Number of nodal metastases and the American Joint Committee on cancer staging of head and neck cutaneous squamous cell carcinoma: A multicenter study

Determinants of Prognosis in Head and Neck Cutaneous Squamous Cell Carcinoma With Nodal Metastases

Importance

The eighth edition tumor, node, metastasis (TNM) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) is a poor predictor of survival in patients with lymph node metastases, possibly due to the inclusion of extranodal extension (ENE).

Objective

To identify the key determinants of prognosis in patients with nodal metastatic HNcSCC and analyze the association of ENE with TNM stage and investigate for prognostic heterogeneity in ENE-positive disease.

Design, Setting, and Participants

This retrospective, multicenter cohort study was conducted at 4 Australian tertiary referral centers using prospectively collected data in patients treated between 1980 and 2017 with a median (IQR) follow-up of 3.2 (3.9) years. The study population included 1309 consecutive patients with HNcSCC that was metastatic to parotid and/or cervical nodes. After excluding cases with perioperative mortality, missing data, or follow-up, the final study population included 1151 patients.

Exposure

Curative intent surgery ± adjuvant radiotherapy.

Main Outcomes and Measures

Differences in locoregional control (LRC), disease-specific survival (DSS), and overall survival were determined using Cox regression analysis.

Results

Among 1151 patients, 976 (84.8%) were male and 175 (15.2%) female, with a median age of 73.3 years (range, 18-100 years). On multivariable analysis, immunosuppression (hazard ratio [HR], 2.48; 95% CI, 1.64-3.74), perineural invasion (HR, 1.69; 95% CI, 1.25-2.30), ENE (HR, 1.53; 95% CI, 0.95-2.44), size (>3-6 cm vs ≤3 cm [HR, 1.41; 95% CI, 1.03-1.93]; >6 cm vs ≤3 cm [HR, 5.01; 95% CI, 2.98-8.42]), and number of nodal metastases (3-4 vs 1-2 [HR, 1.54; 95% CI, 1.01-2.34]; ≥5 vs 1-2 [HR, 2.86; 95% CI, 1.99-4.11]) were associated with DSS. Similar results were found for LRC and overall survival. More than 90% of the population was categorized as TNM stage IV, with 32% attributable to ENE. In the ENE-positive subset (n = 860), DSS ranged from 8% to 88% based on stratification using other clinicopathological factors.

Conclusions and Relevance

The study results suggest that immunosuppression, perineural invasion, ENE, and size and number of nodal metastases are associated with reduced survival and LRC in HNcSCC with nodal metastases. The inclusion of ENE in HNcSCC staging needs to be reassessed, as it ascribes excessive importance to ENE and upstages most patients to TNM stage IV, despite many having a high chance of cure.

Therapeutic Approaches for Non-Melanoma Skin Cancer: Standard of Care and Emerging Modalities

Skin cancer encompasses a range of cutaneous malignancies, with non-melanoma skin cancers (NMSCs) being the most common neoplasm worldwide. Skin exposure is the leading risk factor for initiating NMSC. Ultraviolet (UV) light induces various genomic aberrations in both tumor-promoting and tumor-suppressing genes in epidermal cells. In conjunction with interactions with a changed stromal microenvironment and local immune suppression, these aberrations contribute to the occurrence and expansion of cancerous lesions. Surgical excision is still the most common treatment for these lesions; however, locally advanced or metastatic disease significantly increases the chances of morbidity or death. In recent years, numerous pharmacological targets were found through extensive research on the pathogenic mechanisms of NMSCs, leading to the development of novel treatments including Hedgehog pathway inhibitors for advanced and metastatic basal cell carcinoma (BCC) and PD-1/PD-L1 inhibitors for locally advanced cutaneous squamous cell carcinoma (cSCC) and Merkel cell carcinoma (MCC). Despite the efficacy of these new drugs, drug resistance and tolerability issues often arise with long-term treatment. Ongoing studies aim to identify alternative strategies with reduced adverse effects and increased tolerability. This review summarizes the current and emerging therapies used to treat NMSC.

Lymph node metastasis in cutaneous squamous cell carcinoma of the head and neck

BACKGROUND

The study aimed to assess the impact of parotid lymph nodes (LNs) on the prognosis of patients with cutaneous squamous cell carcinomas of the head and neck (HNcSCC), and to develop an alternative LN assessment method to enhance locoregional control (LRC) and overall survival (OS) stratification.

METHODS

We retrospectively enrolled patients with surgically treated HNcSCC. Primary outcome variables were LRC and OS. The influence of parotid LNs and different LN assessment methods on prognosis was analyzed using Cox models, and comparisons were made using the C-index, Akaike Information Criterion, and Bayesian Information Criterion.

RESULTS

A total of 126 patients were included. Both intraparotid and periparotid LN statuses significantly linked with prognosis. The presence of extranodal extension (ENE) in cervical LNs, rather than parotid LNs, was predictive of decreased LRC and OS. In the Cox analysis, only N3 of the AJCC N classification, when compared to N0, showed reduced LRC and OS. In comparison to N0P1, only N0P3/N1P1 and N2P2/N2P3 of the O'Brien staging system tended to predict poorer LRC, with no subgroup emerging as an independent predictor for OS. The proposed LN assessment method, based on the number of metastatic LNs and ENE status in cervical LNs, demonstrated superior performance in terms of C-index, Akaike Information Criterion, and Bayesian Information Criterion compared to other systems.

CONCLUSION

Parotid LNs were significant determinants of prognosis in metastatic HNcSCC. The novel LN assessment method proposed (1-2 vs. 3-4 vs. 5 + or ENE) displayed similar survival stratification to the AJCC N and O'Brien staging systems.

The Current Treatment Landscape of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers (NMSCs) are the most common form of skin cancer worldwide. The global incidence of cutaneous squamous cell carcinoma (CSCC) is rising, with an estimated 2.4 million cases diagnosed in 2019. Chronic exposure to ultraviolet (UV) radiation is a major risk factor for developing CSCC. Most early-stage CSCCs are treated successfully with surgery or radiotherapy; however, locally advanced or metastatic disease can be associated with significant morbidity or mortality. Recently, the treatment paradigm for advanced CSCC has been revolutionised by the introduction of immunotherapy, which can achieve a response rate of approximately 50% with durable cancer control, and significant improvement in quality of life. With the regulatory approval of programmed death-1 (PD-1)-targeting drugs since 2018, immunotherapy is now recognised as the standard of care for first-line systemic therapy in advanced or metastatic CSCC.

Radiotherapy for cutaneous squamous cell carcinoma: current standards and outlooks

Cutaneous squamous cell carcinoma accounts for 20 % of all malignant non-melanoma skin tumors, which is one of the most common cancers worldwide. Antitumor treatment is usually very effective: cure rate reaches 90 %, while local recurrence rate is 25 %. The main treatment option for primary skin cancers is surgery. The most significant risk factors for locoregional recurrence include tumor location (head and neck), size (>2 cm), depth of invasion (>4 mm), tumor differentiation grade, perineural invasion, immune system disorders (immunosuppression), severe concomitant diseases, and previous treatment.

In patients with advanced cutaneous squamous cell carcinoma, 1-year, 2-year, and 3-year survival rates are 50–80, 30–35 and 15–16 %, respectively. Radiotherapy is a radical treatment option that increases the 5-year survival rate to 90 % and ensures good cosmetic results in 80 % of cases. There are 3 main variants of radiotherapy for cutaneous squamous cell carcinoma: sole radiotherapy according to a radical program, adjuvant radiotherapy in combination with surgery, and palliative radiotherapy. most frequently, radiotherapy is used as part of adjuvant postoperative treatment and is not initially considered as a sole conservative treatment for cutaneous squamous cell carcinoma patients below 45 years of age with resectable tumors, especially high-risk tumors. palliative radiotherapy is an affordable and effective method for combating painful symptoms; moreover, it often provides long-term local control. 

Evolution of Head and Neck Cutaneous Squamous Cell Carcinoma Nodal Staging—An Australian Perspective

Simple Summary

Australia has the highest incidence of cutaneous squamous cell carcinoma of the head and neck (HNcSCC) in the world. Although the majority of HNcSCCs are cured by simple surgical excision, those that spread to lymph nodes require aggressive and debilitating surgery in conjunction with radiation therapy, with a significant risk of treatment failure and subsequent loss of life. Cancer staging is critical to guide prognosis, treatment (to maximise disease control and minimise morbidity), and for research. Australian institutions have been at the forefront of prognostication for HNcSCC with lymph node spread. Despite this, the search for a well performing staging system is ongoing. This review chronologically explores and summarises the Australian contribution to date and highlights the ongoing challenges.

Abstract

Cutaneous squamous cell carcinoma of the head and neck (HNcSCC) is one of the commonest malignancies. When patients present with regional metastatic disease, treatment escalation results in considerable morbidity and survival is markedly reduced. Owing to the high incidence, Australian institutions have been at the forefront of advocating for reliable, accurate, and clinically useful staging systems that recognise the distinct biological characteristics of HNcSCC. As a result, an extensive body of literature has been produced over the past two decades, which has defined critical prognostic factors, critiqued existing staging systems, and proposed alternative staging models. Notwithstanding, a suitable staging system has proved elusive. The goal of cancer staging is to group patients according to cancer characteristics for which survival differs between groups (distinctiveness), consistently decreases with increasing stage (monotonicity), and is similar within a group (homogeneity). Despite implementing major changes based on published data, the latest edition of the American Joint Committee on Cancer (AJCC) staging manual fails to satisfy these fundamental requirements. This review chronologically explores and summarises the Australian contribution to prognostication and nodal staging of HNcSCC and highlights the ongoing challenges.

Adequacy of Disease Control by Supraomohyoid Neck Dissection in cT1/T2 Tongue Cancer

Background: Patients affected by oral tongue squamous cell carcinoma (OTSCC) underwent a supraomohyoid neck dissection (SOHND) or modified radical neck dissection (mRND) according to the clinical nodal status (cN0 vs. cN+). We investigate whether the type of neck dissection affects survival with the presence of extranodal extension (ENE) and multiple nodal metastases (MNM). Methods: We conducted a retrospective study enrolling surgically treated patients affected by cT1/T2 OTSCC and MNM or ENE. The outcomes assessed were: overall survival (OS), disease-free survival (DFS), and neck-control- and metastases-free survival (NC-MFS). Survival curves were plotted by the Kaplan–Meier method and the log-rank test. Furthermore, we conducted a multivariable analysis with the Cox regression model. Results: We included a total of 565 patients (36% cT1, 64% cT2). Of these, 501 patients underwent a SOHND, and 64 underwent an mRND. A total of 184 patients presented rpN+, with 28.7% of these in the SOHND group and 62.5% of these in the mRND group. We identified no significant differences in OS, DFS, and NC-MFS in the whole pN+ cohort, in the MNM, and the ENE subgroups. In the multivariable analysis, the type of ND did not affect OS and DFS. Conclusions: Treating cT1-2 N0/+ tongue cancer with SOHND is oncologically safe. ENE and MNM patients do not benefit from an mRND.

Regional disease in head and neck cutaneous squamous cell carcinoma: the role of primary tumor characteristics and number of nodal metastases

PURPOSE

To identify potential risk factors impacting on overall survival (OS) of patients affected by lymph node metastasis from cutaneous squamous cell carcinoma (cSCC) of the head and neck (HN), with special emphasis on primary tumor characteristics and pattern of nodal recurrence (intraparotid and/or cervical).

METHODS

A bi-institutional retrospective study on consecutive patients affected by cervical and/or intraparotid NM from HN cSCC and surgically treated with curative intent from May 2010 to January 2020 was conducted. OS was considered the outcome of interest.

RESULTS

The study included 89 patients (M:F = 3.4:1; median age, 78 years; range, 22-99). Among the primary tumor characteristics, the most relevant prognostic factors were diameter ≥ 4 cm (hazard ratio [HR] = 2.56, p = 0.010) and depth of infiltration ≥ 6 mm (HR = 3.54, p = 0.027). Cervical NM was associated with worse OS (HR = 2.09, p = 0.016) compared to purely intraparotid NM (5-year OS: 60.9% vs. 28.1%, p = 0.014). At multivariable analysis, age, immunosuppression, pT3-T4 categories and a high burden of nodal disease (> 2 NM) confirmed to be independent risk factors, whereas adjuvant radiotherapy was independently associated with better outcome.

CONCLUSION

This study confirms the association of several independent prognosticators related to the patient, primary tumor, and nodal burden status. Patients with cervical NM should be considered at risk for harboring a higher number of metastatic lymph nodes.

The analysis of metabolomics and transcriptomics data in head and neck squamous cell carcinoma

OBJECTIVE

Studies have shown that cancer progression of head and neck squamous cell carcinoma (HNSCC) is related with metabolic alterations. The aim of this study is to identify the clinical roles of metabolic alterations in HNSCC.

MATERIALS AND METHODS

Metabolism-related genes associated with HNSCC were searched in public databases. A predictive and efficacious LASSO model was fabricated to optimize the diagnosis that was based on these genes. Meantime, Ultra-Performance Liquid Chromatography-Quadrupole/Orbitrap High Resolution Mass Spectrometry (UHPLC-Q-Orbitrap HRMS) was used to compare patients with HNSCC (n=73) with healthy controls (HC) (n=51) for serum metabolites. Potential biomarkers and alterations in serum metabolites were analysed and evaluated using t-test analysis, principal component analysis and orthogonal partial least square discrimination analysis (OPLS-DA).

RESULTS

Overall, 21 differential metabolites were probed in serum, of which 8 metabolites had potential for clinical uses. Transcriptome analysis showed that 4 genes in the constructed LASSO model were found to be associated with 7 differential metabolites. Metabolic pathway analysis by MetaboAnalyst showed that the biomarkers that were related with HNSCC were closely related to 4 metabolism pathways (p<0.05).

CONCLUSION

To conclude, future research on HNSCC should be directed toward multi-omics to provide treatment, intervention, or diagnosis of the disease.

The number of metastatic lymph nodes optimizes staging in patients aged 55 years or older with papillary thyroid cancer

PURPOSE

Current staging criteria for papillary thyroid cancer (PTC) do not include the number of metastatic lymph nodes (LNs), which is highly predictive of survival in multiple cancers. The LN metastasis burden is particularly relevant for older adults with thyroid cancer because of their poor prognosis. We examined a modified staging system for this population utilizing node number (Nn).

METHODS

Overall, 14,341 patients aged 55 years or older with stage I-IVB PTC were identified in the 2004-2015 Surveillance, Epidemiology and End Results database. Cox regression models were conducted to test the relationship between positive LN number and PTC-specific survival (PTCSS). Independent training/validation sets were used to derive and validate a new revised TNnM grouping. The 8th edition American Joint Committee on Cancer TNM staging system was compared with TNnM stage by calculating the 10-year PTCSS rates, Harrell's concordance index (C-index), and Akaike's information criterion (AIC).

RESULTS

An increase in number of LN metastases was identified as an independent, negative prognostic factor for PTCSS in multivariate analysis. 10-year PTCSS for stage I-IVB based on the AJCC 8th edition TNM were 98.83%, 93.49%, 71.21%, 72.95%, and 58.52%, respectively, while 10-year PTCSS for the corresponding stage in the TNnM were 98.59%, 92.2%, 83.26%, 75.24%, and 56.73%, respectively. The revised TNnM stage was superior, with a higher C-index and a lower AIC in both the training and validation cohorts.

CONCLUSION

The TNnM staging system for PTC patients ≥ 55 years could be associated with improved outcomes. External validation studies of this system are warranted.

The Prognostic Value of Lymph Node Burden in Oral Cavity Cancer: Systematic Review and Meta-Analysis

OBJECTIVES

Lymph node burden has been proposed to estimate the cumulative adverse effect of nodal metastasis. In this study, a meta-analysis was conducted to evaluate the prognostic value of lymph node burden in oral cavity squamous cell carcinoma.

STUDY DESIGNS

Systemic review and meta-analysis.

METHODS

PubMed, EMBASE and the Cochrane Library as well as manual searches were performed until April 2020. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of overall survival, disease-specific survival, and disease-free survival were extracted and pooled.

RESULTS

Eleven included studies were published between 2009 and 2019. The cumulative number of patients was 20,607 (range 35-14,554). Extranodal extension was adjusted or evaluated in all of the studies. The meta-analysis indicated that a higher lymph node burden was significantly related to worse overall survival (HR 2.62, 95% CI 2.12-3.25), worse disease-specific survival (HR 3.14, 95% CI 1.85-5.33) and worse disease-free survival (HR 2.30, 95% CI 1.62-3.26). The highest hazard ratio was observed when the cutoff value was 3 for overall survival, 3 for disease-specific survival, and 4 for disease-free survival. The hazard ratio showed an upward trend before the cutoff value of 3 but no significant incremental change when the cutoff exceeded 3.

CONCLUSIONS

In oral squamous cell carcinoma, lymph node burden is an independent prognosticator for survival outcomes. However, more prospective or high-quality studies are required to determine the optimal cutoff.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.