Extranodal extension in head and neck squamous cell cancer: is there a role for further stratification?

Advances and residual knowledge gaps in the neck management of head and neck squamous cell carcinoma patients with advanced nodal disease undergoing definitive (chemo)radiotherapy for their primary

PURPOSE

Substantial changes have been made in the neck management of patients with head and neck squamous cell carcinomas (HNSCC) in the past century. These have been fostered by changes in cancer epidemiology and technological progress in imaging, surgery, or radiotherapy, as well as disruptive concepts in oncology. We aimed to review changes in nodal management, with a focus on HNSCC patients with nodal involvement (cN+) undergoing (chemo)radiotherapy.

METHODS

A narrative review was conducted to review current advances and address knowledge gaps in the multidisciplinary management of the cN+ neck in the context of (chemo)radiotherapy.

RESULTS

Metastatic neck nodes are associated with poorer prognosis and poorer response to radiotherapy, and have therefore been systematically treated by surgery. Radical neck dissection (ND) has gradually evolved toward more personalized and less morbid approaches, i.e., from functional to selective ND. Omission of ND has been made feasible by use of positron-emission tomography/computed tomography to monitor the radiation response in cN+ patients. Human papillomavirus-driven oropharyngeal cancers and their cystic nodes have shown dramatically better prognosis than tobacco-related cancers, justifying a specific prognostic classification (AJCC) creation. Finally, considering the role of lymph nodes in anti-tumor immunity, de-escalation of ND and prophylactic nodal irradiation in combination are intense areas of investigation. However, the management of bulky cN3 disease remains an issue, as aggressive multidisciplinary strategies or innovative combined treatments have not yet significantly improved their prognosis.

CONCLUSION

Personalized neck management is an increasingly important aspect of the overall therapeutic strategies in cN+ HNSCC.

Criteria for the diagnosis of extranodal extension detected on radiological imaging in head and neck cancer: Head and Neck Cancer International Group consensus recommendations

Extranodal extension of tumour on histopathology is known to be a negative prognostic factor in head and neck cancer. Compelling evidence suggests that extranodal extension detected on radiological imaging is also a negative prognostic factor. Furthermore, if imaging detected extranodal extension could be identified reliably before the start of treatment, it could be used to guide treatment selection, as patients might be better managed with non-surgical approaches to avoid the toxicity and cost of trimodality therapy (surgery, chemotherapy, and radiotherapy together). There are many aspects of imaging detected extranodal extension that remain unresolved or are without consensus, such as the criteria to best diagnose them and the associated terminology. The Head and Neck Cancer International Group conducted a five-round modified Delphi process with a group of 18 international radiology experts, representing 14 national clinical research groups. We generated consensus recommendations on the terminology and diagnostic criteria for imaging detected extranodal extension to harmonise clinical practice and research. These recommendations have been endorsed by 19 national and international organisations, representing 34 countries. We propose a new classification system to aid diagnosis, which was supported by most of the participating experts over existing systems, and which will require validation in the future. Additionally, we have created an online educational resource for grading imaging detected extranodal extensions.

Extranodal extension in oral squamous cell carcinoma: clinical and histopathological analysis

OBJECTIVE

Extranodal extension (ENE) is an important prognostic factor in oral squamous cell carcinoma (OSCC). This study aimed to evaluate the clinical significance of stratifying minor or major ENE in OSCC.

STUDY DESIGN

This retrospective cohort study included 75 patients who had undergone neck dissection for OSCC and were classified as pN+. ENE was measured using hematoxylin-eosin-stained specimens and stratified into major (ENEma, >2 mm) and minor (ENEmi, ≤2 mm) by distance. Their association with survival, locoregional relapse, and distant metastases were assessed.

RESULTS

Of 49 patients with pathological ENE, 23 had ENEmi, and 26 had ENEma. The 5-year overall survival (OS) was 38%, 66%, and 76% in the ENEma, ENEmi, and no ENE groups, respectively. Compared with no ENE, ENEma was associated with significantly decreased 5-year cumulative OS and disease-specific survival. ENEma was a risk factor for decreased OS (HR: 2.54, 95% CI: 1.04-6.18, P = .040) in the multivariable Cox regression analysis, and was associated with distant metastasis.

CONCLUSION

In patients with OSCC, ENEma is associated with a significantly poorer prognosis; therefore stratifying ENE is clinically relevant. ENEma may increase the risk of distant metastasis; therefore, new treatment modalities that contribute to distant metastasis control are required.

The 8th AJCC classification is inferior to a new neck stage based on intraparotid lymph node in parotid gland cancer

BACKGROUND

Lymph node (LN) status is an important prognostic factor for parotid gland cancer (PGC). This study aimed to analyze the impact of extranodal extension (ENE) of intraparotid LN and LN metastasis burden on survival in PGC.

METHODS

Patients with surgically treated PGC and at least one metastatic cervical LN were retrospectively enrolled. Primary outcome variables were distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS). The impact of ENE and LN metastasis burden was assessed using the Cox model.

RESULTS

A total of 292 patients were included. ENE in cervical or intraparotid LN was not associated with DMFS, DSS, or OS. Intraparotid LN metastasis had a significant impact on prognosis, and the presence of only one metastatic intraparotid LN offered an approximately 1.5-fold risk of distant metastasis. Prognostic models based on the number of positive LNs (1 vs. 2-3 vs. 4+) were superior to the AJCC N stage in terms of DMFS, DSS, and OS.

CONCLUSIONS

ENE of cervical or intraparotid LN has a limited effect on the prognosis of PGC, and the number of positive LNs is better than the AJCC N stage in LN status evaluation.

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.

High fusion and cytopathy of SARS-CoV-2 variant B.1.640.1

SARS-CoV-2 variants with undetermined properties have emerged intermittently throughout the COVID-19 pandemic. Some variants possess unique phenotypes and mutations which allow further characterization of viral evolution and Spike functions. Around 1,100 cases of the B.1.640.1 variant were reported in Africa and Europe between 2021 and 2022, before the expansion of Omicron. Here, we analyzed the biological properties of a B.1.640.1 isolate and its Spike. Compared to the ancestral Spike, B.1.640.1 carried 14 amino acid substitutions and deletions. B.1.640.1 escaped binding by some anti-N-terminal domain and anti-receptor-binding domain monoclonal antibodies, and neutralization by sera from convalescent and vaccinated individuals. In cell lines, infection generated large syncytia and a high cytopathic effect. In primary airway cells, B.1.640.1 replicated less than Omicron BA.1 and triggered more syncytia and cell death than other variants. The B.1.640.1 Spike was highly fusogenic when expressed alone. This was mediated by two poorly characterized and infrequent mutations located in the Spike S2 domain, T859N and D936H. Altogether, our results highlight the cytopathy of a hyper-fusogenic SARS-CoV-2 variant, supplanted upon the emergence of Omicron BA.1. (This study has been registered at ClinicalTrials.gov under registration no. NCT04750720.)IMPORTANCEOur results highlight the plasticity of SARS-CoV-2 Spike to generate highly fusogenic and cytopathic strains with the causative mutations being uncharacterized in previous variants. We describe mechanisms regulating the formation of syncytia and the subsequent consequences in a primary culture model, which are poorly understood.

Extracapsular nodal extension and tumor deposits in head and neck squamous cell carcinoma

BACKGROUND

Tumor deposits (TDs) are an infrequently mentioned feature of head and neck squamous cell carcinoma (HNSCC) that are currently grouped under extranodal extension (ENE) in the AJCC 8th edition of HNSCC TNM staging. The prognostic implication of TDs in comparison to ENE remains uncertain.

METHODS

This observational, retrospective, non-randomized study evaluated patients with HNSCC who underwent initial surgical resection, with neck dissection and adjuvant radiotherapy ± chemotherapy. Clinical variables were considered, and statistical analyses were conducted to compare time progression and overall survival (OS) in patients with TDs against those with ENE.

RESULTS

Of the 71 patients included in the study, 50 were diagnosed with ENE (pN2a-ENE in 38 patients and pN3b-ENE in 12), while 21 had TDs ± ENE. The median time to progression was significantly different based on the presence of ENE or TDs (p = .002) and pN2a-ENE/pN3b-ENE or TDs (p = .007). The three-year OS was 55.7% for the entire group, 60.4% in ENE and 38.4% in TDs (p = .021). The OS difference between the pN2a-ENE, pN3b-ENE, and the TDs group was also significant (p = .05). The hazard ratio between ENE and TDs was Exp (B) 4.341 (p = .044).

CONCLUSIONS

TDs in HNSCC are associated with a lower OS than ENE, despite intensified adjuvant therapy. Our results confirm a better prognosis for pN2a-ENE vs. pN3b-ENE, and pN3b-ENE vs. TDs. TDs may serve as an indicator of poor prognosis and require separate TNM classification in HNSCC staging. Larger studies are needed to evaluate TDs impact on treatment strategies and outcomes.

Comparison of alternative N-staging models in patients with oral cancer. Is nodal yield or burden the most critical parameter?

BACKGROUND

There is increasing evidence in the literature that alternative N-classification systems offer a simpler and more precise risk stratification than the current N- classification in patients with oral squamous cell carcinoma. The purpose of this study is to compare three broadly proposed models incorporating lymph node ratio, log odds of positive lymph nodes and number of positive lymph nodes regarding disease-free and overall survival.

METHODS

This is a retrospective study of patients treated in a single center between 2013 and 2019. Cox proportional hazard models, Kaplan Meier curves, the long rank test and the area under the curve were implemented to compare the risk-stratification ability of the three models. Moreover, a hazard ratio plot was calculated to investigate the association between nodal yield and disease-free survival.

RESULTS

231 patients were included. All three proposed N-models were significantly correlated to the patient's prognosis in the multivariate analysis. Pairwise comparisons between the groups showed that the current pN classification offers the worst stratification and that the model incorporating the number of positive lymph nodes had a better performance for predicting both endpoints. Finally, a decrease in hazard ratio was observed with each additional lymph node removed up to the number of 39 lymph nodes.

CONCLUSIONS

The model incorporating the nodal burden offered a better predictive ability. The current N-classification cannot adequately identify patients with different prognosis. A non-linear relationship was found between nodal yield and survival, which could be the disadvantage of the lymph node ratio and log odds models.

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.

Beyond Traditional Approaches: A Pilot Study Exploring the Role of Injection Mitomycin C on the Surgical Resection Bed in Oral Cancer Treatment

Background Oral cavity cancer ranks sixth among all cancers worldwide. India has the most oral cancer cases and accounts for one-third of the global oral cancer burden. Oral cavity cancer is known to be associated with an elevated likelihood of locoregional recurrences, which account for the bulk of post-surgery and radiotherapy treatment failures. Mitomycin C (MMC) is an antineoplastic and antibiotic agent that is administered topically rather than intravenously to treat bladder and intraperitoneal tumors to avoid recurrences. This study aimed to investigate the use of injection MMC as a local application on surgical resection beds for patients undergoing surgery for oral cancer and to assess its efficacy in preventing regional recurrences. Methodology In this prospective, interventional, pilot study, patients were assigned randomly to two groups using simple randomization. Group A involved the application of two gauze pieces soaked with MMC injection. Group B involved the application of two gauze pieces soaked with a 10% betadine solution. During the pectoralis major myocutaneous flap harvest procedure for reconstruction, two gauze pieces soaked with either injection MMC solution (20 mg MMC in 20 mL of 0.9% normal saline) or 10% betadine solution were placed on the surgical resection bed for a 45-minute contact period. Patients were evaluated daily in the postoperative period for local complications. Regular follow-up visits were scheduled for 15 months of follow-up. Results After exclusions at various phases, the final analysis included 50 patients in Group A and 50 patients in Group B. Minor complications, specifically blackening of the skin flap in the neck resulting in surgical site infections, were observed in 16% (eight patients) of the MMC group and in 6% (three patients) of the betadine group (p = 0.1997) patients. In the MMC group, two (4%) patients experienced locoregional recurrences at three months, four (8%) patients at six months, six (12%) patients at nine months, eight (16%) patients at 12 months, and 10 (20%) patients at 15 months of follow-up. In contrast, locoregional recurrences occurred in two (4%) patients in the betadine group at three months, six (12%) patients at six months, nine (18%) patients at nine months, 12 (24%) patients at 12 months, and 15 (30%) patients at 15 months. Although the difference in locoregional recurrences between the two groups was not statistically significant, there was a trend of decreasing locoregional recurrences in the MMC group relative to the betadine group as the duration of follow-up increased. In the subgroup analysis of patients with pathological extranodal extension (ENE), only 10 of 18 patients with ENE in Group A (55.55%) experienced a recurrence, whereas all 12 patients with ENE in Group B (100%) experienced a recurrence within the same time frame. This difference in locoregional recurrence rates between the two groups was statistically significant, with a p-value of 0.0100. Conclusions Our study demonstrated that the local administration of MMC on surgical resection beds may lower the risk of locoregional recurrences in patients with oral cancer, especially those with ENE. These findings contribute to the ongoing efforts to enhance treatment strategies and patient outcomes for this challenging malignancy.

Prediction of extranodal extension in oropharyngeal cancer patients and carcinoma of unknown primary: value of metabolic tumor imaging with hybrid PET compared with MRI and CT

OBJECTIVES

The aim of this study was to investigate the value of metabolic tumor imaging using hybrid PET for the preoperative detection of extranodal extension (ENE) in lymph node metastases of oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

We performed a retrospective analysis of a consecutive cohort of patients with OPSCC treated with primary surgery with or without adjuvant (chemo-) radiotherapy at the Kantonsspital Sankt-Gallen and the University Hospital Zurich, Switzerland, from 2010 until 2019. Hybrid PET was compared to conventional cross-sectional imaging with MRI and CT. Histopathological presence of ENE of neck dissection specimen served as gold standard.

RESULTS

A total number of 234 patients were included in the study, 95 (40.6%) of which had pathological ENE (pENE). CT has a good specificity with 93.7%; meanwhile, MRI was the most sensitive diagnostic method (72.0%). The nodal metabolic tumor parameters (SUV_max, TLG, MTV) were significantly higher in patients with positive ENE (p < 0.001 for all three parameters) than in patients with negative ENE (p < 0.001, for all three parameters).

CONCLUSIONS

CT achieved the best specificity, while MRI had the best sensitivity to detect ENE. Nodal metabolic tumor parameters differed significantly between ENE-positive/negative and p16-positive/negative patients. Hence, quantitative data obtained by metabolic imaging might predict presence of ENE and, therefore, could be helpful in customizing therapy management.

Prognostic Value of Radiological Extranodal Extension Detected by Computed Tomography for Predicting Outcomes in Patients With Locally Advanced Head and Neck Squamous Cell Cancer Treated With Radical Concurrent Chemoradiotherapy

Objective

Extra Nodal Extension (ENE) assessment in locally advanced head and neck cancers (LAHNCC) treated with concurrent chemo radiotherapy (CCRT) is challenging and hence the American Joint Committee on Cancer (AJCC) N staging. We hypothesized that radiology-based ENE (rENE) may directly impact outcomes in LAHNSCC treated with radical CCRT.

Materials and Methods

Open-label, investigator-initiated, randomized controlled trial (RCT) (2012–2018), which included LAHNSCC planned for CCRT. Patients were randomized 1:1 to radical radiotherapy (66–70 grays) with concurrent weekly cisplatin (30 mg/m²) [cisplatin radiation arm (CRT)] or same schedule of CRT with weekly nimotuzumab (200 mg) [nimotuzumab plus CRT (NCRT)]. A total of 536 patients were accrued and 182 were excluded due to the non-availability of Digital Imaging and Communications in Medicine (DICOM) computed tomography (CT) data. A total of 354 patients were analyzed for rENE. Metastatic nodes were evaluated based on five criteria and further classified as rENE as positive/negative based on three-criteria capsule irregularity with fat stranding, fat invasion, and muscle/vessel invasion. We evaluated the association of rENE and disease-free survival (DFS), loco-regional recurrence-free survival (LRRFS), and overall survival (OS).

Results

A total of 244 (68.9%) patients had radiologically metastatic nodes (rN), out of which 140 (57.3%) had rENE. Distribution of rENE was balanced in the two study groups CRT or NCRT (p-value 0.412). The median follow-up period was 39 months (ranging from 35.5 to 42.8 months). Complete response (CR) was seen in 204 (57.6%); incomplete response (IR), i.e., partial response plus stable disease (PR + SD), in 126 (35.6%); and progressive disease (PD) in 24 (6.8%). rENE-positive group had poor survival compared to rENE-negative group 3-year OS (46.7% vs. 63.6%), poor DFS (48.8% vs. 87%), and LRRFS (39.9% vs. 60.4%). rENE positive had 1.71 times increased risk of IR than rENE negative. Overall stage, site, clinical metastatic node (cN), response, and rENE were the significant factors for predicting OS, DFS, and LRRFS on univariate analysis. After making adjustment on multivariate analysis, rENE was an independent prognostic factor for DFS and trending to be significant for OS.

Conclusion

Pre-treatment rENE is an independent prognostic marker for survival in patients with LAHNSCC treated radically with CCRT that can be used as a potential predictive marker for response to treatment and hence stratify patients into responders vs. non-responders. We propose the mahajan rENE grading system applicable on CT, magnetic resonance imaging, positron emission tomography–contrast-enhanced CT, and ultrasound.

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.