Nationwide Incidence of Metastatic Cutaneous Squamous Cell Carcinoma in England

Phototoxic Effect of UVA-Responsive Fe3O4@ZnO Nanoparticles on Squamous Skin Cell

Zinc oxide (ZnO) is a resource-rich metal oxide with a certain degree of phototoxicity toward cancer cells using ultraviolet light radiation. Therefore, it is a promising photosensitizer for photodynamic therapy against cancer. The current study synthesized core-shell structure nanoparticles using Fe3O4 as the core and ZnO as the shell. The core–shell nanoparticles were spherical-like and superparamagnetic, with a zeta potential of −22.7±7.6 mV. ZnO-coated ferroferric oxide nanoparticles (Fe3O4@ZnO NPs) under ultraviolet A (UVA) irradiation could induce a lot more reactive oxygen species in the squamous skin cells causing the evident inhibitory effect. In contrast, they indicated no toxicity to skin squamous cells without UVA radiation. Therefore, it can be inferred that their great potential as the targeting photosensitizer for photodynamic therapy on skin squamous cell carcinoma is due to their good biocompatibility without UVA radiation and excellent toxicity under UVA radiation on skin squamous cells.

Topical treatment of actinic keratoses in organ transplant recipients: a feasibility study for SPOT (Squamous cell carcinoma Prevention in Organ transplant recipients using Topical treatments)

BACKGROUND

The risk of cutaneous squamous cell carcinoma (cSCC) is significantly increased in organ transplant recipients (OTRs). Clearance of actinic keratoses (AKs) is generally regarded as a surrogate biomarker for cSCC prevention. OTR-cSCC chemoprevention with topical AK treatments has not been investigated in randomized controlled trials (RCTs), although there is evidence that 5% 5-fluorouracil (5-FU) may be chemoprotective in immunocompetent patients.

OBJECTIVES

To assess the feasibility, activity and evaluation outcomes relevant to the design of a future phase III RCT of topical cSCC chemoprevention in OTRs.

METHODS

OTRs with 10 or more AKs in predefined areas were randomized 1 : 1 : 1 to topical 5-FU, 5% imiquimod (IMIQ) or sunscreen (sun-protective factor 30+) in a phase II, open-label RCT over 15 months. Feasibility outcomes included proportions of eligible OTRs randomized, completing treatment and willing to be re-treated. AK activity [AK clearance, new AK development, patient-centred outcomes (toxicity, health-related quality of life, HRQoL)] and evaluation methodology (clinical vs. photographic) were assessed.

RESULTS

Forty OTRs with 903 AKs were randomized. All feasibility outcomes were met (56% of eligible OTRs were randomized; 89% completed treatment; 81% were willing to be re-treated). AK activity analyses found 5-FU and IMIQ were superior to sunscreen for AK clearance and prevention of new AKs. 5-FU was more effective than IMIQ in AK clearance and prevention in exploratory analyses. Although toxicity was greater with 5-FU, HRQoL outcomes were similar.

CONCLUSIONS

Trials of topical AK treatments in OTRs for cSCC chemoprevention are feasible and AK activity results support further investigation of 5-FU-based treatments in future phase III trials. What is already known about this topic? Cutaneous squamous cell carcinoma (cSCC) is significantly more common in immunocompromised individuals including organ transplant recipients (OTRs) compared with immunocompetent populations. cSCC chemoprevention activity of sunscreen and 5-fluorouracil-based (5-FU) actinic keratosis (AK) treatments has been demonstrated in randomized controlled trials (RCTs) in immunocompetent populations but not in OTRs. AKs are cSCC precursors and their clearance and prevention are generally regarded as surrogate endpoint biomarkers for potential cSCC chemoprevention activity. What does this study add? SPOT (SCC Prevention in OTRs using Topical treatments) has confirmed that RCTs of OTR-cSCC chemoprevention with topical AK treatments are feasible. It also suggests that topical 5-FU may be superior to 5% imiquimod and sunscreen in AK clearance and prevention. Together with recent evidence from several RCTs in the general population, these data provide a compelling rationale for further studies of intervention with 5-FU-based topical chemoprevention approaches in OTR-cSCC prevention.

Whole genome analysis reveals the genomic complexity in metastatic cutaneous squamous cell carcinoma

Metastatic cutaneous squamous cell carcinoma (CSCC) is a highly morbid disease requiring radical surgery and adjuvant therapy, which is associated with a poor prognosis. Yet, compared to other advanced malignancies, relatively little is known of the genomic landscape of metastatic CSCC. We have previously reported the mutational signatures and mutational patterns of CCCTC-binding factor (CTCF) regions in metastatic CSCC. However, many other genomic components (indel signatures, non-coding drivers, and structural variants) of metastatic CSCC have not been reported. To this end, we performed whole genome sequencing on lymph node metastases and blood DNA from 25 CSCC patients with regional metastases of the head and neck. We designed a multifaceted computational analysis at the whole genome level to provide a more comprehensive perspective of the genomic landscape of metastatic CSCC. In the non-coding genome, 3′ untranslated region (3′UTR) regions of EVC (48% of specimens), PPP1R1A (48% of specimens), and ABCA4 (20% of specimens) along with the tumor-suppressing long non-coding RNA (lncRNA) LINC01003 (64% of specimens) were significantly functionally altered (Q-value < 0.05) and represent potential non-coding biomarkers of CSCC. Recurrent copy number loss in the tumor suppressor gene PTPRD was observed. Gene amplification was much less frequent, and few genes were recurrently amplified. Single nucleotide variants driver analyses from three tools confirmed TP53 and CDKN2A as recurrently mutated genes but also identified C9 as a potential novel driver in this disease. Furthermore, indel signature analysis highlighted the dominance of ID signature 13 (ID13) followed by ID8 and ID9. ID9 has previously been shown to have no association with skin melanoma, unlike ID13 and ID8, suggesting a novel pattern of indel variation in metastatic CSCC. The enrichment analysis of various genetically altered candidates shows enrichment of “TGF-beta regulation of extracellular matrix” and “cell cycle G1 to S check points.” These enriched terms are associated with genetic instability, cell proliferation, and migration as mechanisms of genomic drivers of metastatic CSCC.

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.

The State of the Art of Radiotherapy for Non-melanoma Skin Cancer: A Review of the Literature

Due to the general aging population and the fashion trend of sun exposure, non-melanoma skin cancer (NMSC) is rising. The management of NMSC is difficult and necessitates a multidisciplinary team (i.e., pathologists, dermatologists, medical oncologists, surgeons, and radiation oncologists). When surgery is not an option or will cause unacceptably functional morbidity, radiation therapy (RT) may be a preferable tissue-preserving option. Whether used alone or in conjunction with other treatments, RT has been shown to be quite effective in terms of cosmetic results and local control. Contact hypofractionated RT, brachytherapy, and electronic brachytherapy are all promising new treatments. However, rigorous, randomized trials are missing, explaining the disparity in dose, fractionation, and technique recommendations. Therefore, it is essential that interdisciplinary teams better understand RT modalities, benefits, and drawbacks. Our review will provide the role and indications for RT in patients with NMSC.

Sentinel lymph node biopsy in high-risk cutaneous squamous cell carcinoma of the head and neck: Systematic review and meta-analysis

The aim of our study was to better define the role of sentinel lymph node biopsy (SLNB) in high-risk cutaneous squamous cell carcinoma of the head and neck (cSCCHN). A systematic review and meta-analysis was performed according to the PRISMA statement. Seven-hundred and five patients were included from 20 studies. The pooled SLN identification rate was 98.8% (95%CI: 97.0-99.8). The median number of SLN excised was 3.6 (n = 371, 95%CI: 2.0-4.4). The pooled SLNB positive rate and cumulative regional recurrence rate (RRR) in negative SLNB were 5.6% (95%CI: 2.6-9.6) and 2.9% (95%CI: 0.5-7.2), respectively. The high SLN identification rate demonstrates SLNB feasibility in cSCCHN. The low SLNB positive rate and the relatively high RRR raise some doubts concerning its clinical utility. Further studies are mandatory to define predictors of lymph node metastases able to better select patients that may benefit from a SLNB.

Identification of metastatic primary cutaneous squamous cell carcinoma utilizing artificial intelligence analysis of whole slide images

Cutaneous squamous cell carcinoma (cSCC) harbors metastatic potential and causes mortality. However, clinical assessment of metastasis risk is challenging. We approached this challenge by harnessing artificial intelligence (AI) algorithm to identify metastatic primary cSCCs. Residual neural network-architectures were trained with cross-validation to identify metastatic tumors on clinician annotated, hematoxylin and eosin-stained whole slide images representing primary non-metastatic and metastatic cSCCs (n = 104). Metastatic primary tumors were divided into two subgroups, which metastasize rapidly (≤ 180 days) (n = 22) or slowly (> 180 days) (n = 23) after primary tumor detection. Final model was able to predict whether primary tumor was non-metastatic or rapidly metastatic with slide-level area under the receiver operating characteristic curve (AUROC) of 0.747. Furthermore, risk factor (RF) model including prediction by AI, Clark’s level and tumor diameter provided higher AUROC (0.917) than other RF models and predicted high 5-year disease specific survival (DSS) for patients with cSCC with 0 or 1 RFs (100% and 95.7%) and poor DSS for patients with cSCCs with 2 or 3 RFs (41.7% and 40.0%). These results indicate, that AI recognizes unknown morphological features associated with metastasis and may provide added value to clinical assessment of metastasis risk and prognosis of primary cSCC.

A tEMTing target? Clinical and experimental evidence for epithelial-mesenchymal transition in the progression of cutaneous squamous cell carcinoma (a scoping systematic review)

Cutaneous squamous cell carcinoma (cSCC) is a disease with globally rising incidence and poor prognosis for patients with advanced or metastatic disease. Epithelial-mesenchymal transition (EMT) is a driver of metastasis in many carcinomas, and cSCC is no exception. We aimed to provide a systematic overview of the clinical and experimental evidence for EMT in cSCC, with critical appraisal of type and quality of the methodology used. We then used this information as rationale for potential drug targets against advanced and metastatic cSCC. All primary literature encompassing clinical and cell-based or xenograft experimental studies reporting on the role of EMT markers or related signalling pathways in the progression of cSCC were considered. A screen of 3443 search results yielded 86 eligible studies comprising 44 experimental studies, 22 clinical studies, and 20 studies integrating both. From the clinical studies a timeline illustrating the alteration of EMT markers and related signalling was evident based on clinical progression of the disease. The experimental studies reveal connections of EMT with a multitude of factors such as genetic disorders, cancer-associated fibroblasts, and matrix remodelling via matrix metalloproteinases and urokinase plasminogen activator. Additionally, EMT was found to be closely tied to environmental factors as well as to stemness in cSCC via NFκB and β-catenin. We conclude that the canonical EGFR, canonical TGF-βR, PI3K/AKT and NFκB signalling are the four signalling pillars that induce EMT in cSCC and could be valuable therapeutic targets. Despite the complexity, EMT markers and pathways are desirable biomarkers and drug targets for the treatment of advanced or metastatic cSCC.

The efficacy of immune checkpoint inhibitors in rare tumors: A systematic review of published clinical trials

The immune checkpoint inhibitors (ICIs) entered treatment algorithms in most tumors. However, the data on the efficacy is limited in rare tumors with no phase III studies. We systemically reviewed the clinical trials evaluating the ICI efficacy in rare tumors and included a total of 47 clinical trials in this review. The ICIs demonstrated over 30% response rates in Merkel cell carcinoma and squamous cell carcinoma of the skin and became the standard of care. Additionally, the ICI efficacy was promising in thymic epithelial tumors and gestational trophoblastic neoplasia. In contrast, the ICI efficacy is limited in most sarcomas, germ cell tumors and low-grade neuroendocrine tumors. The ICI efficacy seemed to be improved with combinations targeting tumor microenvironment in sarcomas. The available evidence on ICI efficacy in rare tumors denote a need for better patient selection and novel combination strategies to improve outcomes.

Matrix Effectors in the Pathogenesis of Keratinocyte-Derived Carcinomas

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), referred to as keratinocyte carcinomas, are skin cancer with the highest incidence. BCCs, rarely metastasize; whereas, though generally not characterized by high lethality, approximately 2–4% of primary cSCCs metastasize with patients exhibiting poor prognosis. The extracellular matrix (ECM) serves as a scaffold that provides structural and biological support to cells in all human tissues. The main components of the ECM, including fibrillar proteins, proteoglycans (PGs), glycosaminoglycans (GAGs), and adhesion proteins such as fibronectin, are secreted by the cells in a tissue-specific manner, critical for the proper function of each organ. The skin compartmentalization to the epidermis and dermis compartments is based on a basement membrane (BM), a highly specialized network of ECM proteins that separate and unify the two compartments. The stiffness and assembly of BM and tensile forces affect tumor progenitors' invasion at the stratified epithelium's stromal border. Likewise, the mechanical properties of the stroma, e.g., stiffness, are directly correlated to the pathogenesis of the keratinocyte carcinomas. Since the ECM is a pool for various growth factors, cytokines, and chemokines, its' intense remodeling in the aberrant cancer tissue milieu affects biological functions, such as angiogenesis, adhesion, proliferation, or cell motility by regulating specific signaling pathways. This review discusses the structural and functional modulations of the keratinocyte carcinoma microenvironment. Furthermore, we debate how ECM remodeling affects the pathogenesis of these skin cancers.

Assessment of the Diagnostic Accuracy of Baseline Clinical Examination and Ultrasonographic Imaging for the Detection of Lymph Node Metastasis in Patients With High-risk Cutaneous Squamous Cell Carcinoma of the Head and Neck

IMPORTANCE

Patients with cutaneous squamous cell carcinoma (SCC) of the head and neck may develop lymph node metastasis; therefore, additional workup of the regional lymph nodes in these patients should be considered. However, there is uncertainty regarding the value of baseline ultrasonographic imaging in addition to clinical examination for the detection of metastasis.

OBJECTIVE

To assess the diagnostic accuracy of clinical examination and baseline ultrasonography for the detection of metastasis among patients with high-risk cutaneous SCC of the head and neck and to assess the accuracy of ultrasonography when baseline clinical examination produces negative results.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study was conducted among a retrospective cohort of 233 patients with 246 high-risk cutaneous SCC tumors of the head and neck. The study included all patients with high-risk cutaneous SCC of the head and neck who received clinical examination and baseline ultrasonographic imaging of their lymph nodes at the Erasmus Medical Center Cancer Institute, a tertiary referral hospital for patients with skin cancer in Rotterdam, the Netherlands, between January 1, 2015, and December 31, 2017. Data were analyzed from October 13, 2020, to September 29, 2021.

MAIN OUTCOMES AND MEASURES

Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Fine-needle aspiration cytologic biopsy and 6 months of follow-up per patient were used as the reference standards.

RESULTS

Among 233 patients (176 men [75.5%]; median age, 79.1 years [IQR, 71.5-83.7 years]; data on race and ethnicity were not collected) with 246 high-risk cutaneous SCC tumors of the head and neck, 20 metastases were cytologically confirmed at baseline, and 2 metastases were detected during 6 months of follow-up, yielding a 9% metastasis rate. The sensitivity of clinical examination was 50% (95% CI, 28%-72%), and the specificity was 96% (95% CI, 93%-98%). The PPV and NPV were 55% (95% CI, 36%-72%) and 95% (95% CI, 93%-97%), respectively. In the total cohort, ultrasonography had a sensitivity of 91% (95% CI, 71%-99%) and a specificity of 78% (95% CI, 72%-83%), with a PPV of 29% (95% CI, 23%-35%) and an NPV of 99% (95% CI, 96%-100%). In the group of patients with negative results at baseline clinical examination, 9 of 11 metastases were detected by ultrasonography, with 82% sensitivity (95% CI, 48%-98%); specificity was 79% (95% CI, 73%-84%), PPV was 17% (95% CI, 12%-23%), and NPV was 99% (95% CI, 96%-100%).

CONCLUSIONS AND RELEVANCE

In this diagnostic study, among a cohort of patients with high-risk cutaneous SCC of the head and neck, baseline ultrasonography was more sensitive than clinical examination alone for the detection of lymph node metastasis. In the setting of a negative result at baseline clinical examination, ultrasonography had high sensitivity for detecting nodal metastases, but this sensitivity should be evaluated against the high rate of false-positive findings.

Identifying candidates for immunotherapy with cemiplimab to treat advanced cutaneous squamous cell carcinoma: an expert opinion

Cutaneous squamous cell carcinoma (CSCC) is the second most common skin malignancy in white-skinned populations. Only a minority of patients (<5%) develop advanced disease, but this is often difficult to treat and characterised by a poor prognosis. Cemiplimab, a fully human IgG4 monoclonal antibody against programmed cell death-1 receptor, is indicated for advanced (i.e. locally advanced or metastatic) CSCC. Although the definition of metastatic CSCC is clear, there is currently no agreed definition of locally advanced CSCC. In recent guidelines, locally advanced CSCC was described as non-metastatic CSCC that is unlikely to be cured with surgery, radiotherapy or combination treatment. A multi-disciplinary advisory group of Italian CSCC experts was convened to develop criteria to assist in identifying appropriate candidates for cemiplimab therapy in advanced CSCC, based on the literature and clinical experience. In locally advanced CSCC, absolute, or mandatory, criteria for the use of cemiplimab are deep invasion, multiple lesions without defined margins, inadequate surgical excision margins and multiple recurrences, whereas relative criteria include large lesions, in critical or functionally significant areas and that are surgically complex. In addition, physicians should consider patient willingness/preferences (an absolute criterion), and their age and health status/comorbidities (relative criteria). It is hoped that these proposed absolute and relative criteria will help guide rational identification of patients who will receive maximum benefit from immunotherapy, while more clinical data accumulate.

Validation of Four Cutaneous Squamous Cell Carcinoma Staging Systems Using Nationwide Data

Background

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer worldwide with relatively low metastatic potential (2–5%). Developments in therapeutic options have highlighted the need to better identify high‐risk patients who could benefit from closer surveillance, adjuvant therapies and baseline/follow‐up imaging, while at the same time safely omitting low‐risk patients from further follow‐up. Controversy remains regarding the predictive performance of current cSCC staging systems and which methodology to adopt.

Objectives

To validate the performance of four cSCC staging systems [American Joint Committee on Cancer 8th edition (AJCC8), Brigham and Women’s Hospital (BWH), Tübingen and Salamanca T3 refinement] in predicting metastasis using a nationwide cohort.

Methods

A nested case–control study using data from the National Disease Registration Service, England, 2013–2015 was conducted. Metastatic cSCC cases were identified using an algorithm to identify all potential cases for manual review. These were 1 : 1 matched on follow‐up time to nonmetastatic controls randomly selected from 2013. Staging systems were analysed for distinctiveness, homogeneity, monotonicity, specificity, positive predictive value (PPV), negative predictive value (NPV) and c‐index.

Results

We included 887 metastatic cSCC cases and 887 nonmetastatic cSCC controls. The BWH system showed the highest specificity [92.8%, 95% confidence interval (CI) 90.8–94.3%, PPV (13.2%, 95% CI 10.6–16.2) and c‐index (0.84, 95% CI 0.82–0.86). The AJCC8 showed superior NPV (99.2%, 95% CI 99.2–99.3), homogeneity and monotonicity compared with the BWH and Tübingen diameter and thickness classifications (P < 0.001). Salamanca refinement did not show any improvement in AJCC8 T3 cSCC staging.

Conclusions

We validated four cSCC staging systems using the largest nationwide dataset of metastatic cSCC so far. Although the BWH system showed the highest overall discriminative ability, PPV was low for all staging systems, which shows the need for further improvement and refining of current cSCC staging systems.

Update of advanced cutaneous squamous cell carcinoma

The incidence of cutaneous squamous cell carcinoma (cSCC) is rapidly increasing. A growing part of this patient group is formed by immunocompromised patients, for example organ-transplant recipients (OTR). Although over 90% of the cSCC show a relatively harmless clinical behaviour, there is also a chance of developing advanced cSCC and metastases. Locally advanced cSCC are defined as cSCC that have locally advanced progression and are no longer amenable to surgery or radiation therapy. Better understanding of the clinical behaviour of cSCC is essential to discriminate between low- and high-risk cSCC. Staging systems are important and have recently been improved. Genetic characterisation of SCC will likely become an important tool to help distinguish low and high-risk cSCC with an increased potential to metastasise in the near future. Available treatments for high-risk and advanced cSCC include surgery, radiotherapy, chemotherapy and targeted therapy with epidermal growth factor receptors inhibitors. Anti-PD-1 antibodies show promising results with response rates of up to 50% in both locally advanced and metastatic cSCC but, in its present form, is not suitable for OTR.

Treatment of metastatic cutaneous squamous cell carcinoma in a solid organ transplant recipient with programmed death-1 checkpoint inhibitor therapy

Limited data exist on the use of immune checkpoint inhibitors (ICI) for the treatment of metastatic cutaneous squamous cell carcinoma (CSCC) in solid organ transplant recipients (SOTR). We report a case of a SOTR who developed metastatic disease following multiple surgeries, three cycles of adjuvant radiotherapy, and minimization of immunosuppression. He was subsequently treated with pembrolizumab and achieved a complete response. However, the patient developed ICI-induced allograft rejection requiring therapy discontinuation. The allograft was salvaged following IVIg and steroids. The patient developed recurrent disease which failed rechallenge with pembrolizumab but achieved a partial response following cemiplimab administration. This case illustrates the potential to treat metastatic CSCC in a SOTR with anti-programmed death-1 therapy and preserve graft function despite allograft rejection.

An updated report on the incidence and epidemiological trends of keratinocyte cancers in the United Kingdom 2013-2018

Introduction

The most common cancers in the UK are keratinocyte cancers (KCs): the combined term for basal cell carcinomas (BCCs) and cutaneous squamous cell carcinomas (cSCCs). Registration of KC is challenging due to high numbers and multiplicity of tumours per person.

Methods

We provide an updated report on the descriptive epidemiology of trends in KC incidence for the resident populations of UK countries (England, Northern Ireland, Scotland and Wales) using population-based cancer registry and pathology report data, 2013-18.

Results

Substantial increases in cSCC incidence in England, Scotland and Northern Ireland can be detected for the period of 2013-18, and the incidence of cSCC also increased in Wales from 2016 to 2018. In contrast, however, the pattern of annual change in the incidence of BCC across the nations differs. In England, the incidence of BCC declined slightly from 2016 to 2018, however, the overall trend across 2013-18 is not statistically significant. In Scotland, the incidence of BCC shows some variability, declining in 2017 before increasing in 2018, and the overall trend across 2013-18 was also not statistically significant. In Northern Ireland, the incidence of BCC increased significantly over the study period, and in Wales, the incidence of BCC increased from 2016 to 2018. One in five people will develop non-melanoma skin cancers (NMSC) in their lifetime in England. This estimate is much higher than the lifetime risk of melanoma (1 in 36 males and 1 in 47 females born after 1960 in the UK), which further highlights the burden of the disease and importance of early prevention strategies.

Conclusions

We highlight how common these tumours are by publishing the first ever lifetime incidence of NMSC. Additionally, the first time reporting of the age standardised incidence of KC in Wales further confirms the scale of the disease burden posed by these cancers in the UK. With approximately one in five people developing NMSC in their lifetime, optimisation of skin cancer prevention, management and research are essential.

Cumulative incidence and disease-specific survival of metastatic cutaneous squamous cell carcinoma: A nationwide cancer registry study

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) represents the most serious form of keratinocyte cancers because of its metastatic potential. Studies on nationwide incidence and disease-specific survival rates of metastatic cSCC (mcSCC) are lacking.

OBJECTIVE

To investigate the cumulative incidence and disease-specific survival of patients with mcSCC in the Dutch population and assess patient-based risk factors.

METHODS

We conducted a nationwide cancer registry study including all patients with the first cSCC in 2007 or 2008, using data from the Netherlands Cancer Registry, the nationwide network and registry of histopathology and cytopathology, and Statistics Netherlands. Cumulative incidence and Kaplan-Meier curves were calculated, and time-dependent Cox proportional hazards regression analyses were used.

RESULTS

Of the 11,137 patients, metastases developed in 1.9% (n = 217). The median time to metastasis was 1.5 years (interquartile range 0.6-3.8 years). The risk factors were age (adjusted hazard ratio [aHR] 1.03, 95% CI 1.02-1.05), male sex (aHR 1.7, 95% CI 1.3-2.3), and immunosuppression (aHR [organ transplant recipient] 5.0, 95% CI 2.5-10.0; aHR [hematologic malignancy] 2.7, 95% CI 1.6-4.6). The 5-year disease-specific survival for patients with mcSCC was 79.1%.

LIMITATIONS

Only histopathologically confirmed mcSCCs were included.

CONCLUSION

About 2% of cSCCs metastasize, with higher risk for men, increasing age, and immunocompromised patients. Disease-specific survival for patients with mcSCC is high.

Epidemiology of advanced cutaneous squamous cell carcinoma

Cutaneous invasive squamous cell carcinoma (cSCC) most commonly presents as a typically indolent tumour with five-year cure rates of >90%. Advanced cSCC has been defined as locally advanced or metastatic (locoregional or distant) cSCC. The epidemiological data on advanced cSCC are rare due to underreporting or exclusion of cSCC from national cancer registries. Although the frequency of local recurrence has been reported, there is no clear evidence on the incidence or mortality of locally advanced cSCCs, e.g. locally infiltrating or locally recurrent cSCCs that are not further amenable to curative surgery or radiotherapy. This gap of knowledge on the epidemiology of locally advanced cSCC, highlights the need for standardisation in defining and reporting both locally advanced and metastatic cSCC. Even though metastatic cSCCs are a small part of cSCCs (3%-5%), their aggressive characteristics contribute to significant morbidity, higher mortality and are those likely to require systemic treatments. Locally recurrent and metastatic cSCC may occur more frequently in high-risk cSCCs (up to 35%). The site of metastasis involves in the vast majority the regional lymph nodes, with the head and neck lymph nodes or parotid most commonly affected. Metastasis occurs mostly within 2-3 years of the primary cSCC diagnosis. The knowledge of the incidence and prognosis of advanced cSCC and the risk stratification of patients, who may progress to advanced cSCC, emerge as pressing research areas with important implications for cost-efficiency planning and optimisation of patient care.

A summary of the updated report on the incidence and epidemiological trends of keratinocyte cancers in the United Kingdom 2013-2018

Skin cancer is the commonest cancer in the UK. Skin cancer referrals via the two-week wait (urgent suspected cancer) pathway outnumber any other suspected malignancy.^{1, 2} The commonest skin cancers are keratinocyte cancers (KCs) which represents Basal Cell Carcinomas (BCC) and Cutaneous Squamous Cell Carcinomas (cSCC). Accurate KC incidence reporting is crucial for healthcare planning.

The Role of p53 in Progression of Cutaneous Squamous Cell Carcinoma

Skin cancers are the most common types of cancer worldwide, and their incidence is increasing. Melanoma, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC) are the three major types of skin cancer. Melanoma originates from melanocytes, whereas BCC and cSCC originate from epidermal keratinocytes and are therefore called keratinocyte carcinomas. Chronic exposure to ultraviolet radiation (UVR) is a common risk factor for skin cancers, but they differ with respect to oncogenic mutational profiles and alterations in cellular signaling pathways. cSCC is the most common metastatic skin cancer, and it is associated with poor prognosis in the advanced stage. An important early event in cSCC development is mutation of the TP53 gene and inactivation of the tumor suppressor function of the tumor protein 53 gene (TP53) in epidermal keratinocytes, which then leads to accumulation of additional oncogenic mutations. Additional genomic and proteomic alterations are required for the progression of premalignant lesion, actinic keratosis, to invasive and metastatic cSCC. Recently, the role of p53 in the invasion of cSCC has also been elucidated. In this review, the role of p53 in the progression of cSCC and as potential new therapeutic target for cSCC will be discussed.

The Role of Circular RNAs in Keratinocyte Carcinomas

Keratinocyte carcinomas (KC) include basal cell carcinomas (BCC) and cutaneous squamous cell carcinomas (cSCC) and represents the most common cancer in Europe and North America. Both entities are characterized by a very high mutational burden, mainly UV signature mutations. Predominately mutated genes in BCC belong to the sonic hedgehog pathway, whereas, in cSCC, TP53, CDKN2A, NOTCH1/2 and others are most frequently mutated. In addition, the dysregulation of factors associated with epithelial to mesenchymal transition (EMT) was shown in invasive cSCC. The expression of factors associated with tumorigenesis can be controlled in several ways and include non-coding RNA molecules, such as micro RNAs (miRNA) long noncoding RNAs (lncRNA) and circular RNAs (circRNA). To update findings on circRNA in KC, we reviewed 13 papers published since 2016, identified in a PubMed search. In both BCC and cSCC, numerous circRNAs were identified that were differently expressed compared to healthy skin. Some of them were shown to target miRNAs that are also dysregulated in KC. Moreover, some studies confirmed the biological functions of individual circRNAs involved in cancer development. Thus, circRNAs may be used as biomarkers of disease and disease progression and represent potential targets of new therapeutic approaches for KC.

Elective management of regional nodal basins in cutaneous squamous cell carcinoma of the head and neck: Controversies and contemporary perspectives

Non-melanoma skin cancer (NMSC) is among the most common cancers worldwide, with an incidence that continues to rise. Although cutaneous squamous cell carcinoma (cSCC) constitutes only approximately 20% of such cases, it represents the most common cause of NMSC mortality, owing largely to the propensity for development of regional lymph node metastases (LNM), which, when present, carry a dismal prognosis. Whilst overall rates of LNM are low, there are a number of patient and tumour factors that likely confer considerably higher risks, which has led several investigators to propose more proactive elective management of regional nodal basins in selected high-risk cases. Current international guidelines, however, do not recommend any elective treatment or sampling of regional nodal basins in the absence of clinically apparent disease. The purpose of this review is to explore in detail the fundamental issues underlying this controversy, focusing specifically on cSCC of the head and neck (cSCCHN). In particular the rationale for more a proactive elective approach to regional nodal basins, including the evidence-base underlying identification of potentially high-risk factors for development of LNM is discussed, along with oncological outcomes for those patients that do go onto suffer LNM. We also provide contemporary perspectives and evidence for approaches to electively managing regional nodal basins, and offer insight into how these may develop both in the clinical and research arenas.

Antibody-Based Targeted Interventions for the Diagnosis and Treatment of Skin Cancers

BACKGROUND

Cutaneous malignancies most commonly arise from skin epidermal cells. These cancers may rapidly progress from benign to a metastatic phase. Surgical resection represents the gold standard therapeutic treatment of non-metastatic skin cancer while chemo- and/or radiotherapy are often used against metastatic tumors. However, these therapeutic treatments are limited by the development of resistance and toxic side effects, resulting from the passive accumulation of cytotoxic drugs within healthy cells.

OBJECTIVE

This review aims to elucidate how the use of monoclonal Antibodies (mAbs) targeting specific Tumor Associated Antigens (TAAs) is paving the way to improved treatment. These mAbs are used as therapeutic or diagnostic carriers that can specifically deliver cytotoxic molecules, fluorophores or radiolabels to cancer cells that overexpress specific target antigens.

RESULTS

mAbs raised against TAAs are widely in use for e.g. differential diagnosis, prognosis and therapy of skin cancers. Antibody-Drug Conjugates (ADCs) particularly show remarkable potential. The safest ADCs reported to date use non-toxic photo-activatable Photosensitizers (PSs), allowing targeted Photodynamic Therapy (PDT) resulting in targeted delivery of PS into cancer cells and selective killing after light activation without harming the normal cell population. The use of near-infrared-emitting PSs enables both diagnostic and therapeutic applications upon light activation at the specific wavelengths.

CONCLUSION

Antibody-based approaches are presenting an array of opportunities to complement and improve current methods employed for skin cancer diagnosis and treatment.

Invasive and in situ squamous cell carcinoma of the skin: a nationwide study in Iceland

BACKGROUND

The worldwide incidence of cutaneous squamous cell carcinoma (cSCC) is increasing.

OBJECTIVES

To evaluate the tumour burden of in situ and invasive cSCC in Iceland, where the population is exposed to limited ultraviolet radiation.

METHODS

This whole-population study used the Icelandic Cancer Registry, which contains records of all in situ and invasive cSCC cases from 1981 to 2017. Incidence of cSCC was evaluated according to age, anatomical location, residence and multiplicity, and trends were assessed using joinpoint analysis. Age-standardized rates (WSR) and age-specific incidence rates per 100 000 person-years were calculated, along with cumulative and lifetime risks.

RESULTS

Between 1981 and 2017, in situ cSCC WSR increased from 1·2 to 19·1 for men and from 2·0 to 22·3 for women. Invasive cSCC WSR rose from 4·6 to 14 for men and from 0·3 to 13·2 for women. The average number of in situ cSCC lesions was 1·71 per woman and 1·39 per man. Women developed more in situ cSCCs than invasive cSCCs in almost all anatomical locations, whereas men developed more invasive cSCCs, mostly on the head and neck. The rates of in situ cSCC were higher in Reykjavik compared with rural areas. Furthermore, women more commonly developed multiple in situ lesions. For lip cSCCs, invasive lesions occurred more frequently than in situ lesions among both sexes. Joinpoint analysis showed that in situ cSCC in women exhibited the most rapid incidence increase.

CONCLUSIONS

cSCC has become an increasingly significant public health problem in Iceland. Tanning bed use and travelling abroad may contribute to skin cancer development. Public health efforts are needed to stem the behaviours leading to this rapid rise in cSCC.

Female Immunity Protects from Cutaneous Squamous Cell Carcinoma

PURPOSE

Cancer susceptibility and mortality are higher in males, and the mutational and transcriptomic landscape of cancer differs by sex. The current assumption is that men are at higher risk of epithelial cancers as they expose more to carcinogens and accumulate more damage than women. We present data showing women present with less aggressive primary cutaneous squamous cell carcinoma (cSCC) and early strong immune activation.

EXPERIMENTAL DESIGN

We explored clinical and molecular sexual disparity in immunocompetent and immunosuppressed patients with primary cSCC (N = 738, N = 160), advanced-stage cSCC (N = 63, N = 20) and FVB/N mice exposed to equal doses of DMBA, as well as in human keratinocytes by whole-exome, bulk, and single-cell RNA sequencing.

RESULTS

We show cSCC is more aggressive in men, and immunocompetent women develop mild cSCC, later in life. To test whether sex drives disparity, we exposed male and female mice to equal doses of carcinogen, and found males present with more aggressive, metastatic cSCC than females. Critically, females activate cancer immune-related expression pathways and CD4 and CD8 T-cell infiltration independently of mutations, a response that is absent in prednisolone-treated animals. In contrast, males increase the rate of mitosis and proliferation in response to carcinogen. Women's skin and keratinocytes also activate immune-cancer fighting pathways and immune cells at UV radiation-damaged sites. Critically, a compromised immune system leads to high-risk, aggressive cSCC specifically in women.

CONCLUSIONS

This work shows the immune response is sex biased in cSCC and highlights female immunity offers greater protection than male immunity.

Risk Factors Party Together: The Role of Perineural Invasion and Desmoplasia in Cutaneous Squamous Cell Carcinoma Prognosis

In the current issue, Haug et al. 2020 report on the prognostic impact of perineural invasion (PNI) and desmoplasia on cutaneous squamous cell carcinoma (CSCC) recurrence and metastasis. They find that PNI occurs exclusively in desmoplastic CSCC, and desmoplasia is independently associated with CSCC recurrence and metastasis after adjusting for well-established CSCC risk factors. Future studies should assess the contribution of desmoplasia in CSCC prognosis.

Metastases of Cutaneous Squamous Cell Carcinoma Seem to be the Most Frequent Malignancies in the Parotid Gland: A Hospital-Based Study From a Salivary Gland Center

Malignant parotid tumors account for approximately 20% of all parotid lesions. In addition to the various primary parotid lesions there are secondary parotid malignancies, such as metastases or lymphomas. Data on histopathological distribution of all malignancies-including secondary parotid lesions-is limited. Recent evidence indicated a rising surgical incidence of secondary parotid malignancies. This study aims to review the distribution of malignancies in parotid resections from a salivary gland center. A retrospective review of prospectively collected data for all patients who had received parotidectomy between 2014 and 2019 was performed. Histopathological distribution was displayed separately for all parotid malignancies and for primary parotid malignancies. Further, patients` characteristics were compared between benign and malignant parotid lesions and between the two most common malignant parotid lesions. Out of 777 patients, 614 (78.9%) patients had a benign and 164 (21.1%) patients had a malignant parotid lesion. The most common parotid malignancy was metastatic cutaneous squamous cell carcinoma (cSCC) accounting for 35.4% of all parotid malignancies. 71.5% of all malignant lesions were secondary malignancies. Patients with metastatic cSCC were significantly older (p < 0.001) and significantly more likely to be male (p < 0.001) than patients with primary parotid malignancies. No significant difference was found when the lesion size of metastatic cSCC was compared to primary parotid malignancies (p = 0.216). The present study shows the high prevalence of secondary parotid malignancies in patients who had received parotidectomy. Furthermore, it confirms a rising surgical incidence of metastatic cSCC to the parotid gland in a series from a salivary gland center. At this time, parotid surgery for malignant lesions is more likely to be performed for metastases than for primary parotid malignancies.

Development of a core outcome set for cutaneous squamous cell carcinoma trials: identification of core domains and outcomes

BACKGROUND

The lack of uniformity in the outcomes reported in clinical studies of the treatment of cutaneous squamous cell carcinoma (cSCC) complicates efforts to compare treatment effectiveness across trials.

OBJECTIVES

To develop a core outcome set (COS), a minimum set of agreed-upon outcomes to be measured in all clinical trials of a given disease or outcome, for the treatment of cSCC.

METHODS

One hundred and nine outcomes were identified via a systematic literature review and interviews with 28 stakeholders. After consolidation of this long list, 55 candidate outcomes were rated by 19 physician and 10 patient stakeholders, in two rounds of Delphi exercises. Outcomes scored 'critically important' (score of 7, 8 or 9) by ≥ 70% of patients and ≥ 70% of physicians were provisionally included. At the consensus meeting, after discussion and voting of 44 international experts and patients, the provisional list was reduced to a final core set, for which consensus was achieved among all meeting participants.

RESULTS

A core set of seven outcomes was finalized at the consensus meeting: (i) serious or persistent adverse events, (ii) patient-reported quality of life, (iii) complete response, (iv) partial response, (v) recurrence-free survival, (vi) progression-free survival and (vii) disease-specific survival.

CONCLUSIONS

In order to increase the comparability of results across trials and to reduce selective reporting bias, cSCC researchers should consider reporting these core outcomes. Further work needs to be performed to identify the measures that should be reported for each of these outcomes.

Matrix metalloproteinases in keratinocyte carcinomas

The incidence of cutaneous keratinocyte-derived cancers is increasing globally. Basal cell carcinoma (BCC) is the most common malignancy worldwide, and cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer. BCC can be classified into subtypes based on the histology, and these subtypes are classified further into low- and high-risk tumors. There is an increasing need to identify new therapeutic strategies for the treatment of unresectable and metastatic cSCC, and for aggressive BCC variants such as infiltrating, basosquamous or morpheaform BCCs. The most important risk factor for BCC and cSCC is solar UV radiation, which causes genetic and epigenetic alterations in keratinocytes. Similar gene mutations are noted already in sun-exposed normal skin emphasizing the role of the alterations in the tumor microenvironment in the progression of cSCC. Early events in cSCC progression are alterations in the composition of basement membrane and dermal extracellular matrix induced by influx of microbes, inflammatory cells and activated stromal fibroblasts. Activated fibroblasts promote inflammation and produce growth factors and proteolytic enzymes, including matrix metalloproteinases (MMPs). Transforming growth factor-β produced by tumor cells and fibroblasts induces the expression of MMPs by cSCC cells and promotes their invasion. Fibroblast-derived keratinocyte growth factor suppresses the malignant phenotype of cSCC cells by inhibiting the expression of several MMPs. These findings emphasize the importance of interplay of tumor and stromal cells in the progression of cSCC and BCC and suggest tumor microenvironment as a therapeutic target in cSCC and aggressive subtypes of BCC.

Cost of illness del carcinoma cutaneo a cellule squamose (CSCC)

Background:

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent form of nonmelanoma skin cancer (NMSC) and accounts for 20-25% of skin cancers (AIOM Guidelines 2019).

Objectives:

The aim of this study was to estimate the total annual direct costs incurred by the National Health Service for the management and treatment of CSCC and advanced CSCC patients in Italy.

Methods:

An incidence-based cost of illness (COI) model was developed to estimate direct costs associated with the treatment and management of CSCC patients in Italy. The identified treatment pathway was validated with a team of clinical experts and was distinguished between resectable CSCC and locally advanced CSCC or metastatic CSCC. Treatments costs were obtained through the analysis of the National Hospital Discharge Database (HDD) for the years 2015-2018; monitoring and terminal care costs were obtained from national tariffs of outpatient care service and from the literature respectively.

Results:

Associating the estimated costs for each phase of the treatment pathway with the proportion of patients present in each phase, the COI model estimated an annual economic burden of about € 25.9 million for the management and treatment of patients with CSCC in Italy, € 2.7 million of which were associated to patients with advanced CSCC. The average cost per patient with advanced CSCC was higher compared to that of patient with resectable CSCC (€ 4,490 vs € 2,236 respectively).

Conclusions:

Our analysis showed that advanced CSCC patients are associated with a higher average cost than patients with resectable CSCC.

Comprehensive Mutational and Phenotypic Characterization of New Metastatic Cutaneous Squamous Cell Carcinoma Cell Lines Reveal Novel Drug Susceptibilities

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer. Most patients who develop metastases (2–5%) present with advanced disease that requires a combination of radical surgery and adjuvant radiation therapy. There are few effective therapies for refractory disease. In this study, we describe novel patient-derived cell lines from cSCC metastases of the head and neck (designated UW-CSCC1 and UW-CSCC2). The cell lines genotypically and phenotypically resembled the original patient tumor and were tumorogenic in mice. Differences in cancer-related gene expression between the tumor and cell lines after various culturing conditions could be largely reversed by xenografting and reculturing. The novel drug susceptibilities of UW-CSCC1 and an irradiated subclone UW-CSCC1-R to drugs targeting cell cycle, PI3K/AKT/mTOR, and DNA damage pathways were observed using high-throughput anti-cancer and kinase-inhibitor compound libraries, which correlate with either copy number variations, targetable mutations and/or the upregulation of gene expression. A secondary screen of top hits in all three cell lines including PIK3CA-targeting drugs supports the utility of targeting the PI3K/AKT/mTOR pathway in this disease. UW-CSCC cell lines are thus useful preclinical models for determining targetable pathways and candidate therapeutics.

Mucoscopy of lip squamous cell carcinoma and correlation with skin phototype and histological differentiation: a multicentric retrospective observational study by the International Dermoscopy Society

BACKGROUND

There is a scarcity of published data on the dermoscopic morphology of lip squamous cell carcinoma (SCC) and its variability according to the histological differentiation degree and patient's ethnicity as per skin phototype.

OBJECTIVES

To evaluate the dermoscopic features of SCC of the lips and identify possible dermoscopic clues that may aid in differentiation between well-differentiated, moderately-differentiated, and poorly-differentiated lesions, as well as between "fair" skin (Fitzpatrick skin phototypes I-III) and "dark" skin (Fitzpatrick skin phototypes IV-VI).

METHODS

The clinical profile and dermoscopic images of patients of any age and either gender with histologically confirmed lip SCC collated from seven dermatological centers were retrospectively evaluated for dermoscopic clues as per certain predefined criteria.

RESULTS

A total of 60 lesions from 60 patients were included in the analysis. Histologically, well, moderate, and poordifferentiation were seen in 24 (40%), 14 (23.3%), and 22 (36.7%) of the lesions, respectively. Other than the presence of brown-to-gray dots/globules, which was exclusively seen in cases with dark phototypes (19.4% P = 0.035), no other dermoscopic feature was statistically significant in differentiating between the two skin types. Some dermoscopic findings were observed specifically with statistical significance: perivascular white halos (P = 0.049) and whitish-yellow background in well-differentiated lesions (P = 0.003); pink background in moderately-differentiated lesions (P = 0.003); and red background with dense vascularity in poorly-differentiated lesions (P < 0.001).

CONCLUSIONS

The presence of vessels, scale/crust, and keratinization-associated white structures were the most common dermoscopic clues in lip SCC.

Efficacy of axitinib in metastatic head and neck cancer with novel radiographic response criteria

BACKGROUND

There are limited treatment options for unresectable recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Vascular endothelial growth factor is of significant interest for targeted therapy in R/M HNSCC because of its central role in tumorigenesis and immunosuppression. Axitinib is a potent inhibitor of vascular endothelial growth factor receptor (VEGFR) 1 , VEGFR2, VEGFR3, platelet-derived growth factor receptor, as well as c-kit and offers such an approach.

METHODS

This article reports the results of a phase 2 trial evaluating axitinib in R/M HNSCC according to the Choi criteria for radiographic response assessment. The primary endpoint of this trial was 6-month overall survival.

RESULTS

Twenty-nine patients were enrolled, and 28 were evaluable for a response. Patients were heavily pretreated with 61% having had at least 1 previous systemic treatment in the metastatic setting (range, 0-5). The median overall survival of 9.8 months and the 6-month overall survival rate of 70% met the protocol-defined criteria for clinical efficacy. The best overall response rate was 42%. Correlative analyses demonstrated that PI3K signaling pathway alterations were associated with an increased response to therapy (75% vs 17%). A marked response to therapy was seen in a subgroup of patients who were treated with an immune checkpoint inhibitor after progression on axitinib.

CONCLUSIONS

Treatment with axitinib is associated with improved survival in patients with heavily pretreated head and neck cancer, and PI3K pathway alterations may serve as a biomarker for response. Further investigation is warranted to evaluate axitinib in biomarker-selected populations, especially in combination with immune checkpoint inhibitor therapy.

LAY SUMMARY

Metastatic head and neck squamous cancer is an incurable disease with limited treatment options and a poor prognosis. This study is the first to demonstrate that the targeted oral drug axitinib improves survival in patients with heavily pretreated metastatic head and neck cancer. Furthermore, patients whose tumors have specific mutations derive the greatest benefit from therapy. The investigation of axitinib alone or in combination with immunotherapy in a genomic biomarker-selected population is warranted.

Metastatic Squamous Cell Carcinoma: A Cautionary Tale

Cutaneous squamous cell carcinoma (cSCC) typically arises from a malignant proliferation of keratinocytes. It is the second most common cancer in the United States and typically affects older white men. Risk factors for cSCC include ultraviolet radiation exposure, light skin tone, and immunosuppression. Although metastasis in cSCC is rare, primary tumor characteristics such as location, size, and depth of invasion, among others, can help risk-stratify lesions for local recurrence, metastatic events, and death. We present a case of primary cutaneous metastatic squamous cell carcinoma masquerading as a cyst on the left temple of a 73-year-old Caucasian man following numerous treatments of cryotherapy to an ipsilateral helical lesion.

Management of primary skin cancer during a pandemic: Multidisciplinary recommendations

During the coronavirus disease 2019 (COVID-19) pandemic, providers and patients must engage in shared decision making regarding the pros and cons of early versus delayed interventions for localized skin cancer. Patients at highest risk of COVID-19 complications are older; are immunosuppressed; and have diabetes, cancer, or cardiopulmonary disease, with multiple comorbidities associated with worse outcomes. Physicians must weigh the patient's risk of COVID-19 complications in the event of exposure against the risk of worse oncologic outcomes from delaying cancer therapy. Herein, the authors have summarized current data regarding the risk of COVID-19 complications and mortality based on age and comorbidities and have reviewed the literature assessing how treatment delays affect oncologic outcomes. They also have provided multidisciplinary recommendations regarding the timing of local therapy for early-stage skin cancers during this pandemic with input from experts at 11 different institutions. For patients with Merkel cell carcinoma, the authors recommend prioritizing treatment, but a short delay can be considered for patients with favorable T1 disease who are at higher risk of COVID-19 complications. For patients with melanoma, the authors recommend delaying the treatment of patients with T0 to T1 disease for 3 months if there is no macroscopic residual disease at the time of biopsy. Treatment of tumors ≥T2 can be delayed for 3 months if the biopsy margins are negative. For patients with cutaneous squamous cell carcinoma, those with Brigham and Women's Hospital T1 to T2a disease can have their treatment delayed for 2 to 3 months unless there is rapid growth, symptomatic lesions, or the patient is immunocompromised. The treatment of tumors ≥T2b should be prioritized, but a 1-month to 2-month delay is unlikely to worsen disease-specific mortality. For patients with squamous cell carcinoma in situ and basal cell carcinoma, treatment can be deferred for 3 months unless the individual is highly symptomatic.

Outcomes and prognosticators in regionally recurrent cutaneous squamous cell carcinoma of the head and neck

INTRODUCTION

Data regarding regionally metastatic cutaneous squamous cell carcinoma of the head and neck (cSCCHN) is limited and derived almost exclusively from Australian and United States (US) institutions. We report the first United Kingdom perspective, with the aims of benchmarking survival outcomes and identifying clinically relevant prognosticators.

MATERIALS AND METHODS

Ninety-one patients with regionally recurrent cSCCHN treated with curative intent over a ten-year period (2009-2018) were studied retrospectively. Time-to-event analyses were used to estimate oncological outcomes, and log-rank statistics and Cox proportional hazards models used to examine potential prognosticators. Receiver operating characteristics were also used to analyse the influence of nodal disease burden.

RESULTS

Parotid involvement (with or without neck involvement) was most common (79.2%), and time to recurrence in those with parotid disease alone significantly shorter than for any other disease distribution (p = 0.034). Respective five-year overall, disease-specific, and disease-free survival estimates were 43.8%, 63.8%, and 36.2%. Extracapsular spread (ECS) portended reduced DFS and DSS (p = 0.012 and p = 0.005 respectively). Increasing nodal burden (≥4 involved nodes) also reduced DSS (p = 0.020), while parotid disease alone predicted more favourable DSS (p = 0.008). ECS and isolated parotid involvement remained significant on multi-variate analysis (p = 0.014 and p = 0.028 respectively).

CONCLUSIONS

Oncological outcomes were unfavourable but broadly consistent with previous reports, notionally lending support to a more proactive approach in managing the clinically node negative neck/parotid in selected high-risk cases. Our data also support distinct parotid classification and consideration of involved lymph node number in future staging systems.

Epidemiology of cutaneous sebaceous carcinoma

There has been uncertainty about the demographics and anatomical distribution of cutaneous sebaceous carcinoma. This study aims to investigate these uncertainties by analysing data from various countries. Data were obtained from cancer registries of the United States, England, Norway and Taiwan, and incidence rates were calculated with uniform age-adjustment. sebaceous carcinoma was more commonly reported in males than females in white populations, whereas the inverse was true in Taiwan. Ocular sebaceous carcinoma was more commonly reported in females than males in all populations, despite male predominance in white populations. The majority (approx. 70-90%) occurred on head and neck in Asians and whites. Age-adjusted incidence rate (to the 2000-2025 WHO World Standard Population) ranged from 0.07 to 0.18 per 100 000 person-years and was not higher in Taiwanese than in white populations.

Treatment approaches in immunosuppressed patients with advanced cutaneous squamous cell carcinoma

Immunosuppression, both iatrogenic and disease-related, is associated with a greatly increased incidence of cutaneous SCC (cSCC) and with aggressive cSCC and worse disease outcomes. Consequently, rapid access to skin cancer services and prudent surgical choices, such as circumferential margin assessment, is essential when treating advanced cSCC in an immunosuppressed patient. For high-risk cancers and control of cSCC multiplicity, additional strategies should be actively considered within the multidisciplinary clinical care team. These include minimization or revision of immunosuppressive medications, systemic chemoprevention (including retinoids, nicotinamide, capecitabine) and adjuvant therapies such as radiotherapy. Unfortunately, there is a relative paucity of good evidence for many of these treatments in the immunosuppressed. Systemic treatments for metastatic cSCC are often contraindicated in organ transplant recipients, notably checkpoint inhibitor immunotherapy. There are also toxicity concerns with some conventional chemotherapies and EGFR inhibitors. Until recently, clinical trials have largely excluded immunosuppressed individuals. Development of more effective treatment for advanced cSCC in this high-risk group and prospective clinical trials are now research priorities.

Environmental effects of stratospheric ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2019

This assessment, by the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP), one of three Panels informing the Parties to the Montreal Protocol, provides an update, since our previous extensive assessment (Photochem. Photobiol. Sci., 2019, 18, 595-828), of recent findings of current and projected interactive environmental effects of ultraviolet (UV) radiation, stratospheric ozone, and climate change. These effects include those on human health, air quality, terrestrial and aquatic ecosystems, biogeochemical cycles, and materials used in construction and other services. The present update evaluates further evidence of the consequences of human activity on climate change that are altering the exposure of organisms and ecosystems to UV radiation. This in turn reveals the interactive effects of many climate change factors with UV radiation that have implications for the atmosphere, feedbacks, contaminant fate and transport, organismal responses, and many outdoor materials including plastics, wood, and fabrics. The universal ratification of the Montreal Protocol, signed by 197 countries, has led to the regulation and phase-out of chemicals that deplete the stratospheric ozone layer. Although this treaty has had unprecedented success in protecting the ozone layer, and hence all life on Earth from damaging UV radiation, it is also making a substantial contribution to reducing climate warming because many of the chemicals under this treaty are greenhouse gases.