Predicting Radiotherapy Necessity in Tongue Cancer Using Lymph Node Yield

Defining a minimum nodal yield for neck dissection in mucosal head and neck squamous cell carcinoma, a systematic review

BACKGROUND

Analysis of existing literature on lymph node yield (LNY) in neck dissection (ND) for head and neck squamous cell carcinomas (HNSCC) used as a prognostic factor and an indication of treatment adequacy.

METHODS

PubMed, EMBASE and Web of Science databases were systematically searched from January 2010 to June 2023. Inclusion criteria encompassed studies on mucosal HNSCC patients undergoing ND with data on LNY and its association with survival outcomes. The quality assessment followed the REMARK guidelines.

RESULTS

Among 29 included studies, minimum LNY tresholds associated with improved survival outcomes ranged from 10 to 36.5 nodes. The heterogeneity in subsite involvement and cN0/cN + status constituted a challenge in establishing a consensus cutoff. The review highlights the need for standardized surgical techniques and pathological assessments to ensure data comparability.

CONCLUSIONS

LNY is a prognostic indicator and could reflect ND quality in HNSCC.

Radiotherapy for salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for radiotherapy in salivary gland cancer and to specify the modalities and target radiation volumes.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group which drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Postoperatively, radiotherapy to the primary tumor site±to the lymph nodes is indicated if one or more of the following adverse histoprognostic factors are present (risk>10% of locoregional recurrence): T3-T4 category, lymph node invasion, extraglandular invasion, close or positive surgical margins, high tumor grade, perineural invasion, vascular emboli, and/or bone invasion. Intensity-modulated radiation therapy (IMRT) is the gold standard. For unresectable cancers or inoperable patients, carbon ion hadrontherapy may be considered.

CONCLUSION

Radiotherapy in salivary gland cancer is indicated in postoperative situations in case of adverse histoprognostic factors and for inoperable tumors.

Postoperative radiotherapy versus surgery alone in pN1 oral cavity cancer patients: A meta-analysis

Objectives

The aim of this meta-analysis is to evaluate the potential benefits of postoperative radiotherapy (PORT) in patients with pN1 oral cavity squamous cell carcinoma.

Methods

A literature search through major databases was conducted until January 2023. The adjusted hazard ratio (aHR) or risk ratio (RR) with 95% confidence intervals (CIs) of different survival outcomes were extracted and pooled.

Results

Ten studies published between 2005 and 2022, with a pooled patient population of 2888, were included in this meta-analysis. Due to differences in study design and reported outcomes, the studies were categorized into distinct groups. In pN1 patients without extranodal extension (ENE), PORT was associated with a significant improvement in overall survival (OS) (aHR 0.76, 95% CI: 0.61-0.94). In pN1 patients without ENE and positive margins, PORT improved OS (aHR 0.71, 95% CI: 0.56-0.89) and was associated with a lower regional recurrence rate (RR 0.35, 95% CI: 0.15-0.83). However, in pN1 patients without ENE, positive margins, perineural invasion, and lymphovascular invasion, there were no significant differences observed between the PORT and observation groups in either 5-year OS (RR 0.48, 95% CI: 0.07-3.41) or 5-year disease-free survival (RR 0.37, 95% CI: 0.07-2.06).

Conclusions

The current study demonstrated that PORT has the potential to improve OS in pN1 disease. However, the decision of whether to administer PORT still hinges on diverse clinical scenarios, and additional research is necessary to furnish a more conclusive resolution.

Level of Evidence

2.

Oncologic outcome with versus without target volume compartmentalization in postoperative radiotherapy for oral cavity squamous cell carcinoma

Background and purpose

The volume treated with postoperative radiation therapy (PORT) in patients with oral cavity squamous cell carcinoma (OCSCC) is a mediator of toxicity affecting quality of life. Current guidelines only allow for very limited reduction of PORT volumes. This study investigated the safety and efficacy of de-intensified PORT for patients with OCSCC by refined compartmentalization of the treatment volume.

Materials and methods

This retrospective cohort study identified 103 OCSCC patients treated surgically from 2014 to 2019 with a loco-regional risk profile qualifying for PORT according to guidelines. PORT was administered only to the at-risk compartment and according to a refined compartmentalization concept (CC). Oncological outcome of this CC cohort was compared to a historical cohort (HC) of 98 patients treated before the CC was implemented.

Results

Median follow-up time was 4.5 and 4.8 years in the CC and HC cohorts, respectively. In the CC cohort, a total of 72 of 103 patients (70%) had a pathological risk profile that allowed for further compartmentalization and, hence, received a reduced treatment volume or omission of PORT altogether. Loco-regional control at 3 and 5 years was 77% and 73% in the CC cohort versus 78% and 73% in the HC (p = 0.93), progression-free survival was 72% and 64% versus75% and 68% (p = 0.58), respectively. Similarly, no statistically significant difference was seen in other outcome measures.

Conclusions

De-intensified PORT limiting the treatment volume to the at-risk compartment or avoiding PORT altogether for low-risk patients with OCSCC does not seem to compromise disease control in this retrospective comparison. Based on these hypothesis-generating findings, a prospective study is being planned.

Isoprenylcysteine carboxyl methyltransferase promotes the progression of tongue squamous cell carcinoma via the K-Ras and RhoA signaling pathways

OBJECTIVE

This research investigated the biological role of isoprenylcysteine carboxyl methyltransferase (ICMT) in tongue squamous cell carcinoma (TSCC) progression meanwhile to explore the conceivable mechanism.

METHODS

The mRNA and protein expression were measured using real-time PCR and Western blot. Cell proliferation, apoptosis, cycle distribution, migration and invasion were evaluated by CCK-8 assay, flow cytometry, wound-healing assay and transwell assay. The anti-tumor activity of ICMT silencing was observed in nude mice.

RESULTS

Our results indicated that silencing of ICMT-mediated methylation effectively inhibited TSCC cells proliferation in vitro and reduced tumor growth in vivo. Moreover, ICMT knockdown also induced cell apoptosis and cell cycle arrest of both CAL-27 and SCC-4 cells. In addition, CAL-27 and SCC-4 cells migration and invasion were weakened by ICMT siRNA. Mechanistically, ICMT deficiency significantly decreased the K-Ras and RhoA membrane targeting localization, leading to the suppression of K-Ras- and RhoA-mediated downstream signaling in CAL-27 and SCC-4 cells.

CONCLUSIONS

Altogether, our findings identified a crucial role played by ICMT in the progression of TSCC and the potential mechanisms by which exerted its effects, indicating that targeting ICMT may represent a promising therapeutic strategy for TSCC.

Effect of RhoE expression on the migration and invasion of tongue squamous cell carcinoma

OBJECTIVES

This study aims to investigate the effect of RhoE expression on the migration and invasion of tongue squamous cell carcinoma (TSCC).

METHODS

Forty-eight TSCC cases were selected from the Maxillofacial Surgery Center of Qingdao Municipal Hospital from 2017 to 2019. The expression of RhoE in the specimens (TSCC and adjacent tissues) was detected by immunohistochemistry, and RhoE mRNA and protein were extracted to further detect the expression of RhoE. SCC-4 and CAL-27 cells were selected for in vitro experiments. Transient transfection was used to overexpress RhoE. Real-time fluorescence quantitative PCR (qRT-PCR) and Western blot analyses were conducted to detect the overexpression efficiency. Scratch test and Transwell cell invasion tests were used to detect the migration and invasion ability of TSCC, respectively. The expression levels of Rho-associated coiled-coil-containing protein kinase 1 (ROCK1), matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-9 (MMP-9) were detected by Western blot. Experimental data were analyzed by Graphpad prism 8.2.1 software.

RESULTS

The expression level of RhoE in TSCC was significantly lower than that in adjacent tissues (P<0.05). The migration and invasion abilities of TSCC were significantly lower than those in the control group (P<0.05). The Western blot showed significantly lower expression levels of ROCK1, MMP-2, and MMP-9 in the experimental group than in the control group (P<0.05).

CONCLUSIONS

RhoE expression is low in TSCC. Over expression RhoE in TSCC can significantly decrease its migration and invasion abilities. Hence, RhoE may play an important role in regulating the metastasis and invasion of TSCC and provide a new target for gene therapy.

The role of postoperative radiotherapy in pN1 oral cavity cancer without extranodal extension

Background

The administration of postoperative radiotherapy remains controversial in pN1 oral cavity cancer patients without extranodal extension. The aim is to determine whether postoperative radiotherapy reduces the neck recurrence rate and improves the survival outcomes of pN1 patients.

Methods

This study consecutively enrolled 1056 patients with newly diagnosed oral squamous cell carcinoma who underwent tumor wide excision and neck dissection from September 2002 to November 2019. One hundred two pN1 patients without extranodal extension were eligible for analysis. Then, a subgroup analysis of 40 patients was performed after patients with other adverse risk factors (positive margins, close margins, lymphovascular invasion, perineural invasion, tumor depth ≥ 10 mm, and poor histological differentiation) were excluded.

Results

Of the 102 eligible pN1 patients, 26 patients received surgery alone, and 76 received postoperative radiotherapy. No significant differences were observed in the neck recurrence rate (7.7% vs. 15.8%, p = 0.30). Similarly, in patients without other adverse risk factors, no significant differences were observed in the neck recurrence rate (5% vs. 20%, p = 0.15) between surgery alone group and postoperative radiotherapy group. Moreover, no significant difference was found in the neck recurrence-free survival rate, overall survival, and disease-specific survival (77.1% vs. 52.5%, p = 0.42, 83.5% vs. 64.5%, p = 0.81, and 88.2% vs. 67.9%, p = 0.34, respectively).

Conclusion

Postoperative radiotherapy did not significantly decrease the probability of neck recurrence and survival outcomes in pN1 patients without extranodal extension. Radical surgery alone may be considered sufficient treatment for pN1 patients without other adverse risk factors.

High-risk early-stage oral tongue squamous cell carcinoma, when free margins are not enough: Critical review

Oral tongue squamous cell carcinoma (OTSCC) is a quite peculiar disease from an anatomical and biological standpoint. An increasing amount of literature highlights the existence of a small subset of T1-T2N0 OTSCC, properly resected on a margin-dependent basis, which conversely proved higher than expected rates of loco-regional/distant failure and disease-specific mortality. These specific high-risk tumors might not have a margin-dependent disease and could possibly benefit from a more aggressive upfront loco-regional treatment, especially addressing the so-called T-N tract. Widespread adoption of a histopathological risk model would allow early recognition of these high-risk diseases and, consequently, intensification of the traditional treatment strategies in that specific niche. We reviewed the available knowledge trying to shed light on the potential determinants of the dismal prognosis of these high-risk OTSCC, with special reference to the role of overlooked T-N tract involvement and possible alternatives in terms of elective neck management and risk stratification.

Effects of isoprenylcysteine carboxyl methyltransferase silencing on the proliferation and apoptosis of tongue squamous cell carcinoma

OBJECTIVES

This study aimed to explore the effects of silencing isoprenylcysteine carboxyl methyltransfe-rase (Icmt) through small interfering RNA (siRNA) interference on the proliferation and apoptosis of tongue squamous cell carcinoma (TSCC).

METHODS

Three siRNA were designed and constructed for the Icmt gene sequence and were then transfected into TSCC cells CAL-27 and SCC-4 to silence Icmt expression. The tested cells were divided as follows: RNA interference groups Icmt-siRNA-1, Icmt-siRNA-2, and Icmt-siRNA-3, negative control group, and blank control group. The transfection efficiency of siRNA was detected by the fluorescent group Cy3-labeled siRNA, and the expression of Icmt mRNA was screened by quantitive real-time polymerase chain reaction (qRT-PCR) selected the experimental group for subsequent experiments. The expression of Icmt, RhoA, Cyclin D1, p21, extracellular regulated protein kinases (ERK), and phospho-extracellular regulated protein kinases (p-ERK) were analyzed by Western blot. The proliferation abilities of TSCC cells were determined by cell counting kit-8 assay. The change in apoptosis was detected by AnnexinV-APC/propidium staining (PI) assay. Cell-cycle analysis was conducted by flow cytometry.

RESULTS

The expression of Icmt mRNA and protein in TSCC cells significantly decreased after Icmt-siRNA transfection (P<0.05). No significant difference in RhoA mRNA and protein expression was detected (P>0.05), but the expression of RhoA membrane protein decreased compared with the negative control group and blank control groups (P<0.05). Cyclin D1 expression decreased, whereas p21 expression significantly increased and the relative expression of ERK protein in the experimental group did not significantly different that in the control group (P>0.05). However, the phosphorylation level of ERK was significantly reduced (P<0.05). The cell cycles of TSCC CAL-27 and SCC-4 were altered in G1/S, cell proliferation activity was inhibited, and apoptosis was induced (P<0.05).

CONCLUSIONS

Silencing Icmt can effectively downregulate its expression in TSCC cells, reduce the RhoA membrane targeting localization and cell proliferation, and induce apoptosis. Thus, Icmt may be a potential gene therapy target for TSCC.

Lymph node yield in treatment naïve cases of head and neck squamous cell carcinoma: en bloc lymphadenectomy versus level-by-level dissection

BACKGROUND

Lymph node yield is an important prognostic factor in head and neck squamous cell carcinoma. Variability in neck dissection sampling techniques has not been studied as a determinant of lymph node yield.

METHODS

This retrospective study used lymph node yield and average nodes per level to compare level-by-level and en bloc neck dissection sampling methods, in primary head and neck squamous cell carcinoma cases operated between March 2017 and February 2020.

RESULTS

From 123 patients, 182 neck dissections were analysed, of which 133 were selective and the rest were comprehensive: 55 had level-by-level sampling and 127 had undergone en bloc dissection. The level-by-level method yielded more nodes in all neck dissections combined (20 vs 17; p = 0.097), but the difference was significant only for the subcohort of selective neck dissection (18.5 vs 15; p = 0.011). However, the gain in average nodes per level achieved by level-by-level sampling was significant in both groups (4.2 vs 3.33 and 4.4 vs 3, respectively; both p < 0.001).

CONCLUSION

Sampling of cervical lymph nodes level-by-level yields more nodes than the en bloc technique. Further studies could verify whether neck dissection sampling technique has any impact on survival rates.

Knockdown of ectodysplasin-A receptor-associated adaptor protein exerts a tumor-suppressive effect in tongue squamous cell carcinoma cells

Tongue squamous cell carcinoma (TSCC) is a common malignancy in oral cancer with a high mortality and morbidity. The ectodysplasin-A receptor-associated adaptor protein (EDARADD) is a death domain-containing adaptor protein that interacts with the TNF family ligand ectodysplasin A receptor. It is known that EDARADD has an effect on the development of ectodermal derivative tissues, such as hair and teeth. EDARADD expression is also associated with the development of melanoma. However, the role of EDARADD in TSCC remains unknown. The aim of the present investigation was to explore whether EDARADD plays a role in the biological function of TSCC. Immunohistochemistry was used to measure the expression of EDARADD in TSCC tissues and adjacent normal tissue. EDARADD was knocked down in a TSCC cell line in vitro using a specific lentivirus. The expression level of the EDARADD gene and the efficacy of gene knockdown were evaluated by reverse transcription-quantitative PCR, while EDARADD protein expression and the expression levels of Bcl-2, MYC and NF-κBp65 were determined by western blotting. Additionally, MTT assays, colony formation assays and apoptosis assays were carried out to examine the effect of EDARADD knockdown on the TSCC cells. A previous study showed that the majority of the TSCC tissues that were tested had high EDARADD expression. The expression of EDARADD both at mRNA and protein levels was significantly lower (P<0.01) after the gene was knocked down in the CAL27 cells compared with the level in control cells. Downregulation of EDARADD expression inhibited colony formation and proliferation and induced apoptosis of CAL27 cells when compared to control cells (P<0.01). Taken together, these results suggested that EDARADD may be actively involved in the progression of TSCC and that EDARADD may be a novel therapeutic target for the treatment of TSCC.

High expression of TMEM40 contributes to progressive features of tongue squamous cell carcinoma

Transmembrane protein 40 (TMEM40) is a 23-kDa protein and its association with tongue squamous cell carcinoma (TSCC) remains unclear. This study aimed to investigate the expression and clinical significance of TMEM40 in TSCC and its roles in TSCC cells. Immunohistochemical analysis was performed to detect the expression levels of TMEM40 in 60 tongue tissue samples. Furthermore, TMEM40 was overexpressed and inhibited in two TSCC cell lines by transfection with pEZ-M98-TMEM40 plasmid or TMEM40 small interfering RNA, respectively. Cell Counting Kit-8 and colony formation assays were used to investigate the effects of TMEM40 on cell proliferation and colony formation ability, respectively. Flow cytometry was performed to determine cell apoptosis and cycle conditions of transfected cells. Wound-healing and Transwell assays were processed to explore the effects of TMEM40 on cell migration and invasion, respectively. The results indicated that TMEM40 expression levels were significantly increased in TSCC tissues compared with adjacent normal tongue tissues (P<0.01). Clinicopathological analysis revealed that TMEM40 expression was positively correlated with pathological TNM (pTNM) status (P<0.05), histological grade (P<0.001) and clinical stage (P<0.01), but not with sex or age. Results of cell proliferation, apoptosis, migration and invasion assays indicated that when TMEM40 had been successfully overexpressed or knocked down in CAL27 and SCC9 TSCC cell lines, cell growth and invasion increased in the TMEM40 overexpressing cells, while they decreased in TMEM40-knockdown cells. Furthermore, experiments revealed that TMEM40 knockdown resulted in increased levels of p53 and Bax, and decreased levels of MMP-9, which indicated that TMEM40 regulated cell apoptosis and migration via involvement of p53, Bax and MMP-9 in TSCC cells. Our findings indicated that increased expression of TMEM40 contributed to progressive features of TSCC via regulation of p53, Bax and MMP-9.

Lymph node ratio is associated with adverse clinicopathological features and is a crucial nodal parameter for oral and oropharyngeal cancer

The lymph node ratio(LNR) has been described as a novel predictor of the survival of patients with oral and oropharyngeal squamous cell carcinoma(O/OPSCC). The purpose of this study was to evaluate whether LNR is better at predicting survival and the need for adjuvant treatment than traditional tumour-nodal-metastasis(TNM) staging. Eight hundred nine patients with O/OPSCC and positive lymph node disease were retrospectively enrolled in this study. LNR equal to 0.075 is the best cut-off value for stratifying 5-year disease-free survival(DFS). High LNR is closely associated with more advanced T stage, higher N stage, more severe pathological grade, the presence of diffuse infiltration and extracapsular spread(ECS). LNR is better for evaluating prognosis than the pathological N stage. Patients with high LNR coupled with high number of positive lymph nodes who received adjuvant concurrent chemo-radiotherapy(CCRT) had a better 5-year DFS than patients who received surgery alone. Multivariate analyses revealed that T stage, ECS and LNR are independent prognostic factors of 5-year DFS and disease-specific survival(DSS). Therefore, high LNR is closely correlated with adverse parameters that markedly hinder prognosis. LNR is superior to traditional TNM staging for the evaluation of prognosis,and the combination of the LNR with the number of positive lymph nodes can predict the benefits of adjuvant CCRT.