Depth of Invasion as a Predictor of Cervical Nodal Metastasis of Oral Tongue Squamous Cell Carcinoma: Findings From a Tertiary Care Center in Pakistan

Pathological Risk Factors for Occult Nodal Metastasis in Early-Stage Squamous Cell Carcinoma of the Oral Cavity

Occult neck metastasis is the presence of metastasis in the cervical lymph nodes that cannot be radiologically or clinically identified. Presence of metastasis in any neck node can have a significant impact on overall survival of patients with oral squamous cell carcinoma (OSCC). Our aim was to analyze the correlation of various histopathological parameters with occult nodal metastasis in early-stage OSCC and to obtain an optimal DOI cut-off value for predicting its increased risk. We conducted a retrospective study on patients who reported to our institute with clinical stage I and II OSCC. The patients having well-differentiated and moderately differentiated OSCC were included. Association of various histopathological parameters with occult nodal metastasis was assessed using statistical analysis. A total of 102 patients of early-stage well-differentiated and moderately differentiated OSCC with clinically negative necks who underwent elective neck dissection at our institute from the year 2018 to 2023 were enrolled in the study. Depth of invasion (DOI), perineural invasion (PNI), worst pattern of invasion (WPOI), and grade of tumor differentiation were the histopathological parameters entered into the univariate regression analysis as predictive variables, and they were found to be predictors of occult nodal metastasis. An optimal DOI cut-off value of 5.5 mm was obtained for predicting the increase in the risk of occult nodal metastasis. DOI, PNI, WPOI, and grade of tumor differentiation are predictors of occult nodal metastasis. There is a need for searching methods for preoperative and intraoperative detection of all these histopathological factors so that unnecessary elective neck treatment can be avoided.

Prediction of nodal disease in oral squamous cell carcinoma of the tongue: histopathological risk assessment with the focus on depth of invasion

OBJECTIVE

Cervical lymph node metastasis (CLNM) is one of the most relevant influencing factors for the oncological outcome of patients with oral squamous cell carcinoma (OSCC). Several studies showed that the tumors depth of invasion (DOI) influences the risk for CLNM, however varying across the oral subsites. The aim of this study is to investigate the role of DOI and other risk factors in OSCC of the tongue in relation to the occurrence of occult CLNM.

MATERIALS AND METHODS

In this retrospective study, n = 139 patients with primary OSCC of the tongue, treated by complete surgical resection (R0) with curative intention between 2013 and 2021, were included. For data analysis, epidemiologic data as well as preoperative tumor staging, surgical therapy including neck management, histopathological tumor data and follow-up were considered. Uni- and multivariate logistic regression were used to determine association between histopathological risk factors and the occurrence of occult CLNM.

RESULTS

The rate of occult cervical metastasis was 19.4%. T-staging, cervical nodal disease (pN+) and lymphatic invasion were significantly associated with reduced OS and RFS. While DOI had no relevant influence on the OS and RFS (p = 0.88 and p = 0.91 respectively), there was significant correlation between DOI and the occurrence of occult CLNM (OR: 1.17, 95%CI: 1.05-1.30; p < 0.01). The optimal cutoff in predicting occult CLNM was 6 mm (Sensitivity: 84.2%, Specificity: 73.5%, AUC: 0.75).

CONCLUSIONS

The DOI is a helpful risk parameter to predict the occurrence of occult nodal disease in OSCC of the tongue. Given the critical decision cutoff between 2 and 4 mm DOI for performing elective neck dissection in the current guidelines, our data suggests that in these cases, surgical de-escalation could be feasible with close follow-up.

CLINICAL RELEVANCE

This study highlights the relevance of DOI as a risk parameter in the prediction of CLNM with the aim to specify the individual patient risk and to deescalate surgical therapy in order to decrease comorbidities while improving the oncological prognosis.

Accuracy of magnetic resonance imaging in the assessment of depth of invasion in tongue carcinoma: A systematic review and meta-analysis

Tongue carcinoma constitutes 10.4-46.9% of all oral squamous cell carcinomas (OSCCs) and is notoriously known for invading tissues deeper than the evident gross margins. The deeper the tumor invades, the higher are its chances of future morbidity and mortality due to extensive neck dissection and risk of recurrence. Magnetic resonance imaging (MRI) is a noninvasive diagnostic aid used for measuring a preoperative tumor's depth of invasion (DOI) as it can efficiently outline soft tissue tumors from adjacent normal tissue. To assess various MRI modalities used in measuring DOI in tongue carcinoma and their reliability compared with other DOI measuring modalities. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022330866), and the following Preferred Reporting Items for a Systematic Review and Meta-Analysis (PRISMA) Diagnostic Test Accuracy guidelines were performed. PubMed electronic database was searched using a combination of keywords for relevant articles in the English language since 2016. Critical appraisal was carried out using the Quality Assessment of Diagnostic Accuracy Studies-Comparative (QUADAS-C) risk-of-bias (RoB) assessment tool. A weighted mean difference (WMD) was calculated between MRI and histopathological DOI along with pooled correlation and subgroup analysis, where possible. A total of 795 records were retrieved of which 17 were included in the final review with 13 included for meta-analysis. A high RoB was found for most studies for all parameters except flow and timing. WMD showed a statistically significant MRI overestimation of 1.90 mm compared with histopathology. Subgroup analysis showed the 1.5 Tesla machine to be superior to the 3.0 Tesla machine, while imaging sequence subgroup analysis could not be performed. MRI is a viable preoperative DOI measurement modality that can help in efficient treatment planning to decrease surgical morbidity and mortality.

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.