Neoadjuvant Chemotherapy: Does It Have Benefits for the Surgeon in the Treatment of Advanced Squamous Cell Cancer of the Oral Cavity?

Less is more: Exploring neoadjuvant immunotherapy as a de-escalation strategy in head and neck squamous cell carcinoma treatment

Head and neck squamous cell carcinoma (HNSCC) constitutes a significant global cancer burden, given its high prevalence and associated mortality. Despite substantial progress in survival rates due to the enhanced multidisciplinary approach to treatment, these methods often lead to severe tissue damage, compromised function, and potential toxicity. Thus, there is an imperative need for novel, effective, and minimally damaging treatment modalities. Neoadjuvant treatment, an emerging therapeutic strategy, is designed to reduce tumor size and curtail distant metastasis prior to definitive intervention. Currently, neoadjuvant chemotherapy (NACT) has optimized the treatment approach for a subset of HNSCC patients, yet it has not produced a noticeable enhancement in overall survival (OS). In the contemporary cancer therapeutics landscape, immunotherapy is gaining traction at an accelerated pace. Notably, neoadjuvant immunotherapy (NAIT) has shown promising radiological and pathological responses, coupled with encouraging efficacy in several clinical trials. This potentially paves the way for a myriad of possibilities in treatment de-escalation of HNSCC, which warrants further exploration. This paper reviews the existing strategies and efficacies of neoadjuvant immune checkpoint inhibitors (ICIs), along with potential de-escalation strategies. Furthermore, the challenges encountered in the context of the de-escalation strategies of NAIT are explored. The aim is to inform future research directions that strive to improve the quality of life (QoL) for patients battling HNSCC.

Thymosin β4 induces proliferation, invasion, and epithelial-to-mesenchymal transition of oral squamous cell carcinoma

The epithelial-to-mesenchymal transition (EMT) plays a vital role in carcinogenesis, invasion, and metastasis of many epithelial tumors including oral squamous cell carcinoma (OSCC), a common malignancy of the head and neck. However, the functional role of the actin-sequestering protein thymosin β4 (Tβ4) in the EMT in OSCCs remains unclear. Thus, we investigated whether overexpression of Tβ4 could induce in vitro tumorigenesis such as cell proliferation and anchorage independency and an EMT-like phenotype in OSCCs. Also, we examined whether it affects invasiveness and cell motility-associated signaling molecules. Tβ4-overexpressing OSCCs, SCC-15_Tβ4 and SCC-25_Tβ4, enhanced cell proliferation and colony formation. In addition, we observed that Tβ4 overexpression induced an EMT-like phenotype, accompanied by a decrease in expression of the epithelial cell marker E-cadherin and an increase in expression of mesenchymal cell markers vimentin and N-cadherin. Also, the expression level of Twist1, an EMT-inducing transcription factor, was significantly enhanced in SCC-15_Tβ4 and SCC-25_Tβ4 cells. Tβ4 overexpression augmented in vitro invasion and MMP-2 activity and enhanced the phosphorylation of paxillin and cortactin and expression of LIMK1. Taken together, these results suggest that Tβ4 overexpression could be one of the causes of tumorigenesis and progression in OSCCs. Further investigation on the Tβ4 molecule would encourage the development of specific targets for cancer treatment.

Loss of VHL expression contributes to epithelial-mesenchymal transition in oral squamous cell carcinoma

OBJECTIVE

Loss of Von Hippel-Lindau (VHL) gene expression has been implicated in the development of human cancers. However, its function in oral squamous cell carcinoma (OSCC) remains undefined. The aim of this study was to clarify the VHL expression in OSCC and to explore the underlying mechanisms of VHL in modulating the epithelial-mesenchymal transition (EMT) in OSCC.

MATERIALS AND METHODS

The expression of VHL, HIF-1α and EMT related proteins in OSCC tissues were evaluated by immunohistochemistry. The correlation of VHL with clinico-pathological characteristics, prognosis and EMT related proteins were analyzed. The roles of VHL on the cell morphology, proliferation, migration, and invasion were determined by MTT, scratch and transwell invasion assay in Tscca and Tca8113P160 cells. The EMT related proteins were determined by Western blot and immunofluorescence (IF) methods.

RESULTS

Loss of VHL expression was closely associated with pathologic grading, lymph node metastasis, poor prognosis, and EMT in OSCC. After re-expression of VHL, there was a cell morphologic change and motivation, proliferation, invasion of the cells were inhibited. The expression of Snail, N-cadherin and MMP-2/9, HIF-1α and VEGF were down-regulated in both the cell lines after transfection with VHL plasmid, while E-cadherin was up-regulated. Moreover, the effect of VHL suppressing β-catenin accumulation in nucleus was proved by Western blot and IF.

CONCLUSION

VHL was significantly correlated with EMT process of OSCC. β-Catenin was an important downstream gene of VHL besides HIF-1α, which could induce the EMT process in OSCC.

Expression of the cancer stem cell markers CD44v6 and ABCG2 in tongue cancer: effect of neoadjuvant chemotherapy on local recurrence

The efficacy of neoadjuvant chemotherapy (NAC) is controversial, and no report supports NAC with a high evidence level. Recently, we showed that a deep surgical margin was resected very close to the tumor site in many NAC-treated oral squamous cell carcinoma patients, suggesting that NAC may lead to local recurrence and poor outcomes. The purpose of this study was to evaluate the effect of NAC on tumor local recurrence using cancer stem cell marker immunohistochemistry. We retrospectively analyzed 89 patients who underwent radical surgery for tongue cancer, and examined the effect of NAC on tumor local recurrence. Cancer stem cell marker (CD44v6 and ABCG2) expression was detected by immunohistochemistry. In our study, the local recurrence rate was 12.4%. CD44v6 and ABCG2 expression was significantly associated with regional lymph node metastasis, pattern of invasion, depth of invasion, perineural invasion and local recurrence, respectively. Tumor local recurrence was a significant independent predictive factor of the 5-year disease specific survival. CD44v6 or ABCG2 positivity in NAC-treated patients was significantly associated with tumor local recurrence. It was suggested that local recurrence in NAC-treated cases is associated with cancer stem-like cells. We propose that NAC leads to the selection and/or residue of more aggressive cancer stem-like cells.

Predictors of locoregional recurrence in T1-2N0 tongue cancer patients

Locoregional recurrence of oral tongue squamous cell carcinoma (OTSCC) has been considered a poor prognostic entity in terms of survival rate. The purpose of this study was to evaluate the incidence of locoregional recurrence and to identify significant risk factors for locoregional recurrence in early-stage OTSCC. We retrospectively reviewed the records of 58 patients who underwent radical surgery for T1-2N0 OTSCC. The local recurrence and regional recurrence rates were 10.3 % (6/58 patients) and 15.5 % (9/58 patients) in this study, respectively. The survival rate of patients with local recurrence was 66.7 %, which was significantly lower than that (96.2 %) of patients without local recurrence, whereas the survival rates of patients with or without regional recurrence were not significantly difference. Pattern of invasion (POI), neoadjuvant chemotherapy (NAC) and the status of the surgical margin were identified as factors influencing local recurrence. In particular, the status of the deep surgical margin was a high potential independent risk factor. The deep surgical margin was resected closely in many NAC-treated cases, suggesting that NAC may lead to local recurrence and a poor outcome. No efficacy of NAC was observed, suggesting that the standard treatment for early OTSCC is surgery alone.