Evaluation of 122 advanced-stage cutaneous squamous cell carcinomas by comprehensive genomic profiling opens the door for new routes to targeted therapies

The Mutational and Microenvironmental Landscape of Cutaneous Squamous Cell Carcinoma: A Review

Cutaneous squamous cell carcinoma (cSCC) manifests through the complex interactions of UV-induced DNA damage, genetic mutations, and alterations in the tumor microenvironment. A high mutational burden is present in cSCC, as well as both cSCC precursors and normal skin, making driver genes difficult to differentiate. Despite this, several key driver genes have been identified, including TP53, the NOTCH family, CDKN2A, PIK3CA, and EGFR. In addition to mutations, the tumor microenvironment and the manipulation and evasion of the immune system play a critical role in cSCC progression. Novel therapeutic approaches, such as immunotherapy and EGFR inhibitors, have been used to target these dysregulations, and have shown promise in treating advanced cSCC cases, emphasizing the need for targeted interventions considering both genetic and microenvironmental factors for improved patient outcomes.

Establishment and molecular characterization of HCB-541, a novel and aggressive human cutaneous squamous cell carcinoma cell line

Cutaneous squamous cell carcinoma (cSCC) is a common type of skin cancer that can result in significant morbidity, although it is usually well-managed and rarely metastasizes. However, the lack of commercially available cSCC cell lines hinders our understanding of this disease. This study aims to establish and characterize a new metastatic cSCC cell line derived from a Brazilian patient. A tumor biopsy was taken from a metastatic cSCC patient, immortalized, and named HCB-541 after several passages. The cytokeratin expression profile, karyotypic alterations, mutational analysis, mRNA and protein differential expression, tumorigenic capacity in xenograft models, and drug sensitivity were analyzed. The HCB-541 cell line showed a doubling time between 20 and 30 h and high tumorigenic capacity in the xenograft mouse model. The HCB-541 cell line showed hypodiploid and hypotetraploidy populations. We found pathogenic mutations in TP53 p.(Arg248Leu), HRAS (Gln61His) and TERT promoter (C228T) and high-level microsatellite instability (MSI-H) in both tumor and cell line. We observed 37 cancer-related genes differentially expressed when compared with HACAT control cells. The HCB-541 cells exhibited high phosphorylated levels of EGFR, AXL, Tie, FGFR, and ROR2, and high sensitivity to cisplatin, carboplatin, and EGFR inhibitors. Our study successfully established HCB-541, a new cSCC cell line that could be useful as a valuable biological model for understanding the biology and therapy of metastatic skin cancer.

Molecular Profiling and the Interaction of Somatic Mutations with Transcriptomic Profiles in Non-Melanoma Skin Cancer (NMSC) in a Population Exposed to Arsenic

Exposure to inorganic arsenic (As) is recognized as a risk factor for non-melanoma skin cancer (NMSC). We followed up with 7000 adults for 6 years who were exposed to As. During follow-up, 2.2% of the males and 1.3% of the females developed basal cell carcinoma (BCC), while 0.4% of the male and 0.2% of the female participants developed squamous cell carcinoma (SCC). Using a panel of more than 400 cancer-related genes, we detected somatic mutations (SMs) in the first 32 NMSC samples (BCC = 26 and SCC = 6) by comparing paired (tissue-blood) samples from the same individual and then comparing them to the SM in healthy skin tissue from 16 participants. We identified (a) a list of NMSC-associated SMs, (b) SMs present in both NMSC and healthy skin, and (c) SMs found only in healthy skin. We also demonstrate that the presence of non-synonymous SMs in the top mutated genes (like PTCH1, NOTCH1, SYNE1, PKHD1 in BCC and TP53 in SCC) significantly affects the magnitude of differential expressions of major genes and gene pathways (basal cell carcinoma pathways, NOTCH signaling, IL-17 signaling, p53 signaling, Wnt signaling pathway). These findings may help select groups of patients for targeted therapy, like hedgehog signaling inhibitors, IL17 inhibitors, etc., in the future.

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.

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.

Comprehensive profiling identifies tumour and immune microenvironmental differences in clinical subsets of cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinomas (cSCCs) are the second most diagnosed skin cancer worldwide; however, little is known about the pathobiological factors that contribute to the diverse clinical outcomes seen.

OBJECTIVES

To profile cSCCs comprehensively and identify the pathological processes that contribute to the disparities seen in their clinical behaviour.

METHODS

We characterized the genomic, transcriptomic and immunohistochemical profiles of 211 cSCC tumours, including 37 cSCCs from immunocompromised patients.

RESULTS

cSCCs from immunocompromised patients were characterized by a lack of B cells in the peritumoral stroma compared with immunocompetent patients. Further, an abundance of a memory B-cell-like population in the peritumoral stroma was associated with a better prognosis in all patients (immunocompetent and immunocompromised), as well as only immunocompetent patients. No differences in genetic -variants, tumour mutational burden or mutational signatures were observed between cSCCs from immunocompetent and immunocompromised patients. Thus, differences in survival between cSCCs from immunocompromised patients and immunocompetent patients are not likely to be driven by tumour genomic factors, but may be associated with differential host immune response. cSCC not from a primary head and neck site had lower tumour mutational burden and exhibited upregulation of the epithelial-mesenchymal transition programme compared with head and neck cSCC. Both factors were implicated with poorer responses to immune checkpoint inhibition, and the latter with poorer survival.

CONCLUSIONS

We identified tumour and host immune factors that contribute to the disparate clinical behaviour of cSCC, with broad translational application, including prognostication, treatment prediction to current therapies and the identification of novel anticancer therapy approaches in cSCC.

Next-generation sequencing in dermatology

Over the past decade, Next-Generation Sequencing (NGS) has advanced our understanding, diagnosis, and management of several areas within dermatology. NGS has emerged as a powerful tool for diagnosing genetic diseases of the skin, improving upon traditional PCR-based techniques limited by significant genetic heterogeneity associated with these disorders. Epidermolysis bullosa and ichthyosis are two of the most extensively studied genetic diseases of the skin, with a well-characterized spectrum of genetic changes occurring in these conditions. NGS has also played a critical role in expanding the mutational landscape of cutaneous squamous cell carcinoma, enhancing our understanding of its molecular pathogenesis. Similarly, genetic testing has greatly benefited melanoma diagnosis and treatment, primarily due to the high prevalence of BRAF hot spot mutations and other well-characterized genetic alterations. Additionally, NGS provides a valuable tool for measuring tumor mutational burden, which can aid in management of melanoma. Lastly, NGS demonstrates promise in improving the sensitivity of diagnosing cutaneous T-cell lymphoma. This article provides a comprehensive summary of NGS applications in the diagnosis and management of genodermatoses, cutaneous squamous cell carcinoma, melanoma, and cutaneous T-cell lymphoma, highlighting the impact of NGS on the field of dermatology.

Update on the Molecular Pathology of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, originating from keratinocytes of the spinous layer. Numerous risk factors have been discovered for the initiation and growth of this type of cancer, such as exposure to UV and ionizing radiation, chemical carcinogens, the presence of immunosuppression states, chronic inflammation, infections with high-risk viral strains, and, last but not least, the presence of diseases associated with genetic alterations. The important socio-economic impact, as well as the difficulty associated with therapy for advanced forms, has made the molecular mechanisms underlying this neoplasia more and more intensively studied, with the intention of achieving a better understanding and advancing the treatment of this pathology. This review aims to provide a brief foray into the molecular, genetic, and epigenetic aspects of this cancer, as well as the treatment methods, ranging from the first used to the latest targeted therapies.

Molecular Alterations in Cutaneous Squamous Cell Carcinoma in Immunocompetent and Immunosuppressed Hosts-A Systematic Review

The characterization of cutaneous squamous cell carcinoma (cSCC) at the molecular level is lacking in the current literature due to the high mutational burden of this disease. Immunosuppressed patients afflicted with cSCC experience considerable morbidity and mortality. In this article, we review the molecular profile of cSCC among the immunosuppressed and immunocompetent populations at the genetic, epigenetic, transcriptomic, and proteometabolomic levels, as well as describing key differences in the tumor immune microenvironment between these two populations. We feature novel biomarkers from the recent literature which may serve as potential targets for therapy.

Keratinocytic skin cancers-Update on the molecular biology

Although much attention has been devoted to a detailed genomic exposition of cutaneous melanoma, other nonmelanoma skin cancers have also recently been subjected to similar analytical scrutiny. Chief among these are the most common malignancies worldwide: basal cell carcinomas and cutaneous squamous cell carcinomas. In this review, the authors summarize their latest knowledge about the molecular pathways and therapeutic opportunities attendant to these keratinocytic skin cancers. PLAIN LANGUAGE SUMMARY: The most common cancers in the United States arise from skin cells called keratinocytes. Although these tumors are not formally tracked by the National Cancer Institute, it is estimated that there are millions of skin cancers called basal cell carcinomas and squamous cell carcinomas. This article reviews the current recent genetic insights into these tumors and therapeutic opportunities.

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.

Molecular Mechanisms of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers are cutaneous malignancies representing the most common form of cancer in the United States. They are comprised predominantly of basal cell carcinomas and squamous cell carcinomas (cSCC). The incidence of cSCC is increasing, resulting in substantial morbidity and ever higher treatment costs; currently in excess of one billion dollars, per annum. Here, we review research defining the molecular basis and development of cSCC that aims to provide new insights into pathogenesis and drive the development of novel, cost and morbidity saving therapies.

Sequencing of cutaneous squamous cell carcinoma primary tumors and patient-matched metastases reveals ALK as a potential driver in metastases and low mutational concordance in immunocompromised patients

Cutaneous squamous cell carcinoma is a common skin cancer that is responsible for 1,000,000 cases and up to 9,000 deaths annually in the United States. Metastases occur in 2–5% of patients and are responsible for significant morbidity and mortality. The objective of this study is to perform targeted next-generation sequencing on a cohort of squamous cell carcinoma primary tumors and patient-matched lymph node metastases. An oncology 76-gene panel was run from formalin-fixed paraffin-embedded samples of patient-matched primary squamous cell carcinomas (10) and resultant metastases (10). ALK was discovered to be a driver mutation in metastases using two different algorithms, oncoCLUSTand dNdScv. Mutational concordance between primary tumors and metastases was notably lower in immunosuppressed patients, especially among pathogenic mutations (41.7% vs. 83.3%, P = 0.01). Sequencing of matched squamous cell carcinoma primary tumors and lymph node metastases identified genes and pathways that may have clinical importance, most notably ALK as a potential driver mutation of metastasis. Sequencing of both primary tumors and metastases may improve the efficacy of targeted therapies.

Cutaneous squamous cell carcinoma arising in immunosuppressed patients: a systematic review of tumor profiling studies

As solid organ transplantation becomes more prevalent, more individuals are living as members of the immunosuppressed population with an elevated risk for cutaneous squamous cell carcinoma (cSCC). Although great progress has been made in understanding the pathogenesis of cSCC in general, little is known about the drivers of tumorigenesis in immunosuppressed patients and organ-transplant recipients, specifically. This systematic review sought to synthesize information regarding the genetic and epigenetic alterations as well as changes in protein and mRNA expression that place this growing population at risk for cSCC, influence treatment response, and promote tumor aggressiveness. This review will provide investigators with a framework to identify future areas of investigation and clinicians with additional insight into how to best manage these patients.

The Multidisciplinary Management of Cutaneous Squamous Cell Carcinoma: A Comprehensive Review and Clinical Recommendations by a Panel of Experts

Cutaneous squamous cell carcinomas (CSCC) account for about 20% of all keratinocyte carcinomas, which are the most common form of cancer. Heterogeneity of treatments and low mortality are a challenge in obtaining accurate incidence data and consistent registration in cancer registries. Indeed, CSCC mostly presents as an indolent, low-risk lesion, with five-year cure rates greater than 90% after surgical excision, and only few tumors are associated with a high-risk of local or distant relapse; therefore, it is particularly relevant to identify high-risk lesions among all other low-risk CSCCs for the proper diagnostic and therapeutic management. Chemotherapy achieves mostly short-lived responses that do not lead to a curative effect and are associated with severe toxicities. Due to an etiopathogenesis largely relying on chronic UV radiation exposure, CSCC is among the tumors with the highest rate of somatic mutations, which are associated with increased response rates to immunotherapy. Thanks to such strong pre-clinical rationale, clinical trials led to the approval of anti-PD-1 cemiplimab by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), and anti-PD-1 pembrolizumab by the FDA only. Here, we provide a literature review and clinical recommendations by a panel of experts regarding the diagnosis, treatment, and follow-up of CSCC.

Oh, the Mutations You'll Acquire! A Systematic Overview of Cutaneous Squamous Cell Carcinoma

Nearly two million cases of cutaneous squamous cell carcinoma (cSCC) are diagnosed every year in the United States alone. cSCC is notable for both its prevalence and its propensity for invasion and metastasis. For many patients, surgery is curative. However, patients experiencing immunosuppression or recurrent, advanced, and metastatic disease still face limited therapeutic options and significant mortality. cSCC forms after decades of sun exposure and possesses the highest known mutation rate of all cancers. This mutational burden complicates efforts to identify the primary factors driving cSCC initiation and progression, which in turn hinders the development of targeted therapeutics. In this review, we summarize the mutations and alterations that have been observed in patients’ cSCC tumors, affecting signaling pathways, transcriptional regulators, and the microenvironment. We also highlight novel therapeutic opportunities in development and clinical trials.

Immunotherapy for the Treatment of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) accounts for approximately 20% of all keratinocytic tumors. In most cases, the diagnosis and treatments are made on small, low-risk lesions. However, in about 5% of cases, CSCC may present as either locally advanced or metastatic (i.e. with locoregional lymph nodes metastases or distant localizations). Prior to the introduction of immunotherapy in clinical practice, the standard treatment of advanced CSCC was not clearly defined, and up to 60% of patients received no systemic therapy. Thanks to a strong pre-clinical rationale, clinical trials led to the FDA (Food and Drug Administration) and EMA (European Medicines Agency) registration of cemiplimab, a PD-1 inhibitor that achieved encouraging results in terms of objective response, overall survival, and quality of life. Subsequently, the anti-PD-1 pembrolizumab received the approval for the treatment of advanced CSCC by the FDA only. In this review, we will focus on the definition of advanced CSCC and on the current and future therapeutic options, with a particular regard for immunotherapy.

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.

Non-Melanoma Skin Cancer in People Living With HIV: From Epidemiology to Clinical Management

Skin cancers represent the most common human tumors with a worldwide increasing incidence. They can be divided into melanoma and non-melanoma skin cancers (NMSCs). NMSCs include mainly squamous cell (SCC) and basal cell carcinoma (BCC) with the latest representing the 80% of the diagnosed NMSCs. The pathogenesis of NMSCs is clearly multifactorial. A growing body of literature underlies a crucial correlation between skin cancer, chronic inflammation and immunodeficiency. Intensity and duration of immunodeficiency plays an important role. In immunocompromised patients the incidence of more malignant forms or the development of multiple tumors seems to be higher than among immunocompetent patients. With regards to people living with HIV (PLWH), since the advent of combined antiretroviral therapy (cART), the incidence of non-AIDS-defining cancers (NADCs), such as NMSCs, have been increasing and now these neoplasms represent a leading cause of illness in this particular population. PLWH with NMSCs tend to be younger, to have a higher risk of local recurrence and to have an overall poorer outcome. NMSCs show an indolent clinical course if diagnosed and treated in an early stage. BCC rarely metastasizes, while SCC presents a 4% annual incidence of metastasis. Nevertheless, metastatic forms lead to poor patient outcome. NMSCs are often treated with full thickness treatments (surgical excision, Mohs micro-graphic surgery and radiotherapy) or superficial ablative techniques (such as cryotherapy, electrodesiccation and curettage). Advances in genetic landscape understanding of NMSCs have favored the establishment of novel therapeutic strategies. Concerning the therapeutic evaluation of PLWH, it’s mandatory to evaluate the risk of interactions between cART and other treatments, particularly antiblastic chemotherapy, targeted therapy and immunotherapy. Development of further treatment options for NMSCs in PLWH seems needed. We reviewed the literature after searching for clinical trials, case series, clinical cases and available databases in Embase and Pubmed. We review the incidence of NMSCs among PLWH, focusing our attention on any differences in clinicopathological features of BCC and SCC between PLWH and HIV negative persons, as well as on any differences in efficacy and safety of treatments and response to immunomodulators and finally on any differences in rates of metastatic disease and outcomes.

Huaier Inhibits Proliferation, Migration, and Invasion of Cutaneous Squamous Cell Carcinoma Cells by Inhibiting the Methylation Levels of CDKN2A and TP53

Cutaneous squamous cell carcinoma (CSCC) is a malignant tumor that originates from keratinocytes in the epidermis or appendage. Traditional Chinese medicine Huaier has anti-tumor activity in various malignancies. Little is known about the role of Huaier in CSCC. Here, we investigated the function of Huaier in CSCC. We treated CSCC cell line (SCL-1 and A431) with a series of concentration gradients of Huaier to examine the half maximal inhibitory concentration (IC50) of Huaier on SCL-1 and A431 cells. The IC50 of Huaier on growth of SCL-1 and A431 cells were 6.96 and 7.57 mg/mL, respectively. Moreover, Huaier reduced the methylation levels of CDKN2A and TP53, and enhanced the expression of CDKN2A and TP53 in SCL-1 and A431 cells in a dosage-dependent manner. The expression of DNA methyltransferase DNMT1 was severely repressed by Huaier treatment in SCL-1 and A431 cells. DNMT1 overexpression enhanced the methylation levels of CDKN2A and TP53, and suppressed the expression of CDKN2A and TP53 in Huaier-treated SCL-1 and A431 cells. Huaier treatment inhibited proliferation, migration, and invasion of SCL-1 and A431 cells. However, inhibition of CDKN2A or TP53 reversed the influence of Huaier treatment on proliferation, migration, and invasion of CSCC cells. In conclusion, our data demonstrate that Huaier inhibits proliferation, migration, and invasion of CSCC cells by regulating DNA methylation of CDKN2A and TP53, thereby attenuating the progression of CSCC. Thus, Huaier extract may act as a drug for treating CSCC.

Gene expression profiling of perineural invasion in head and neck cutaneous squamous cell carcinoma

Perineural invasion (PNI) is frequently associated with aggressive clinical behaviour in head and neck cutaneous squamous cell carcinoma (HNcSCC) leading to local recurrence and treatment failure. This study evaluates the gene expression profiles of HNcSCC with PNI using a differential expression analysis approach and constructs a tailored gene panel for sensitivity and specificity analysis. 45 cases of HNcSCC were stratified into three groups (Extensive, Focal and Non PNI) based on predefined clinicopathological criteria. Here we show HNcSCC with extensive PNI demonstrates significant up- and down-regulation of 144 genes associated with extracellular matrix interactions, epithelial to mesenchymal transition, cell adhesion, cellular motility, angiogenesis, and cellular differentiation. Gene expression of focal and non PNI cohorts were indistinguishable and were combined for further analyses. There is clinicopathological correlation between gene expression analysis findings and disease behaviour and a tailored panel of 10 genes was able to identify extensive PNI with 96% sensitivity and 95% specificity.

Extra-anogenital giant cutaneous squamous cell carcinomas require multidisciplinary management

Cutaneous squamous cell carcinoma (cSCC) is a highly prevalent cancer and the majority of cSCC have a good prognosis. However, a subset of cSCC can progress to advanced disease. We present the first reported case of a giant cSCC located on the breast. In addition, a systematic literature search on extra-anogenital giant (EAG) cSCC was performed using Pubmed and MEDLINE databases. Thirty-one articles could be retained which were relevant for this review. A total of 42 well-described cases were identified. Median age at presentation was 70 years (range 9-100 years). Twenty-four (57%) patients were male, eighteen were female (43%). The estimated median delay of treatment was 12 months (range 1 to >240 months). In 27 patients (64%) the giant cSCC was localized on the neck, face or scalp, 6 on the thoracic wall or back (14%), 4 on the lower limb (10%), 2 on the hip or buttock (5%), 2 on the upper limb (5%), one (2%) on the breast. Tumor stage at presentation was T2, T3 and T4 in respectively 26 (62%), 11 (26%) and 5 (12%) cases. Lymph node metastases were identified in 1 patient (2%) and distant metastases in another patient (2%). In 34 out of 42 cases (81%) primary radical surgical excision was performed, 3 received radiotherapy, 2 chemotherapy and 3 palliative care. In the cases with reported follow-up, four patients (4/30: 13%) died of disease. The treatment of EAG cSCC poses many problems, making a multidisciplinary approach of paramount importance.

Growth and Viability of Cutaneous Squamous Cell Carcinoma Cell Lines Display Different Sensitivities to Isoform-Specific Phosphoinositide 3-Kinase Inhibitors

Cutaneous squamous cell carcinomas (cSCCs) account for about 20% of keratinocyte carcinomas, the most common cancer in the UK. Therapeutic options for cSCC patients who develop metastasis are limited and a better understanding of the biochemical pathways involved in cSCC development/progression is crucial to identify novel therapeutic targets. Evidence indicates that the phosphoinositide 3-kinases (PI3Ks)/Akt pathway plays an important role, in particular in advanced cSCC. Questions remain of whether all four PI3K isoforms able to activate Akt are involved and whether selective inhibition of specific isoform(s) might represent a more targeted strategy. Here we determined the sensitivity of four patient-derived cSCC cell lines to isoform-specific PI3K inhibitors to start investigating their potential therapeutic value in cSCC. Parallel experiments were performed in immortalized keratinocyte cell lines. We observed that pan PI3Ks inhibition reduced the growth/viability of all tested cell lines, confirming the crucial role of this pathway. Selective inhibition of the PI3K isoform p110α reduced growth/viability of keratinocytes and of two cSCC cell lines while affecting the other two only slightly. Importantly, p110α inhibition reduced Akt phosphorylation in all cSCC cell lines. These data indicate that growth and viability of the investigated cSCC cells display differential sensitivity to isoform-specific PI3K inhibitors.

Analysis of mutations in cutaneous squamous cell carcinoma reveals novel genes and mutations associated with patient-specific characteristics and metastasis: a systematic review

Cutaneous squamous cell carcinoma (SCC) causes approximately 1,000,000 cases and 9000 deaths each year in the United States. While individual tumor sequencing studies have discovered driver mutations in SCC, there has yet to be a review and subsequent analysis synthesizing current studies. To conduct a comprehensive synthesis and analysis of SCC sequencing studies with individual patient-level data, a comprehensive literature search was performed. Statistical analyses were performed to identify trends. Studies meeting inclusion criteria included a total of 279 patients (189 localized SCCs, 90 metastatic SCCs). Several mutations were correlated with demographic characteristics (TP53, MLL4, BRCA2, COL4A1). TP53, TERT, SPEN, MLL3, and NOTCH2 mutations were significantly more likely to be found in metastatic versus localized SCCs even after the Bonferroni correction for multiple comparisons. Silent mutations were found more in localized SCCs than metastatic SCCs, and nonsense mutations were found more in metastatic SCCs than localized SCCs (p = 0.0003 and p = 0.04, respectively). Additional mutations were identified that have not yet been explored in SCC including AHNAK2, LRP1B, TRIO, MDN1, COL4A2, SVIL, VPS13C, DST, DMD, and DYSF. Overall, novel mutations were identified and differences between mutation patterns in localized and metastatic SCCs were found. These findings may have clinical applications.

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.

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.

Identifying Opportunities and Challenges for Patients With Sarcoma as a Result of Comprehensive Genomic Profiling of Sarcoma Specimens

PURPOSE

Comprehensive genomic profiling (CGP) of sarcomas is rapidly being integrated into routine clinical care to help refine diagnosis and prognosis and determine treatment. However, little is known about barriers to successful CGP or its clinical utility in sarcoma. We set out to determine whether CGP alters physician treatment decision-making, and whether sarcoma subtypes influence the frequency of successful technical performance of CGP.

METHODS

A single-institution study evaluated profiling outcomes of 392 samples from patients with sarcoma, using a commercially available CGP panel. Of this group, 34 patients were evaluated prospectively (Decision Impact Trial) to evaluate the utility of CGP in physician decision-making. All cases were retrospectively analyzed to identify causes of CGP failure.

RESULTS

CGP successfully interrogated 75.3% (n = 295 of 392) of patients with sarcoma. Bone sarcomas had lower passing rates at 65.3% (n = 32 of 49) compared with soft tissue sarcomas at 76.7% (n = 263 of 343; P = .0008). Biopsy location also correlated with profiling efficiency. Bone biopsy specimens had a 52.8% (n = 19 of 36) passing rate versus lung (61.1%; n = 33 of 54) and abdomen (80.1%; n = 109 of 136) specimens. CGP altered physician treatment selection in 25% of evaluable patients (n = 7 of 28) and was associated with improved progression-free survival.

CONCLUSION

To our knowledge, this is the largest technical evaluation of the performance of CGP in sarcoma. CGP was effectively performed in the vast majority of sarcoma samples and altered physician treatment selection. Tumor location and tissue subtype were key determinants of profiling success and associated with preanalytic variables that affect DNA and RNA quality. These results support standardized biopsy collection protocols to improve profiling outcomes.

Long non-coding RNAs in cutaneous biology and keratinocyte carcinomas

Long non-coding RNAs (lncRNAs) are a largely uncharacterized group of non-coding RNAs with diverse regulatory roles in various biological processes. Recent observations have elucidated the functional roles of lncRNAs in cutaneous biology, e.g. in proliferation and differentiation of epidermal keratinocytes and in cutaneous wound repair. Furthermore, the role of lncRNAs in keratinocyte-derived skin cancers is emerging, especially in cutaneous squamous cell carcinoma (cSCC), which presents a significant burden to health care services worldwide and causes high mortality as metastatic disease. Elucidation of the functions of keratinocyte-specific lncRNAs will improve understanding of the molecular pathogenesis of epidermal disorders and skin cancers and can be exploited in development of new diagnostic and therapeutic applications for keratinocyte carcinomas. In this review, we summarize the current evidence of functionally important lncRNAs in cutaneous biology and in keratinocyte carcinomas.

Immunologic Characteristics of Nonmelanoma Skin Cancers: Implications for Immunotherapy

In this review, we summarize the immunology of nonmelanoma skin cancers (NMSCs) and the clinical data with immunotherapy in this heterogeneous group of cancers that include basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (CSCC), and Merkel cell carcinoma (MCC). NMSCs are exceedingly common, and their treatment consumes substantial health care resources. Annual global mortality from NMSCs is comparable to that from malignant melanoma. Although the majority of NMSCs are localized at diagnosis and are treated effectively with surgery, metastases (nodal and distant) can sometimes arise and require systemic therapy. Given the success of immunotherapy in treating cutaneous melanoma, there has been an increasing interest in studying the immunology of NMSCs. Immunocompromised patients have a substantially higher risk of developing NMSCs (particularly CSCC and MCC), suggesting a role of the immune system in the pathogenesis of these cancers. Similar to cutaneous melanoma, the pathogenesis of BCC, CSCC, and virus-negative MCC is related to DNA damage from ultraviolet radiation exposure, and these cancers have a very high tumor mutational burden, which likely results in higher levels of tumor neoantigens that may be targets for the immune system. Viral antigens in virus-positive MCC are also strongly immunogenic. Emerging data from clinical trials of immune checkpoint inhibitors in NMSCs look very promising and are rapidly changing the treatment landscape of these cancers. Specifically, pembrolizumab and avelumab are U.S. Food and Drug Administration-approved for treatment of metastatic MCC and cemiplimab for metastatic CSCC. Several ongoing trials are investigating novel immunotherapies (monotherapies as well as combination) for treatment of NMSCs.

Neurofibromatosis type 1: New developments in genetics and treatment

Neurofibromatosis type 1 is the most common neurocutaneous syndrome, with a frequency of 1 in 2500 persons. Diagnosis is paramount in the pretumor stage to provide proper anticipatory guidance for a number of neoplasms, both benign and malignant. Loss-of-function mutations in the NF1 gene result in truncated and nonfunctional production of neurofibromin, a tumor suppressor protein involved in downregulating the RAS signaling pathway. New therapeutic and preventive options include tyrosine kinase inhibitors, mTOR inhibitors, interferons, and radiofrequency therapy. This review summarizes recent updates in genetics, mutation analysis assays, and treatment options targeting aberrant genetic pathways. We also propose modified diagnostic criteria and provide an algorithm for surveillance of patients with neurofibromatosis type 1.

Efficacy of a programmed death-1 checkpoint inhibitor in a case of cutaneous squamous cell carcinoma harboring mutations of TP53 and BRCA2

Immune checkpoint blockades were reported to result in clinical responses in inoperable and metastatic cutaneous squamous cell carcinoma (cSCC). This report describes an 87-year-old woman with recurrent cSCC that was initially responsive to cetuximab (the monoclonal antibody against epithelial growth factor receptor) but eventually became refractory to cetuximab and multiple subsequent salvage chemotherapy regimens. Next-generation sequencing of the tumor discovered three single-nucleotide mutations in TP53, copy number amplification in Src, and a heterozygous deletion in BRCA2. Because of the high mutation burden of her neoplasm (35.2 mutations per megabase), we treated her with a programmed death-1 (PD-1) checkpoint inhibitor, pembrolizumab, for 10 months. The tumor regressed 3 months later and complete pathological remission was achieved 10 months after starting treatment. As of writing, the patient has been disease free for 17 months after discontinuing treatment. This is the first reported case of heterozygous deletion of BRCA2 in cSCC. The high mutation burden and BRCA2 mutation might explain why this tumor was highly sensitive to anti-PD-1 treatment.

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

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

Integrative clinical and biopathology analyses to understand the clinical heterogeneity of infantile rhabdomyosarcoma: A report from the French MMT committee

BACKGROUND

Rhabdomyosarcoma (RMS) in infants is a particular entity with various clinical presentations and outcomes. To better understand the clinical heterogeneity of RMS in infants, an integrative clinical, histological, and molecular analysis was performed.

METHODS

From 1989 to 2015, 37 infants aged less than 6 months with a diagnosis of RMS and archival tumor materials were identified in France. Clinical data, central pathologic review, and molecular profile including RNA sequencing were analyzed.

RESULTS

Nineteen patients (51%) had embryonal RMS (ERMS) (including three highly differentiated ERMS with PTCH deletion), eight (22%) had spindle cell RMS (SRMS) (three VGLL2-, one NTRK-, and two (B)RAF-fusions), six (16%) had alveolar RMS (ARMS) (all FOXO1- or PAX3-fusion), two had unclassified RMS, and two poorly differentiated RMS were retrospectively diagnosed as rhabdoid tumors (RT) with loss of INI1 expression. The two RT patients died of rapid disease progression. Five-year event-free (EFS) and overall survival (OS) for RMS were 62% (95%CI, 47-82) and 52% (95%CI, 37-72). Eleven patients (31%) relapsed and four (11%) had primary refractory disease (all ERMS). In univariate analysis, EFS and OS were only associated with histology subtype, with 100% survival of known fusion-positive SRMS. RNA cluster expression showed three main clusters: ARMS, ERMS, and "VGLL2-fusion" cluster, consisting of SRMS and ERMS.

CONCLUSIONS

Biopathology findings from this study support the different prognosis of infantile RMS. New fusion-positive SRMS has a very good outcome which may allow more conservative treatment in the future.

Epidermal Growth Factor Receptor's Function in Cutaneous Squamous Cell Carcinoma and Its Role as a Therapeutic Target in the Age of Immunotherapies

OPINION STATEMENT

Recent studies have evidenced the potential of combining anti-EGFR therapies with anti-PD-1/PD-L1 checkpoint therapies. Both anti-EGFR and anti-PD-1/PD-L1 have been separately tested in the treatment of cutaneous SCC (cSCC). Here, we review recent data on EGFR in the context of cancer progression, as a prognostic and as a therapeutic target in cSCC. Anti-EGFR/checkpoint immunotherapy and other combination therapy approaches are discussed. With the advent of immunotherapy, EGFR is still a valid cSCC target.

Molecular genetics of cutaneous squamous cell carcinoma: perspective for treatment strategies

Cutaneous squamous cell carcinoma (cSCC) represents 20% of all skin cancers. Although primary cSCCs can be successfully treated with surgery, a subset of highly aggressive lesions may progress to advanced disease, representing a public healthcare problem with significant cancer-related morbidity and mortality. A complex network of genes (TP53, CDKN2A, NOTCH1 and NOTCH2, EGFR and TERT) and molecular pathways (RAS/RAF/MEK/ERK and PI3K/AKT/mTOR) have been shown to play an important role in the pathogenesis of cSCC. The epigenetic regulation of TP53 and CDKN2A is an attractive therapeutic target for the treatment of cSCC, as well as NOTCH-activating agents capable to restore its tumour-suppressor function. EGFR inhibitors including both monoclonal antibodies (cetuximab and panitumumab) and tyrosine kinase inhibitors (erlotinib, gefitinib and dasatinib) have been used in clinical trials for the treatment of advanced cSCC, achieving only partial clinical benefit. Recently, an immune-modulatory drug (cemiplimab) has been introduced for the treatment of advanced cSCC with good clinical results and a favourable safety profile, while other PD1/PD-L1 inhibitors, either as monotherapy or in combination with targeted therapies, are currently under investigation. This review focuses on molecular findings involved in the pathogenesis of cSCC and their implications for the future development of new treatment strategies. In addition, current and ongoing treatments on targeted therapies and/or immunotherapy are illustrated.

Epidermolysis bullosa: Advances in research and treatment

Epidermolysis bullosa (EB) is the umbrella term for a group of rare inherited skin fragility disorders caused by mutations in at least 20 different genes. There is no cure for any of the subtypes of EB resulting from different mutations, and current therapy only focuses on the management of wounds and pain. Novel effective therapeutic approaches are therefore urgently required. Strategies include gene-, protein- and cell-based therapies. This review discusses molecular procedures currently under investigation at the EB House Austria, a designated Centre of Expertise implemented in the European Reference Network for Rare and Undiagnosed Skin Diseases. Current clinical research activities at the EB House Austria include newly developed candidate substances that have emerged out of our translational research initiatives as well as already commercially available medications that are applied in off-licensed indications. Squamous cell carcinoma is the major cause of death in severe forms of EB. We are evaluating immunotherapy using an anti-PD1 monoclonal antibody as a palliative treatment option for locally advanced or metastatic squamous cell carcinoma of the skin unresponsive to previous systemic therapy. In addition, we are evaluating topical calcipotriol and topical diacerein as potential agents to improve the healing of skin wounds in EBS patients. Finally, the review will highlight the recent advancements of gene therapy development for EB.

Wnt Signaling Pathways in Keratinocyte Carcinomas

The skin functions as a barrier between the organism and the surrounding environment. Direct exposure to external stimuli and the accumulation of genetic mutations may lead to abnormal cell growth, irreversible tissue damage and potentially favor skin malignancy. Skin homeostasis is coordinated by an intricate signaling network, and its dysregulation has been implicated in the development of skin cancers. Wnt signaling is one such regulatory pathway orchestrating skin development, homeostasis, and stem cell activation. Aberrant regulation of Wnt signaling cascades not only gives rise to tumor initiation, progression and invasion, but also maintains cancer stem cells which contribute to tumor recurrence. In this review, we summarize recent studies highlighting functional evidence of Wnt-related oncology in keratinocyte carcinomas, as well as discussing preclinical and clinical approaches that target oncogenic Wnt signaling to treat cancers. Our review provides valuable insight into the significance of Wnt signaling for future interventions against keratinocyte carcinomas.

The Genomic Landscape of Merkel Cell Carcinoma and Clinicogenomic Biomarkers of Response to Immune Checkpoint Inhibitor Therapy

PURPOSE

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy, which has demonstrated sensitivity to immune checkpoint inhibitor therapy. Here, we perform the largest genomics study in MCC to date to characterize the molecular landscape and evaluate for clinical and molecular correlates to immune checkpoint inhibitor response.

EXPERIMENTAL DESIGN

Comprehensive molecular profiling was performed on 317 tumors from patients with MCC, including the evaluation of oncogenic mutations, tumor mutational burden (TMB), mutational signatures, and the Merkel cell polyomavirus (MCPyV). For a subset of 57 patients, a retrospective analysis was conducted to evaluate for clinical and molecular correlates to immune checkpoint inhibitor response and disease survival.

RESULTS

Genomic analyses revealed a bimodal distribution in TMB, with 2 molecularly distinct subgroups. Ninety-four percent (n = 110) of TMB-high specimens exhibited an ultraviolet light (UV) mutational signature. MCPyV genomic DNA sequences were not identified in any TMB-high cases (0/117), but were in 63% (110/175) of TMB-low cases. For 36 evaluable patients treated with checkpoint inhibitors, the overall response rate was 44% and response correlated with survival at time of review (100% vs. 20%, P < 0.001). Response rate was 50% in TMB-high/UV-driven and 41% in TMB-low/MCPyV-positive tumors (P = 0.63). Response rate was significantly correlated with line of therapy: 75% in first-line, 39% in second-line, and 18% in third-line or beyond (P = 0.0066). PD-1, but not PD-L1, expression was associated with immunotherapy response (77% vs. 21%, P = 0.00598, for PD-1 positive and negative, respectively).

CONCLUSIONS

We provide a comprehensive genomic landscape of MCC and demonstrate clinicogenomic associates of immunotherapy response.

Loss of the PTCH1 tumor suppressor defines a new subset of plexiform fibromyxoma

BACKGROUND

Plexiform fibromyxoma (PF) is a rare gastric tumor often confused with gastrointestinal stromal tumor. These so-called "benign" tumors often present with upper GI bleeding and gastric outlet obstruction. It was recently demonstrated that approximately one-third of PF have activation of the GLI1 oncogene, a transcription factor in the hedgehog (Hh) pathway, via a MALAT1-GLI1 fusion protein or GLI1 up-regulation. Despite this discovery, the biology of most PFs remains unknown.

METHODS

Next generation sequencing (NGS) was performed on formalin-fixed paraffin-embedded (FFPE) samples of PF specimens collected from three institutions (UCSD, NCI and OHSU). Fresh frozen tissue from one tumor was utilized for in vitro assays, including quantitative RT-PCR and cell viability assays following drug treatment.

RESULTS

Eight patients with PF were identified and 5 patients' tumors were analyzed by NGS. An index case had a mono-allelic PTCH1 deletion of exons 15-24 and a second case, identified in a validation cohort, also had a PTCH1 gene loss associated with a suspected long-range chromosome 9 deletion. Building on the role of Hh signaling in PF, PTCH1, a tumor suppressor protein, functions upstream of GLI1. Loss of PTCH1 induces GLI1 activation and downstream gene transcription. Utilizing fresh tissue from the index PF case, RT-qPCR analysis demonstrated expression of Hh pathway components, SMO and GLI1, as well as GLI1 transcriptional targets, CCND1 and HHIP. In turn, short-term in vitro treatment with a Hh pathway inhibitor, sonidegib, resulted in dose-dependent cell killing.

CONCLUSIONS

For the first time, we report a novel association between PTCH1 inactivation and the development of plexiform fibromyxoma. Hh pathway inhibition with SMO antagonists may represent a target to study for treating a subset of plexiform fibromyxomas.

Keratinocyte Carcinomas: Current Concepts and Future Research Priorities

Cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC) are keratinocyte carcinomas, the most frequently diagnosed cancers in fair-skinned populations. Ultraviolet radiation (UVR) is the main driving carcinogen for these tumors, but immunosuppression, pigmentary factors, and aging are also risk factors. Scientific discoveries have improved the understanding of the role of human papillomaviruses (HPV) in cSCC as well as the skin microbiome and a compromised immune system in the development of both cSCC and BCC. Genomic analyses have uncovered genetic risk variants, high-risk susceptibility genes, and somatic events that underlie common pathways important in keratinocyte carcinoma tumorigenesis and tumor characteristics that have enabled development of prediction models for early identification of high-risk individuals. Advances in chemoprevention in high-risk individuals and progress in targeted and immune-based treatment approaches have the potential to decrease the morbidity and mortality associated with these tumors. As the incidence and prevalence of keratinocyte carcinoma continue to increase, strategies for prevention, including effective sun-protective behavior, educational interventions, and reduction of tanning bed access and usage, are essential. Gaps in our knowledge requiring additional research to reduce the high morbidity and costs associated with keratinocyte carcinoma include better understanding of factors leading to more aggressive tumors, the roles of microbiome and HPV infection, prediction of response to therapies including immune checkpoint blockade, and how to tailor both prevention and treatment to individual risk factors and needs.

Effective treatment of a platinum-resistant cutaneous squamous cell carcinoma case by EGFR pathway inhibition

Cutaneous squamous cell carcinoma (cSCC) is the second most common type of non-melanoma skin cancer. Platinum-based regimens have been an integral part of palliative care for patients with locally advanced or metastatic disease. There is no evidence of efficacy for later lines of chemotherapy and no targeted therapy has been introduced as 'standard of care'. Here we report on the case of an elderly cSCC patient, resistant to conventional therapy, however successfully treated with anti-epidermal growth factor receptor (EGFR) agent (Cetuximab) in addition to a daily dose of Curcumin phospholipid. The patient responded to treatment and experienced no recurrence for 11 months with only minor skin-related toxicity. To our knowledge, this is the first report of clinical evidence that an anti EGFR targeted therapy with a daily oral dose of Curcumin phospholipid is well tolerated and results in a highly effective disease control in a heavily pretreated cSCC patient.

Efficacy and safety of single-agent pan-human epidermal growth factor receptor (HER) inhibitor dacomitinib in locally advanced unresectable or metastatic skin squamous cell cancer

BACKGROUND

In recurrent or metastatic (R/M) skin squamous cell cancer (sSCC) not amenable to radiotherapy (RT) or surgery, chemotherapy (CT) has a palliative intent and limited clinical responses. The role of oral pan-HER inhibitor dacomitinib in this setting was investigated within a clinical trial.

METHODS

Patients with diagnosis of R/M sSCC were treated. Dacomitinib was started at a dose of 30 mg daily (QD) for 15 d, followed by 45 mg QD. Primary end-point was response rate (RR). Tumour samples were analysed through next-generation sequencing using a custom panel targeting 36 genes associated with sSCC.

RESULTS

Forty-two patients (33 men; median age 77 years) were treated. Most (86%) received previous treatments consisting in surgery (86%), RT (50%) and CT (14%). RR was 28% (2% complete response; 26% partial response), disease control rate was 86%. Median progression-free survival and overall survival were 6 and 11 months, respectively. Most patients (93%) experienced at least one adverse event (AE): diarrhoea, skin rash (71% each), fatigue (36%) and mucositis (31%); AEs grade 3-4 occurred in 36% of pts. In 16% of cases, treatment was discontinued because of drug-related toxicity. TP53, NOTCH1/2, KMT2C/D, FAT1 and HER4 were the most frequently mutated genes. BRAF, NRAS and HRAS mutations were more frequent in non-responders, and KMT2C and CASP8 mutations were restricted to this subgroup.

CONCLUSIONS

In sSCC, dacomitinib showed activity similar to what was observed with anti-epidermal growth factor receptor agents, and durable clinical benefit was observed. Safety profile was comparable to previous experiences in other cancers. Molecular pt selection could improve therapeutic ratio.

Analysis of clinically relevant somatic mutations in high-risk head and neck cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma is the second most prevalent malignancy, most frequently occurring in the head and neck (head and neck cutaneous squamous cell carcinoma). Treatment of locally advanced or metastatic disease is associated with functional morbidity and disfigurement. Underlying genetic mechanisms are poorly understood. Targeted sequencing of 48 clinically relevant genes was performed on DNA extracted from formalin-fixed and paraffin-embedded high-risk primary head and neck cutaneous squamous cell carcinomas that remained non-metastatic at minimum follow-up of 24 months. Associations of somatic mutations with clinicopathologic characteristics were evaluated and compared with those described in the literature for metastatic disease. Alterations in 44 cancer-associated genes were identified. TP53 was mutated in 100% of cases; APC, ATM, ERBB4, GNAQ, KIT, RB1 and ABL1 were altered in 60% of cases. FGFR2 mutations (40%) were exclusively seen in patients with perineural invasion. MLH1 mutations were exclusively seen in the two younger patients (<45 years). Lower incidences of NOTCH1 mutations were observed compared with that described in metastatic head and neck cutaneous squamous cell carcinoma in the literature. Somatic mutations susceptible to EGFR inhibitors, and other small molecular targeted therapeutics were seen in 60% of cases. This study provides insights into somatic mutations in non-metastatic, high-risk head and neck cutaneous squamous cell carcinoma and identifies potential therapeutic targets. Alterations in FGFR2 and NOTCH1 may have roles in local and distant disease progression.

Overview on Patient Centricity in Cancer Care

Successful implementation of treatment in cancer care partially depends on how patients' perspectives are taken into account, as preferences of health care professionals and patients may differ. Objectives of this exploratory research were (I) to identify patient preferences and values (PPVs) in cancer care as indicated by patient organizations (POs), (II) to determine how these PPVs are captured in cancer care guidelines and (III) to review how guidelines take into account these PPVs. Based on a survey developed and completed by 19 POs, a literature review was conducted to analyse how patient perspectives are incorporated in oncology treatment guidelines. Based on survey results traditional health technology assessment value propositions of oncology care, such as extended life, treatment-free remission and pain reduction, were also highly rated by POs. However, the heterogeneity of cancer PPVs were clearly reflected in the survey results. PPVs in cancer care guidelines were mostly limited to those micro-level aspects that are strictly related to health care provision, such as side-effects and comorbidities. Patient experience, emotional support and convenience of care were relatively neglected fields in the reviewed guidelines. Patient engagement was rarely presented in the guideline development phase. POs believe that patients should be encouraged to take an active role in their own care due to the heterogeneity of cancer patients and PPVs. Even if patient-centricity is a leading paradigm in cancer policy, based on our research it is not yet standard practice to include patients or POs at all appropriate levels of decision-making processes that are related to their health and well-being. Patient engagement should be an integral part of cancer care decision-making. This complexity must be reflected throughout policy making, avoiding a population level “one-size-fits-all” solution.

Gefitinib for patients with incurable cutaneous squamous cell carcinoma: A single-arm phase II clinical trial

BACKGROUND

Preclinical data demonstrate a key role for the epidermal growth factor receptor (EGFR) in the carcinogenesis of cutaneous squamous cell carcinomas (CSCCs). There are, however, limited data on the efficacy of EGFR inhibitors in incurable, recurrent, and/or metastatic CSCC.

OBJECTIVE

To determine the response rate to gefitinib in patients with CSCC not amenable to curative therapy including surgery or radiation.

METHODS

This was a single-arm phase II study. A total of 40 patients were treated with gefitinib, 250 mg orally daily, until disease progression or intolerable toxicities. The prespecified target response rate of interest was 20%.

RESULTS

The overall response rate was 16% (95% confidence interval, 0.06-0.32; 6 partial responses in 37 evaluable patients). An additional 13 patients (35%) had stable disease at 8 weeks. The median durations of response and progression-free survival were 31.4 months (95% confidence interval, 3.91-not applicable) and 3.8 months (95% confidence interval, 2.2-5.7), respectively. The side effect profile was consistent with the previous experience with gefitinib in other tumor types.

LIMITATIONS

This was a single-institution, single-arm study. The prespecified target response rate was not met.

CONCLUSION

Gefitinib demonstrated modest activity in incurable CSCC, with a favorable adverse event profile.

Drug therapy of advanced cutaneous squamous cell carcinoma: is there any evidence?

PURPOSE OF REVIEW

There are few randomized controlled studies to guide the treatment of advanced cutaneous squamous cell carcinoma. The existing treatments are mostly based on case reports and small case series. Here we review recently available insights concerning the treatment of locally advanced and metastatic squamous cell carcinoma, with a special emphasis on novel targeted therapy and immunotherapy.

RECENT FINDINGS

Surgery and combination of chemotherapy and radiation therapy have been long considered the gold standard options for advanced squamous cell carcinoma. The detection of clinically relevant driver mutations has opened the door to the use of novel targeted therapies. Recent studies have shown that aggressive cutaneous squamous cell carcinoma is characterized by a very high mutational background. Furthermore, the importance of the defective immunosurveillance in the growth of cutaneous squamous cell carcinoma and the critical role of programed cell death protein 1 and programmed death-ligand 1 interaction in skin tumor development provides a rationale for the use of immune checkpoint inhibitors.

SUMMARY

Epidermal growth factor receptor inhibitors have shown to have satisfactory antitumor activity with acceptable side-effect profile. However, their place in management of advanced cutaneous squamous cell carcinoma alone or in combination with either radiation therapy and/or chemotherapy needs to be better characterized. The available preliminary findings suggest that immune checkpoint inhibitors represent a potentially valuable alternative in cutaneous aggressive squamous cell carcinoma, promising a further expansion of their indication spectrum. Randomized controlled studies will allow us to better characterize their practical value.