Histopathological Definitions of Extranodal Extension: A Systematic Review

Standardised definitions and diagnostic criteria for extranodal extension detected on histopathological examination in head and neck cancer: Head and Neck Cancer International Group consensus recommendations

Detection of extranodal extension on histopathology in surgically treated head and neck squamous cell carcinoma indicates poor prognosis. However, there is no consensus on the diagnostic criteria, interpretation, and reporting of histology detected extranodal extension, which has contributed to conflicting evidence in the literature, and likely clinical inconsistency. The Head and Neck Cancer International Group conducted a three-round modified Delphi process with a group of 19 international pathology experts representing 15 national clinical research groups to generate consensus recommendations for histology detected extranodal extension diagnostic criteria. The expert panel strongly agreed on terminology and diagnostic features for histology detected extranodal extension and soft tissue metastasis. Moreover, the panel reached consensus on reporting of histology detected extranodal extension and on nodal sampling. These consensus recommendations, endorsed by 19 organisations representing 34 countries, are a crucial development towards standardised diagnosis and reporting of histology detected extranodal extension, and more accurate data collection and analysis.

Impact of histopathological parameters in prognosis of oral squamous cell carcinoma

OBJECTIVE

Squamous cell carcinomas comprise approximately 90% of all oral malignancies. There is a wide geographical variation in the incidence of oral cancer, with South and South East Asia (SSEA) accounting for almost two third of new cases. The prognosis of oral cancer is influenced by a vast array of factors including demographic, clinical, histopathological and molecular factors. The objective this review is to analyse the impact of histopathological features assessed in hematoxylin and eosin stained sections on the prognosis of OSCC.

MATERIALS AND METHODS

Medline and Scopus data base search was performed in order to identify related articles on histopathological parameters in predicting prognosis of oral squamous cell carcinoma. The primary emphasis is on the studies conducted in SSEA, with an accompanying comparison of their findings with those from research conducted in other parts of the world.

RESULTS

It has been shown that the number of studies conducted in SSEA is not proportionate to the high prevalence of Oral Cancer in the region. There is no significant difference between the findings from SSEA compared to the rest of the world. It is clearly shown that most histopathological parameters can be accurately used to predict nodal metastasis and prognosis.

CONCLUSIONS

Histopathological parameters can be used reliably in planning treatment of Oral cancer. Clinicians should combine clinical and histopathological parameters in drawing treatment plan for Oral Cancer.

Extranodal extension in head and neck squamous cell carcinoma: need for accurate pretherapeutic staging to select optimum treatment and minimize toxicity

PURPOSE OF REVIEW

In 2017, the American Joint Committee on Cancer (AJCC) introduced the inclusion of extracapsular nodal extension (ENE) into the N staging of nonviral head and neck squamous cell carcinoma (HNSCC), while retaining the traditional N classification based on the number and sizes of metastatic nodes. The extent of ENE was further defined as microscopic ENE (ENEmi) and major ENE (ENEma) based on extent of disease beyond the nodal capsule (≤ or > 2 mm). This article reviews the evidence and progress made since these changes were introduced.

RECENT FINDINGS

The 'gold standard' for evaluation ENE is histopathologic examination, the current preferred primary treatment of patients with HNSCC is by radiation-based therapy ± chemotherapy or biotherapy. The current pretreatment staging is by imaging, which needs improved reliability of radiologic rENE assessment with reporting needs to consider both sensitivity and specificity (currently computed tomography images have high-specificity but low-sensitivity). Adjuvant chemotherapy is indicated for patients with ENEma to enhance disease control, whereas for patients with ENEmi, there is a need to assess the benefit of adjuvant chemotherapy. Evidence that the presence of pENE in HPV-positive oropharyngeal carcinoma is an independent prognostic factor and should be considered for inclusion in future AJCC editions has recently emerged.

SUMMARY

There remains a paucity of data on the reliability of imaging in the staging of rENE, more so the for the accurate assessment of ENEmi. Optimistic early results from use of artificial intelligence/deep learning demonstrate progress and may pave the way for better capabilities in tumor staging, treatment outcome prediction, resulting in improved survival outcomes.

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.

HPV-negative head and neck cancers with adverse pathological features carry specific molecular changes that are associated with survival

BACKGROUND

Adverse pathological features following surgery in head and neck squamous cell carcinoma (HNSCC) are strongly associated with survival and guide adjuvant therapy. We investigated molecular changes associated with these features.

METHODS

We downloaded data from the Cancer Genome Atlas and Cancer Proteome Atlas HNSCC cohorts. We compared tumors positive versus negative for perineural invasion (PNI), lymphovascular invasion (LVI), extracapsular spread (ECS), and positive margins (PSM), with multivariable analysis.

RESULTS

All pathological features were associated with poor survival, as were the following molecular changes: low cyclin E1 (HR = 1.7) and high PKC-alpha (HR = 1.8) in tumors with PNI; six of 13 protein abundance changes with LVI; greater tumor hypoxia and high Raptor (HR = 2.0) and Rictor (HR = 1.6) with ECS; and low p38 (HR = 2.3), high fibronectin (HR = 1.6), low annexin A1 (HR = 3.1), and high caspase-9 (HR = 1.6) abundances with PSM.

CONCLUSIONS

Pathological features in HNSCC carry specific molecular changes that may explain their poor prognostic associations.

Patterns and distribution of regional nodal involvement and recurrence in a surgically treated oropharyngeal squamous cell carcinoma cohort at a tertiary center

OBJECTIVES

To investigate and describe the patterns of regional metastases and recurrences after surgical treatment of oropharyngeal squamous cell cancer (OPSCC).

MATERIALS AND METHODS

Retrospective study of patients diagnosed with OPSCC from 2006 to 2021 at a tertiary referral center. Only patients treated with surgery including a neck dissection were included. Patients with unknown human papillomavirus (HPV) status, prior head and neck cancer, distant metastases, or synchronous head and neck cancer were excluded.

RESULTS

A total of 928 patients were included. 89% were males, the average age was 58.6 years (range: 25.2-87.5), 874 (94%) were HPV(+), and 513 (55.3%) had a tonsil cancer. Among cN + patients, the most commonly involved levels at presentation were level II (85.2%), level III (33.3%), and level IV (9.4%). In cN0 patients, metastases were only observed in level II (16.2%) and level III (9.2%). Nodal recurrence occurred in 48 (5.2%) patients after a median time of 1.0 years (interquartile range: 0.6-2.0). Nodal recurrence incidence was similar in HPV(+) and HPV(-) patients (5.0% vs. 7.4%, p = 0.44). The most common levels for regional recurrence were ipsilateral level II (45.8%), contralateral level II (43.8%), and ipsilateral level V (25.0%). Multivariable analysis revealed that pN was a significant predictor for regional recurrence (p = 0.02).

CONCLUSION

There is no difference in the distribution of regional metastases and recurrences in HPV(+) and HPV(-) OPSCC patients. Our findings align with the established understanding that regional metastases predominantly manifest in the ipsilateral level II-IV at presentation. Moreover, the data support the clinical recommendation to restrict elective neck dissection in cN0 patients to ipsilateral levels IIa and III, excluding level IIb. Regional recurrence is significantly associated with pN status.

MMP14 expression levels accurately predict the presence of extranodal extensions in oral squamous cell carcinoma: a retrospective cohort study

BACKGROUND

Extranodal extension (ENE) is an adverse prognostic factor for oral squamous cell carcinoma (OSCC), and patients with OSCC along with ENE require neck dissection. In this study, we developed a novel ENE histology-based pathological predictor using MMP14 expression patterns in small biopsy specimens.

METHODS

A total of 71 surgically resected tissue, 64 dissected lymph node (LN), and 46 biopsy specimens were collected from 71 patients with OSCC. Immunohistochemical analyses of total MMP14 expression in the tumour nest and cancer-associated fibroblasts (CAFs) were performed using the MMP14 co-scoring system (high- or low-risk). The association analysis of MMP14 expression in metastatic LNs was performed with respect to the presence and absence of ENE. Clinicopathological analyses and multivariate examinations were performed to assess the risks of metastasis and ENE presence. The predictive value of ENE and the impact of ENE and MMP14 expression on 5-year overall survival were examined.

RESULTS

High-risk MMP14 expression was detected in metastatic LN specimens with ENE. MMP14 expression in tumour nests and CAFs and its overexpression at the tumour-stromal interface significantly correlated with the presence of ENE. The MMP14 co-scoring system was an independent risk predictor for ENE, with sensitivity, specificity, and accuracy of over 80% in biopsy samples; patients with a high risk in the MMP14 co-scoring system had significantly worse prognoses in both resections and biopsies.

CONCLUSION

The MMP14 co-scoring system accurately predicted ENE presence and poor prognosis via immunohistochemical evaluation of small biopsies. This system is a simple, accurate, and inexpensive immunohistochemical approach that can be used in routine pathological diagnosis for effective treatment planning.

Lymph nodes in health and disease - A pathologist's perspective

A lymph node (LN) being a unique immunological organ has the ability to adapt when exposed to emigrants. The structural and architectural components are tampered, and it acts as an efficient immune checker in the presence of an antigen and also exhibits a morphological drift when neoplastic cells evade the organ. So, understanding the basics of histology of a lymph node is essential for the better identification and interpretation of pathological events occurring in a lymph node. A phenomenon pertaining to LNs, interpretation of reactive and neoplastic lymph nodes at morphological levels and pathological diversity of LNs in selected disease processes are emphasised.

Prognostic impact of extranodal extension (ENE) in surgically managed treatment-naive HPV-positive oropharyngeal squamous cell carcinoma with nodal metastasis

Extranodal extension (ENE) is a significant prognostic factor for human papilloma virus (HPV)-negative head and neck squamous cell carcinoma and is incorporated into AJCC 8th edition pN stage. It remains controversial whether ENE or the degree of ENE is prognostically relevant in HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). A detailed clinicopathologic review was conducted in a large retrospective cohort of 232 surgically treated patients with HPV-positive OPSCC and nodal metastasis. Fifty-six patients (24%) had nodal metastasis with ENE. The median vertical extent of ENE was 2.9 mm (range 0.2-20.3 mm), and the median horizontal span of ENE was 2.5 mm (range: 0.3-14.0 mm). Comparing with patients without ENE, those with ENE were associated with a higher number of positive lymph nodes, lymphovascular invasion, perineural invasion, adjuvant chemotherapy, larger primary tumor size, and shorter follow up period. Patients with ENE had shortened overall survival (OS), disease specific survival (DSS), disease free survival (DFS), distant metastasis free survival (DMFS), and regional recurrence free survival (RRFS) on univariate survival analysis. The 5-year OS, DSS, and DFS were 95%, 97%, and 90% respectively for the group without ENE, and 64%, 71%, and 65% respectively for the group with ENE. On Multivariate survival analysis, the presence of ENE was an independent adverse prognostic factor for OS, DSS, and DFS. Additionally, major ENE defined as a vertical extent of ≥4 mm or irregular soft tissue deposit independently predicted shortened OS, DSS, and RFS. In conclusion, the presence of ENE, in particular major ENE, is an independent prognostic factor in HPV-positive OPSCC. Therefore, we propose to document the presence and extent of ENE for these tumors. Consideration may be given for AJCC 9th edition to include ENE into pN stage of HPV-positive OPSCC.

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.

The Impact of Histopathological Features on the Prognosis of Oral Squamous Cell Carcinoma: A Comprehensive Review and Meta-Analysis

OBJECTIVE

Over many decades, studies on histopathological features have not only presented high-level evidence of contribution for treatment directions and prognosis of oral squamous cell carcinoma (OSCC) but also provided inconsistencies, making clinical application difficult. The 8th TNM staging system of OSCC has acknowledged the importance of some histopathological features, by incorporating depth of invasion (DOI) to T category and extranodal extension (ENE) to N category. The aim of this systematic review with meta-analysis is to determine the most clinically relevant histopathological features for risk assessment and treatment planning of OSCC and to elucidate gaps in the literature.

METHODS

A systematic review was conducted using PRISMA guidelines, and the eligibility criteria were based on population, exposure, comparison, outcome, and study type (PECOS). PubMed, Cochrane, Scopus, and Web of Science were searched for articles exploring the impact of histopathological features on OSCC outcomes with Cox multivariate analysis. Pooled data were subjected to an inverse variance method with random effects or fixed effect model, and the risk of bias was evaluated using quality in prognosis studies (QUIPS). Quality of evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria.

RESULTS

The study included 172 articles published from 1999 to 2021. Meta-analyses confirmed the prognostic potential of DOI, ENE, perineural invasion, lymphovascular invasion, and involvement of the surgical margins and brought promising results for the association of bone invasion, tumor thickness, and pattern of invasion with increased risk for poor survival. Although with a small number of studies, the results also revealed a clinical significance of tumor budding and tumor-stroma ratio on predicted survival of patients with OSCC. Most of the studies were considered with low or moderate risk of bias, and the certainty in evidence varied from very low to high.

CONCLUSION

Our results confirm the potential prognostic usefulness of many histopathological features and highlight the promising results of others; however, further studies are advised to apply consistent designs, filling in the literature gaps to the pertinence of histopathological markers for OSCC prognosis.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO), identifier CRD42020219630.

Extranodal Extension in Bilateral Cervical Metastases: A predictor of Undesirable Survival Outcomes despite Aggressive Salvage Treatment in Oral Cancer Patients

Objectives: Despite the inclusion of extranodal extension (ENE) in the recent staging system, the presence of ENE alone is not sufficient to depict all clinical situations, as ENE is frequently found in multiple nodes. Thus, the purpose of this study was to evaluate the surgery-based treatment outcomes and clinicopathological features of oral cavity squamous cell carcinoma (OCSCC) patients with ENE found in bilateral multiple cervical metastases.

Materials and methods: A retrospective single-institutional study of OCSCC patients with bilateral ENE nodes was performed from January 2011 to December 2018. OCSCC patients of different admission statuses (with primary lesions (PL), recurrent lesions (RL) and isolated neck metastases (INM)) were included for subgroup comparisons. All patients received surgical treatment with/without adjuvant therapies and had complete follow-up data. Disease-free survival (DFS) was regarded as the main outcome. Time-to-relapse data were also collected for comparison.

Results: A total of 128 patients were included, of whom 97 (75.8%) were male. The mean follow-up period reached 15 months. Among the patients, 85 (66.4%) were treated for PLs, followed by 26 (20.3%) treated for RLs after failed prior therapy and 17 (13.3%) treated for INMs (concurrent or sequential). The DFS rate was merely 35.2%. Treatment-related factors such as surgical margin (p=0.003), postoperative adjuvant therapy (p=0.014) and perioperative complications (p=0.036) were significantly associated with patient outcomes. In addition, oral lesion-related variables such as oral subsites (p=0.037), T classification (p=0.026) and skull base involvement (p=0.040) were indicators of a worse prognosis. For bilateral ENE features, ENE subclassification (p=0.036), maximum size of ENE nodes (p=0.039) and arterial nodal encasement (p=0.025) tended to predict the surgery-based treatment outcomes of these patients.

Conclusions: Bilateral cervical metastases with ENE features, though uncommon, are a serious regional burden, and these patients have lower-than-expected treatment outcomes, especially those with RLs or INMs. A fairly large number of OCSCC patients with advanced oral lesions gain little benefit from intensified salvage surgical treatment. Such treatment should instead be offered to select patients with smaller bilateral ENE nodes (<3 cm) and those with lower ENE subclassifications and no arterial nodal encasement.