Treatment implications of postoperative chemoradiotherapy for squamous cell carcinoma of the oral cavity with minor and major extranodal extension

Evaluating the impact of the degree of extranodal extension on outcomes in locally advanced oral cavity cancer

BACKGROUND

Evaluate whether extranodal extension (ENE) extent impacts outcomes in patients with oral cavity squamous cell carcinoma (OCSCC).

METHODS

From an institutional database, patients with OCSCC and pathologic ENE who received adjuvant treatment were included. Surgical slides were reviewed to confirm ENE extent. Multivariable Cox regression was used to relate patient/treatment characteristics with disease-free survival (DFS) and overall survival (OS). ENE was analyzed as both a dichotomous and continuous variable.

RESULTS

A total of 113 patients were identified. Between major (>2 mm) versus minor ENE (≤2 mm), there was no significant difference in DFS (HR 1.18, 95%CI 0.72-1.92, p = 0.51) or OS (HR 1.17, 95%CI 0.70-1.96, p = 0.55). There was no significant association between ENE as a continuous variable and DFS (HR 0.97 per mm, 95%CI 0.87-1.4, p = 0.96) or OS (HR 0.96 per mm, 95%CI 0.83-1.11, p = 0.58).

CONCLUSION

No significant relationship was seen between ENE extent and DFS or OS in individuals with OCSCC.

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.

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 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.

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

BACKGROUND

For oral cavity squamous cell carcinoma (OSCC), extent of extranodal extension (ENE) (minor, ≤2 mm; major, >2 mm) is differentially prognostic, whereas limitations exist with the 8th edition of American Joint Committee on Cancer/International Union Against Cancer TNM N-classification (TNM-8-N).

METHODS

Resected OSCC patients at four centers were included and extent of ENE was recorded. Thresholds for optimal overall survival (OS) discrimination of lymph node (LN) features were established. After dividing into training and validation sets, two new N-classifications were created using 1) recursive partitioning analysis (RPA), and 2) adjusted hazard ratios (aHRs) and were ranked against TNM-8-N and two published proposals.

RESULTS

A total of 1460 patients were included (pN0: 696; pN+: 764). Of the pN+ cases, 135 (18%) had bilateral/contralateral LNs; 126 (17%) and 244 (32%) had minor and major ENE, and two (0.3%) had LN(s) >6 cm without ENE (N3a). LN number (1 and >1 vs. 0: aHRs, 1.92 [95% confidence interval (CI), 1.44-2.55] and 3.21 [95% CI, 2.44-4.22]), size (>3 vs. ≤3 cm: aHR, 1.88 [95% CI, 1.44-2.45]), and ENE extent (major vs. minor: aHR, 1.40 [95% CI, 1.05-1.87]) were associated with OS, whereas presence of contralateral LNs was not (aHR, 1.05 [95% CI, 0.81-1.36]). The aHR proposal provided optimal performance with these changes to TNM-8-N: 1) stratification of ENE extent, 2) elimination of N2c and 6-cm threshold, and 3) stratification of N2b by 3 cm threshold.

CONCLUSION

A new N-classification improved staging performance compared to TNM-8-N, by stratifying by ENE extent, eliminating the old N2c category and the 6 cm threshold, and by stratifying multiple nodes by size.

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.

Prognostic Value of CRP-Albumin-Lymphocyte (CALLY) Index in Patients Undergoing Surgery for Oral Cavity Cancer

Background: The prognostic value of the CRP-albumin-lymphocyte index (CALLY index) was analyzed in patients with oral cavity squamous cell carcinoma (OSCC) undergoing curative surgery.

Methods: We retrospectively included 279 patients who were diagnosed as having primary OSCC and being treated with surgery. The optimal cutoff for the preoperative CALLY index was identified by considering the area under the receiver operating characteristic curve; subsequently, the discriminatory ability of the cutoff was determined. We employed Kaplan-Meier analysis and the log-rank test to elucidate associations between the CALLY index and survival outcomes. We identified prognostic variables by using the Cox proportional hazards model. Finally, we devised a nomogram based on the CALLY index for predicting individualized survival.

Results: The cutoff value of the CALLY index was determined to be 0.65. A CALLY index < 0.65 exhibited a significant association with pathological aggressiveness as well as shorter overall and disease-free survival (OS and DFS, both P < 0.001). A low CALLY index was an independent risk factor for short OS and DFS [hazard ratio = 3.816; 95% confidence interval (CI) 2.393-6.086; P < 0.001; and hazard ratio = 2.103; 95% CI 1.451-3.049; P < 0.001, respectively] in multivariate Cox analysis. The prognostic nomogram based on the CALLY index yielded accurate predictions of OS, as revealed by a concordance index of 0.797.

Conclusions: The preoperative CALLY index is easy and inexpensive to calculate and, in patients with OSCC, can be a valuable prognostic biomarker. The CALLY-index-based nomogram established in this study provides accurate survival predictions.

Adding Concomitant Chemotherapy to Postoperative Radiotherapy in Oral Cavity Carcinoma with Minor Risk Factors: Systematic Review of the Literature and Meta-Analysis

When presenting with major pathological risk factors, adjuvant radio-chemotherapy for oral cavity cancers (OCC) is recommended, but the addition of chemotherapy to radiotherapy (POCRT) when only minor pathological risk factors are present is controversial. A systematic review following the PICO-PRISMA methodology (PROSPERO registration ID: CRD42021267498) was conducted using the PubMed, Embase, and Cochrane libraries. Studies assessing outcomes of POCRT in patients with solely minor risk factors (perineural invasion or lymph vascular invasion; pN1 single; DOI ≥ 5 mm; close margin < 2−5 mm; node-positive level IV or V; pT3 or pT4; multiple lymph nodes without ENE) were evaluated. A meta-analysis technique with a single-arm study was performed. Radiotherapy was combined with chemotherapy in all studies. One study only included patients treated with POCRT. In the other 12 studies, patients were treated with only PORT (12,883 patients) and with POCRT (10,663 patients). Among the patients treated with POCRT, the pooled 3 year OS rate was 72.9% (95%CI: 65.5−79.2%); the pooled 3 year DFS was 70.9% (95%CI: 48.8−86.2%); and the pooled LRFS was 69.8% (95%CI: 46.1−86.1%). Results are in favor of POCRT in terms of OS but not significant for DFS and LRFS, probably due to the heterogeneity of the included studies and a combination of different prognostic factors.

The impact of microscopic versus macroscopic extranodal extension in oral cavity squamous cell carcinoma: National cancer database analysis and review of the literature

OBJECTIVE

To analyze the prognostic significance of microscopic vs macroscopic extranodal extension and to assess the impact of chemoradiation on overall survival among patients with oral cavity squamous cell carcinoma and varying degrees of extranodal extension.

METHODS

Utilizing the National Cancer Database, we performed a retrospective cohort study of 7975 patients with oral cavity squamous cell carcinoma and varying degrees of extranodal extension who underwent primary surgical intervention. Propensity-score matched models following Cox regression analyses allowed us to assess the impact of adjuvant radiation alone vs adjuvant chemoradiation on overall survival in patients with microscopic extranodal extension and macroscopic extranodal extension.

RESULTS

7975 patients with oral cavity squamous cell carcinoma were included in the final analysis. Within this cohort, 25.4% had microscopic extranodal extension and 5.2% had macroscopic extranodal extension. On univariate analysis, we found that microscopic and macroscopic extranodal extension were associated with decreased overall survival when compared to those with positive nodes without extranodal extension (HR = 1.67; 95% CI 1.56, 1.79 and HR = 1.88; 95% CI 1.66, 2.14, respectively). On multivariate analysis after propensity-score matching, we found no significant difference in overall survival in patients who received adjuvant radiation alone vs. adjuvant chemoradiation for both microscopic and macroscopic extranodal extension.

CONCLUSION

Our data suggest that microscopic extranodal extension in oral cavity squamous cell carcinoma is associated with worse overall survival than patients without extranodal extension following primary surgical intervention with neck dissection. The results of this study also suggest that the addition of chemotherapy to adjuvant radiation may not provide a significant survival benefit in patients with oral cavity squamous cell carcinoma with microscopic and macroscopic extranodal extension. Comprehensive assessment of the benefits of adjuvant chemoradiation in the setting of microscopic vs macroscopic extranodal extension would need to be studied in a randomized controlled trial.

Radiologic-pathologic correlation of major versus minor extranodal extension in oral cavity cancer

BACKGROUND

To evaluate the diagnostic performance of radiologic extranodal extension (rENE) in predicting major (>2 mm) and minor (≤2 mm) pathologic ENE (pENE).

METHODS

All oral cavity squamous cell carcinoma patients who underwent neck dissection with pathological nodal disease (pN+) between 2010 and 2015 were reviewed. Preoperative computed tomography and/or magnetic resonance imaging were reviewed by two head and neck neuroradiologists.

RESULTS

Three hundred and thirty-four patients were included. The sensitivity and specificity of rENE were 37% [95% CI 29-44] and 98% [95% CI 96-100], respectively. Sensitivity for pENE improved in the subset of patients with major ENE (48% [95% CI 38-57]). The presence of rENE was associated with inferior 3-year overall survival: 26% [95% CI 17-41] versus 60% [95% CI 54-67].

CONCLUSIONS

This large cohort study demonstrates high specificity, but low sensitivity for preoperative imaging in the detection of pENE in OCSCC. Patients with rENE demonstrated poor OS. pENE in the absence of rENE is still an adverse risk factor.

Fructose-1,6-Bisphosphatase 2 Inhibits Oral Squamous Cell Carcinoma Tumorigenesis and Glucose Metabolism via Downregulation of c-Myc

Background

Fructose-1,6-bisphosphatase 2 (FBP2), known as a rate-limiting enzyme in gluconeogenesis, is a tumor suppressor downregulated in various cancers. However, the role of FBP2 in oral squamous cell carcinoma (OSCC) remains largely unclear.

Methods

The level of FBP2 in OSCC tissues and matched adjacent normal tissues was determined by western blot and RT-qPCR assays. In addition, analysis of FBP2 function in OSCC cells was assessed using both gain-of-function and loss-of-function studies.

Results

In this study, we found that the expression of FBP2 was remarkably downregulated in OSCC tissues and OSCC cells. Overexpression of FBP2 suppressed the viability, proliferation, migration, and glycolysis of OSCC cells, whereas FBP2 knockdown exhibited the opposite results. Moreover, downregulation of FBP2 promoted the growth and glycolysis of OSCC cells in nude mice in a xenograft model. Specifically, FBP2 colocalizes with the c-Myc transcription factor in the nucleus. Significantly, inhibitory effects of FBP2 overexpression on the viability, proliferation, migration, and glycolysis of OSCC cells were reversed by c-Myc overexpression.

Conclusion

Collectively, FBP2 could suppress the proliferation, migration and glycolysis in OSCC cells through downregulation of c-Myc. Our study revealed a FBP2-c-Myc signaling axis that regulates OSCC glycolysis and may provide a potential intervention strategy for OSCC treatment.

Novel pathological predictive factors for extranodal extension in oral squamous cell carcinoma: a retrospective cohort study based on tumor budding, desmoplastic reaction, tumor-infiltrating lymphocytes, and depth of invasion

Background

Extranodal extension (ENE) is a poor prognostic factor for oral squamous cell carcinoma (OSCC). Identifying ENE by clinical and/or radiological examination is difficult, thereby leading to unnecessary neck dissections. Currently, no definitive predictors are available for ENE. Thus, we aimed to determine the histological predictors of ENE by routine histopathological examination using biopsy and surgically resected specimens.

Methods

This retrospective study included 186 surgically resected OSCC and 83 matched biopsy specimens. Clinical features associated with the tumor microenvironment, including desmoplastic reaction (DR), tumor budding (TB), and tumor-infiltrating lymphocytes (TILs), were evaluated using hematoxylin and eosin-stained primary OSCC and neck dissection specimens. These histological features were divided into two groups: DR-immature (DR-I) and DR-mature (DR-M); TB-high (TB-H) and TB-low (TB-L); and TILs-low (TILs-L) and TILs-high (TILs-H). Clinical depth of invasion (cDOI) and pathological DOI (pDOI) were adapted for biopsies and resections, respectively; DOI was evaluated as DOI > 10 mm and DOI ≤ 10 mm. The clinicopathological relationships between these histopathological features and ENE and the independent risk factors for ENE were analyzed. The histological predictors of ENE were evaluated.

Results

The histological status of DR, TILs, and TB present in biopsy and resection specimens showed high accuracy with that of ENE. DR-I, TILs-L, and TB-H were significantly associated with lymph node metastasis, cDOI, and pDOI. Bivariate and multivariate analyses revealed that TB-H and pDOI > 10 mm in resections were independent factors for the presence of ENE (ENE +). The combination of TB-H/pDOI > 10 mm in resection specimens showed high specificity (91%) and accuracy (83%) regarding ENE + . Although there proved to be no independent factors in biopsies, DR-I and TILs-L were significantly associated with ENE + (p < 0.001). The combination of DR-I/TILs-L/cDOI > 10 mm in biopsies exhibited high sensitivity and specificity with ENE + (70% and 77%, respectively, p < 0.001). These histological predictors could detect even minor ENE (< 2 mm).

Conclusions

The tumor microenvironment status in primary OSCC was significantly associated with that of ENE, and TB-H was an independent risk factor for ENE. The histological status of DR-I/TILs-L/cDOI > 10 mm in biopsy specimens and TB-H/pDOI > 10 mm in resection specimens is a useful predictor of ENE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09393-8.

Incidence and prognostic significance of extranodal extension in isolated nodal recurrence of oral squamous cell carcinoma

BACKGROUND

Extranodal extension (ENE) is a crucial prognostic factor of oral squamous cell carcinoma (OSCC). However, the role of ENE in regional recurrence (rENE) remains unclear. The purpose of our study is to assess the salvage outcome according to the presence of rENE in oral cancer patients with isolated nodal recurrence.

METHODS

Oral cancer patients diagnosed with isolated nodal recurrence at the National Taiwan University Hospital between January 2010 and December 2015 were reviewed. All patients were classified into two groups: with and without rENE. The treatment included salvage neck dissection (ND) ± metronomic chemotherapy, salvage ND and radiation (RT)/concurrent chemoradiation (CCRT), Salvage RT/CCRT alone, metronomic chemotherapy, or supportive care.

RESULTS

We analyzed 198 patients, 156 with rENE and 42 without rENE. rENE presented more frequently in patients with initial ENE+ (OR = 3.17, p = 0.04), prior RT+ (OR = 2.96, p = 0.02), initial N2/N3 (OR = 2.76, p = 0.01), and recurrent LN size >1.5 cm (OR = 2.33, p = 0.03). The extent of rENE were also significantly different in these patients. The 2-year disease-free survival for patients with and without rENE were 15.7% and 31.7%, respectively (p = 0.002). The 2-year overall survival for patients with and without rENE were 19.6% and 43.9%, respectively (p = 0.004). For patients without rENE, those received salvage ND had better survival outcome (p < 0.001). By contrast, for patients with rENE, those received salvage RT/CCRT had better survival outcome (p < 0.001).

CONCLUSION

The rENE is frequently present (78.79%) in OSCC patients with isolated nodal recurrence. Individualized treatment modalities based on the presence of rENE should be recommended to achieve better salvage outcomes.

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.

Microscopic Extranodal Extension in HPV-Negative Head and Neck Cancer and the Role of Adjuvant Chemoradiation

OBJECTIVE

Pathologic extranodal extension (ENE) is an important adverse feature for human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC), but the prognostic significance of microscopic ENE (ENEmi) and role of adjuvant concurrent chemoradiation (CRT) for ENEmi remain unclear. This study evaluates (1) the prognostic significance of ENEmi in HPV-negative HNSCC and (2) whether adjuvant CRT is associated with improved overall survival (OS) for these patients.

STUDY DESIGN

Retrospective cohort study.

SETTING

Commission on Cancer (CoC)-accredited facilities.

METHODS

This retrospective cohort study included patients in the National Cancer Database from 2009 to 2015 with pathologic node-positive (pN+) HPV-negative HNSCC with either pathologic ENEmi or no ENE who had undergone margin-negative surgery. The association of ENEmi with OS was evaluated using Cox proportional hazard analyses. Analyses were repeated in patients with ENEmi receiving adjuvant therapy to evaluate the association of adjuvant CRT with OS.

RESULTS

We included 5483 patients with pN+ HPV-negative HNSCC, of whom 24% had ENEmi. On multivariable analysis, ENEmi was associated with decreased OS relative to no ENE (adjusted hazard ratio [aHR], 1.43; 95% CI, 1.28-1.59). Among patients with ENEmi who received ≥60 Gy of adjuvant radiation therapy (RT) (n = 617), adjuvant CRT was not associated with improved OS relative to RT (aHR, 0.91; 95% CI, 0.66-1.27).

CONCLUSION

For patients with HPV-negative HNSCC, pN+ with ENEmi is associated with worse OS than pN+ without ENE. However, for patients with ENEmi, concurrent CRT is not associated with improved OS relative to RT. The optimal adjuvant paradigm for ENEmi requires additional investigation.