Contralateral lymph neck node metastasis of squamous cell carcinoma of the oral cavity: a retrospective analytic study in 315 patients

Identifying factors related to delayed neck metastasis after surgical treatment in patients with oral squamous cell carcinoma

BACKGROUND

General treatment of oral squamous cell carcinoma (OSCC) is surgical treatment with or without neck dissection. Although the incidence of delayed neck metastasis is rare, it may occur after the surgery and is known to be the most important factor in the prognosis. The purpose of is study is to evaluate the clinical and histopathological factors associated with delayed neck metastasis case among patients.

METHODS

A total of 195 patients who underwent surgical treatment for OSCC from 2016 to 2022 were investigated. Among them, delayed neck metastasis (DNM) was analyzed. The criterion for delayed neck metastasis was a newly developed neck lesion after the primary operation without neck dissection in cN0 necks. To identify the correlation between prognostic factors and the incidence of delayed neck metastasis, χ2 analysis with phi correlation and Cramer's V test was performed. Cumulative survival rates (CRS) were compared between the groups with the incidence of DNM and without DNM. Also, the log rank test for CSR and Cox proportional hazard model was analyzed to estimate the significance of the CSR and confirm the correlations between prognostic factors and DNM.

RESULT

Among 195 patients, 14 were discovered to have DNM. The primary tumor locations were the tongue (n = 5), floor of the mouth (n = 2), mandibular gingiva (n = 1), maxillary gingiva (n = 4), retromolartrigone (n = 1), and buccal mucosa (n = 2) each. The cases consisted of TNM stage I (n = 1), stage II (n = 3), stage III (n = 3), and stage IV (n = 8), respectively. The result of the χ2 analysis identified a correlation between positive neck (p = 0.01), depth of invasion (p = 0.09), radiation therapy (p = 0.003), and DNM. Groups without DNM showed better prognosis compared to groups with DNM. Regarding positive neck, depth of invasion, and radiation therapy, only depth of invasion showed significance in CSR analysis.

CONCLUSION

DNM after surgical treatment of OSCC is a rare event, and few were found in a review of the literature. Also, many prognostic factors have been suggested but controversial. However, in our study, some prognostic factors have been identified to have a significant correlation with the incidence of DNM, and analysis of such factors provides important information predicting neck metastasis and the prognosis.

Evaluation of the prognostic and therapeutic potential of inhibin beta B for oral squamous cell carcinoma

Background/purpose

Oral squamous cell carcinoma (OSCC) is a common cancer worldwide, and its metastasis is difficult to predict and prevent. Inhibin beta B (INHBB) protein has been linked to cancer prognosis and epithelial-mesenchymal transition (EMT). However, previous study about INHBB expression focused on patients in a single region while the risk factors vary among regions. This study aimed to provide a broader perspective on INHBB expression in OSCC.

Materials and methods

Tissue micro-arrays comprising 118 specimens were subjected to immunohistochemistry, and all slides were quantified using StrataQuest software.

Results

The ratio of INHBB-positive cells to total cells was significantly higher in OSCC samples than in normal samples, and the intensity of INHBB expression was significantly greater in the late-stage OSCC. After classifying specimens into high and low INHBB expression groups, a significant association with clinical staging was found. Though a previous study suggested that menin regulates INHBB, menin expression was not detected in specimens.

Conclusion

The ratio of INHBB-positive cells in OSCC may be druggable for targeting tumor cells or assisting in diagnosis, and the intensity of INHBB expression may provide prognostic information for predicting potential metastasis. Moreover, the regulatory mechanism of INHBB in OSCC remains unclear and requires further investigation.

Potential of preoperative fluorodeoxyglucose-positron emission tomography/computed tomography to diagnose contralateral lymph node metastases in patients with oral cancer

OBJECTIVE

To establish a decision tree using preoperative PET/computed tomography (CT) parameters for detecting contralateral lymph node metastasis (CLNM) in oral cancer patients.

METHODS

In total, 140 patients with a confirmed histopathological diagnosis of oral carcinoma showed fluorodeoxyglucose accumulation of contralateral lymph nodes in PET images. Of 260 lymph nodes, eight were metastatic. We compared metastatic and non-metastatic nodes using Fisher-Freeman-Halton exact and Fisher's exact and Mann-Whitney U tests. The diagnostic performance was analyzed using receiver operating characteristic curves. We established a decision tree using exhaustive chi-squared automatic interaction detection algorithm.

RESULTS

Five PET/CT parameters were significantly different between metastatic and non-metastatic nodes: the longest ( P  = 0.015) and shortest ( P  = 0.023) diameter, and the maximum standardized uptake values (SUVmax) of the contralateral node ( P  = 0.030), primary tumor ( P  < 0.001), and ipsilateral node ( P  < 0.001). The area under the curves of SUVmax of the primary tumor (0.887), ipsilateral node (0.886), and longest diameter (0.752) were the largest and these three parameters were used as predictive criteria in the decision tree. The accuracy of the decision tree was 97.7% with 100% sensitivity and 97.6% specificity.

CONCLUSION

Preoperative PET/CT imaging with a decision tree has the potential to diagnose CLNM in patients with oral cancer.

Midline involvement and perineural invasion predict contralateral neck metastasis that affects overall and disease-free survival in locally advanced oral tongue squamous cell carcinoma

Introduction

Although patients with oral squamous cell carcinoma who develop contralateral neck metastasis (CLNM) have worse survival outcomes than those without CLNM, accurate prediction of occult CLNM in clinically negative contralateral neck (contralateral cN0) remains difficult. This study aimed to identify clinicopathological factors that could reliably predict CLNM in patients with locally advanced (clinical T3 and T4a) tongue squamous cell carcinoma (TSCC).

Patients and methods

The medical data of 32 patients with cT3–4a TSCC who underwent curative surgery between 2010 and 2017 were retrospectively analyzed. The correlation of clinicopathological variables with CLNM was examined using logistic regression analysis. The diagnostic performance of significant variables was evaluated using the area under the receiver operating characteristic curves (AUC). Overall survival (OS) and disease-free survival (DFS) were assessed using a Cox proportional hazards model.

Results

CLNM was eventually confirmed in 11 patients (34.4%). Multivariate logistic regression showed that midline involvement [odds ratio (OR) = 23.10, P = 0.017] and perineural invasion (PNI, OR = 14.96, P = 0.014) were independent predictors of CLNM. Notably, the prediction model comprising a combination of midline involvement and PNI exhibited superior diagnostic performance with an even higher OR of 80.00 (P &lt; 0.001), accuracy of 90.3%, and AUC of 0.876. The multivariate Cox hazards model revealed independent significance of CLNM as an unfavorable prognostic factor for both OS [hazard ratio (HR) = 5.154, P = 0.031] and DFS (HR = 3.359, P = 0.038), as well as that of PNI for OS (HR = 5.623, P = 0.033).

Conclusion

Our findings suggest that coexisting midline involvement and PNI of the primary tumor is highly predictive of CLNM development, which independently affects both OS and DFS in patients with locally advanced TSCC. Such reliable prediction enables efficient control of CLNM by optimizing management of the contralateral cN0 neck, which will likely contribute to improved prognosis of those patients without unnecessarily compromising their quality of life.

Treatment and Prognosis of Oral Cancer Patients with Confirmed Contralateral Neck Metastasis: A Multicenter Retrospective Analysis

The prognosis of oral cancer that has metastasized to the contralateral cervical lymph nodes is poor, although the appropriate treatment method has not been established because of its rarity. A multicenter retrospective study on the treatment and prognosis of pN2c oral cancer patients was conducted. We investigated the treatment and prognosis of 62 pN2c patients out of 388 pN+ patients with oral squamous cell carcinomas. Statistical analysis was performed on the various factors with overall survival (OS) and disease specific survival (DSS). In multivariate cox regression analysis, advanced T stage was significantly correlated with poor OS (p = 0.011) and DSS (p = 0.023) of patients with pN2c neck. In pN2c patients, OS, DSS, and neck control was not different between those undergoing ipsilateral neck dissection initially and those undergoing bilateral neck dissection. Thus, contralateral elective neck dissection is not recommended. The most important risk factor for prognosis in pN2c oral cancer patients is advanced T stage. No evidence was found to recommend contralateral elective neck dissection in clinically N1/2b patients. Therefore, the indication for contralateral elective neck dissection in N1/2b patients should be carefully determined in consideration of individual conditions.

Diversity of the Origin of Cancer Stem Cells in Oral Squamous Cell Carcinoma and Its Clinical Implications

Simple Summary

Oral squamous cell carcinoma (OSCC) histopathologically accounts for ≥90% of oral cancer. In this review article, we focus on the diversity of the origin of OSCC and also discuss cancer stem cells (CSCs). CSCs are a subset of cancer cells that occupy a very small portion of the cancer mass and have characteristics of stem cells. When gene abnormalities accumulate in somatic stem cells, those cells transform into CSCs. CSCs as the origin of cancer then autonomously grow and develop into cancer. The histopathological phenotype of cancer cells is determined by the original characteristics of the somatic stem cells and/or surrounding environment. OSCC may be divided into the following three categories with different malignancy based on the origin of CSCs: cancer from oral epithelial stem cell-derived CSCs, cancer from stem cells in salivary gland-derived CSCs, and cancer from bone marrow-derived stem cell-derived CSCs.

Abstract

Oral squamous cell carcinoma (OSCC) histopathologically accounts for ≥90% of oral cancer. Many clinicopathological risk factors for OSCC have also been proposed, and postoperative therapy is recommended in guidelines based on cancer stage and other risk factors. However, even if the standard treatment is provided according to the guidelines, a few cases rapidly recur or show cervical and distant metastasis. In this review article, we focus on the diversity of the origin of OSCC. We also discuss cancer stem cells (CSCs) as a key player to explain the malignancy of OSCC. CSCs are a subset of cancer cells that occupy a very small portion of the cancer mass and have characteristics of stem cells. When gene abnormalities accumulate in somatic stem cells, those cells transform into CSCs. CSCs as the origin of cancer then autonomously grow and develop into cancer. The histopathological phenotype of cancer cells is determined by the original characteristics of the somatic stem cells and/or surrounding environment. OSCC may be divided into the following three categories with different malignancy based on the origin of CSCs: cancer from oral epithelial stem cell-derived CSCs, cancer from stem cells in salivary gland-derived CSCs, and cancer from bone marrow-derived stem cell-derived CSCs.

Fructose-1,6-Bisphosphatase 2 Inhibits Oral Squamous Cell Carcinoma Tumorigenesis and Glucose Metabolism via Downregulation of c-Myc

Background

Fructose-1,6-bisphosphatase 2 (FBP2), known as a rate-limiting enzyme in gluconeogenesis, is a tumor suppressor downregulated in various cancers. However, the role of FBP2 in oral squamous cell carcinoma (OSCC) remains largely unclear.

Methods

The level of FBP2 in OSCC tissues and matched adjacent normal tissues was determined by western blot and RT-qPCR assays. In addition, analysis of FBP2 function in OSCC cells was assessed using both gain-of-function and loss-of-function studies.

Results

In this study, we found that the expression of FBP2 was remarkably downregulated in OSCC tissues and OSCC cells. Overexpression of FBP2 suppressed the viability, proliferation, migration, and glycolysis of OSCC cells, whereas FBP2 knockdown exhibited the opposite results. Moreover, downregulation of FBP2 promoted the growth and glycolysis of OSCC cells in nude mice in a xenograft model. Specifically, FBP2 colocalizes with the c-Myc transcription factor in the nucleus. Significantly, inhibitory effects of FBP2 overexpression on the viability, proliferation, migration, and glycolysis of OSCC cells were reversed by c-Myc overexpression.

Conclusion

Collectively, FBP2 could suppress the proliferation, migration and glycolysis in OSCC cells through downregulation of c-Myc. Our study revealed a FBP2-c-Myc signaling axis that regulates OSCC glycolysis and may provide a potential intervention strategy for OSCC treatment.

Serine hydroxymethyltransferase 2 (SHMT2) potentiates the aggressive process of oral squamous cell carcinoma by binding to interleukin enhancer-binding factor 2 (ILF2)

Oral squamous cell carcinoma (OSCC) is a frequent threatening head and neck malignancy. Serine hydroxymethyltransferase 2 (SHMT2) was identified to be upregulated in OSCC and its high expression was associated with poor patient prognosis. This paper set out to assess the influence of SHMT2 on OSCC progression and the potential mechanisms related to interleukin enhancer-binding factor 2 (ILF2). First of all, reverse transcription-quantitative PCR (RT-qPCR) and western blot examined the expression of SHMT2 and ILF2 in OSCC cells. Cell Counting Kit-8 (CCK-8) and colony formation assays appraised cell proliferation. Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling (TUNEL) staining was to estimate the apoptotic rate of cells. Further, wound healing and transwell assays verified the migration and invasion of cells. Western blot was adopted to detect the expression of factors related to apoptosis, migration, and epithelial–mesenchymal transition (EMT). The possible interaction of SHMT2 and ILF2 was predicted by a Molecular INTeraction (MINT) and BioGRID databases and determined using co-immunoprecipitation (IP) assay. Subsequently, ILF2 was overexpressed to investigate whether SHMT2 regulated OSCC progression by binding to ILF2. Results implied that SHMT2 possessed increased expression in OSCC cells, and OSCC cell viability, migration, invasion, EMT were inhibited and apoptosis was potentiated after its silencing. ILF2 bound to SHMT2 and ILF2 expression was downregulated after SHMT2 silencing in OSCC cells. Importantly, ILF2 overexpression abolished the suppressive role of SHMT2 interference in the progression of OSCC. Collectively, SHMT2 could promote the progression of OSCC by binding to ILF2.

Adjuvant contralateral neck irradiation for oral cavity cancer - A systematic review and meta-analysis

INTRODUCTION

Whether contralateral neck irradiation should be administered for oral cavity cancer is a critical question because patients receiving bilateral neck irradiation experience more adverse effects. Patients not receiving contralateral neck irradiation are at risk of contralateral neck recurrence of oral cavity cancer MATERIALS AND METHODS: Meta-analysis and subgroup analysis were performed for the rates of contralateral neck recurrence of oral cavity cancer in patients receiving no contralateral neck radiation. We aimed to identify the patient group suitable for contralateral neck radiotherapy omission. The PRISMA guideline was used for this study. We extracted data including the first author, country, sample size, numbers of patients receiving ipsilateral neck radiotherapy and experiencing contralateral neck recurrence, participant characteristics, and details of cancer types RESULTS: The rate of contralateral neck recurrence is extremely low, 3.4% (95% confidence interval: 2.2%-5.4%). Isolated contralateral neck recurrence occurred in 18 of 524 patients receiving radiotherapy to the primary tumor site with or without ipsilateral irradiation. The subgroup analysis was conducted to investigate pathological lymph node stage and subsite. Subgroup analysis showed that the N2-3 group was more likely to exhibit recurrence in contralateral neck than the N0-1 group was (14.4% versus 1.5%, p = 0.0008). In addition, the contralateral neck recurrence rate was 6.3% (95% CI = 2.3%-13.1%) and 2.8% (95% CI = 1.5%-4.8%), in the tongue cancer patient group and the non-tongue cancer patient group, respectively. Meta-regression showed that the rate of contralateral recurrence was not different between both groups (p = 0.08). Only 2 exhibited isolated contralateral neck recurrence (5.1%) in pN0-1 tongue cancer patient. Most of them (>90%) are lateralized.

CONCLUSION

In conclusion, the omission of contralateral irradiation is reasonable in pN0-1, well lateralized oral cavity cancer.

Contralateral lymph node recurrence rate and its prognostic factors in stage IVA-B well-lateralized oral cavity cancer

PURPOSE

To evaluate the contralateral lymph node recurrence rate (clLNRR) of stage IVA to IVB well-lateralized oral cavity cancer. To evaluate the risk factors of clLNRR.

MATERIALS AND METHODS

Pathologic stage IVA-B squamous cell carcinoma of oral cavity, originating from buccal mucosa, gingiva, or retromolar trigone were retrospectively recruited. Those who did not receive definitive surgery, with previous cancer history, or with contralateral nodal metastasis at diagnosis were excluded.

RESULTS

From 2010 to 2017, 120 cases were enrolled, including 103 pT4 and 38 pN2. Thirty-one patients underwent contralateral neck dissection, and 18 had contralateral elective nodal irradiation. After median follow up of 35.1 months, the 3-year clLNRR was 15.7% (95% CI: 8.8 - 22.6%) as first event and was 17.1% (95% CI: 9.8 - 24.4%) for overall recurrences. The 3-year disease-free survival and overall survival were 52.8% and 63.1%, respectively. In multivariate analysis, positive nodal metastasis, gingival origin, and perineural invasion were associated with significantly higher clLNRR. Nodal metastasis was the strongest prognostic factor for clLNRR (pN1, HR: 17.1, p = 0.010; pN2, HR: 16.7, p = 0.004, comparing to pN0). The 3-year clLNRR were 2.9% for pN0 (n = 71, 95% CI: 0 - 6.8%), 37.7% for pN1 (n = 11, 95% CI: 8.3 - 67.1%), and 38.4% for pN2 (n = 38, 95% CI: 19.2 - 57.6%). Advanced T classification, elective contralateral neck dissection, and contralateral nodal irradiation did not have significant impact on clLNRR.

CONCLUSIONS

Positive homolateral nodal metastasis, gingival origin, and perineural invasion were risk factors correlated with significantly higher clLNRR. For patient without nodal metastasis, the clLNRR was low and elective contralateral neck management might be safely omitted. For patients with homolateral nodal disease, the contralateral nodal recurrence was not unusual. The optimal treatment for these high risk patients warrant further research.

Knockdown of RhoC Inhibits Oral Squamous Cell Carcinoma Cell Invasion and Metastasis via Regulation of HMGA2

Ras homolog family member C (RhoC) is an important component of intracellular signal transduction and its overexpression has been reported to be involved in regulating tumor proliferation, invasion, and metastasis in various malignant tumors. However, its role and underlying mechanism in oral squamous cell carcinoma (OSCC) still remain obscure. In our study, RhoC expression, its relation with clinical stages, and survival rate in OSCC were analyzed using datasets from The Cancer Genome Atlas (TCGA). Next, a RhoC knockdown cell model was established in vitro, and the effects of RhoC knockdown in OSCC cells were detected by the MTT assay, colony formation assay, transwell invasion assay, scratch assay, and F-actin phalloidin staining. An in vivo tongue-xenografted nude mouse model was established to measure the effects of knockdown of RhoC on tumor cell growth and lymph node metastasis. A mechanism study was conducted by real-time PCR and immunocytochemistry. The results of TCGA analysis showed that RhoC was overexpressed in OSCC tumor tissues. In vitro assays indicated that knockdown of RhoC did not have much effect on OSCC cell growth but significantly suppressed cell colony formation, invasion, and migration abilities, and F-actin polymerization was also reduced. The tongue-xenografted in vivo model demonstrated that knockdown of RhoC suppressed OSCC cell growth and inhibited metastasis to the superficial cervical lymph nodes. Further mechanism studies showed that knockdown of RhoC downregulated HMGA2 expression, and HMGA2 expression was highly correlated with RhoC expression in OSCC tumor tissues via the analysis of TCGA datasets. Overall, our study showed that knockdown of RhoC inhibited OSCC cells invasion and migration in vitro and OSCC cell growth and lymph node metastasis in vivo. Moreover, the potential mechanisms involved in these activities may be related to the regulation of HMGA2 expression. The RhoC gene could serve as a promising therapeutic target for OSCCs in the future.

Salvage Surgery for Recurrent Tongue Cancer With Contralateral Neck Metastasis

PURPOSE

Treatment recommendations have been widely reported for primary tongue squamous cell carcinoma (TSCC) with contralateral neck metastases (CNMs), but little is known concerning recurrent TSCCs with CNMs, especially in patients who have undergone ipsilateral neck dissection. The aim of this study was to estimate overall survival (OS) and to identify prognostic factors associated with OS in patients treated for recurrent TSCCs.

PATIENTS AND METHODS

We performed a retrospective cohort study of patients who underwent salvage surgery (SS) for recurrent TSCC in our institution between January 2010 and December 2014. Before SS, all patients had been surgically treated for primary TSCC with ipsilateral neck dissection. The primary outcome variable was OS, and the patients were grouped by the primary predictor variable of CNM status for comparison. Other heterogeneous variables of interest included demographics, medical histories, clinicopathologic characteristics, surgical data, and adjuvant treatment modalities. In addition, the midline involvement and anatomic subsites of local recurrences were evaluated. Univariate log-rank and Cox regression tests were used for statistical analyses.

RESULTS

The study sample included 177 subjects with a mean age of 55.4 years, and 44.6% were males. The median OS was 18 months. Within the entire cohort, the incidence of CNM was 23.7% (n = 42), with an inclination (n = 30) for contralateral level I or II. Factors associated with improved survival included CNM (hazard ratio [HR], 2.108; 95% confidence interval [95% CI], 1.341 to 3.315; P = .001), disease-free interval (HR, 0.601; 95% CI, 0.387 to 0.934; P = .023), and local recurrence subsite score (HR, 3.276; 95% CI, 0.924 to 11.623; P = .001).

CONCLUSIONS

Patients with both recurrent TSCCs and CNMs had a dismal prognosis (OS rate, 16.2%) compared with those without CNMs (OS rate, 52.7%). SS for TSCC patients with collateral failures should be used cautiously because of the very unfavorable outcomes.

CT-Based Radiomics Signature for the Preoperative Discrimination Between Head and Neck Squamous Cell Carcinoma Grades

Background: Radiomics has been widely used to non-invasively mine quantitative information from medical images and could potentially predict tumor phenotypes. Pathologic grade is considered a predictive prognostic factor for head and neck squamous cell carcinoma (HNSCC) patients. A preoperative histological assessment can be important in the clinical management of patients. We applied radiomics analysis to devise non-invasive biomarkers and accurately differentiate between well-differentiated (WD) and moderately differentiated (MD) and poorly differentiated (PD) HNSCC.

Methods: This study involved 206 consecutive HNSCC patients (training cohort: n = 137; testing cohort: n = 69). In total, we extracted 670 radiomics features from contrast-enhanced computed tomography (CT) images. Radiomics signatures were constructed with a kernel principal component analysis (KPCA), random forest classifier and a variance-threshold (VT) selection. The associations between the radiomics signatures and HNSCC histological grades were investigated. A clinical model and combined model were also constructed. Areas under the receiver operating characteristic curves (AUCs) were applied to evaluate the performances of the three models.

Results: In total, 670 features were selected by the KPCA and random forest methods from the CT images. The radiomics signatures had a good performance in discriminating between the two cohorts of HNSCC grades, with an AUC of 0.96 and an accuracy of 0.92. The specificity, accuracy, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of the abovementioned method with a VT selection for determining HNSCC grades were 0.83, 0.92, 0.96, 0.94, and 0.91, respectively; without VT, the corresponding results were 0.70, 0.83, 0.88, 0.80, and 0.84. The differences in accuracy, sensitivity and NPV were significant between these approaches (p < 0.05). The AUCs with VT and without VT were 0.96 and 0.89, respectively (p < 0.05). Compared to the combined model and the radiomics signatures, The clinical model had a worse performance, and the differences were significant (p < 0.05). The combined model had the best performance, but the difference between the combined model and the radiomics signature weren't significant (p > 0.05).

Conclusions: The CT-based radiomics signature could discriminate between WD and MD and PD HNSCC and might serve as a biomarker for preoperative grading.

Hallmarks of Cancer-Related Newly Prognostic Factors of Oral Squamous Cell Carcinoma

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth leading malignancy worldwide. OSCC is an aggressive tumor and its prognosis has exhibited little improvement in the last three decades. Comprehensive elucidation of OSCC's molecular mechanism is imperative for early detection and treatment, improving patient survival. Based on broadly accepted notions, OSCC arises from multiple genetic alterations caused by chronic exposure to carcinogens. In 2011, research revealed 10 key alterations fundamental to cancer cell development: sustaining proliferative signaling, evading growth suppressors, avoiding immune destruction, activating invasion and metastasis, tumor-promoting inflammation, enabling replicative immortality, inducing angiogenesis, genome instability and mutation, resisting cell death, and deregulating energetics. This review describes molecular pathological findings on conventional and novel hallmarks of OSCC prognostic factors. In addition, the review summarizes the functions and roles of several molecules as novel OSCC prognosticators.

How Histopathologic Tumor Extent and Patterns of Recurrence Data Inform the Development of Radiation Therapy Treatment Volumes in Solid Malignancies

The ability to deliver highly conformal radiation therapy using intensity-modulated radiation therapy and particle therapy provides for new opportunities to improve patient outcomes by reducing treatment-related morbidities following radiation therapy. By reducing the volume of normal tissue exposed to radiation therapy (RT), while also allowing for the opportunity to escalate the dose of RT delivered to the tumor, use of conformal RT delivery should also provide the possibility of expanding the therapeutic index of radiotherapy. However, the ability to safely and confidently deliver conformal RT is largely dependent on our ability to clearly define the clinical target volume for radiation therapy, which requires an in-depth knowledge of histopathologic extent of different tumor types, as well as patterns of recurrence data. In this article, we provide a comprehensive review of the histopathologic and radiographic data that provide the basis for evidence-based guidelines for clinical tumor volume delineation.

Natriuretic peptide receptor A is related to the expression of vascular endothelial growth factors A and C, and is associated with the invasion potential of tongue squamous cell carcinoma

Natriuretic peptide receptor A (NPRA) is one of the natriuretic peptide receptors. NPRA has been reported to play a role in the carcinogenesis of various tumours, as well as functional roles in renal, cardiovascular, endocrine, and skeletal homeostasis. The clinicopathological significance of NPRA in tongue squamous cell carcinoma (TSCC) was examined in this study. The overexpression of NPRA was more frequent in TSCC (21/58, 36.2%) than in the normal oral epithelium (0/10, 0%) (P<0.05). It was also more frequently observed in cancers with higher grades according to the pattern of invasion (grades 1-2 vs. grades 3-4, P<0.01). Additionally, there was a tendency towards an association between the N classification and NPRA expression (N0 vs. N1-2, P=0.06). Significant correlations were also observed between the expression of NPRA and that of VEGF-A (P<0.001) and VEGF-C (P<0.001). The high-NPRA expression group had a significantly poorer prognosis, with a 5-year disease-specific survival rate of 39.7%, compared to 97.0% in the low-expression group (P<0.001). Multivariate analysis suggested that the overexpression of NPRA may also be an independent prognostic factor (P<0.05). In conclusion, NPRA is associated with VEGF expression levels, invasion, and metastasis, and may be a prognostic factor in TSCC patients.

Skp2 Regulates the Expression of MMP-2 and MMP-9, and Enhances the Invasion Potential of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the head and neck regions and accounts for more than 90 % of cancers in the oral cavity. S-phase kinase-associated protein-2 (Skp2) is a member of the F-box protein family and the substrate recognition subunit of the Skp1-Cullin-F box protein E3 ubiquitin ligase complex. Skp2 is oncogenic and overexpressed in human cancers. The aims of the present study were to determine the clinicopathological significance of Skp2 in OSCC and clarify its function in OSCC cell lines in vitro. Multiple methods including immunohistochemical staining, RT-PCR, western blotting, migration and invasion assays, and siRNA transfection were employed in order to investigate the clinicopathological significance and molecular function of Skp2 in OSCC. The overexpression of Skp2 was more frequent in OSCC than in the normal oral epithelium. It was also more frequently detected in cancers with higher grades according to the T classification, N classification, and pattern of invasion. The high-Skp2 expression group had a significantly poorer prognosis, at 30.1 %, than that of the low-expression group, at 63.0 %. The downregulation of Skp2 decreased migration and invasion potentials in HSC3 cells. Moreover, the suppression of Skp2 reduced the enzyme activities of MMP-2 and MMP-9 via Sp1. Skp2 may be a prognostic factor in OSCC patients, and may also play crucial roles in the migration and invasion potentials of OSCC cells.

Contralateral neck failure in lateralized oral squamous cell carcinoma

BACKGROUND

Elective treatment of the contralateral clinically node-negative (cN0) neck is not routinely recommended for lateralized oral cavity squamous cell carcinoma (SCC). We sought to determine the failure rate in the untreated contralateral neck in patients with lateralized oral SCC undergoing treatment of the primary and ipsilateral neck and to identify any features placing patients at sufficient risk of contralateral regional failure to justify elective treatment.

METHODS

We identified 688 patients with oral SCC undergoing curative surgery ± adjuvant therapy between 1985 and 2012 from a prospectively collected database. Patients with midline primaries and those undergoing bilateral neck treatment were excluded. The primary endpoint was isolated contralateral neck failure.

RESULTS

Of 481 patients, 14 (2.9%) developed isolated contralateral neck recurrence, with median time to recurrence of 8 months. Patients with poorly differentiated tumours or pathologically proven ipsilateral nodal metastases were at significantly higher risk of contralateral failure (hazard ratio (HR) 3.6, 95% confidence interval (CI) 1.1-11.9, P = 0.037 and HR 4.6, 95% CI 1.5-13.8, P = 0.006 respectively). Presence of both of these factors conferred a 10% risk of contralateral failure.

CONCLUSION

Patients with lateralized oral SCC undergoing treatment of the primary tumour and ipsilateral neck have a low rate of isolated contralateral neck failure. Although poorly differentiated primaries and ipsilateral nodal metastases were predictors of contralateral recurrence, the risk remains relatively modest in this subset of patients suggesting close observation may be more appropriate than elective treatment. Our results support current recommendations for observation of the cN0 contralateral neck in lateralized oral SCC.

FOXC2 expression is associated with tumor proliferation and invasion potential in oral tongue squamous cell carcinoma

Forkhead box protein C2 (FOXC2) is a gene encoding a transcription factor that controls the generation of mesodermal tissue including vascular and lymphatic tissues. FOXC2 has previously been associated with EMT and tumor angiogenesis in various cancers. Moreover, a relationship between the expression of FOXC2 and poor prognosis has been reported in various cancers. We herein examined the clinicopathological significance of FOXC2 in oral tongue squamous cell carcinoma (OTSCC) and attempted to clarify the function of FOXC2 in OTSCC cell lines in vitro. The overexpression of FOXC2 was more frequent in cancers with higher grades according to the pattern of invasion (grade 4 vs. 1-3; p < 0.05). A correlation was observed between the expression of FOXC2 and that of VEGF-A and -C (VEGF-A; p < 0.05, VEGF-C; p < 0.001). The high-FOXC2 expression group had a significantly poorer prognosis than that of the low-expression group (p < 0.001). Multivariate analysis indicated that the overexpression of FOXC2 may also be an independent prognostic factor, similar to N classification (N0 vs 1/2; p < 0.05), stage classification (stage I/II vs III/IV; p < 0.05), pattern of invasion (grade 1-3vs 4; p < 0.05), local recurrence (local recurrence (+) vs (-); p < 0.01), and the overexpression of FOXC2 (FOXC2 overexpression (-) vs.(+); p < 0.05). In the OTSCC cell line analysis, the expression of FOXC2 was also associated with proliferation and invasion potential. These results strongly suggest that the overexpression of FOXC2 may be a potent predictor of survival in OTSCC patients.

Risk factors and treatment of contralateral neck recurrence for unilateral oral squamous cell carcinoma: a retrospective study of 1482 cases

BACKGROUND

The aim of this study was to describe risk factors of contralateral neck recurrence (CLNR) and to identify its high-risk population after treatment for unilateral oral squamous cell carcinoma.

METHODS

Between June 1991 and June 2012, a total of 1482 eligible patients who were treated with radical surgery with or without adjuvant therapy were retrospectively reviewed.

RESULTS

The outcome assessment parameters were the rate of 5-year CLNR and the rate of disease-specific survival (DSS). In the entire study cohort, the 5-year CLNR rate was 4.1%. In a multivariate analysis, only extracapsular spread (ECS) status (hazard ratio [HR]: 12.978, 95% confidence interval [CI]: 1.328-126.829, P=0.028) was an independent risk factor for 5-year CLNR. In addition, 5-year CLNR (HR: 36.410, 95% CI: 7.093-186.914, P<0.001), T stage (HR: 3.475, 95% CI: 1.151-10.488, P=0.027) and growth pattern (HR: 4.831, 95% CI: 1.776-13.140, P=0.002) were independent risk factors for 5-year DSS. Patients with at least two risk factors were identified as a high-risk population for CLNR; these patients also had a poor prognosis. Elective contralateral neck dissection (ND) plus concurrent chemoradiotherapy (CCRT) can improve the 5-year DSS in these high-risk patients, but it does not decrease the 5-year CLNR rate.

CONCLUSION

For low- and moderate-risk patients, contralateral neck observation should be considered sufficient if strict compliance with a cancer surveillance protocol is followed. However, whether high-risk patients benefit from contralateral ND plus adjuvant CCRT can only be answered in a prospective trial.

Occurrence of contralateral lymph neck node metastasis in patients with squamous cell carcinoma of the oral cavity

Introduction: Squamous cell carcinoma represents about 90% of malignancies of the mouth and about 38% of the head and neck tumors. The behavior of the cancer is very aggressive, presenting early cervical metastasis and, often contralateral ranging from 0.9 to 36%. Objectives: This study aims to analyze clinical and pathological factors that may influence metastasis of squamous cell carcinoma in cervical lymph nodes and relate this occurrence in the contralateral primary tumor, with disease prognosis and the interference of this type of metastasis in the survival rate of patients with this pathology. Material and Metohds: It was conducted a retrospective study from medical records of patients with Squamous Cell Carcinomas with homolateral lymph node metastasis and contralateral attended at the clinic of Head and neck surgery of Hospital São Vicente de Paulo in Passo Fundo – RS - Brazil, from 2000 to 2008. Results: Analyzing the charts of patients with metastatic and metastatic contralateral side it was observed that patients with initial stage presented a higher survival with statistical significance (p=0,035). Conclusions: The occurrence of metastases in lymph nodes of contralateral position to the primary lesion was not the main fator that influenced the survival of the group.

Key words:Squamous cell carcinoma, oral cavity, contralateral, death rate, lymphatic metastasis, prognosis.

Delayed lymph node metastases after elective neck dissection in patients with oral and oropharyngeal cancer and pN0 neck

PURPOSE

Patients with surgically treated head and neck cancer and clinical N0 neck with high risk of occult lymph node metastasis undergo elective neck dissection (ND). Late lymph node metastasis may appear in those patients with pN0 neck. The aim of the present study was to analyze the incidence and clinical relevance of late lymph node metastasis in patients with head and neck cancer.

MATERIALS AND METHODS

The clinical data of 61 patients with head and neck cancer who had undergone elective ND with pN0 neck were retrospectively analyzed. Only patients without local failure, second primary, or radiochemotherapy were included in the study.

RESULTS

Late lymph node metastasis could be observed in 4 (6.5%) cases at the margin or outside the initially dissected lymph node levels. In those patients, the primary tumor was localized in the oral cavity (n = 3) or oropharynx (n = 1) and was classified in all cases as T1 or T2. Lymph node metastasis could be found in levels I (n = 2), II (n = 1), and IV (n = 1), respectively.

CONCLUSION

Even in the case of pN0 neck after an elective ND, the appearance of late lymph node metastases must be expected. The low proportion of patients with late lymph node metastases after a selective ND in clinical and histologic N0 does not justify an extended form of neck surgery.

Concomitant radio- and fluorescence-guided sentinel lymph node biopsy in squamous cell carcinoma of the oral cavity using ICG-(99m)Tc-nanocolloid

PURPOSE

For oral cavity malignancies, sentinel lymph node (SLN) mapping is performed by injecting a radiocolloid around the primary tumour followed by lymphoscintigraphy. Surgically, SLNs can then be localized using a handheld gamma ray detection probe. The aim of this study was to evaluate the added value of intraoperative fluorescence imaging to the conventional radioguided procedure. For this we used indocyanine green (ICG)-(99m)Tc-nanocolloid, a hybrid tracer that is both radioactive and fluorescent.

METHODS

Fourteen patients with oral cavity squamous cell carcinoma were peritumourally injected with ICG-(99m)Tc-nanocolloid. SLNs were preoperatively identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT)/CT for anatomical localization. During surgery, SLNs were detected with a handheld gamma ray detection probe and a handheld near-infrared fluorescence camera. Pre-incision and post-excision imaging with a portable gamma camera was performed to confirm complete removal of all SLNs.

RESULTS

SLNs were preoperatively identified using the radioactive signature of ICG-(99m)Tc-nanocolloid. Intraoperatively, 43 SLNs could be localized and excised with combined radio- and fluorescence guidance. Additionally, in four patients, an SLN located close to the primary injection site (in three patients this SLN was located in level I) could only be intraoperatively localized using fluorescence imaging. Pathological analysis of the SLNs revealed a metastasis in one patient.

CONCLUSION

Combined preoperative SLN identification and intraoperative radio- and fluorescence guidance during SLN biopsies for oral cavity cancer proved feasible using ICG-(99m)Tc-nanocolloid. The addition of fluorescence imaging was shown to be of particular value when SLNs were located in close proximity to the primary tumour.

Significance of tumor satellite variables in reflecting the epithelial-mesenchymal transition of tongue cancer

The epithelial-mesenchymal transition (EMT) is important in determining the biological behaviors and clinical prognosis of tongue cancer. However, the heterogeneous nature of the cancer populations renders clinical grading controversial. The main purpose of EMT analysis is to identify the cell population with the greatest metastatic potentials. Therefore, tumor satellites that form at the invasive front of tongue cancer may be the optimal target for EMT evaluation. From 1999 to 2002, surgical samples of 117 consecutive tongue cancer patients diagnosed and treated at the National Taiwan University Hospital were collected. EMT-related biomarkers, including E-cadherin and vimentin, were analyzed in tongue cancer specimens to verify the association with tumor satellite variables. The results showed that the down-regulation of epithelial markers, manifested by E-cadherin loss, was significantly different compared to the pattern of invasion (p=0.011), tumor satellite formation (p=0.019), and tumor satellite size (p=0.019). For mesenchymal phenotype acquisition, vimentin expression significantly differs in groups stratified by tumor satellite distance (TSD) (p=0.018). EMT positive immunoreaction was more frequent in the cases with tumor satellite formation (p=0.042) and in those with greater TSD (p=0.023). In addition, in the EMT positive cases, the average TSD was 0.79±1.20mm compared to 0.36±0.52mm in the EMT-negative cases (p=0.010). The results demonstrated the correlation between tumor satellite variables and EMT. Loss of epithelial features contributes to tumor satellite formation, whereas acquisition of the mesenchymal phenotype is beneficial to tumor satellite spreading. The current results indicate the importance of evaluating tumor satellite variables in assessing the EMT of tongue cancer.

Frequency of bilateral cervical metastases in oropharyngeal squamous cell carcinoma: a retrospective analysis of 352 cases after bilateral neck dissection

BACKGROUND

The decision whether to perform an elective neck dissection in patients with head and neck squamous cell carcinoma (HNSCC) and clinically negative lymph nodes (cN0) is made based on the probability of micrometastases in the neck for the given subsite and size of the primary. To date there is limited information about contralateral and bilateral cervical lymph node metastases of oropharyngeal carcinoma.

METHODS

A retrospective chart review was performed of 352 patients with oropharyngeal SCC who received a bilateral neck dissection. The frequency of histologically unveiled bilateral neck metastases was determined.

RESULTS

Carcinomas of the tonsillar fossa starting with a T2 classification and carcinomas of the soft palate, base of tongue, and pharyngeal wall at any stage showed a high frequency of bilateral metastases.

CONCLUSIONS

Bilateral neck dissection should be recommended for all but T1 and selected cases of T2 carcinomas of the tonsillar fossa.

Significance of galectins-1, -3, -4 and -7 in the progression of squamous cell carcinoma of the tongue

The aim of this study was to analyze the immunohistochemical expression of galectins-1, -3, -4, and -7 in 65 cases of squamous cell carcinoma of the tongue and to correlate this expression with clinical (disease outcome, metastasis, and clinical stage) and morphological parameters (histological grade of malignancy). Clinical data were obtained from the patient records. The histological grading system of malignancy proposed by Bryne (1998) [9] was used for the analysis of morphological parameters. The results were analyzed statistically by χ(2) test (p < 0.05). Galectin-1 expression was observed in 87.7% of cases and was significantly correlated with metastasis (p = 0.033) and clinical stage (p = 0.016). Immunoexpression of galectin-3 was observed in 87.7% of cases and was correlated with the presence of metastasis (p = 0.033) and histological grade of malignancy (p = 0.031). Galectin-4 showed no significant correlation with any of the parameters studied. Expression of galectin-7 was observed in 73.8% of cases and was significantly correlated with the histological grade of malignancy (p = 0.005). In conclusion, the intense immunoexpression of galectins-1, -3, and -7 suggests the participation of these proteins in oral carcinogenesis and their use as markers of biological behavior and tumor progression in squamous cell carcinoma of the tongue.

Overexpression of CRKII increases migration and invasive potential in oral squamous cell carcinoma

CT10 regulator of kinase (CRK) was originally identified as an oncogene product of v-CRK in a CT10 chicken retrovirus system. Overexpression of CRKII has been reported in several human cancers. CRKII regulates cell migration, morphogenesis, invasion, phagocytosis, and survival; however, the underlying mechanisms are not well understood. In the present study, we evaluated the possibility of CRKII as an appropriate molecular target for cancer gene therapy. The expression of CRKII in 71 primary oral squamous cell carcinomas and 10 normal oral mucosal specimens was determined immunohistochemically, and the correlation of CRKII overexpression with clinicopathological factors was evaluated. Overexpression of CRKII was detected in 41 of 70 oral squamous cell carcinomas, the frequency being more significant than in normal oral mucosa. In addition, CRKII overexpression was more frequent in higher-grade cancers according to the T classification, N classification, and invasive pattern. Moreover, RNAi-mediated suppression of CRKII expression reduced the migration and invasion potential of an oral squamous cell carcinoma cell line, OSC20. Downregulation of CRKII expression also reduced the expression of Dock180, p130Cas, and Rac1, and the actin-associated scaffolding protein cortactin. These results indicate that the overexpression of CRKII is tightly associated with an aggressive phenotype of oral squamous cell carcinoma. Therefore, we propose that CRKII could be a potential molecular target of gene therapy by RNAi-targeting in oral squamous cell carcinoma.

Overexpression of cortactin increases invasion potential in oral squamous cell carcinoma

Cortactin, an F-actin binding protein, stabilizes F-actin networks and promotes actin polymerization by activating the Arp2/3 complex. Overexpression of cortactin has been reported in several human cancers. Cortactin stimulates cell migration, invasion, and experimental metastasis. However, the underlying mechanism is not still understood. In the present study, we therefore evaluated the possibility that cortactin could be appropriate as a molecular target for cancer gene therapy. In 70 primary oral squamous cell carcinomas and 10 normal oral mucosal specimens, cortactin expression was evaluated by immunological analyses, and the correlations of the overexpression of cortactin with clinicopathologic factors were evaluated. Overexpression of cortactin was detected in 32 of 70 oral squamous cell carcinomas; significantly more frequently than in normal oral mucosa. Cortactin overexpression was more frequent in higher grade cancers according to T classification, N classifications, and invasive pattern. Moreover, RNAi-mediated decrease in cortactin expression reduced invasion. Downregulation of cortactin expression increased the expression levels of E-cadherin, β-catenin, and EpCAM. The siRNA of cortactin also reduced PTHrP expression via EGF signaling. These results consistently indicate that the overexpression of cortactin is strongly associated with an aggressive phenotype of oral squamous cell carcinoma. In conclusion, we propose that cortactin could be a potential molecular target of gene therapy by RNAi targeting in oral squamous cell carcinoma.

RNAi-mediated down-regulation of alpha-actinin-4 decreases invasion potential in oral squamous cell carcinoma

alpha-actinin-4, originally identified as an actin-binding protein associated with cell motility, invasion, and metastasis of cancer cells, appears to be overexpressed in various human epithelial carcinomas, including colorectal, breast, esophageal, ovarian, and non-small cell lung carcinomas. The authors evaluated whether alpha-actinin-4 might be appropriate as a molecular target for cancer gene therapy. In 64 primary oral squamous cell carcinomas (OSCCs) and 10 normal oral mucosal specimens, and in seven human OSCC cell lines, alpha-actinin-4 expression was evaluated immunologically and correlations with clinicopathologic factors were examined. Overexpression of alpha-actinin-4 was detected in 38 of 64 oral squamous cell carcinomas (70%); significantly more frequently than in normal oral mucosa. The expression of alpha-actinin-4 was significantly associated with invasion potential defined by the Matrigel invasion assay. Cancer cell lines with higher alpha-actinin-4 expression had greater invasive potential. An RNAi-mediated decrease in alpha-actinin-4 expression reduced the invasion potential. These results indicated that the overexpression of alpha-actinin-4 was associated with an aggressive phenotype of OSCC. The study indicated that alpha-actinin-4 could be a potential molecular target for gene therapy by RNAi targeting for OSCC.

Risk stratification of patients with oral cavity squamous cell carcinoma and contralateral neck recurrence following radical surgery

Clinical outcome of patients with oral cavity squamous cell carcinoma (OSCC) and contralateral neck recurrence (CLNR) remains poor. We sought to identify factors associated with CLNR and incorporate them into a risk stratification scheme. Between January 1996 and June 2006, a total of 913 consecutive OSCC patients treated by radical surgery were investigated. Postoperative adjuvant therapy was performed in the presence of pathological risk factors. The duration of follow-up was at least 24 months in all surviving patients. Outcome measures were the 5-year CLNR and overall survival rates. In the entire study cohort, the 5-year CLNR rate was 7% (55/913). Specifically, it was 18% (17/132) in patients with local recurrence (LR), and 5% (38/781) in those without (P = 0.0002). In multivariate analysis, extracapsular spread (ECS) was the only independent risk factor for CLNR in patients with LR. Tumor subsite, poor differentiation, and presence of pN + disease were significant predictors of CLNR in patients without LR. We identified two groups of patients with high CLNR rates. The first group consisted of patients with ECS at the initial diagnosis and LR. The second group consisted of subjects with tongue cancer without LR harboring at least two risk factors. We conclude that, in patients who achieved local control, postoperative contralateral neck treatment is recommended for subjects with tongue cancer and at least two risk factors. Once LR occurs, contralateral neck treatment is recommended in patients with ECS.