Lymph node extracapsular extension as a marker of aggressive phenotype: Classification, prognosis and associated molecular biomarkers

Proposals for the delineation of neck clinical target volume for definitive Radiation therapy in patients with oral/ oropharyngeal squamous cell cancer based on lymph node distribution

PURPOSE/OBJECTIVE(S)

To establish the distribution pattern of cervical lymph node metastasis (LNM) and propose optimized clinical target volume (CTV) boundaries specific to oral/ oropharyngeal squamous cell cancer (OSCC/OPSCC).

MATERIALS/METHODS

531 patients with pathologically confirmed OSCC/OPSCC were enrolled from January 2013 to June 2022. Patients were stratified into two groups based on the minimal distance from the lesion's edge to the body's midline: ≤1 cm or > 1 cm. The geometric center of cervical metastatic LN was marked on a template CT. LN distribution probability maps were established. The relationships between the LN distribution and consensus guidelines were analyzed to propose modifications for CTV boundaries specific to OSCC/OPSCC.

RESULTS

A total of 1962 positive LNs were enrolled. Compared with the > 1 cm group, the ≤ 1 cm group has following feature tendencies: male smokers, younger, median organs, large gross lesion, infiltrative growth pattern, contralateral LNM. The most frequently involved level of LNM was ipsilateral II, but ipsilateral Ib had the highest involvement rate in the > 1 cm OSCC group. In addition, tongue cancer had a higher incidence of LN extranodal extension (ENE), which mainly distributes in ipsilateral level II. The skip metastasis was prone to from level III to Vb (3.5 %) in LN(+)/ENE (-), and level Ib to VIa (3.7 %) in LN(+)/ENE (+). Accordingly, we proposed the following modifications: 1. only including lateral and posterior margin of submandibular gland within 5 mm; 2. retracting posterior boundary of level II to front edge of levator scapula muscle, and descending the upper boundary to transverse process of C2 vertebra only for OSCC; 3. including posterior third of thyroglossal muscle or anterior edge of sternocleidomastoid muscle; 4. sparing level Va in case of only level II involvement; 5. including upper area of the thyroid cartilage plate in case of level Ib LN(+)/ENE (+); 6. sparing level VIIa is considered.

CONCLUSION

This is the first description of LN topographic spread patterns for OSCC/OPSCC. Modified CTV for prophylactic irradiation was proposed to spare the organs at risk and minimize adverse effects.

The prognostic effect of radiological extranodal extension in HPV-positive oropharyngeal squamous cell carcinomas: a retrospective cohort analysis

PURPOSE

Radiological extranodal extension (rENE) is a well-known negative prognosticator in head and neck squamous cell carcinoma (HNSCC). However, controversy remains regarding the prognostic effect of rENE in HPV-positive oropharyngeal SCCs (OPSCC). This single-center retrospective cohort analysis assessed the prognostic role of rENE in an HPV + OPSCC population and tried to validate a recently proposed modification of the TNM8 N-classification.

METHODS

129 patients with HPV + OPSCC, of whom 106 cN + patients, were included. Radiological imaging (CT, MRI or both) was reanalyzed by a senior head and neck radiologist. Overall survival (OS), disease-free survival (DFS), locoregional recurrence-free survival (LRFS), and disease-specific survival (DSS) were evaluated. Cox proportional hazard models were used for estimating hazard ratios (HR).

RESULTS

A non-significant trend towards better outcomes in the rENE- group, as compared to the rENE + population, was observed for 5 year OS [80.99% vs 68.70%, HR: 2.05, p = 0.160], 5 year RFS [78.81% vs 67.87%, HR: 1.91, p = 0.165], 5 year DFS [77.06% vs 60.16%, HR: 2.12, p = 0.0824] and 5 year DSS [88.83% vs 81.93%, HR: 2.09, p = 0.195]. OS declined with ascending levels of rENE (p = 0.020). Multivariate analysis identified cT-classification and smoking as independent negative predictors for OS/DFS. The proposed modification of the TNM8 N-classification could not be validated.

CONCLUSIONS

Although rENE could not be identified as an independent negative prognosticator for outcome in our HPV + OPSCC population, outcomes tend to deteriorate with increasing rENE.

T2WI-based MRI radiomics for the prediction of preoperative extranodal extension and prognosis in resectable rectal cancer

OBJECTIVE

To investigate whether T2-weighted imaging (T2WI)-based intratumoral and peritumoral radiomics can predict extranodal extension (ENE) and prognosis in patients with resectable rectal cancer.

METHODS

One hundred sixty-seven patients with resectable rectal cancer including T3T4N + cases were prospectively included. Radiomics features were extracted from intratumoral, peritumoral 3 mm, and peritumoral-mesorectal fat on T2WI images. Least absolute shrinkage and selection operator regression were used for feature selection. A radiomics signature score (Radscore) was built with logistic regression analysis. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of each Radscore. A clinical-radiomics nomogram was constructed by the most predictive radiomics signature and clinical risk factors. A prognostic model was constructed by Cox regression analysis to identify 3-year recurrence-free survival (RFS).

RESULTS

Age, cT stage, and lymph node-irregular border and/or adjacent fat invasion were identified as independent clinical risk factors to construct a clinical model. The nomogram incorporating intratumoral and peritumoral 3 mm Radscore and independent clinical risk factors achieved a better AUC than the clinical model in the training (0.799 vs. 0.736) and validation cohorts (0.723 vs. 0.667). Nomogram-based ENE (hazard ratio [HR] = 2.625, 95% CI = 1.233-5.586, p = 0.012) and extramural vascular invasion (EMVI) (HR = 2.523, 95% CI = 1.247-5.106, p = 0.010) were independent risk factors for predicting 3-year RFS. The prognostic model constructed by these two indicators showed good performance for predicting 3-year RFS in the training (AUC = 0.761) and validation cohorts (AUC = 0.710).

CONCLUSION

The nomogram incorporating intratumoral and peritumoral 3 mm Radscore and clinical risk factors could predict preoperative ENE. Combining nomogram-based ENE and MRI-reported EMVI may be useful in predicting 3-year RFS.

CRITICAL RELEVANCE STATEMENT

A clinical-radiomics nomogram could help preoperative predict ENE, and a prognostic model constructed by the nomogram-based ENE and MRI-reported EMVI could predict 3-year RFS in patients with resectable rectal cancer.

KEY POINTS

• Intratumoral and peritumoral 3 mm Radscore showed the most capability for predicting ENE. • Clinical-radiomics nomogram achieved the best predictive performance for predicting ENE. • Combining clinical-radiomics based-ENE and EMVI showed good performance for 3-year RFS.

Extra-Capsular Spread of Lymph Node Metastasis in Oral, Oropharyngeal and Hypopharyngeal Cancer: A Comparative Subsite Analysis

BACKGROUND

The extra-capsular spread (ECS) of lymph node metastasis (LNM) is a hallmark of aggressive primary tumor phenotype in head and neck cancer (HNC); however, the factors influencing ECS are poorly understood.

PATIENTS AND METHODS

This was a retrospective study, including 190 cases of oral tongue cancer (OTC), 148 cases of oropharyngeal cancer (OPC) (118 HPV-positive and 30 HPV-negative), and 100 cases of hypopharyngeal cancer (HPC). Tumor dimension, tumor biological variables (lymphovascular/perineural invasion and histologic grade), and LNM variables (LNM number and size) were analyzed according to the presence of ECS using multivariable logistic regression and receiver operating characteristic (ROC) curve analyses.

RESULTS

LNM variables were significant factors for ECS in all subsites of HNC (p < 0.05), except HPV-positive OPC. In OTC, tumor dimensional variables were significantly related to ECS (p < 0.01). Meanwhile, in OPC and HPC, neither the primary tumor dimension nor the T status were significant factors for ECS occurrence. The predictability of ECS by ROC curve using multiple variables was 0.819 [95% confidence interval: 0.759-0.878] in OTC, 0.687 [0.559-0.815] in HPV-positive OPC, 0.823 [0.642-1.000] in HPV-negative OPC, and 0.907 [0.841-0.973] in HPC.

CONCLUSION

LNM variables were correlated with ECS occurrence for most HNC subsites, and site-dependent primary tumor characteristics might contribute differentially to the ECS development of LNM in HNC.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

Diagnostic challenges and prognostic implications of extranodal extension in head and neck cancer: a state of the art review and gap analysis

Extranodal extension (ENE) is a pattern of cancer growth from within the lymph node (LN) outward into perinodal tissues, critically defined by disruption and penetration of the tumor through the entire thickness of the LN capsule. The presence of ENE is often associated with an aggressive cancer phenotype in various malignancies including head and neck squamous cell carcinoma (HNSCC). In HNSCC, ENE is associated with increased risk of distant metastasis and lower rates of locoregional control. ENE detected on histopathology (pathologic ENE; pENE) is now incorporated as a risk-stratification factor in human papillomavirus (HPV)-negative HNSCC in the eighth edition of the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) TNM classification. Although ENE was first described almost a century ago, several issues remain unresolved, including lack of consensus on definitions, terminology, and widely accepted assessment criteria and grading systems for both pENE and ENE detected on radiological imaging (imaging-detected ENE; iENE). Moreover, there is conflicting data on the prognostic significance of iENE and pENE, particularly in the context of HPV-associated HNSCC. Herein, we review the existing literature on ENE in HNSCC, highlighting areas of controversy and identifying critical gaps requiring concerted research efforts.

Lymph Node Ratio as a Prognostic Factor for Oral Tongue Squamous Cell Carcinoma: A Retrospective Study

Background Oral squamous cell carcinoma (OSCC) incidence and its mortality have increased recently. The oral part of the tongue is one of the commonest sites for OSCC. Apart from Tumour-Node-Metastasis (TNM) staging, lymph node ratio (LNR) has been implicated as one of the useful predictors for the better clinical outcome of the disease. The aim of the present study was to assess the LNR as a prognostic factor for patients having oral tongue squamous cell carcinoma (OTSCC). Materials and methods It is a retrospective study of 122 patients with OTSCC who were managed primarily by surgery with curative intent from January 2014 to December 2016. The mean lymph node ratio was measured and compared with various parameters of clinical outcome such as five-year overall survival (OS), five-year disease-free survival (DFS), locoregional failure (LRF) within three years, and distant metastasis (DM) within five years using Kruskal-Wallis Test followed by Mann-Whitney Post Hoc Test. The association of LNR with other tumor characteristic features like perineural invasion, extra-nodal extension (ENE), and histopathological grading was also elicited. Results The study population's mean age was 50.5 ± 11.77 years. Among them, 85 were males and 37 were females. On comparing the mean LNR value with patient status after primary treatment, the patients with minimal LNR value had statistically significant five-year OS and five-year DFS (p< 0.001). High mean LNR values were associated with other adverse features like perineural invasion and ENE, which were statistically significant (p<0.001). Receiver operator characteristics (ROC) curve analysis for the LNR parameter for determining the cut-off (0.02) between OS and DFS had 86% sensitivity and 40% specificity. Conclusion The LNR could be an important prognosis factor for OTSCC that helps in determining better clinical outcomes.

Extranodal extension influences prognosis in pancreatic head cancer: A retrospective cohort study

BACKGROUND

Extranodal extension (ENE) is an established prognostic factor in several gastrointestinal cancers. However, the prognostic impact remains unclear. Here, we investigated the prognostic implications of ENE in patients with surgically resected pancreatic cancer.

METHODS

We retrospectively reviewed 476 surgically resected pancreatic head cancer patients who consecutively underwent upfront pancreaticoduodenectomy for pathologically confirmed pancreatic ductal adenocarcinoma between January 2009 and December 2013. We compared the disease-free survival (DFS) rates of the patients according to ENE status.

RESULTS

Among the 476 patients, patients with ENE had lower DFS rates than those without ENE (N0, 13 months; LN+/ENE-, 7 months; LN+/ENE+, 6 months; P < .001). In addition, even in the same N stage, patients with ENE had lower DFS rates than those without ENE (N0, 13 months; N1/ENE- 8 months; N1/ENE+, 7 months; N2/ENE-, 7 months; N2/ENE+, 4 months, P < .001). However, there was no significant difference in survival rates between patients in the N1/ENE+ group and those in the N2/ENE- group. Additionally, ENE was an independent prognostic factor for pancreatic cancer.

CONCLUSIONS

Extranodal extension significantly predicted a poor prognosis among patients with pancreatic head cancer, especially those with nodal metastasis. Therefore, ENE should be considered a prognostic factor in future editions of the staging system.

Melanoma lymph node metastases - moving beyond quantity in clinical trial design and contemporary practice

The presence of lymph node metastases is a well-studied prognostic factor for cutaneous melanoma. Characterization of melanoma lymph node metastases and their association with survival in multiple, large observational studies has led to recognition of the following high-risk features: quantity of lymph node metastases (number of nodes), size of the nodal tumor deposit (in mm), and extracapsular extension. Despite increasing utilization of these features in the design of randomized clinical trials, in addition to their role in contemporary clinical decision-making, current staging systems lag behind, only accounting for the quantity of lymph nodes with metastases. Herein, we review the prognostic role of melanoma lymph node metastases and their high-risk features, current reporting standards, how such features have been utilized in practice-changing trials, and best practices for future clinical trial design and clinical decision-making.

Carbonic anhydrase IX stratifies patient prognosis and identifies nodal status in animal models of nasopharyngeal carcinoma using a targeted imaging strategy

PURPOSE

Accurate identification of nodal status enables adequate neck irradiation for nasopharyngeal carcinoma (NPC). However, most conventional techniques are unable to pick up occult metastases, leading to underestimation of tumor extensions. Here we investigate the clinical significance of carbonic anhydrase IX (CAIX) in human NPC samples, and develop a CAIX-targeted imaging strategy to identify occult lymph node metastases (LNMs) and extranodal extension (ENE) in animal studies.

METHODS

A total of 211 NPC samples are performed CAIX staining, and clinical outcomes are analyzed. The metastatic murine models are generated by foot pad injection of NPC cells, and a CAIX-targeted imaging agent (CAIX-800) is intravenously administered. We adopt fluorescence molecular tomography and ultrasonography (US)-guided spectroscopic photoacoustic (sPA) imaging to perform in vivo studies. Histological and immunohistochemical characterization are carried out via node-by-node analysis.

RESULTS

For clinical samples, 90.1% (91/101) primary tumors, 73.3% (66/90) metastases, and 100% (20/20) local recurrences are CAIX positive. In metastases group, 84.7% (61/72) nodal metastases and 22.2% (4/18) organ metastases are CAIX positive. CAIX expression in primary tumors is significantly associated with NPC stage and prognosis. For animal studies, CAIX-800-based fluorescence imaging achieves 81.3% sensitivity and 93.8% specificity in detecting occult LNMs in vivo, with a minimum detectable diameter of 1.7 mm. Coupled with CAIX-800, US-guided sPA imaging could not only detect subcapsular deposits of metastatic cancer cells 2 weeks earlier than conventional techniques, but also successfully track pathological ENE.

CONCLUSION

CAIX remarkably expresses in human NPCs and stratifies patient prognosis. In preclinical studies, CAIX-800-based imaging successfully identifies occult LNMs and tracks early stage of pathological ENE. This attractive method shows potential in clinic, allowing medical workers to longitudinally monitor nodal status and helping to reduce unnecessary nodal biopsy for patients with NPC. The schematic diagram for the study. CAIX, carbonic anhydrase IX; NPC, nasopharyngeal carcinoma; US, ultrasonography; sPA, spectroscopic photoacoustic.

Inter- and Intrarater Reliability and Agreement Among Danish Head and Neck Pathologists Assessing Extranodal Extension in Lymph Node Metastases from Oropharyngeal Squamous Cell Carcinomas

BACKGROUND

Extranodal extension (ENE) in lymph node metastases is one of the most important prognostic factors in head and neck squamous cell carcinomas. Studies have shown inconsistency among pathologists in the assessment of ENE. The aims of this study were: (1) to determine the interrater and intrarater reliability and agreement in the assessment of ENE among Danish pathologists and (2) to test if a standardized assessment method may increase interrater agreement.

METHODS

Four Danish head and neck pathologists assessed ENE presence or absence in 120 histological slides from lymph nodes with oropharyngeal squamous cell carcinoma metastases (first round). Subsequently, guidelines were introduced to the pathologists and a new assessment was performed (second round). Finally, two of the pathologists assessed the slides to determine intrarater reliability and agreement (third round).

RESULTS

Interrater kappa coefficients varied between 0.57 and 0.67 in the first round and between 0.59 and 0.72 in the second round. The intrarater agreement between round 2 and 3 was 0.88 for pathologist 1 and 0.92 for pathologist 2 with resulting kappa coefficients of 0.76 (95% CI 0.64-0.88) and 0.84 (95% CI 0.74-0.94), respectively.

CONCLUSION

We found a moderate level of reliability and agreement among pathologists for ENE in lymph node metastases from oropharyngeal squamous cell carcinomas. The intrarater reliability and agreement was generally higher than interrater measures. Interrater agreement was slightly improved by standardized assessment.

Differential expression of podoplanin in metastatic lymph node is associated with extranodal extension in oropharyngeal cancer

This study aimed to investigate the spatial distribution and clinical significance of podoplanin expression in the metastatic lymph nodes of oropharyngeal squamous cell carcinomas (OPSCCs). The immunohistochemical podoplanin expression in the metastatic lymph nodes was evaluated in the pathologic specimens of 47 consecutive OPSCC patients. Clinicopathologic factors, including podoplanin expression and extranodal extension (ENE) status, were analyzed. Podoplanin was significantly expressed in the perinodal stroma (p = 0.001), and the average score of podoplanin was higher (p = 0.008) in ENE-positive lymph nodes than ENE-negative lymph nodes, although intranodal podoplanin expression did not differ significantly between the groups. Multivariable analysis revealed perinodal podoplanin expression as an independent marker of ENE in all the patients and the human papilloma virus (HPV)-positive group (p = 0.007 and p = 0.018, respectively). Podoplanin is differentially expressed in the metastatic lymph nodes in OPSCC, and its expression in perinodal stroma is associated with ENE, suggesting that podoplanin can be used clinically as a diagnostic biomarker.

Imaging in head and neck cancers: Update for non-radiologist

Head and neck cancer (HNC) is the fifth most frequent cancer worldwide and associated with significant morbidity. Along with clinical examination and endoscopic evaluation, imaging plays an important role in pre- and posttherapeutic evaluation of patients with HNC. Cross-sectional Imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography / computed tomography (PET/CT) are routinely used in the assessment of these patients. This review provides an overview of the various cross-sectional imaging modalities used in the evaluation of HNC and will give a short summary of the latest imaging technologies regarding head and neck cancer diagnosis.

Assessment Criteria and Clinical Implications of Extranodal Extension in Head and Neck Cancer

Tumor breaching the capsule of a lymph node is termed extranodal extension (ENE). It reflects aggressiveness of a tumor, creates anatomic challenges for disease clearance, and increases the risk of distant metastasis. Extranodal extension can be assessed on a pathology specimen, by radiology studies, and by clinical examination. Presence of ENE in a pathology specimen has long been considered a high-risk feature of disease progression and would ordinarily benefit from the addition of chemotherapy to adjuvant radiotherapy. Although the eighth edition of the Union for International Cancer Control/American Joint Committee on Cancer stage classification dichotomizes pathologic ENE according to its presence or absence, emerging evidence suggests that the extent of a pathologic ENE may provide additional value for risk stratification to guide adjuvant therapy. Recent data suggest that the prognostic importance of pathologic ENE is also applicable for HPV-associated head and neck squamous cell carcinoma. In addition, compelling data demonstrate that indisputable radiologic ENE is a powerful risk stratification tool to identify patients at high risk for treatment failure, especially distant metastasis, applicable for both HPV-positive and HPV-negative head and neck squamous cell carcinoma. However, the definition and taxonomy of radiologic ENE requires standardization. The goal of this review is to clarify the contemporary understanding of the prognostic implications of ENE in head and neck squamous cell carcinoma, present the nuances of what is presently known and unknown, and elucidate how to classify ENE pathologically and radiologically with an understanding of the strengths and weaknesses of each approach. Finally, with the development of several risk stratification methods, the relative role of ENE and other prognostic schema will be explored.