Postoperative radiotherapy is dispensable for OSCC patients with micrometastases in lymph nodes

Oral squamous cell carcinoma - do we always need elective neck dissection? evaluation of clinicopathological factors of greatest prognostic significance: a cross-sectional observational study

The aim of the study was to find clinical and pathological factors with the greatest prognostic significance in patients with OSCC. The analysis included 125 patients grouped according to the tumor primary site (TPS): the floor of the mouth (FOM), tongue (TC) and retromolar triangle (RMT). Grading (G), tumor size (pT), nodal metastases (NM), local recurrence (LR), nodal recurrence (NR), perineural invasion (PNI), lymphovascular invasion (LVI), extranodal extension (pENE), and nodal yield (NY) were evaluated in each group.

Results

With regard to TPS, FOM appeared to be the most metastatic. However, the recurrence rate was similar to TC tumors, which were characterized by higher G than those in other locations. When analyzing G, the highest percentage of LR (40.5%) and NM (34.5%) was observed among patients with G2. As G increased, so did the number of pENE G1 - 7.4%; G2 - 31%; G3 - 35.7%; LVI: G1 - 25.9%; G2 - 50%; G3 - 57.1%; PNI: G1 - 29.6%; G2 - 47.6%; G3 - 92.9%; NR G1 - 14.8%; G2 - 32.1%; G3 - 21.4%. Grading did not affect the type of growth and did not directly affect the occurrence of NR. pT and DOI increased the frequency of NM but we did not observe any effect of pT and DOI on LR, PNI, and LVI. NY in the study group did not increase the risk of NR.

Conclusion

Tumor primary sites within the FOM, TC, and pT classification are the factors that increase the risk of NM and LR. However, apart from the primary site predisposing to the occurrence of NM, the histological structure of the tumor turned out to be the most important feature affecting the patient's prognosis. The number of cases of pENE+, LVI+, PNI+, NM+, and NR+ increased with the increase in G. Although the pT, DOI increased the frequency of NM, we did not observe the effect of the pT and DOI on LR, PNI and LVI. Thus, even in the case of a small tumor of the FOM and TC with at least G2, elective neck dissection should be performed each time.

ET-1 Promotes Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma Cells via the microRNA-489-3p /TWIST Axis

Objective

Oral squamous cell carcinoma (OSCC) constitutes almost 90% of head and neck malignancies and has a poor prognosis. To improve the efficacy of OSCC therapy, it is of great significance to explore other therapy for OSCC. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, is implicated in cancer pathogenesis. Moreover, ET-1 promotes epithelial-mesenchymal transition (EMT) during the development of human cancers. We further to found that ET-1 exposure induced EMT in human squamous cell carcinoma cell lines SCC4 and SAS, by enhancing the expression of EMT biomarkers N-cadherin and vimentin and reducing E-cadherin expression via upregulation of the transcription factor TWIST.

Materials and Methods

Cell motility was examined by migration, invasion and wound-healing assays. Quantitative real time polymerase chain reaction (q-PCR), and promoter assays confirmed the inhibitory effects of ET-1 on miRNAs expression in oral cancer cells. We demonstrate an intravenous injection model of lung metastasis followed by an advanced method for quantifying metastatic tumor using image analysis software.

Results

In addition, ET-1/ETAR reduced levels of microRNA-489-3p (miR-489-3p), a transcriptional repressor of TWIST. We have identified a novel bypass mechanism through which ET-1/ETAR are involved in TWIST signaling and downregulate miR-489-3p expression, enabling OSCC cells to acquire the EMT phenotype. Notably, ET-1 knockdown dramatically decreased levels of EMT markers and cell migration potential.

Conclusion

The role of ET-1 in OSCC progression is supported by our findings from an in vivo murine model of OSCC. ET-1 may therefore represent a novel molecular therapeutic target in OSCC metastasis.