Enhanced metastatic risk assessment in cutaneous squamous cell carcinoma with the 40-gene expression profile test

Association of a 40-Gene Expression Profile With Risk of Metastatic Disease Progression of Cutaneous Squamous Cell Carcinoma and Specification of Benefit of Adjuvant Radiation Therapy

PURPOSE

Adjuvant radiation therapy (ART) for cutaneous squamous cell carcinoma is recommended based on a number of wide-ranging clinicopathologic features, which encompass a broad array of patients. The 40-gene expression profile (GEP) test classifies cutaneous squamous cell carcinoma tumors into low (class 1), higher (class 2A), or highest (class 2B) risk of nodal and/or distant metastasis. This study's hypotheses are as follows: (1) local recurrence is associated with metastatic disease progression and (2) 40-GEP, by identifying high risk for metastasis, could predict a metastasis-specific benefit from ART.

METHODS AND MATERIALS

Samples were obtained from 920 patients (ART-untreated: 496 class 1, 335 class 2A, and 33 class 2B; ART-treated: 11 class 1, 35 class 2A, and 10 class 2B) who were matched on clinical risk factors and stratified by ART status to create 49 matched patient strata. To control for the variety of characteristics and treatment selection bias, randomly sampled pairs of matched ART and non-ART patients comprising 10,000 resampled cohorts were each analyzed for 5-year metastasis-free survival and predicted time to metastatic event.

RESULTS

Of 96 patients experiencing local recurrence, 56.3% experienced metastasis; of those experiencing both, 88.9% experienced local recurrence before (75.9%) or concurrently (13.0%) with metastasis. After matching for clinicopathologic risk, median 5-year disease progression rates for resampled cohorts demonstrated approximately 50% improvement for class 2B ART-treated compared with ART-untreated cohorts. ART-treated class 2B cohorts had a 5-fold delay in predicted time to metastatic event and deceleration of disease progression compared with ART-untreated cohorts (Kolmogorov-Smirnov test, P < .01); this was not observed for patients with class 1 or 2A cSCC (P > .05 for each). No risk factor or staging system combined with ART status identified groups that would benefit from ART as well as 40-GEP.

CONCLUSIONS

Forty-GEP identifies patients at the highest risk of nodal/distant metastasis who may derive the greatest benefit from ART, as well as patients who may have clinical indications for ART but are at low risk of metastasis. Compared with current guidelines, 40-GEP could provide greater specificity concerning the benefit of ART in individual patients.

Predicting adjuvant radiation therapy benefit in cutaneous squamous cell carcinoma with the 40-gene expression profile

Aim: To independently confirm that the 40-gene expression profile (40-GEP) test can identify patients with high-risk cutaneous squamous cell carcinoma who are more or less likely to benefit from adjuvant radiation therapy (ART).Materials & methods: Primary cutaneous squamous cell carcinoma tumors from two academic centers received retrospective 40-GEP testing and were analyzed for 5-year metastasis-free survival and projected time to event.Results: Random sampling of matched patient pairs (n = 52 ART-treated; 371 no ART) showed a median 50% decrease in 5-year progression rate for ART-treated patients (vs no ART) with 40-GEP Class 2B. Class 2A was associated with a modest ART benefit, but not Class 1.Conclusion: The 40-GEP identified patients most likely to benefit from ART (Class 2B) and those that can consider deferring treatment (Class 1).

Inconsistent Associations Between Risk Factor Profiles and Adjuvant Radiation Therapy (ART) Treatment in Patients with Cutaneous Squamous Cell Carcinoma and Utility of the 40-Gene Expression Profile to Refine ART Guidance

INTRODUCTION

National Comprehensive Cancer Network (NCCN) recommendations for adjuvant radiation therapy (ART) use are similar for High Risk and Very High Risk cutaneous squamous cell carcinoma (cSCC) with negative post-surgical margins. Although studies report reductions in disease progression following ART treatment, ART use is likely inconsistent when guided by available risk factors. This study evaluated the association of ART with clinical risk factors in ART-treated and untreated patients and showed the clinical utility of the 40-gene expression profile (40-GEP) for guiding ART.

METHODS

A multicenter study of 954 patients was conducted with institutional review board (IRB) approval. The 40-GEP test was performed using primary tumor tissue from patients with either a minimum of 3 years of follow-up or a documented regional or distant metastasis. Unsupervised hierarchical cluster analysis identified patterns of clinical risk factors for ART-treated patients, then identified untreated patients with matching risk factor profiles. Results were cross-referenced to 40-GEP test results to determine utility of the test to guide ART.

RESULTS

Analysis demonstrated inconsistent implementation of ART for eligible patients. Cluster analysis identified four patient profiles based on clusters of risk factors and, notably, matching profiles in ART-treated and untreated patients. Further, the analysis identified patients who received but could have deferred ART on the basis of 40-GEP test result and biologically low risk of metastasis, and untreated patients who likely would have benefitted from ART on the basis of their 40-GEP test result.

CONCLUSIONS

ART guidance is not determined by the presence of specific clinicopathologic factors, with treated and untreated patients sharing the same risk factor profiles. cSCC risk determination based on NCCN recommendations for clinical factor assessment results in inconsistent use of ART. Including tumor biology-based prognostic information from the 40-GEP refines risk and identifies patients who are most appropriate and likely to benefit from ART, and those that can consider deferring ART.

Hypertrophic Lichen Planus: A Precursor Lesion for Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) is the second most common malignant tumor of the skin. This case report aims to report a case of cutaneous squamous cell carcinoma in an elderly male presenting with a non-healing ulceroproliferative growth on the shin of the right lower limb and a hypopigmented patch on the shin of the left lower limb. The significant feature of this case is that in the shin of the left lower limb, SCC appears in the background of chronic hypertrophic lichen planus (HLP) but in the right lower limb, there is no evidence of a background hypertrophic lichen planus. There are only a few similar cases reported so far in the literature showing long-standing hypertrophic lichen planus as a risk factor for the development of cutaneous squamous cell carcinoma. This case illustrates that chronic hypertrophic lichen planus should be considered as a potential precursor lesion for SCC. Regular screening is essential for early detection, enabling timely intervention for improving patient outcomes.

Präoperativer Hochfrequenzultraschall: Ein zuverlässiges Managementinstrument bei nichtmelanozytärem Hautkrebs der Ohrmuschel und der Nase: Pre-operative high-frequency ultrasound: A reliable management tool in auricular and nasal non-melanoma skin cancer

Hintergrund und Zielsetzung

Das Wissen über die Tiefeninfiltration bei nichtmelanozytärem Hautkrebs (NMSC) mithilfe präoperativer Sonographie könnte den Ärzten ermöglichen, den am besten geeigneten therapeutischen Ansatz zu wählen, unnötige Operationen und teure bildgebende Verfahren zu vermeiden und die Diagnose und Behandlung nicht zu verzögern. In unserer retrospektiven, monozentrischen Studie haben wir die Nützlichkeit des Hochfrequenzultraschalls (HFUS) zur Beurteilung der Tiefeninfiltration bei aurikulären und nasalen NMSC‐Fällen untersucht und die darauffolgende Änderung des therapeutischen Ansatzes bewertet.

Patienten und Methodik

In 60 NMSC‐Fällen haben wir die Genauigkeit des HFUS bei der Erkennung von Knorpel‐ und Knocheninfiltration sowie die Korrelation sonographischer und histologischer Parameter beurteilt.

Ergebnisse

In 16,6% der Fälle wurde präoperativ eine tiefe Knorpel‐/Knochenbeteiligung oder eine lokoregionale Erkrankung identifiziert, was zu einer geänderten therapeutischen Strategie mit radioimmunologischer Behandlung anstelle von Operation führte. In zwei Fällen identifizierte der präoperative HFUS eine lokale Knorpelinfiltration, was die Anzahl der chirurgischen Eingriffe reduzierte. Bei den verbleibenden 48 Läsionen ohne Tiefeninfiltration wurde eine Korrelation von > 99% zwischen der histologischen und sonographischen Tumoreindringtiefe gefunden (p <0.001).

Schlussfolgerungen

Präoperativer HFUS beeinflusst das therapeutische Vorgehen bei NMSC, indem es eine subklinische Beteiligung tieferer Strukturen erkennt, umfangreichere diagnostische Maßnahmen vermeidet, Kosten reduziert und die Qualität der Gesundheitsversorgung verbessert. HFUS sollte in der Dermatochirurgie vor der Tumorentfernung zur optimierten Therapie und zur verbesserten Patientenberatung eingesetzt werden.

Pre-operative high-frequency ultrasound: a reliable management tool in auricular and nasal non-melanoma skin cancer

BACKGROUND AND OBJECTIVES

The knowledge of depth infiltration in non-melanoma skin cancer (NMSC) using pre-operative ultrasound could enable clinicians to choose the most adequate therapeutic approach, avoiding unnecessary surgeries and expensive imaging methods, delaying diagnosis and treatment. Our single-center retrospective study determined the usefulness of high-frequency ultrasound (HFUS) for depth infiltration assessment in auricular and nasal NMSC and assessed the subsequent change in therapeutic approach.

PATIENTS AND METHODS

In 60 NMSC cases, we assessed the accuracy of HFUS in cartilaginous/bone infiltration detection as well as the correlation of sonographic and histological parameters.

RESULTS

In 16.6% of cases, a deep cartilaginous/bone involvement or locoregional disease was identified pre-operatively, resulting in a changed therapeutical scheme of radio-immunological treatment rather than surgery. In two cases, pre-operative HFUS identified local cartilage infiltration, reducing the number of surgical procedures. Forty-eight remaining lesions with no depth infiltration were excised; a correlation of > 99% between the histologic and sonographic tumor depth (p<0.001) was found.

CONCLUSIONS

Pre-surgical HFUS influences the therapeutic management in NMSC by detecting subclinical involvement of deeper structures, avoiding more extensive diagnostics, reducing costs, and improving healthcare quality. High-frequency ultrasound should be implemented in dermatosurgery before tumor excision for optimized therapy and improved patient counseling.

Integrating the 40-Gene Expression Profile (40-GEP) Test Improves Metastatic Risk-Stratification Within Clinically Relevant Subgroups of High-Risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients

INTRODUCTION

The validated 40-gene expression profile (40-GEP) test independently stratifies risk of regional or distant metastasis for cutaneous squamous cell carcinoma (cSCC) tumors with high-risk clinicopathologic features. This study evaluated the stratification of risk by the 40-GEP test in a large cohort of tumors with one or more high-risk factors and in clinically relevant subgroups, including tumors within National Comprehensive Cancer Network (NCCN) high- and very-high-risk groups, lower-stage BWH T1 and T2a tumors, and patients > 65 years old.

METHODS

This multicenter (n = 58) performance study of the 40-GEP included 897 patients. Kaplan-Meier analyses were performed to assess risk stratification profiles for 40-GEP Class 1 (low), Class 2A (higher) and Class 2B (highest) risk groups, while nested Cox regression models were used to compare risk prediction of clinicopathologic risk classification systems versus risk classification systems in combination with 40-GEP.

RESULTS

Patients classified as 40-GEP Class 1, Class 2A, or Class 2B had significantly different metastatic risk profiles (p < 0.0001). Integrating 40-GEP results into models with individual clinicopathologic risk factors or risk classification systems (Brigham and Women's Hospital, American Joint Committee on Cancer Staging Manual, 8th Edition) and NCCN demonstrated significant improvement in accuracy for prediction of metastatic events (ANOVA for model deviance, p < 0.0001 for all models).

CONCLUSION

The 40-GEP test demonstrates accurate, independent, clinically actionable stratification of metastatic risk and improves predictive accuracy when integrated into risk classification systems. The improved accuracy of risk assessment when including tumor biology via the 40-GEP test ensures more risk-aligned, personalized patient management decisions.

Transcriptomic analysis of cutaneous squamous cell carcinoma reveals a multigene prognostic signature associated with metastasis

BACKGROUND

Metastasis of cutaneous squamous cell carcinoma (cSCC) is uncommon. Current staging methods are reported to have sub-optimal performances in metastasis prediction. Accurate identification of patients with tumors at high risk of metastasis would have a significant impact on management.

OBJECTIVE

To develop a robust and validated gene expression profile signature for predicting primary cSCC metastatic risk using an unbiased whole transcriptome discovery-driven approach.

METHODS

Archival formalin-fixed paraffin-embedded primary cSCC with perilesional normal tissue from 237 immunocompetent patients (151 nonmetastasizing and 86 metastasizing) were collected retrospectively from four centers. TempO-seq was used to probe the whole transcriptome and machine learning algorithms were applied to derive predictive signatures, with a 3:1 split for training and testing datasets.

RESULTS

A 20-gene prognostic model was developed and validated, with an accuracy of 86.0%, sensitivity of 85.7%, specificity of 86.1%, and positive predictive value of 78.3% in the testing set, providing more stable, accurate prediction than pathological staging systems. A linear predictor was also developed, significantly correlating with metastatic risk.

LIMITATIONS

This was a retrospective 4-center study and larger prospective multicenter studies are now required.

CONCLUSION

The 20-gene signature prediction is accurate, with the potential to be incorporated into clinical workflows for cSCC.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: Diagnostics and prevention-Update 2023

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in white populations, accounting for 20% of all cutaneous malignancies. Overall, cSCC mostly has very good prognosis after treatment, with 5-year cure rates greater than 90%. Despite the overall favourable prognosis and the proportionally rare deaths, cSCC is associated with a high total number of deaths due to its high incidence. A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV) and the European Organization of Research and Treatment of Cancer (EORTC), was formed to update recommendations on cSCC, based on current literature and expert consensus. Part 1 of the guidelines addresses the updates on classification, epidemiology, diagnosis, risk stratification, staging and prevention in immunocompetent as well as immunosuppressed patients.

Molecular Classifiers in Skin Cancers: Challenges and Promises

Skin cancers are common and heterogenous malignancies affecting up to two in three Australians before age 70. Despite recent developments in diagnosis and therapeutic strategies, the mortality rate and costs associated with managing patients with skin cancers remain high. The lack of well-defined clinical and histopathological features makes their diagnosis and classification difficult in some cases and the prognostication difficult in most skin cancers. Recent advancements in large-scale "omics" studies, including genomics, transcriptomics, proteomics, metabolomics and imaging-omics, have provided invaluable information about the molecular and visual landscape of skin cancers. On many occasions, it has refined tumor classification and has improved prognostication and therapeutic stratification, leading to improved patient outcomes. Therefore, this paper reviews the recent advancements in omics approaches and appraises their limitations and potential for better classification and stratification of skin cancers.

Recommendations for risk stratification of periocular squamous cell carcinoma

Periocular squamous cell carcinoma is a common cutaneous malignancy with generally favorable outcomes; however, the periocular region is intrinsically a high-risk location, and there exist a subset of lesions with a propensity for poor outcomes. Orbital invasion, intracranial perineural spread, nodal and distant metastasis are feared complications. There are several staging systems for eyelid carcinoma and cutaneous squamous cell carcinoma, but the definition of high-risk lesions remains heterogeneous. It is unclear exactly which lesions can be safely deescalated, and which require nodal evaluation and adjuvant multimodal therapy. We seek to answer these questions by summarizing the literature on clinicopathologic variables, molecular markers, and gene profiling tests in periocular squamous cell carcinoma, with the extrapolation of data from the cutaneous squamous cell carcinoma literature. Standardized pathology reports with information on tumor dimensions, histological subtype and grade, perineural invasion, and lymphovascular invasion should become uniform. Integration with gene expression profiling assessments will individualize and improve the predictive accuracy of risk stratification tools to ultimately inform multidisciplinary decision-making.

Lymph Node Metastases from Non-Melanoma Skin Cancer of the Head and Neck

Non-melanoma skin cancer (NMSC) represents the most common malignancy in the world, comprising exceedingly common lesions such as basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) and rare lesions such as Merkel cell carcinoma. Risk factors are widely recognized and include ultraviolet (UV) light exposure, radiation exposure, immunosuppression, and many others. As a whole, survival and functional outcomes are favorable, but each histopathological subtype of NMSC behaves differently. Treatment regimens for the primary site usually include wide surgical excision and neck dissection in cases of clinically involved metastatic lymph nodes. The elective management of draining nodal basins, however, is a contested topic. Nearly all subtypes, excluding BCC, have a significant risk of lymphatic metastases, and have been studied with regard to sentinel lymph node biopsy (SLNB) and elective neck dissection. To date, no studies have definitively established a true single standard of care, as exists for melanoma, for any of the NMSCs. As a result, the authors have sought to summarize the current literature and identify indications and management options for the management of the cervical lymphatics for each major subtype of NMSC. Further research remains critically necessary in order to develop complete treatment algorithms.

Advances in cutaneous squamous cell carcinoma

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.

The Prognostic Value and Clinical Utility of the 40-Gene Expression Profile (40-GEP) Test in Cutaneous Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

BACKGROUND

The current tumor staging systems for cutaneous squamous cell carcinoma (cSCC) are considered inadequate and insufficient for evaluating the risk of metastasis and for identifying patients at high risk of cSCC. This meta-analysis aimed to assess the prognostic significance of a 40-gene expression profile (40-GEP) both independently and integrated with clinicopathologic risk factors and established staging systems (American Joint Committee on Cancer, eighth edition (AJCC8) and Brigham and Women's Hospital (BWH)).

METHODS

Electronic databases, including PubMed (MEDLINE), Embase, the Cochrane Library, and Google Scholar, were systematically searched to identify cohort studies and randomized controlled trials on evaluations of the prediction value of 40-GEP in cSCC patients up to January 2023. The metastatic risk analysis of a given 40-GEP class combined with tumor stage and/or other clinicopathologic risk factors was based upon log hazard ratios (HRs) and their standard error (SE). Heterogeneity and subgroup analyses were performed, and data quality was assessed.

RESULTS

A total of 1019 patients from three cohort studies were included in this meta-analysis. The overall three-year metastatic-free survival rates were 92.4%, 78.9%, and 45.4% for class 1 (low risk), class 2A (Intermediate risk), and class 2B (high risk) 40-GEP, respectively, indicating a significant variation in survival rates between the risk classification groups. The pooled positive predictive value was significantly higher in class 2B when compared to AJCC8 or BWH. The subgroup analyses demonstrated significant superiority of integrating 40-GEP with clinicopathologic risk factors or AJCC8/BWH, especially for class 2B patients.

CONCLUSIONS

The integration of 40-GEP with staging systems can improve the identification of cSCC patients at high risk of metastasis, potentially leading to improved care and outcomes, especially in the high-risk class 2B group.

Incorporation of the 40-Gene Expression Profile (40-GEP) Test to Improve Treatment Decisions in High-Risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients: Case Series and Algorithm

Cutaneous squamous cell carcinoma (cSCC) has become a significant public health issue due to its rapidly rising incidence and an estimated 1.8 million newly diagnosed cases annually. As with other cancers, treatment decisions for patients with cSCC are based primarily on a patient's risk for poor outcomes. There has been improvement in clinicopathologic factor-based risk assessment approaches, either through informal methods or ever evolving staging approaches. However, these approaches misidentify patients who will eventually have disease progression as low-risk and conversely, over classify patients as high-risk who do not experience relapse. To improve the accuracy of risk assessment for patients with cSCC, the 40-gene expression profile (40-GEP) test has been validated to show statistically significant stratification of a high-risk cSCC patient's risk of nodal or distant metastasis, independent of currently available risk-assessment methods. The 40-GEP test allows for a more accurate classification of metastatic risk for high-risk cSCC patients, with the aim to influence appropriate allocation of clinician time and therapeutic resources to those patients who will most benefit. The objective of this article is to present a treatment algorithm in which clinicians can easily integrate the results of the 40-GEP test into their current treatment approaches to tailor patient care based on individual tumor biology. The following modalities were considered: surveillance imaging, sentinel lymph node biopsy (SLNB), adjuvant radiation therapy (ART), and clinical follow-up. The authors have contributed their own cases for discussion as to how they have seen the beneficial impact of 40-GEP test results in their own practice. Overall, clinicians can identify risk-aligned treatment pathway improvements with the use of the 40-GEP test for challenging to manage, high-risk cSCC patients.

Dermatologic Disease-Directed Targeted Therapy (D3T2): The Application of Biomarker-Based Precision Medicine for the Personalized Treatment of Skin Conditions-Precision Dermatology

Precision dermatology uses individualized dermatologic disease-directed targeted therapy (D3T2) for the management of dermatoses and for the evaluation and therapy of cutaneous malignancies. Personalized/precision strategies are based on biomarkers that are most frequently derived from tissue transcriptomic expression or genomic sequencing or from circulating cytokines. For instance, the pathologic diagnosis of a pigmented lesion and determining the prognosis of a malignant melanocytic neoplasm can be enhanced by genomic/transcriptomic analysis. In addition to biopsy, innovative techniques have been developed for obtaining transcriptomes in skin conditions; as an example, patches can be applied to a psoriasis plaque for a few minutes to capture the epidermis/upper dermis transcriptome. Atopic dermatitis and prurigo nodularis may also be candidate conditions for precision dermatology. Precision dermatology has a role in managing melanoma and nonmelanoma skin cancers and rare cutaneous tumors-such as perivascular epithelioid cell tumor (PEComa)-that can originate in or metastasize to the skin. For instance, advanced/metastatic basal cell carcinomas can be treated with Hedgehog inhibitors (vismodegib and sonidegib) targeting the smoothened (SMO) or patched 1 (PTCH1) gene alterations that are a hallmark of these cancers and activate the Hedgehog pathway. Advanced/metastatic basal and cutaneous squamous cell cancers often have a high tumor mutational burden (which predicts immunotherapy response); immune checkpoint blockade with cemiplimab, a programmed cell death protein 1 (PD1) inhibitor, is now approved for these malignancies. Gene expression profiling of primary cutaneous squamous cell carcinoma can identify those individuals at high risk for subsequent metastases. In the realm of rare neoplasms, PEComas-which can originate in the skin, albeit uncommonly-have tuberous sclerosis complex 1 (TSC1)/tuberous sclerosis complex 2 (TSC2) gene alterations, which activate mammalian target of rapamycin (mTOR) signaling, and can be suppressed by nab-sirolimus, now approved for this condition. In summary, precision dermatologic techniques/strategies are an important emerging approach for evaluation and management of skin disorders and cutaneous neoplasms, and may serve as a paradigm for the application of precision medicine beyond dermatology.

Real-world Evidence Shows Clinicians Appropriately Use the Prognostic 40-gene Expression Profile (40-GEP) Test for High-risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients

Treatment decisions for patients with cutaneous squamous cell carcinoma (cSCC) are traditionally based upon clinicopathologic risk factors and staging systems. Due to the accuracy limitations of these resources in predicting poor outcomes, there is a clinically significant need for more accurate methods of risk assessment. The 40-gene expression profile (40-GEP) test was developed to augment metastatic risk prediction of high-risk cSCC patients and has been validated in two independent, multi-center studies involving over 1,000 patients. This study substantiates that the 40-GEP is appropriately utilized by clinicians and that the personalized risk-stratification results are impactful in guiding risk-aligned patient management.

Recent Advances in the Diagnosis and Management of High-Risk Cutaneous Squamous Cell Carcinoma

High-risk cSCC is defined as invasive cSCC staged as N0 (without detectable regional lymph nodes) and M0 (without distant metastasis), that has features associated with a higher risk of poorer prognosis. The focus of this review is on the recent advances in the diagnosis and management of high-risk cSCC. The interest in high-risk cSCC relies on its higher risk of progression to advanced cSCC, as it represents the main pool of cSCCs that give rise to advanced tumors. Assessment of the risk is thus particularly relevant for common cSCC to identify the few with a high-risk risk of local recurrence, metastasis, or disease-specific death among all other low-risk tumors. The timely diagnosis and effective treatment of high-risk cSCCs may halt their further progression and aim to prevent and lower the incidence of advanced cSCCs. Clearance of the tumor with negative surgical margins is the main goal of surgery, which is the primary treatment of cSCC. It seems that it is difficult to discern the group of high-risk cSCCs that may benefit from adjuvant RT, as a universal beneficial effect for a cSCC with any high-risk factor which was resected with clear surgical margins has not been established. In the case of a high-risk cSCC with positive margins after surgery, and re-excision not feasible, post-operative radiotherapy is performed when possible. Recommendations on further management are discussed. Regarding the follow-up of patients diagnosed with high-risk cSCC, factors to consider regarding the frequency and intensity of the follow-up schedule include the risk and possible time of occurrence of metastasis from cSCC.

Cancer Progression Gene Expression Profiling Identifies the Urokinase Plasminogen Activator Receptor as a Biomarker of Metastasis in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) of the head and neck region is the second most prevalent skin cancer, with metastases to regional lymph nodes occurring in 2%–5% of cases. To further our understanding of the molecular events characterizing cSCC invasion and metastasis, we conducted targeted cancer progression gene expression and pathway analysis in non-metastasizing (PRI-) and metastasizing primary (PRI+) cSCC tumors of the head and neck region, cognate lymph node metastases (MET), and matched sun-exposed skin (SES). The highest differentially expressed genes in metastatic (MET and PRI+) versus non-metastatic tumors (PRI-) and SES included PLAU, PLAUR, MMP1, MMP10, MMP13, ITGA5, VEGFA, and various inflammatory cytokine genes. Pathway enrichment analyses implicated these genes in cellular pathways and functions promoting matrix remodeling, cell survival and migration, and epithelial to mesenchymal transition, which were all significantly activated in metastatic compared to non-metastatic tumors (PRI-) and SES. We validated the overexpression of urokinase plasminogen activator receptor (uPAR, encoded by PLAUR) in an extended patient cohort by demonstrating higher uPAR staining intensity in metastasizing tumors. As pathway analyses identified epidermal growth factor (EGF) as a potential upstream regulator of PLAUR, the effect of EGF on uPAR expression levels and cell motility was functionally validated in human metastatic cSCC cells. In conclusion, we propose that uPAR is an important driver of metastasis in cSCC and represents a potential therapeutic target in this disease.

Gene expression profiling for metastatic risk in head and neck cutaneous squamous cell carcinoma

OBJECTIVE

Over 50% of newly diagnosed cutaneous squamous cell carcinoma (cSCC) lesions occur in the head and neck (cSCC-HN), and metastasis to nodal basins in this region further complicates surgical and adjuvant treatment. The current study addressed whether the 40-gene expression profile (40-GEP) test can predict metastatic risk in cSCC-HN with improved accuracy and provide independent prognostic value to complement current risk assessment methods.

STUDY DESIGN

Multicenter, retrospective cohort study.

METHODS

Formalin-fixed paraffin-embedded primary tumor tissue and associated clinical data from patients with cSCC-HN (n = 278) were collected from 33 independent centers. Samples were analyzed via the 40-GEP test. Cases were staged per American Joint Committee on Cancer, Eighth Edition (AJCC8) and Brigham and Women's Hospital (BWH) criteria after comprehensive medical record and pathology report review. Metastasis-free survival (MFS) rates were determined, and risk factors were analyzed via Cox regression.

RESULTS

The 40-GEP test classified the cohort into low (Class 1, n = 126; 45.3%), moderate (Class 2A, n = 134; 48.2%), and high (Class 2B, n = 18; 6.5%) metastatic risk at 3 years postdiagnosis. Regional/distant metastasis occurred in 54 patients (19.4%). MFS rates were 92.1% (Class 1), 76.1% (Class 2A), and 44.4% (Class 2B; p < .0001). Multivariate analysis of 40-GEP results with AJCC8 or BWH tumor stage, or clinicopathologic risk factors, demonstrated independent prognostic value of the 40-GEP test (p < .03). Accuracy of predicting metastatic risk was also improved using 40-GEP classification (p < .02).

CONCLUSIONS

Improved metastatic risk stratification through the 40-GEP test could complement cSCC-HN risk assessment for better-informed decision-making for treatment and surveillance and ultimately improve patient outcomes.

LEVEL OF EVIDENCE

3.

Clinical Utility of the 40-Gene Expression Profile (40-GEP) Test for Improved Patient Management Decisions and Disease-Related Outcomes when Combined with Current Clinicopathological Risk Factors for Cutaneous Squamous Cell Carcinoma (cSCC): Case Series

Introduction

While improvements have been made to risk assessment of cutaneous squamous cell carcinoma (cSCC) patients, there is a critical need for a uniform and more precise stratification system of their care. To address this unmet clinical need, a prognostic 40-gene expression profile (40-GEP) test has recently been developed and independently validated to show improved stratification of metastatic risk in high-risk cSCC patients compared with current staging systems.

Methods

Two cSCC cases, both male with similar patient profiles and the same staging status across two different staging systems, yet with opposing outcomes, were chosen for retrospective review of their primary biopsy using the 40-GEP test.

Results

Case 1 declined further treatment, even when presented with evidence of a small focus of cSCC found in the last layer of nonmarginal tissue obtained from Mohs micrographic surgery (MMS). Case 1 remained recurrence free, and retrospective analysis of the initial biopsy with the 40-GEP test provided a Class 1 result (low likelihood of metastasis). Case 2, even with subsequent clearing of the primary cSCC with MMS, noted another metastatic cSCC 3 months later. Case 2, after multimodal adjuvant treatments, died due to disease progression. Retrospective analysis of the initial biopsy with the 40-GEP test provided a Class 2B result (high likelihood of metastasis).

Conclusions

The cases discussed highlight the utility in 40-GEP to provide additional information to guide treatment decisions and improve outcomes. Integrating novel molecular prognostication with traditional clinicopathological risk factors can improve stratification of high-risk cSCC patients and may inform selection of risk-appropriate treatment and surveillance strategies.