A critical analysis of the prognostic performance of the 8th edition American Joint Committee on Cancer staging for metastatic cutaneous squamous cell carcinoma of the head and neck

Metastatic patterns and treatment options for head and neck cutaneous squamous cell carcinoma (Review)

According to current predictions, one-fifth of all Americans will develop skin cancer during their lifetime. Cutaneous squamous cell carcinoma (cSCC) most commonly occurs in the head and neck region, which is the area of the body with the highest level of sun exposure. High-risk head and neck cSCC (HNcSCC) is a broad category with numerous high-risk factors that are associated with unfavorable results. In cSCC staging systems, clinical and tumor traits that are likely to result in poor outcomes are identified. Metastasis occurs in ~2.5% of patients with cSCC, most often in the local lymph nodes, and there is some indication that lymph node metastasis has a distinct pattern based on the tumor site. Current findings on tumor molecular targets have suggested the use of systemic treatments, particularly immunotherapy (such as cemiplimab, pembrolizumab and nivolumab), over radiotherapy or chemotherapy for this type of metastasis. However, when used simultaneously with immunotherapy, radiotherapy may be beneficial in the treatment of metastatic HNcSCC by improving the efficacy of immunotherapy. The present review aims to assess the existing literature on metastatic HNcSCC pathways and treatment options, in order to define current and future directions. Notably, there is an urgent need to identify patients who may benefit from local or systemic cancer treatments. The treatment of lymph node metastasis presents a therapeutic challenge and requires comprehensive management.

Results of surgical treatment of lymph node metastases in patients with cutaneous squamous cell carcinoma of the head and neck

INTRODUCTION

Out of all cutaneous squamous cell carcinomas originating in the head and neck (HNCSCC), 2-4% are associated with parotid or cervical lymph node metastasis. The aim of this study is to analyse the prognostic factors of patients with HNCSCC with lymph node involvement treated surgically. Additionally, we aim to compare the prognostic capacity of the classification of these patients according to the 8th edition of the TNM, and an alternative classification proposed by O'Brien et al. PATIENTS AND METHODS: Retrospective review of 65 patients with HNCSCC with lymph node metastasis treated surgically during the period 2000-2020.

RESULTS

During the study period we carried out 13 neck dissections and 52 parotidectomies + neck dissection in patients with lymph node metastases from a HNCSCC. The great majority of patients (89.2%) received post-operative radiotherapy. The 5 year disease-specific survival was 69.9%, and the overall survival it was 42.8%. The classification proposed by O'Brien et al., based on the parotid or cervical location of the lymph node metastases, and the size and number of the metastatic lymph nodes, had a better prognostic capacity than the TNM classification.

CONCLUSIONS

The surgical treatment of lymph node metastases in patients with HNCSCC achieved a high disease control. The classification based on the location, size and number of lymph node metastases proposed by O'Brien et al had better prognostic capacity than the TNM classification.

Aggressive Cutaneous Squamous Cell Carcinoma of the Head and Neck: A Review

Non-melanoma skin cancer of the head and neck (NMSCHN) is one of the most common malignancies worldwide, and its incidence is growing at a significant rate. It has been found to be aggressive in its spread and has the capacity to metastasize to regional lymph nodes. Cutaneous squamous cell carcinoma (cSCC) has a considerably high mortality rate. It has remarkable characteristics: diameter >2 cm, depth >5 mm, high recurrence, perineural invasion, and locoregional metastases. Aggressive cSCC lesions most commonly metastasize to the parotid gland. Also, immunocompromised patients have a higher risk of developing this aggressive cancer along with the worst prognostic outcomes. It is very important to discuss and assess the risk factors, prognostic factors, and outcomes of patients with cSCC, which will give clinicians future directives for making modifications to their treatment plans. The successful treatment of aggressive cSCC of the head and neck includes early detection and diagnosis, surgery alone or adjuvant chemotherapy, and radiotherapy as required. Multimodal therapy options should be considered by clinicians for better outcomes of aggressive cSCC of the head and neck.

American Head and Neck Society position statement on the use of PD-1 inhibitors for treatment of advanced cutaneous squamous cell carcinoma

BACKGROUND

A position statement put forth by the American Head and Neck Society (AHNS) was constructed to provide evidence-based treatment recommendations for PD-1 inhibitor use in advanced cutaneous squamous cell carcinoma (cSCC). Secondarily, we sought to identify knowledge gaps warranting further investigation.

METHODS

A literature search utilizing key terms: cutaneous squamous cell carcinoma, cutaneous cancer, checkpoint inhibitors, systemic therapy, Program Cell Death, PD-1 (PubMed, Cochrane, and Google Scholar) was carried out to generate evidence-based statements. The statements were distributed among the AHNS membership. Delphi methodology was applied to identify statements achieving 70% or greater consensus among the leadership team.

RESULTS

Twenty-six position statements achieved consensus. Knowledge gaps for future research included: impact of immunosuppression on cSCC staging and associated treatment; role of PD-1 inhibitors in immunosuppressed patients.

CONCLUSION

This comprehensive position statement put forth by the AHNS represents majority consensus by practicing head and neck surgeons throughout the country.

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.

New Developments in the Management of Cutaneous Squamous Cell Carcinoma

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. List important prognostic features that affect cutaneous squamous cell carcinoma risk. 2. Summarize the changes to the AJCC Cancer Staging Manual, Eighth Edition, staging system for cutaneous squamous cell carcinoma. 3. Evaluate the draining nodal basin with appropriate imaging modalities. 4. Recommend adjuvant radiation therapy in the correct clinical setting for high-risk tumors. 5. Recognize the currently available treatments for advanced cutaneous squamous cell carcinoma.

SUMMARY

This continuing medical education article reviews the features, management, and prognosis of cutaneous squamous cell carcinoma with an emphasis on high-risk squamous cell carcinoma and data from the past 3 years. This review will discuss the primary tumor management, high-risk features of a squamous cell carcinoma, changes to the American Joint Committee on Cancer staging system, and the utility of sentinel lymph node biopsy, and critically review the evidence regarding adjuvant therapy.

Clinician perspectives on the factors influencing prognostic stratification by the American Joint Commission on Cancer Head and Neck Cutaneous Squamous Cell Carcinoma Staging

BACKGROUND

The eighth edition of the American Joint Committee on Cancer Staging Manual includes a staging system for head and neck cutaneous squamous cell carcinoma for the first time. The pN categories for head and neck cutaneous squamous cell carcinoma and mucosal squamous cell carcinoma are identical, despite the vastly different biological behavior of these diseases. This study aimed to survey head and neck cancer specialists' views regarding the clinical utility of the American Joint Committee on Cancer Staging Manual for head and neck cutaneous squamous cell carcinoma and to identify avenues for improvement.

DESIGN

An electronic survey of 19 questions relating to the prognostic utility of the staging system was designed based on the findings of a literature review. The survey was distributed internationally to specialists managing head and neck cutaneous squamous cell carcinoma.

RESULTS

Literature review identified 9 articles describing primary research relevant to the performance of the American Joint Committee on Cancer Staging Manual for head and neck cutaneous squamous cell carcinoma, which recognized a lack of homogeneity, monotonicity, and distinctiveness in the pN staging system. One hundred and five survey responses were received: 71% indicated that mucosal and head and neck cutaneous squamous cell carcinoma require different nodal staging categories; 63% indicated that immunosuppression should be included in the staging system; 70% thought that soft tissue metastases portend a worse prognosis compared with extranodal extension; 38% almost never saw pN3a tumors; and 40% felt that the N stage is a poor predictor of survival.

CONCLUSION

The views of head and neck cancer specialists across disciplines and countries align with evidence suggesting that head and neck cutaneous squamous cell carcinoma merits a staging system distinct from mucosal squamous cell carcinoma, that immunosuppression should be considered in prognostication, and that the use of extranodal extension should be modified.

A critical analysis of the 8th edition TNM staging for head and neck cutaneous squamous cell carcinoma with lymph node metastases and comparison to N1S3 stage and ITEM risk score: A multicenter study

BACKGROUND AND OBJECTIVES

We performed a critical analysis of the 8th edition American Joint Committee on Cancer (AJCC) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) with nodal metastases and compared the performance to the N1S3 and ITEM systems.

METHODS

Multicenter study of 990 patients with metastatic HNcSCC treated with curative intent. The end points of interest were disease-specific (DSS) and overall survival (OS). Model fit was evaluated using Harrell's Concordance Index (C-index), proportion of variation explained (PVE), Akaike information criterion, and Bayesian information criterion.

RESULTS

N1S3 and ITEM demonstrated good distribution into risk categories in contrast to the AJCC system, which classified the majority (90.6%) of patients as N2-3 and Stage IV due to the high rate of extranodal extension. The N2c and N3a categories appeared redundant. There was considerable discordance between systems in risk allocation on an individual patient basis. N1S3 was the best performed (DSS: C-index 0.62, PVE 10.9%; OS: C-index 0.59, PVE 4.5%), albeit with relatively poor predictive value.

CONCLUSIONS

The AJCC N category and tumor node metastasis stage have poor patient distribution and predictive performance in HNcSCC. The AJCC stage, N1S3, and ITEM score all provide limited prognostic information based on objective measures highlighting the need to develop a staging system specific to HNcSCC.

Prognostic value of the 8th edition American Joint Commission Cancer nodal staging system for patients with head and neck cutaneous squamous cell carcinoma: A multi-institutional study

BACKGROUND

The 8th edition American Joint Committee on Cancer staging manual (AJCC8) introduced a separate staging system for head and neck cutaneous squamous cell carcinoma (HNcSCC) which parallels mucosal SCC and incorporates extranodal extension (ENE). This study aims to evaluate its prognostic utility.

METHODS

Univariate analysis of 1146 patients with metastatic HNcSCC from four Australian cancer centers was performed according to both AJCC 7th (AJCC7) and the 8th editions.

RESULTS

AJCC8 increased classification of 924 (80.6%) patients to either pN2a or pN3b and 341 patients (29.8%) from stage III to IV compared to AJCC7. The disease-specific survival (DSS) was not significantly different between pN1, pN2 or pN3a categories per AJCC8. Estimates of model performance for the AJCC8 pN staging revealed modest predictive capacity (Harrell's C of 0.62 for DSS).

CONCLUSIONS

The risk stratification according to pN classification of AJCC8 staging system performed poorly as a prognostic indicator.

The American Joint Committee on Cancer staging for metastatic head and neck cutaneous squamous cell carcinoma: A multi-institutional study of within-stage heterogeneity and impact on prognostic performance

BACKGROUND

The American Joint Committee on Cancer (AJCC) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) stratifies risk poorly. We hypothesized that this results from prognostic heterogeneity within N and TNM groups.

METHODS

Retrospective analysis of disease-specific survival (DSS) in a multicenter study of 1146 patients with nodal metastases from HNcSCC.

RESULTS

The majority of patients were classified as pN2a or pN3b (83.1%) and TNM stage IV (90.6%). On multivariate analysis, there was statistically significant prognostic heterogeneity within these groups based on the number and size of nodal metastases, immunosuppression, and perineural invasion. When stage IV patients were categorized into low, moderate, and high-risk groups based on adverse features, there was wide variation in prognosis with 5-year DSS ranging from 90% to 60% (P < .001).

CONCLUSIONS

The AJCC staging system stratifies risk poorly in HNcSCC due to significant prognostic heterogeneity within pN2a, pN3b, and stage IV groups.

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

OBJECTIVES

We aimed to determine if the number of nodal metastases is an independent predictor of survival in HNcSCC, whether it provides additional prognostic information to the AJCC N and TNM stage and identify optimal cut-points for risk stratification.

MATERIALS AND METHODS

Retrospective multi-institutional cohort study of patients with parotid and/or cervical nodal metastases from HNcSCC treated with curative intent by surgery ± adjuvant therapy. The impact of number of nodal metastases on disease-specific and overall survival was assessed using multivariate Cox regression. Optimal cut-points for prognostic discrimination modelled using the AIC, BIC, C-index and PVE.

RESULTS

The study cohort included 1128 patients, with 962 (85.3%) males, median age of 72.9 years (range: 18-100 years) and median follow-up 3.4 years. Adjuvant radiotherapy was administered to 946 (83.9%) patients. Based on objective measures of model performance, number of nodal metastases was classified as 1-2 (N = 816), 3-4 (N = 162) and ≥5 (N = 150) nodes. In multivariate analyses, the risk of disease-specific mortality progressively increased with 3-4 nodes (HR, 1.58; 95% CI: 1.03-2.42; p = 0.036) and ≥5 nodes (HR, 2.91; 95% CI: 1.99-4.25; p < 0.001) with similar results for all-cause mortality. This simple categorical variable provided superior prognostic information to the TNM stage.

CONCLUSION

Increasing number of nodal metastases is an independent predictor of mortality in HNcSCC, with categorization as 1-2, 3-4 and ≥5 nodes optimizing risk stratification and providing superior prognostic information to TNM stage. These findings may aid in the development of future staging systems as well as identification of high-risk patients in clinical trials.

European interdisciplinary guideline on invasive squamous cell carcinoma of the skin: Part 1. epidemiology, diagnostics and prevention

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in the white populations, accounting for 20% of all cutaneous malignancies. Factors implicated in cSCC etiopathogenesis include ultraviolet radiation exposure and chronic photoaging, age, male sex, immunosuppression, smoking and genetic factors. A collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organisation of Research and Treatment of Cancer (EORTC) was formed to update recommendations on cSCC classification, diagnosis, risk stratification, staging and prevention, based on current literature, staging systems and expert consensus. Common cSCCs are typically indolent tumors, and most have a good prognosis with 5-year cure rates of greater than 90%, and a low rate of metastases (<4%). Further risk stratification into low-risk or high-risk common primary cSCC is recommended based on proposed high-risk factors. Advanced cSCC is classified as locally advanced (lacSCC), and metastatic (mcSCC) including locoregional metastatic or distant metastatic cSCC. Current systems used for staging include the American Joint Committee on Cancer (AJCC) 8th edition, the Union for International Cancer Control (UICC) 8th edition, and Brigham and Women's Hospital (BWH) system. Physical examination for all cSCCs should include total body skin examination and clinical palpation of lymph nodes, especially of the draining basins. Radiologic imaging such as ultrasound of the regional lymph nodes, magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography-computed tomography (PET-CT) scans are recommended for staging of high-risk cSCC. Sentinel lymph node biopsy is currently not recommended. Nicotinamide, oral retinoids, and topical 5-FU have been used for the chemoprevention of subsequent cSCCs in high-risk patients but are not routinely recommended. Education about sun protection measures including reducing sun exposure, use of protective clothing, regular use of sunscreens and avoidance of artificial tanning, is recommended.