Development and validation of a novel TNM staging N-classification of oral cavity squamous cell carcinoma

Nodal assessment and extranodal extension in head and neck squamous cell cancer: insights from computed tomography and magnetic resonance imaging

PURPOSE

The aim of the study was to evaluate the concordance between computed tomography (CT)/magnetic resonance imaging (MRI) and histological examination in the evaluation of lymph nodal involvement (N+) and extranodal extension (ENE+) in patients with squamous cell cancer of the head-neck district (HNSCC). The second end point was to evaluate which of the imaging features was more sensitive and specific in establishing N+ and ENE+, and comparing the diagnostic accuracy between CT and MRI.

MATERIAL AND METHODS

58 patients with HNSCC undergoing surgical treatment with lymph node dissection at the Policlinico of Bari were enrolled in this retrospective study. The criteria used for identifying radiological N+ (rN+) included six characteristics; the presence of any two or more criteria out of these six was considered rN+. For each rN+, the radiological extranodal extension (rENE+) was evaluated analyzing three characteristics; rENE was considered positive if any one criterion was present.

RESULTS

Of 167 lymph nodes, 45/167 (27%) had rN+, out of which 20/45 (44%) were rENE+. On pathological examination, 38/45 (84%) nodes were N+ and 11/20 (55%) were ENE+. The agreement between imaging and histology in the evaluation of N was (149/167) 89% with a good concordance (k = 0.7). The agreement between imaging and histology in the evaluation of ENE was (35/45) 78% with a moderate concordance (k = 0.5). Loss of fatty hilum was found to be the most sensitive (84%) imaging finding in N+ evaluation. Capsular irregularity with fat stranding had the highest sensitivity (82%) for the determination of ENE+. Comparing CT and MRI imaging in the evaluation of N+ and ENE+, we found no statistically significant differences (p-value of 0.3 for N+ and p-value of 0.3 for ENE +).

CONCLUSIONS

Imaging has good confidence in detecting rN+ but modest in assessing rENE+. Further research could improve the imaging specificity for the determination of rENE.

Radiology-Pathology Concordance and Prognostication of Nodal Features in pN+ Oral Cavity Cancer

BACKGROUND AND PURPOSE

The aims of our study are to evaluate the diagnostic performance and prognostic value of radiological lymph node (LN) characteristics in pN+ oral cavity squamous carcinoma (OSCC).

MATERIALS AND METHODS

pN+ OSCC treated between 2012 and 2020 were included. Preoperative imaging was reviewed by a single radiologist blinded to pathologic findings for the following nodal features: imaging-positive LN (iN+), laterality and total number, and image-identified extranodal extension (iENE). The sensitivity of iN+ for pN+ was calculated. The diagnostic performance of other nodal features was evaluated in the iN+ subgroup. The association of radiologic nodal features with overall survival (OS) was evaluated. Inter-rater kappa for radiologic nodal features was assessed in 100 randomly selected cases.

RESULTS

Of 406 pN+ OSCC, 288 were iN+. The sensitivity of iN+ for pN+ was 71% overall, and improved to 89% for pN+ LN >1.5 cm. Within iN+, sensitivity/specificity for LN size (>3 cm), total LN number (>4), and ENE were 0.44/0.95, 0.57/0.84, and 0.27/0.96, respectively. Sensitivity of iENE was higher in the subset, with major (>2 mm) versus minor (≤2 mm) pENE (43% vs. 13%, p = 0.001). Reduced OS was observed in iN+ versus iN- (p = 0.006), iENE+ versus iENE- (p = 0.004), LN size >3 versus ≤3 cm (p < 0.001), and higher LN number (p < 0.001). Inter-rater kappa for iN+, laterality, total LN number, and presence of iENE were 0.71, 0.57, 0.78, and 0.69, respectively.

CONCLUSION

Our study shows that despite modest sensitivity of most radiological nodal features, the specificity of image-identified nodal features is high and their prognostic values are retained in pN+ OSCC.

LEVEL OF EVIDENCE

3 (retrospective review comparing cases and controls) Laryngoscope, 134:4947-4955, 2024.

Correlation of Lymph Node Characteristics and Extranodal Extension in Oral Cavity Squamous Cell Carcinoma

Objective

Identify correlations between lymph node characteristics and extranodal extension (ENE).

Study Design

Retrospective chart review.

Setting

Tertiary care center.

Methods

Patients who underwent neck dissection for oral cavity squamous cell carcinoma from 2004 to 2018 were included, with a starting sample of 496. The primary outcome was ENE in at least 1 lymph node. Additional variables included number of dissected nodes, positive nodes by level, positive lymph node ratio (LNR), and diameter of metastatic deposit and ENE focus. Univariate and multivariate binary logistic regression analyses were performed to determine correlations between included variables and ENE.

Results

Of the 496 patients, 233 had nodal metastasis (47.0%). 13,814 nodes were removed, with 714 (5.2%) containing metastasis. Of the positive nodes, 28.0% had ENE, 47.2% did not have ENE, and 24.8% were unknown. The mean ENE diameter was 5.1 mm (SD, 9.9). On univariate logistic regression analysis, ipsilateral neck LNR per 0.1 unit increase (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.02-1.32, P = .02), metastatic deposit size per 1 mm increase (OR 1.06, CI 1.04-1.08, P < .0001), and clinical T- (P = .02) and N-class (P = .0003) significantly correlated with ENE. On multivariate logistic regression analysis, size of metastatic deposit (OR 1.06, CI 1.03-1.08, P < .0001) remained significantly correlated with ENE.

Conclusion

Controlling for confounding variables, size of metastatic deposit was an independent predictor of ENE, suggesting that as the metastatic deposit size increases, the odds of extension through the capsule also increases. This may be due to capsule thinning as the deposit grows or could represent the invasive nature of aggressive disease.

Prognostic and predictive biomarkers in head and neck cancer: something old, something new, something borrowed, something blue and a sixpence in your shoe

A biomarker is a measurable indicator of biological or pathological processes or the response to an exposure or intervention and is used to guide management decisions. In head and neck pathology, biomarkers are assessed by histological criteria and immunohistochemical and molecular studies. Surgical resection remains the mainstay of management of many head and neck malignancies. Adjuvant radiotherapy and/or systemic therapy may be administered depending on the presence of adverse prognostic factors identified on histopathological or immunohistochemical examination. In this review, we outline the clinically relevant prognostic and predictive factors in head and neck malignancies including conventionally recognised factors such as tumour size, depth of invasion, lymphovascular and perineural invasion and margin status as well as novel evolving factors such as recurrent genetic rearrangements and assessment of immune checkpoints. Practical issues are discussed to assist with recognising and reporting of these factors. A summary of useful tools such as structured pathology report formats is also included to assist with comprehensive reporting of all clinically relevant parameters, minimise risk and improve workflow efficiencies.