Objectives/Hypothesis: To examine if macroscopic classification with a magnifying gastrointestinal endoscope with narrow band imaging (ME-NBI) is useful in predicting pathological depth of tumor invasion in laryngo-pharyngeal cancer.Study Design: Retrospective study. Methods: Preoperative endoscopy reports and postoperative pathological reports on 139 laryngo-pharyngeal cancer lesions were retrospectively reviewed, and the association between macroscopic findings in the lesions and the depth of tumor invasion was analyzed statistically.Results: The ratios of lesions macroscopically classified as 0-I (superficial and protruding), 0-IIa (slightly elevated), 0-IIb (true flat), 0-IIc (slightly depressed), and 0-III (superficial and excavated) in the preoperative endoscopy reports were 3%, 25%, 71%, 1%, and 0%, respectively. Regarding the depth of tumor invasion in the postoperative pathological reports, the ratios of lesions classified as EP (carcinoma in situ), SEP (tumor invades subepithelial layer), and MP (tumor invades muscularis propria) were 73%, 26%, and 1%, respectively. The ratios of subepithelial invasion or muscular invasion in 0-I, 0-IIa, and 0-IIb were 100%, 54%, and 14%, respectively, and showed significant difference (P < 0.0001). Only one of 139 lesions invaded the muscular propria.Conclusions: This study is the first one to show that macroscopic findings by ME-NBI predict the depth of tumor invasion in superficial laryngo-pharyngeal cancer. It was indicated that there is a little chance of muscular invasion if the lesion is endoscopically diagnosed as 0-I or 0-II. A new T stage classification based on the depth of tumor invasion may be needed in order to adapt the classification to include transoral surgery.

BackgroundThe incidence of oral squamous cell carcinoma (OSCC) continues to increase each year. Clinical examination and biopsy usually detect OSCC at an advanced stage that is difficult to treat, leading to poor prognosis. DNA methylation pattern is tissue specific and has emerged as a biomarker for the detection of cancers of tissue origin. Herein, we aimed to discover a novel site-specific methylation marker for OSCC.MethodsWe selected OSCC datasets analyzed using the IlluminaHumanMethylation27 BeadChip from the Gene Expression Omnibus repository of the National Center for Biotechnology Information using a bioinformatics approach. From 27,578 CG dinucleotide (CpG) sites, the CpG site with the highest difference in methylation level between healthy and cancerous cells was selected for further validation. A total of 18 mucosal tissue samples were collected from nine healthy controls and nine from OSCC subjects and subjected to microdissection for cell purification, followed by DNA extraction, bisulfite conversion, and pyrosequencing. Additionally, epithelial cells were collected from 2 cohorts including oral rinse from healthy controls, oral rinse and oral swab from OSCC subjects and oral rinse from oropharyngeal squamous cell carcinoma (SCC) were examined for their methylation status using real-time polymerase chain reaction (PCR).ResultsAmong the 27,578 differentially methylated CpG sites, cg01009664 of the thyrotropin-releasing hormone (TRH) gene showed the greatest difference in methylation level between healthy and cancerous cells. Validation of the TRH gene using pyrosequencing revealed a methylation percentage of 7% ± 3.43% in healthy cells in contrast to 63% ± 19.81% in cancerous cells. Screening of epithelial cells using real-time PCR showed that the DNA methylation level was significantly higher in oral swab and rinse samples collected from OSCC and oropharyngeal SCC subjects than those from healthy controls (p < 0.001). In addition, when using a cutoff at 3.31 ng/μL, the TRH methylation biomarker was able to distinguish OSCC and oropharyngeal SCC subjects from healthy controls with high level of area under the curve, sensitivity and specificity.ConclusionWe demonstrated cg01009664 of TRH as a potential biomarker for OSCC and oropharyngeal SCC screening using oral rinse and swab techniques.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-4706-x) contains supplementary material, which is available to authorized users.

Our data supported that the alteration of LINE-1 methylation levels in PBMCs was influenced by HNSCC secretions. Moreover, the unmethylated LINE-1 allele of PBMCs was proved to be an effective tumor marker and possesses a potential as HNSCC diagnostic tool.