Immunology of Oral Squamous Cell Carcinoma-A Comprehensive Insight with Recent Concepts

Ferroptosis and oral squamous cell carcinoma: connecting the dots to move forward

Oral squamous cell carcinoma (OSCC) is an aggressive disease whose incomplete biological comprehension contributes to the inappropriate clinical management and poor prognosis. Thus, the identification of new promising molecular targets to treat OSCC is of paramount importance. Ferroptosis is a regulated cell death caused by the iron-dependent accumulation of reactive oxygen species and the consequent oxidative damage of lipid membranes. Over the last five years, a growing number of studies has reported that OSCC is sensitive to ferroptosis induction and that ferroptosis inducers exert a remarkable antitumor effect in OSCC, even in those displaying low response to common approaches, such as chemotherapy and radiotherapy. In addition, as ferroptosis is considered an immunogenic cell death, it may modulate the immune response against OSCC. In this review, we summarize the so far identified ferroptosis regulatory mechanisms and prognostic models based on ferroptosis-related genes in OSCC. In addition, we discuss the perspective of inducing ferroptosis as a novel strategy to directly treat OSCC or, alternatively, to improve sensitivity to other approaches. Finally, we integrate data emerging from the research studies, reviewed here, through in silico analysis and we provide a novel personal perspective on the potential interconnection between ferroptosis and autophagy in OSCC.

Evaluation of Tumor-Associated Macrophages and Micro-Vessel Density in Verrucous Carcinoma and Squamous Cell Carcinoma of the Oral Cavity

Background

Tumor-associated macrophages (TAMs) are a crucial cellular component of human tumors, but their exact roles in tumor growth and angiogenesis during cancer progression are still subject to debate. The present study aimed to explore the impact of TAMs on tumor progression and angiogenesis in oral squamous cell carcinoma (OSCC) and oral verrucous carcinoma (OVC).

Materials and Methods

For this cross-sectional study, 60 samples consisting of 40 OSCC and 20 OVC samples were chosen. Immunohistochemical staining was performed on the samples using anti-CD68 and anti-CD31 monoclonal antibodies to evaluate the frequency of TAMs and micro-vessel density (MVD), respectively. The data were analyzed using statistical software SPSS (v. 23) and through the independent samples Student t-test, one-way analysis of variance, and Pearson's correlation coefficient.

Results

The results of our study revealed that the mean number of TAMs and MVD were significantly greater in OSCC samples compared to OVC samples (P = 0.001) (P = 0.004). Also, the average number of TAMs and MVD increased in the high grade of OSCC; however, the correlation between both parameters and histopathological grades of OSCC was significant only for MVD. Our study found no significant correlation between TAMs and MVD (P = 0.005).

Conclusion

Based on the results of our study, both TAMs and MVD were found to be significantly higher in OSCC samples compared to OVC samples. These findings suggest that the progression of oral cancer is associated with an increase in TAMs and vascular density. Additionally, the use of CD68 and CD31 markers may help in differentiating between these two types of tumors.

Predictive factors and repetition numbers for intraoperative additional resection of initially involved soft tissue resection margins in oral squamous cell carcinoma: a retrospective study

BACKGROUND

Intraoperative additional resection (IAR) of initially microscopically involved soft tissue resection margins negatively impacts tumor recurrence in oral squamous cell carcinoma (OSCC). Increasing the selected initial macroscopic resection margin distance beyond the tumor tissue may help prevent IAR; however, the existence of predictive factors for IAR and IAR repetition numbers remains unclear. This study aimed to identify predictive factors for IAR and to evaluate the IAR repetition numbers in soft tissue for surgically treated OSCC.

METHODS

A cohort of 197 patients surgically treated for OSCC between 2008 and 2019 was retrospectively reviewed (44 patients with IAR and 153 patients without IAR). Clinical parameters (tumor location, midline involvement, clinical T-status, time between staging imaging and surgery, bone resection, monopolar use, and reconstruction flap size) and histopathological parameters (pathologic T-status [pT-status], grading, vascular invasion, and lymphatic invasion) of the two groups were compared.

RESULTS

Patients with and without IAR differed in their histopathological parameters, such as pT-status above 2 (47.7% vs. 28.1%, p = 0.014) and lymphatic invasion (13.6% vs. 4.6%, p = 0.033); however, their clinical parameters were similar (all p > 0.05). Only pT-status above 2 was predictive for IAR in a multivariable regression analysis (odds ratio 2.062 [confidence interval 1.008-4.221], p = 0.048). The IAR repetition numbers varied from zero to two (zero = 84.4%, one = 11.4%, and two = 2.3%).

CONCLUSIONS

Only postoperative available pT-status was identified as a predictive factor for IAR, underscoring the importance of improving preoperative or intraoperative tumor visualization in OSCC before selecting the initial macroscopic resection margin distance to avoid IAR.