An update on the latest evidence for managing the clinically negative neck (cN0) in oral squamous cell carcinoma

Predictors of Occult Metastasis and Prognostic Factors in Patients with cN0 Oral Cancer Who Underwent Elective Neck Dissection

Elective neck dissection (END) is recommended for the management of patients with oral squamous cell carcinoma (OSCC) because of the risk of occult metastasis (OM). We hypothesized that some factors predict poor prognosis regardless of a cN0 END. This study aimed to investigate the predictors of OM and prognostic factors in patients with cN0 OSCC who underwent supraomohyoid neck dissection (SOHND). A retrospective cohort study design was created and implemented. The primary predictive variables in this study were OM and risk factors for poor prognosis after SOHND. A Cox proportional hazard model was used to adjust for the effects of potential confounders on the risk factors for poor prognoses. Among 86 patients with OSCC, OMs were observed in 9 (10.5%). The neutrophil-to-lymphocyte ratio (NLR) and vascular invasion are good markers for detecting OM. A Cox multivariable analysis identified two independent predictors of overall survival: pathologic node (pN) and laterality of END. An independent predictive factor for disease-free survival, the surgical margin, was also identified in this study. According to the pN classification, pN1 patients had a worse survival rate than pN2 patients. Therefore, in the case of pN1, regardless of being cN0, additional adjuvant therapy may be necessary.

The Applications and Potential Developments of Ultrasound in Oral Cancer Management

Oral cancer is endemic and causes a great burden in Southern Asia. It is preferably treated by surgery with/without adjuvant radiotherapy (RT) or chemoradiation therapy, depending on the stage of the disease. Close or positive resection margin and cervical lymph node (LN) metastasis are important prognostic factors that have been presented to be related to undesirable locoregional recurrence and poor survival. Ultrasound (US) is a simple, noninvasive, time-saving, and inexpensive diagnostic modality. It can depict soft tissues very clearly without the risk of radiation exposure. Additionally, it is real-time and continuous image is demonstrated during the exam. Furthermore, the clinician can perform US-guided fine needle aspiration (FNA) or core needle biopsy (CNB) at the same time. US with/without US-guided FNA/CNB is reported to be of value in determining tumor thickness (TT), depth of invasion (DOI), and cervical LN metastasis, and in aiding the staging of oral cancer. DOI has a relevant prognostic value as reported in the eighth edition of the American Joint Committee on Cancer staging of oral cancer. In the present review, we describe the clinical applications of US in oral cancer management in different phases and potential applications in the future. In the pretreatment and surgical phase, US can be used to evaluate TT/DOI and surgical margins of oral cancer in vivo and ex vivo. The prediction of a malignant cervical LN (nodal metastasis) by the US-based prediction model can guide the necessity of FNA/CNB and elective neck dissection in clinical early-stage oral cancer. In the posttreatment surveillance phase, US with/without US-guided FNA or CNB is helpful in the detection of nodal persistence or LN recurrence, and can assess the possibility and extent of carotid artery stenosis after irradiation therapy. Both US elastography and US swallowing assessment are potentially helpful to the management of oral cancer.

Comparison of the value of ultrasound and enhanced magnetic resonance imaging in judging cervical lymph node metastasis in patients with oral cancer

BACKGROUND

Oral cancer is the twelfth largest malignant tumor in the world. Oral cancer is prone to lymph node metastasis in the early stages of the disease, and lymph node metastasis will directly affect the treatment and survival rate. Therefore, whether the lymph node metastasis can be accurately evaluated is of great significance to the treatment and prognosis of patients.

OBJECTIVE

The diagnostic efficacy of three methods of preoperative ultrasound, enhanced magnetic resonance (enhanced MR), and ultrasound combined with enhanced MR on cervical lymph node metastasis of oral cancer were compared.

MATERIALS AND METHODS

A retrospective analysis of 399 cases of oral cancer completed by head and neck surgery at Cancer Center of Sun Yat-sen University, China. In all cases, the maxillofacial and neck enhanced MR and cervical lymph node ultrasound examinations were performed before surgery, and imaging diagnosis was made for cervical lymph node metastasis and compared with pathology. All judgment results were statistically processed using the chi-square test.

RESULTS

Compared with the above three methods, the diagnostic efficiency of ultrasound alone is better, and the diagnostic efficiency of enhanced MR combined ultrasound is not significantly better than that of ultrasound alone. There are differences in the diagnostic efficacy of the three inspection methods in different clinical sub-periods, all of which are better for the diagnosis of stage I. For patients with stage I, II, and III, there were no differences between the three examination methods. However, for stage IV patients,the diagnostic efficiency of ultrasound alone is better. For patients with stage N0, there was no difference in diagnostic efficacy between the three methods. For the assessment of lymph nodes in the I-III region, there are differences between the three methods of examination: the diagnostic efficiency of ultrasound alone is better, and enhanced MR combined ultrasound is not significantly better than ultrasound alone. For the evaluation of lymph nodes in the IV-VII region, there was no difference in diagnostic efficacy between the three methods.

CONCLUSION

According to the clinical characteristics and prognosis of patients with oral cancer, although enhanced MR can better evaluate the tumor, ultrasound may be considered as the preferred imaging method for cervical lymph node metastasis.

SIGNIFICANCE

Accurate assessment and proper and timely treatment of lymph node metastasis can help improve the survival rate of patients.

Accurately Locating Metastatic Foci in Lymph Nodes With Lugol's Iodine-Enhanced Micro-CT Imaging

Background

Accurate evaluation of lymph node (LN) status is the key factor to determine the treatment and evaluate prognosis for patients with cancer. However, traditional pathological examination resulted in a 30% false-negative rate of detection of metastases in LNs. This study aimed to utilize Lugol's iodine (I₂-IK)-enhanced micro-CT imaging to reveal the 3-dimensional structure of regional LNs and decrease the false-negative rate in pathological examination.

Methods

To explore the feasibility of I₂-IK-enhanced micro-CT imaging in locating metastatic lesion in LNs, nonmetastatic and metastatic LNs from mice were used to mimic the imaging process. Then, the LNs from oral squamous cell carcinoma (OSCC) patients were applied to verify the value of I₂-IK-enhanced micro-CT imaging in revealing LN structure and locating metastatic lesions in LNs. The glycogen content in nonmetastatic and metastatic LNs was further detected by the use of a glycogen assay kit and periodic acid-Schiff (PAS) staining to explain the imaging differences between them.

Results

In nude mice, 0.5% I₂-IK staining for 4 h was the best parameter for normal LN. The metastatic foci in metastatic LNs were also clearly outlined in this condition. For nonmetastatic LNs from patients with OSCC, 1% I₂-IK staining for 12 h was the best parameter. However, due to the increased volume of metastatic LNs, the image effect of 3% I₂-IK staining for 12 h was superior to 1% I₂-IK staining [tumor background ratio (TBR), 3% vs. 1%, 1.89 ± 0.10 vs. 1.27 ± 0.07, p < 0.001]. Compared with subsequent pathological sections, we found the CT intensity of metastatic foci in LNs and muscle tissues was significantly higher than in nonmetastatic regions. Meanwhile, the glycogen content of metastatic foci in LNs detected was also significantly higher than in nonmetastatic region.

Conclusions

I₂-IK-enhanced micro-CT imaging could identify the spatial location of metastatic foci in LNs. This will be an effective method to assist in decreasing the LN false-negative rate for cancer pathology.

Research on neck dissection for oral squamous-cell carcinoma: a bibliometric analysis

Neck dissection for oral squamous-cell carcinoma (OSCC) is a clinically controversial issue and has therefore been the subject of abundant research. However, no one has performed a bibliometric study on this topic to date. The aim of this study was to assess the development of research on neck dissection for OSCC in terms of the historical evolution, current hotspots and future directions, particularly including research trends and frontiers from 2010 to 2019. Literature records related to research on neck dissection for OSCC were retrieved from the Web of Science Core Collection (WoSCC). CiteSpace was used as a tool to perform a bibliometric analysis of this topic. The survey included 2 096 papers. “Otorhinolaryngology” was the most popular research area. The most active institutions and countries were Memorial Sloan Kettering Cancer Center and the USA, respectively. Shah J.P. was the most cited author. Among the six identified “core journals”, Head & Neck ranked first. The top three trending keywords were ‘invasion’, ‘upper aerodigestive’ and ‘negative neck’. ‘D’Cruz AK (2015)’ was the most cited and the strongest burst reference in the last decade. The study evaluated the effect on survival of elective versus therapeutic neck dissection in patients with lateralized early-stage OSCC. The depth of invasion and the management of N0 OSCC were research frontiers in this field. The present study provides a comprehensive bibliometric analysis of research on neck dissection for OSCC, which will assist investigators in exploring potential research directions.

Prognostic value and therapeutic implications of nodal involvement in head and neck mucosal melanoma

BACKGROUND

The prognostic significance of nodal involvement is not well established in head and neck mucosal melanoma (HNMM).

METHODS

A retrospective, monocentric study was performed on 96 patients with HNMM treated between 2000 and 2017.

RESULTS

At diagnosis, seventeen patients (17.8%) were cN1, with a higher risk for HNMM arising from the oral cavity (p = 0.01). cN status had no prognostic value in patients with nonmetastatic resectable HNMM. No occult nodal metastasis was observed in the cN0 patients after a nodal dissection (ND). The nodal recurrence rate was similar in the cN1 and the cN0 patients. No isolated nodal recurrences were noted. Among the patients who underwent a ND, no benefit of this procedure was noted.

CONCLUSIONS

cN1 status is not a prognostic factor in patients with resectable HNMM. Elective ND should not be systematically performed in cN0 HNMM.

Comparative study on the diagnostic value of intravenous/peritumoral injection of indocyanine green for metastatic lymph node location in patients with head and neck squamous cell carcinoma (HNSCC)

Background

Accurate assessment of regional lymph node (LN) status is essential for the treatment of head and neck squamous cell carcinoma (HNSCC) patients. In this study, we aimed to compare the difference between intravenous injection of indocyanine green (ICG) and peritumoral injection of ICG in the location of metastatic LNs.

Methods

Twenty-nine patients were enrolled in this study with 13 patients receiving intravenous injection of ICG and 16 patients receiving peritumoral injection of ICG. During the surgery, the fluorescence-positive LNs in vivo were sent to undergo frozen section after fluorescence intensity was recorded. After the cervical LN dissection, all LNs were sorted by region, and the fluorescence intensity was recorded before the LNs were sent for paraffin section.

Results

During the surgery, both intravenous or peritumoral injections with near-infrared (NIR) fluorescence imaging of ICG had their respective pros and cons in vivo, with the sensitivity and specificity being 62.5%/75% and 98.1%/89.1% respectively. After the surgery, both methods could reduce the pathological workload by preselecting the LNs at-risk in the premise of accurate assessing the cervical LN stage. However, intravenous ICG administration was more valuable in determining all types of LN status according to the fluorescence intensity [area under the curve (AUC): 0.91 vs. 0.78, P<0.001].

Conclusions

With the assistance of NIR fluorescence imaging using ICG, both administration methods could reduce the postoperative complication and the pathological workload, whereas the intravenous mode of ICG administration is superior in application value.

Prediction of lymph node metastasis in oral squamous cell carcinoma based on protein profile

OBJECTIVE

Lymph node metastasis leads to high mortality rates of oral squamous cell carcinoma (OSCC). However, it is still controversial to define clinically negative neck (cN0) and positive neck (cN1-3).

METHODS

We retrieved candidate biomarkers identified by proteomic analysis in OSCC from published works of literature. In training stage, immunohistochemistry (IHC) analysis was used to determine the expression of proteins and logistic regression models with stepwise variable selection were used to identify potential factors that might affect lymph node metastasis and life status. Furthermore, the prediction model was validated in validating stage.

RESULTS

We screened eight highly expressed proteins related to lymph node metastasis in OSCC and found that the expression levels of SOD2, BST2, CAD, ITGB6, and PRDX4 were significantly elevated in patients with lymph node metastasis compared to the patients without lymph node metastasis. Furthermore, in training and validating stages, the prediction model base on the combination of CAD, SOD2 expression levels, and histopathologic grade was developed and validated in patients with OSCC.

CONCLUSIONS

Our findings showed that the developed model well predicts the lymph node metastasis and life status in patients with OSCC, independent of TNM stage.

Ultrasonography of Cervical Lymph Nodes

Ultrasonography is an excellent method for imaging evaluation of cervical lymph nodes. This article provides an image-rich review of the sonographic manifestations of diseases involving the cervical lymph nodes, with an emphasis on the expected anatomic distribution of diseases.

A model to predict nodal metastasis in patients with oral squamous cell carcinoma

Difficulty in precise decision making on necessity of surgery is a major problem when managing oral squamous cell carcinomas (OSCCs) with clinically negative neck. Therefore, use of clinical and histopathological parameters in combination would be important to improve patient management. The main objective is to develop a model that predicts the presence of nodal metastasis in patients with OSCC.623 patients faced neck dissections with buccal mucosal or tongue squamous cell carcinoma (SCC) were selected from patients’ records. Demographic data, clinical information, nodal status, Depth of invasion (DOI) and pattern of invasion (POI) were recorded. The parameters which showed a significant association with nodal metastasis were used to develop a multivariable predictive model (PM). Univariate logistic regression was used to estimate the strengths of those associations in terms of odds ratios (OR). This showed statistically significant associations between status of the nodal metastasis and each of the following 4 histopathological parameters individually: size of the tumour (T), site, POI, and DOI. Specifically, OR of nodal metastasis for tongue cancers relative to buccal mucosal cancers was 1.89, P-value < 0.001. Similarly, ORs for POI type 3 and 4 relative to type 2 were 1.99 and 5.83 respectively. A similar relationship was found with tumour size; ORs for T2, T3, and T4 compared to T1 were 2.79, 8.27 and 8.75 respectively. These four histopathological parameters were then used to develop a predictive model for nodal metastasis. This model showed that probability of nodal metastasis is higher among tongue cancers with increasing POI, with increasing T, and with larger depths while other characteristics remained unchanged. The proposed model provides a way of using combinations of histopathological parameters to identify patients with higher risks of nodal metastasis for surgical management.

Diagnostic accuracy of contrast-enhanced computed tomography for assessment of mandibular and medial retropharyngeal lymph node metastasis in dogs with oral and nasal cancer

The diagnostic accuracy of contrast-enhanced CT for detection of cervical lymph node metastasis in dogs is unknown. The purpose of this retrospective, observational, diagnostic accuracy study was to assess the efficacy of CT for detection of mandibular and medial retropharyngeal lymph node metastasis in dogs. Histopathology of dogs with cancer of the head, CT and bilateral mandibular and medial retropharyngeal lymphadenectomy was reviewed. A single radiologist measured lymph nodes to derive short axis width and long-short axis ratios. Two blinded radiologists separately assessed lymph node margins, attenuation and contrast enhancement and each provided a final subjective interpretation of each node site as benign or neoplastic. Where radiologists' opinions differed, a consensus was reached. Sensitivity, specificity and accuracy were calculated for mandibular and medial retropharyngeal sites. Agreement between radiologists was assessed. Fisher's exact test and the Kruskal-Wallis H-test were used to assess associations between variables. Forty-one primary tumours were recorded in 40 dogs. Metastasis to mandibular or retropharyngeal lymph nodes occurred in 16 out of 40 dogs (43/160 nodes). Agreement between radiologists was almost perfect for margination, attenuation and enhancement, strong for interpretation of mandibular lymph node metastasis, and weak for interpretation of medial retropharyngeal lymph node metastasis. Sensitivity of CT was 12.5% and 10.5%, specificity was 91.1% and 96.7%, and accuracy was 67.5% and 76.3% for mandibular and medial retropharyngeal lymph nodes respectively. No individual CT findings were predictive of nodal metastasis. Given the low sensitivity of CT, this modality cannot be relied upon alone for assessment of cervical lymph node metastasis in dogs.

Efficacy of postoperative neck irradiation for regional control in patients with pN0 oral tongue cancer: Propensity analysis

BACKGROUND

The purpose of this study was to investigate whether adjuvant radiotherapy (RT) is efficacious for regional control and survival in patients with pN0 oral tongue cancer.

METHODS

Clinicopathological features of 166 patients with pN0 oral tongue cancer were compared between those who underwent adjuvant RT to the neck (neck RT-positive) and those who did not (neck RT-negative). Study endpoints were isolated regional recurrence and 3-year regional recurrence-free survival (RRFS). Propensity score matching was also performed.

RESULTS

Cox regression analysis did not reveal any significant predictor of isolated regional recurrence, including RT field. Three-year RRFS showed modest improvement in neck RT-positive group compared to neck RT-negative group before (92.2% vs 91.9%) and after propensity analysis (93.8% vs 83.3%), without statistical significance (log-rank P = .85 and .37, respectively).

CONCLUSION

Despite more frequent unfavorable factors, the neck RT-positive group had a comparable oncologic outcome to the neck RT-negative group, suggesting that a marginal benefit in regional control might be expected from extending the RT field to the neck for pN0 oral tongue cancer.