Defining the incidence of cutaneous squamous cell carcinoma in coastal NSW Australia

Recent Changes in the Incidence and Characteristics of Cutaneous Squamous Cell Carcinomas in Finland from 2006 to 2020: A Retrospective Cohort Study

Registers recording only 1 tumour per patient do not enable assessment of the real burden of cutaneous squamous cell carcinoma. To investigate recent changes in the incidence and characteristics of tumours, a retrospective 15-year patient cohort study was performed in Finland. Histopathological diagnoses of cutaneous squamous cell carcinomas diagnosed between 2016 and 2020 were obtained from the pathology database and clinical data from patient medical records and combined with previously collected data for the years 2006-2015. Altogether 1,472 patients with 2,056 tumours were identified. The crude incidence increased from 19/100,000 persons in 2006 to 42 in 2020 (p < 0.001), increasing most in people aged over 80 years. The percentage of tumours located on the trunk increased from 5.3% during the first 5-year period, 2006-2010, to 9.0% in 2016-2020. Also, the location of tumours was significantly different between men and women, as men had more tumours on the scalp and ears, and women on the lower limbs. A slight change in the tumours from poorly to well differentiated and a decrease in the invasion depth were noted between 2006 and 2020. As the burden of tumours continues to increase, more attention should be paid to their prevention.

Guidelines for the diagnosis and treatment of cutaneous squamous cell carcinoma: a GRADE approach for evidence evaluation and recommendations by the Italian Association of Medical Oncology

Cutaneous squamous cell carcinoma (CSCC) accounts for ∼20%-25% of all skin tumors. Its precise incidence is often challenging to determine due to limited statistics and its incorporation with mucosal forms. While most cases have a favorable prognosis, challenges arise in patients presenting with locally advanced or metastatic forms, mainly appearing in immunocompromised patients, solid organ transplantation recipients, or those facing social difficulties. Traditionally, chemotherapy and targeted therapy were the mainstays for advanced cases, but recent approvals of immunotherapeutic agents like cemiplimab and pembrolizumab have revolutionized treatment options. These guidelines, developed by the Italian Association of Medical Oncologists (AIOM) using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach, aim to guide clinicians in diagnosing, treating, and monitoring patients with CSCC, covering key aspects from primitive tumors to advanced stages, selected by a panel of experts selected by AIOM and other national scientific societies. The incorporation of these guidelines into clinical practice is expected to enhance patient care and address the evolving landscape of CSCC management.

Ex vivo therapeutic screening of metastatic cSCC: A review of methodological considerations for clinical implementation

Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy worldwide, with most deaths caused by locally advanced and metastatic disease. Treatment of resectable metastases is typically limited to invasive surgery with adjuvant radiotherapy; however, many patients fail to respond and there is minimal data to predict response or propose effective alternatives. Precision medicine could improve this, though genomic biomarkers remain elusive in the high mutational background and genomic complexity of cSCC. A phenotypic approach to precision medicine using patient-derived ex vivo tumour models is gaining favour for its capacity to directly assess biological responses to therapeutics as a functional, predictive biomarker. However, the use of ex vivo models for guiding therapeutic selection has yet to be employed for metastatic cSCC. This review will therefore evaluate the existing experimental models of metastatic cSCC and discuss how ex vivo methods could overcome the shortcomings of these existing models. Disease-specific considerations for a prospective methodological pipeline will also be discussed in the context of precision medicine.

Mortality from Nonmelanoma Skin Cancer in Australia from 1971 to 2021

The number of non-melanoma skin cancers (NMSC) removed from Australians is increasing every year. The number of deaths from NMSC is increasing but so is the population. However, the population has greatly changed with many dark-skinned people migrating to Australia. These people are at low risk for skin cancer even if they live all their lives in Australia. The susceptible population is the rest of the population. The death rate from NMSC for the entire population and susceptible populations since 1971 is examined in this article.

MATERIALS AND METHODS

Data on the Australian population were obtained from the Australian Bureau of Statistics (ABS). Every five years a census is held in Australia and detailed information of the population is provided. The ABS also provided yearly data on the causes of death in Australia.

RESULTS

The total population increased from 12,755,638 in 1971 to 25,738,140 in 2021. However, the susceptible population increased by far less, from 12,493,780 to 19,773,783. The number of deaths from NMSC increased from 143 to 765. The crude death rate for the susceptible population increased from 1.1 per 100,000 to 3.9 per 100,000. The crude death rate in the susceptible population aged 65 or more increased from 9.4 to 18.2 per 100,000.

CONCLUSION

Deaths from NMSC are increasing despite public health campaigns to prevent skin cancer. According to current trends, NMSC will cause more deaths than melanoma in Australia.

PIK Your Poison: The Effects of Combining PI3K and CDK Inhibitors against Metastatic Cutaneous Squamous Cell Carcinoma In Vitro

Cutaneous squamous cell carcinoma (cSCC) is a very common skin malignancy with poor prognosis for patients with locally advanced or metastatic cSCC (mcSCC). PI3K/AKT/mTOR and cell cycle signalling pathways are often dysregulated in mcSCC. A combination drug approach has been theorised to overcome the underwhelming clinical performance of targeted inhibitors as single agents. This study investigates the potential of targeted inhibition of the p110α-subunit of PI3K with PIK-75 or BGT226 (P13Ki), and of CDK1/2/5/9 with dinaciclib (CDKi) as single agents and in combination. The patient-derived mcSCC cell lines, UW-CSCC1 and UW-CSCC2, were used to assess cell viability, migration, cell signalling, cell cycle distribution, and apoptosis. PIK-75, BGT226, and dinaciclib exhibited strong cytotoxic potency as single agents. Notably, the non-malignant HaCaT cell line was unaffected. In 2D cultures, PIK-75 synergistically enhanced the cytotoxic effects of dinaciclib in UW-CSCC2, but not UW-CSCC1. Interestingly, this pattern was reversed in 3D spheroid models. Despite the combination of PIK-75 and dinaciclib resulting in an increase in cell cycle arrest and apoptosis, and reduced cell motility, these differences were largely negligible compared to their single-agent counterpart. The differential responses between the cell lines correlated with driver gene mutation profiles. These findings suggest that personalised medicine approaches targeting PI3K and CDK pathways in combination may yield some benefit for mcSCC, and that more complex 3D models should be considered for drug responsiveness studies in this disease.

Travel-associated cost savings to patients and the health system through provision of specialist head and neck surgery outreach clinics in rural New South Wales, Australia

INTRODUCTION

Centralisation of head and neck surgical services means that patients in regional and remote Australia need to travel long distances for treatment and follow-up, imparting a significant financial burden on patients and the health system.

OBJECTIVE

To estimate costs of travel to local outreach clinics and determine potential cost savings to patients and the health system by avoiding patient travel to major cities for head and neck surgical care.

DESIGN

Retrospective audit of three head and neck surgery outreach clinics in New South Wales, Australia over 4 years (2017-2020). Direct costs of travel from a patient's residence to their local outreach clinic were estimated. Costs of travel and accommodation to Sydney for an appointment were calculated for different travel modes. Estimated reimbursements for travel through government support schemes were calculated based on published rates.

FINDINGS

Some 657 patients attended the three clinics, accounting for 1981 appointments. Depending on mode of travel, the estimated median cost of return travel (including accommodation) to Sydney was $379 to $739 per patient per trip and the median government reimbursement ranged from $182 to $279 per trip. In comparison, the cost of return travel by car to local outreach clinics ranged from $28 to $163 per appointment. Outreach clinics were estimated to save patients a median of $285 per trip and avoided government reimbursements of $215 per trip.

DISCUSSION

Despite uptake in telehealth, outreach medical services remain an important asset for people living in regional areas to address inequities in access. However, the cost benefits are likely to be underestimated as our approach did not account for indirect costs associated with travel.

CONCLUSION

Outreach head and neck surgical services located in regional areas can reduce the financial burden on both patients and the healthcare system. Greater investment in outreach clinics could ensure sustainability of services to promote equitable access to specialised surgical services.

Implementing structured pathology reporting protocol for non-melanocytic skin cancers: practical considerations

Non-melanocytic skin cancers (NMSCs) account for five times the incidence of all other cancers combined and cost US $6 billion annually. These are the most frequent specimens encountered in community pathology practice in many Western countries. Lack of standardised structured pathology reporting protocols (SPRPs) can result in omission of critical information or miscommunication leading to suboptimal patient management. The lack of standardised data has significant downstream public health implications, including insufficient data for reliable development of prognostic tools and health-economy planning. The Royal College of Pathologists of Australasia has developed an NMSC SPRP. A multidisciplinary expert committee including pathologists, surgeons, dermatologists, and radiation and medical oncologists from high volume cancer centres was convened. A systematic literature review was performed to identify evidence for including elements as mandatory standards or best practice guidelines. The SPRP and accompanying commentary of evidence, definitions and criteria was peer reviewed by external stakeholders. Finally, the protocol was revised following feedback and trialled in multiple centres prior to implementation. Some parameters utilised clinically for determining management and prognosis including tumour depth, lymphovascular invasion or distance to the margins lack high level evidence in NMSC. Dermatologists, surgeons, and radiation oncologists welcomed the SPRP. Pathologists indicated that the variety of NMSC specimens ranging from curettes to radical resections as well as significant differences in the biological behaviour of different tumours covered by the NMSC umbrella made use of a single protocol difficult. The feedback included that using a SPRP for low risk NMSC was neither clinically justified nor compensated adequately by the Australian Medicare Reimbursement Schedule. Following stakeholder feedback, the SPRP implementation was restricted to excision specimens of head and neck NMSC; and low-risk NMSC, such as superficial basal cell carcinoma, were excluded. Implementing NMSC SPRP fulfils an unmet clinical need. Unlike other cancers, NMSCs generate a range of specimen types and are reported in a wide range of pathology practices. Limiting use of SPRP to NMSC at higher risk of progression and providing formatted templates for easy incorporation into laboratory information systems were essential to successful deployment. In the future, further consideration should be given to implementing the SPRP to include all relevant specimens, including non-head and neck and low-risk NMSC specimens.

Sex Disparity for Patients with Cutaneous Squamous Cell Carcinoma of the Head and Neck: A Systematic Review

The incidence of head and neck cutaneous squamous cell carcinoma (HNcSCC) is unevenly distributed between men and women. At present, the mechanism behind this disparity remains elusive. This study conducted a systematic review and meta-analysis of proportions to investigate the disparity between sexes for patients with HNcSCC. PubMed, Scopus, EMBASE, MEDLINE, Emcare and CINAHL were searched in November 2021 and June 2022 (N > 50, English, human), and studies which examined the association between sex and HNcSCC were included. Analysis was conducted using RStudio with data and forest plots displaying males as a proportion of total patients with HNcSCC. Two independent researchers performed study selection, data extraction, data analysis and risk of bias. Eighty-two studies (1948 to 2018) comprising approximately 186,000 participants (67% male, 33% female) from 29 countries were included. Significantly more males had HNcSCC overall (71%; CI: 67−74). Males were also significantly more affected by cSCC of the ear (92%; CI: 89−94), lip (74%; CI: 66−81), and eyelid (56%; CI: 51−62). This study found HNcSCC disproportionately affected males overall and across all subtypes. Improving our understanding of sex-specific mechanisms in HNcSCC will better inform our preventive, therapeutic and prognostic practices.

High-Dimensional and Spatial Analysis Reveals Immune Landscape-Dependent Progression in Cutaneous Squamous Cell Carcinoma

PURPOSE

The tumor immune microenvironment impacts the biological behavior of the tumor, but its effect on clinical outcomes in head and neck cutaneous squamous cell carcinomas (HNcSCC) is largely unknown.

EXPERIMENTAL DESIGN

We compared the immune milieu of high-risk HNcSCC that never progressed to metastasis with those that metastasized using multiparameter imaging mass cytometry. The cohort included both immunosuppressed patients (IS) and patients with an absence of clinical immune-suppression (ACIS). Spatial analyses were used to identify cellular interactions that were associated with tumor behavior.

RESULTS

Nonprogressing primary HNcSCC were characterized by higher CD8+ and CD4+ T-cell responses, including numerically increased regulatory T cells. In contrast, primary lesions from HNcSCC patients who progressed were largely devoid of T cells with lower numbers of innate immune cells and increased expression of checkpoint receptors and in the metastatic lesions were characterized by an accumulation of B cells. Spatial analysis reveals multiple cellular interactions associated with nonprogressing primary tumors that were distinct in primary tumors of disease-progressing patients. Cellular regional analysis of the tumor microenvironment also shows squamous cell-enriched tumor regions associated with primary nonprogressing tumors.

CONCLUSIONS

Effective responses from both CD8+ and CD4+ T cells in the tumor microenvironment are essential for immune control of primary HNcSCC. Our findings indicate that the early events that shape the immune responses in primary tumors dictate progression and disease outcomes in HNcSCC.

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

Simple Summary

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

Abstract

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

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.

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.