Background: Tumor-infiltrating lymphocytes (TILs) have been used to predict the prognosis of solid tumors. In this study, we investigated which molecules in TILs play a role in the prognosis of patients with oral squamous cell carcinoma (OSCC). Methods: In a retrospective case-control study, we immunohistochemically evaluated the expression of CD3, CD8, CD45RO, Granzyme B, and the major histocompatibility complex class I chain-related molecule A (MICA) of the histocompatibility complex as predictors of prognosis in 33 patients with OSCC. The patients were classified as TILs^High or TILs^Low according to the number of TILs for each molecule in the central tumor (CT) and invasive margin (IM). Furthermore, MICA expression scores were determined based on the intensity of the staining. Results: CD45RO⁺/TIL in the nonrecurrent group were significantly higher than those in the recurrent group in the CT and IM areas (p < 0.05). The disease-free survival/overall survival rate of the CD45RO⁺/TILs^Low group in the CT and IM areas and the Granzyme B⁺/TILs^Low group in the IM area was significantly lower than that of the CD45RO⁺/TILs^High group and the Granzyme B⁺/TILs^High group, respectively (p < 0.05). Furthermore, the MICA expression score of tumors around the CD45RO⁺/TILs^High group was significantly higher than that of the CD45RO⁺/TILs^Low group (p < 0.05). Conclusions: A high ratio of CD45RO-expressing TILs was associated with a disease-free/overall survival improvement in OSCC patients. Furthermore, the number of TILs that express CD45RO was associated with the expression of MICA in tumors. These results suggest that CD45RO-expressing TILs are useful biomarkers for OSCC.

We evaluated whether fluorescence intensity (FI) and its coefficient of variation (CV) can be used to diagnose squamous cell carcinoma (SCC) through IllumiScan^®, an oral mucosa fluorescence visualisation (FV) device. Overall, 190 patients with oral mucosal lesions (OMLs; SCC, 59; non-SCC OMLs, 131) and 49 patients with normal oral mucosa (NOM) were enrolled between January 2019 and March 2021. The FI of the images was analysed using image analysis software. After establishing regions of interest for SCC, non-SCC, and NOM, the average FI, standard deviation (SD), and CV were compared. There was a significant difference in the average FI for all pairs of comparisons. The SD was not significantly different between the SCC and NOM groups (p = 0.07). The CV differed significantly for NOM (p < 0.001) and non-SCC groups (p < 0.001) relative to the SCC group but was not different between NOM and non-SCC groups (p = 0.15). Univariate analysis of SCC and non-SCC groups showed significant differences for all factors, except age. However, multivariate analysis showed a significant intergroup difference only in the CV (p = 0.038). Therefore, analysing the CV in FV images of OML may be useful for the diagnosis of oral cancer.

Background: Early-stage tongue cancer has a good prognosis in general; however, high-risk patients with late cervical lymph node and distant metastases have a poor prognosis. Elective neck dissection and postoperative chemoradiotherapy are considered for these patients, although no clear criteria have been identified for their evaluation. Methods: This retrospective observational study aimed to determine the predictive factors for late cervical lymph node and distant metastases in 102 patients with cT1-2N0 tongue cancer. The data regarding the demographic characteristics, as well as the depth of invasion, tumor budding, histological grade, and tumor–stromal ratio, among other things, were extracted from medical records. Results: We found that the potential lymph node metastasis rate was 27.5%. The significant clinical predictors of late cervical lymph node metastasis were the tumor thickness and endophytic growth pattern and the significant histopathological factors were poorly and moderately differentiated tumors and ≥3 tumor buds. In addition, the prognostic factors for distant metastasis included ≥4 lymph node metastases, ≥7 tumor budding, and moderate and poor tumor differentiation. Conclusions: The usefulness of tumor budding as a predictor of metastasis for tongue cancer was suggested. The findings of this study can help establish the criteria for evaluating the metastasis risk and prognosis of patients with tongue cancers.

One of the causes of ventilator-associated pneumonia (VAP) is aspiration of oropharyngeal fluid containing pathogenic microorganisms into the lower respiratory tract. In this study, we aimed to investigate whether antibiotic ointment applied to the oral cavity can reduce the number of bacteria in the fluid on the cuff of a tracheal cannula. Tetracycline ointment was applied intraorally once to a patient under endotracheal intubation by postoperative tracheostomy for oral cancer. The tetracycline concentrations in the oropharyngeal fluid and fluid on the cuff of tracheal cannula were determined by bioassay, and the total viable bacterial count was determined by delayed real-time polymerase chain reaction developed by the authors from before to 6 h after application. A total of seven patients were enrolled. Very high antibiotic concentrations were maintained, ranging from 481 μg/ml to 2060 μg/ml in oropharyngeal fluid and from 267 μg/ml to 858 μg/ml in fluid on the cuff from 1 h to 6 h after application. Compared to the pre-application results, the inhibition rates of viable bacteria were 80.0–97.7% for oropharyngeal fluid and 47.6%–91.9% for fluid on the cuff at 1–6 h after application, indicating that antibiotic ointment can inhibit bacteria entering the lower respiratory tract for a long period of time in intubated patients. Oral application of antibiotic ointment reduced the number of bacteria entering the lower respiratory tract, suggesting that it may be useful in the prevention or treatment of VAP.