Nine protein-coding RNAs were discovered ( Table 1 ; Supplementary Material ); HCRTR2, TSC22D1, RGPD5, TBX20, TAS1R2, LYC22D1, AC008764.4, and AC008758.5 are the specific genes of BOT carcinoma. Meanwhile, a research showed the identification of the TSC22D1 as a specific gene of BOT carcinoma ( 19 ). Hence, we finally chose TSC22D1 as a specific gene of BOT carcinoma to carry out the next phase of research.…”

“…Tongue tonsils have crypt structures that are similar to palatine tonsils; thus, they are also the predilection sites of HPV-induced HNSCC ( 21 ). According to the results of gene data analysis of BOT carcinoma and palatine tonsillar carcinoma, BOT carcinoma has almost the same genome as tonsillar carcinoma ( 19 ); the lingual tonsil has always been a research priority on the origin of BOT carcinoma. However, it has been reported that some BOT carcinomas are deep-seated and originate from the large excretory duct of the submucosal minor salivary gland.…”