Cutaneous Squamous Cell Carcinoma: From Pathophysiology to Novel Therapeutic Approaches

Camptothecin-loaded mesoporous silica nanoparticles functionalized with CpG oligodeoxynucleotide as a new approach for skin cancer treatment

The therapeutic efficacy of camptothecin (CPT), a potent antitumor alkaloid, is hindered by its hydrophobic nature and instability, limiting its clinical use in treating cutaneous squamous cell carcinoma (SCC). This study introduces a novel nano drug delivery system (NDDS) utilizing functionalized mesoporous silica nanoparticles (FMSNs) for efficient CPT delivery. The FMSNs were loaded with CPT and subsequently coated with chitosan (CS) for enhanced stability and bioadhesion. Importantly, CpG oligodeoxynucleotide (CpG ODN) was attached onto the CS-coated FMSNs to leverage the immunostimulatory properties of CpG ODN, augmenting the chemotherapy's efficacy. The final formulation FMSN-CPT-CS-CpG displayed an average size of 241 nm and PDI of 0.316 with an encapsulation efficiency of 95 %. Comprehensive in vitro and in vivo analyses, including B16F10 cells and DMBA/TPA-induced SCC murine model, demonstrated that the FMSN-CPT-CS-CpG formulation significantly enhanced cytotoxicity against B16F10 cells and induced complete regression in 40 % of the in vivo subjects, surpassing the efficacy of standard CPT and FMSN-CPT treatments. This study highlights the potential of combining chemotherapeutic and immunotherapeutic agents in an NDDS for targeted, efficient skin cancer treatment.

Antitumor activity of anlotinib in malignant melanoma: modulation of angiogenesis and vasculogenic mimicry

Malignant melanoma presents a formidable challenge due to its aggressive metastatic behavior and limited response to current treatments. To address this, our study delves into the impact of anlotinib on angiogenesis and vasculogenic mimicry using malignant melanoma cells and human umbilical vein endothelial cells. Evaluating tubular structure formation, cell proliferation, migration, invasion, and key signaling molecules in angiogenesis, we demonstrated that anlotinib exerts a dose-dependent inhibition on tubular structures and effectively suppresses cell growth and invasion in both cell types. Furthermore, in a mouse xenograft model, anlotinib treatment resulted in reduced tumor growth and vascular density. Notably, the downregulation of VEGFR-2, FGFR-1, PDGFR-β, and PI3K underscored the multitargeted antitumor activity of anlotinib. Our findings emphasize the therapeutic potential of anlotinib in targeting angiogenesis and vasculogenic mimicry, contributing to the development of novel strategies for combating malignant melanoma.

Therapeutic Approaches for Non-Melanoma Skin Cancer: Standard of Care and Emerging Modalities

Skin cancer encompasses a range of cutaneous malignancies, with non-melanoma skin cancers (NMSCs) being the most common neoplasm worldwide. Skin exposure is the leading risk factor for initiating NMSC. Ultraviolet (UV) light induces various genomic aberrations in both tumor-promoting and tumor-suppressing genes in epidermal cells. In conjunction with interactions with a changed stromal microenvironment and local immune suppression, these aberrations contribute to the occurrence and expansion of cancerous lesions. Surgical excision is still the most common treatment for these lesions; however, locally advanced or metastatic disease significantly increases the chances of morbidity or death. In recent years, numerous pharmacological targets were found through extensive research on the pathogenic mechanisms of NMSCs, leading to the development of novel treatments including Hedgehog pathway inhibitors for advanced and metastatic basal cell carcinoma (BCC) and PD-1/PD-L1 inhibitors for locally advanced cutaneous squamous cell carcinoma (cSCC) and Merkel cell carcinoma (MCC). Despite the efficacy of these new drugs, drug resistance and tolerability issues often arise with long-term treatment. Ongoing studies aim to identify alternative strategies with reduced adverse effects and increased tolerability. This review summarizes the current and emerging therapies used to treat NMSC.

High-Risk Non-Melanoma Skin Cancers: Biological and Therapeutic Advances

Nonmelanoma skin cancers (NMSCs) are the most common cancers, with high-risk NMSCs sharing features such as poor histologic differentiation, invasion into deeper layers, and anatomic location. NMSC includes basal cell carcinoma, cutaneous squamous cell carcinoma, and Merkel cell carcinoma. Herein, the authors describe advances in understanding the genetic mechanisms of malignant transformation and the composition of tumor microenvironment for these cancers. They summarize recent therapeutic advances, including targeted therapy and immunotherapy for NMSCs. Effective skin protection against ultraviolet radiation-induced carcinogenesis remains an urgent unmet need for NMSC prevention. The authors highlight immune-based interventions as novel strategies to address this need.

MiR-34a-5p suppresses cutaneous squamous cell carcinoma progression by targeting SIRT6

Cutaneous squamous cell carcinoma (cSCC) is a malignant tumor originating from epidermal or appendageal keratinocytes, with a rising incidence in recent years. Understanding the molecular mechanism driving its development is crucial. This study aims to investigate whether miR-34a-5p is involved in the pathogenesis of cSCC by targeting Sirtuin 6 (SIRT6).The expression levels of miR-34a-5p and SIRT6 were determined in 15 cSCC tissue specimens, 15 normal tissue specimens and cultured cells via real-time polymerase chain reaction (RT-qPCR). Pearson's correlation analysis was conducted to evaluate the relationship between miR-34a-5p and SIRT6 expression levels in cSCC tissues. A431 and SCL-1 cells were transfected with miR-34a-5p mimic, negative control or miR-34a-5p mimic together with recombinant plasmids containing SIRT6 gene. Cell counting kit-8, clone formation assay, wound healing assay, and flow cytometry were employed to assess the effects of these transfections on proliferation, migration, and apoptosis, respectively. The interaction between miR-34a-5p and SIRT6 was characterized using a dual-luciferase reporter assay.MiR-34a-5p expression was down-regulated in cSCC tissues significantly, while the SIRT6 expression was the opposite. A negative correlation was observed between the expression of miR-34a-5p and SIRT6 in cSCC tissues. Furthermore, overexpression of miR-34a-5p led to a significant reduction in the proliferation and migration abilities of A431 and SCL-1 cells, accompanied by an increase in apoptosis levels and a decrease in SIRT6 expression levels. MiR-34a-5p was identified as a direct target of SIRT6. Importantly, overexpression of SIRT6 effectively counteracted the inhibitory effect mediated by miR-34a-5p in cSCC cells.Our findings suggest that miR-34a-5p functions as a tumor suppressor in cSCC cells by targeting SIRT6.

Molecular mechanisms of human papilloma virus related skin cancers: A review

The human papillomavirus (HPV) belongs to the Papillomaviridae family of viruses which includes small, double-stranded DNA viral agents. Approximately 90% of HPV infections occur asymptomatically and resolve spontaneously. However, infection with high-risk viral strains can lead to the development of preneoplastic lesions, with an increased propensity to become cancerous. The location of these malignancies includes the oral cavity, cervix, vagina, anus, and vulva, among others. The role of HPV in carcinogenesis has already been demonstrated for the aforementioned neoplasia. However, regarding skin malignancies, the mechanisms that pinpoint the role played by HPV in their initiation and progression still elude our sight. Until now, the only fully understood mechanism of viral cutaneous oncogenesis is that of human herpes virus 8 infection in Kaposi sarcoma. In the case of HPV infection, however, most data focus on the role that beta strains exhibit in the oncogenesis of cutaneous squamous cell carcinoma (cSCC), along with ultraviolet radiation (UVR) and other environmental or genetic factors. However, recent epidemiological investigations have highlighted that HPV could also trigger the onset of other non-melanocytic, for example, basal cell carcinoma (BCC), and/or melanocytic skin cancers, for example, melanoma. Herein, we provide an overview of the role played by HPV in benign and malignant skin lesions with a particular focus on the main epidemiological, pathophysiological, and molecular aspects delineating the involvement of HPV in skin cancers.

Cutaneous squamous cell carcinoma characterized by MALDI mass spectrometry imaging in combination with machine learning

Cutaneous squamous cell carcinoma (SCC) is an increasingly prevalent global health concern. Current diagnostic and surgical methods are reliable, but they require considerable resources and do not provide metabolomic insight. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) enables detailed, spatially resolved metabolomic analysis of tissue samples. Integrated with machine learning, MALDI-MSI could yield detailed information pertaining to the metabolic alterations characteristic for SCC. These insights have the potential to enhance SCC diagnosis and therapy, improving patient outcomes while tackling the growing disease burden. This study employs MALDI-MSI data, labelled according to histology, to train a supervised machine learning model (logistic regression) for the recognition and delineation of SCC. The model, based on data acquired from discrete tumor sections (n = 25) from a mouse model of SCC, achieved a predictive accuracy of 92.3% during cross-validation on the labelled data. A pathologist unacquainted with the dataset and tasked with evaluating the predictive power of the model in the unlabelled regions, agreed with the model prediction for over 99% of the tissue areas. These findings highlight the potential value of integrating MALDI-MSI with machine learning to characterize and delineate SCC, suggesting a promising direction for the advancement of mass spectrometry techniques in the clinical diagnosis of SCC and related keratinocyte carcinomas.

Rapidly Growing Giant Squamous Cell Carcinoma of the Head: A Case Report

Giant squamous cell carcinoma (GSCC) of the skin arising on the head presents a distinctive clinical challenge due to its rarity, aggressive behavior, and potential for disfigurement. A male in his 70s with a history of tobacco cigarette use presented to the emergency department with a painful, bleeding mass on the right parietal scalp. On admission, a brain CT revealed a fungating mass with no cortical breakthrough or osseous erosion, measuring 7.9 x 5.7 x 2.5 cm. An ultrasound-guided tissue biopsy was performed and revealed poorly differentiated squamous cell carcinoma. The patient was discharged home with instructions from oncology to continue with outpatient treatment. At this time, the prognosis is good if treatment is received.

The Tumor Stroma of Squamous Cell Carcinoma: A Complex Environment That Fuels Cancer Progression

The tumor microenvironment (TME), a complex assembly of cellular and extracellular matrix (ECM) components, plays a crucial role in driving tumor progression, shaping treatment responses, and influencing metastasis. This narrative review focuses on the cutaneous squamous cell carcinoma (cSCC) tumor stroma, highlighting its key constituents and their dynamic contributions. We examine how significant changes within the cSCC ECM-specifically, alterations in fibronectin, hyaluronic acid, laminins, proteoglycans, and collagens-promote cancer progression, metastasis, and drug resistance. The cellular composition of the cSCC TME is also explored, detailing the intricate interplay of cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), endothelial cells, pericytes, adipocytes, and various immune cell populations. These diverse players modulate tumor development, angiogenesis, and immune responses. Finally, we emphasize the TME's potential as a therapeutic target. Emerging strategies discussed in this review include harnessing the immune system (adoptive cell transfer, checkpoint blockade), hindering tumor angiogenesis, disrupting CAF activity, and manipulating ECM components. These approaches underscore the vital role that deciphering TME interactions plays in advancing cSCC therapy. Further research illuminating these complex relationships will uncover new avenues for developing more effective treatments for cSCC.

Nanozymes with biomimetically designed properties for cancer treatment

Nanozymes, as a type of nanomaterials with enzymatic catalytic activity, have demonstrated tremendous potential in cancer treatment owing to their unique biomedical properties. However, the heterogeneity of tumors and the complex tumor microenvironment pose significant challenges to the in vivo catalytic efficacy of traditional nanozymes. Drawing inspiration from natural enzymes, scientists are now using biomimetic design to build nanozymes from the ground up. This approach aims to replicate the key characteristics of natural enzymes, including active structures, catalytic processes, and the ability to adapt to the tumor environment. This achieves selective optimization of nanozyme catalytic performance and therapeutic effects. This review takes a deep dive into the use of these biomimetically designed nanozymes in cancer treatment. It explores a range of biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry. A significant focus is on tweaking the nanozyme structures to boost their catalytic performance, integrating them into complex enzyme networks similar to those in biological systems, and adjusting functions like altering tumor metabolism, reshaping the tumor environment, and enhancing drug delivery. The review also covers the applications of specially designed nanozymes in pan-cancer treatment, from catalytic therapy to improved traditional methods like chemotherapy, radiotherapy, and sonodynamic therapy, specifically analyzing the anti-tumor mechanisms of different therapeutic combination systems. Through rational design, these biomimetically designed nanozymes not only deepen the understanding of the regulatory mechanisms of nanozyme structure and performance but also adapt profoundly to tumor physiology, optimizing therapeutic effects and paving new pathways for innovative cancer treatment.

Photodynamic Therapy for the Treatment of Bowen's Disease: A Review on Efficacy, Non-Invasive Treatment Monitoring, Tolerability, and Cosmetic Outcome

Bowen's disease represents the in situ form of cutaneous squamous cell carcinoma; although it has an excellent prognosis, 3-5% of lesions progress to invasive cutaneous squamous cell carcinoma, with a higher risk in immunocompromised patients. Treatment is therefore always necessary, and conventional photodynamic therapy is a first-line option. The aim of this review is to provide an overview of the clinical response, recurrence rates, safety, and cosmetic outcome of photodynamic therapy in the treatment of Bowen's disease, considering different protocols in terms of photosensitizers, light source, and combination treatments. Photodynamic therapy is a valuable option for tumors at sites where wound healing is poor/delayed, in the case of multiple and/or large tumors, and where surgery would be difficult or invasive. Dermoscopy and reflectance confocal microscopy can be used as valuable tools for monitoring the therapeutic response. The treatment is generally well tolerated, with mild side effects, and is associated with a good/excellent cosmetic outcome. Periodic follow-up after photodynamic therapy is essential because of the risk of recurrence and progression to cSCC. As the incidence of keratinocyte tumors increases, the therapeutic space for photodynamic therapy will further increase.

Identifying SCC Lesions Capable of Spontaneous Regression by Using Immunohistochemistry: A Systematic Review and Meta-Analysis

INTRODUCTION

Keratoacanthoma (KA) and squamous cell carcinoma (SCC) are two cutaneous conditions with morphological resemblance, which can complicate the diagnosis in some cases. Using immunohistochemistry staining of biomarkers could be beneficial in resolving this obstacle.

OBJECTIVES

We investigated a variety of biomarkers assessed in different studies in order to find the most important and helpful biomarkers for differentiation between SCC and lesions capable of spontaneous regression.

METHODS

MEDLINE via PubMed and Google Scholar database were used to identify relevant literature up to 15 June 2022. The aim of our analyses was to determine the capability of biomarkers to distinguish between SCC and lesions capable of spontaneous regression using calculated individual and pooled odds ratios (OR) and 95% confidence intervals (CI) and I2 tests.

RESULTS

Six potential biomarkers were CD10 with pooled OR= 0.006 (95% CI: 0.001-0.057) and I2=0%; COX-2 with pooled OR=0.089 (95% CI: 0.029-0.269) and I2=17.1%; elastic fibers with pooled OR= 6.69 (95% CI: 2.928-15.281) and I2=0%; IMP-3 with pooled OR=0.145 (95% CI: 0.021-1.001) and I2=44.5%; P53 with pooled OR=0.371 (95% CI: 0.188-0.733) and I2=55.9%; AT1R with OR=0.026 (95% CI: 0.006-0.107).

CONCLUSIONS

We suggest the utilization of the following IHC biomarkers for discrimination between lesions with spontaneous regression such as KA and SCC: CD10, COX-2, and elastic fibers.

Patterns of major cutaneous surgeries and reconstructions in patients with cutaneous squamous cell carcinoma in the USA

Aim: Since use of major cutaneous surgeries/reconstructions among patients with cutaneous squamous cell carcinoma (CSCC) is not well described, we sought to quantify major cutaneous surgeries/reconstructions among patients with CSCC who were newly diagnosed and for those treated with systemic therapy, stratified by immune status. Methods: We used the Optum® Clinformatics® Data Mart database (2013-2020) and Kaplan-Meier estimators to assess risk of surgeries/reconstructions. Results: 450,803 patients were identified with an incident CSCC diagnosis, including 4111 patients with CSCC who initiated systemic therapy. The respective 7-year risks of major cutaneous surgeries/reconstructions were 10.9% (95% CI: 10.7-11.0) and 21.8% (95% CI: 17.6-25.8). Overall risk of major cutaneous surgeries/reconstructions was higher in patients who were immunocompromised than those who were immunocompetent. Conclusion: Approximately one in nine patients with CSCC will undergo ≥1 major cutaneous surgeries/reconstructions within 7 years of diagnosis; the risk increases in patients who initiate systemic therapy and among those who are immunocompromised.

Development of a Stability Indicating UPLC Method for the Determination of Tirbanibulin in Bulk and Its Pharmaceutical Dosage Form

Objectives

The primary goal of this study was to create and validate a simple, precise, sensitive, and accurate ultra-performance liquid chromatography (UPLC) method for estimating tirbanibulin in pure and dosage form.

Materials and Methods

A UPLC technique was developed using a Waters Acquity UPLC Phenyl (100 x 2.1 mm, 1.7 µm) column. The developed technique was validated in accordance with the International Conference on Harmonization (ICH) guidelines.

Results

Tirbanibulin was separated chromatographically with high resolution using the mobile phase acetonitrile: buffer (30:70 v/v) at 0.5 mL/min, 5 µL injection volume, and 220 nm wavelength. The validated technique was found to be linear in the 1-15 µg/mL range. The detection and quantification limits for tirbanibulin were 0.03 and 0.1 µg/mL, respectively. The percentage relative standard deviation was less than 2%, demonstrating the precision of the developed technique. Furthermore, the recovery rate was nearly 100%, confirming the accuracy of the method. Minor modifications to the chromatographic conditions demonstrated the robustness of the method.

Conclusion

The developed analytical method was precise, simple, reproducible, and sensitive. Consequently, it can be used to determine tirbanibulin.

PTCH1 Gene Variants, mRNA Expression, and Bioinformatics Insights in Mexican Cutaneous Squamous Cell Carcinoma Patients

BACKGROUND

Skin cancer is one of the most frequent types of cancer, and cutaneous squamous cell carcinoma (cSCC) constitutes 20% of non-melanoma skin cancer (NMSC) cases. PTCH1, a tumor suppressor gene involved in the Sonic hedgehog signaling pathway, plays a crucial role in neoplastic processes.

METHODS

An analytical cross-sectional study, encompassing 211 cSCC patients and 290 individuals in a control group (CG), was performed. A subgroup of samples was considered for the relative expression analysis, and the results were obtained using quantitative real-time PCR (qPCR) with TaqMan® probes. The functional, splicing, and disease-causing effects of the proposed variants were explored via bioinformatics.

RESULTS

cSCC was predominant in men, especially in sun-exposed areas such as the head and neck. No statistically significant differences were found regarding the rs357564, rs2236405, rs2297086, and rs41313327 variants of PTCH1, or in the risk of cSCC, nor in the mRNA expression between the cSCC group and CG. A functional effect of rs357564 and a disease-causing relation to rs41313327 was identified.

CONCLUSION

The proposed variants were not associated with cSCC risk in this Mexican population, but we recognize the need for analyzing larger population groups to elucidate the disease-causing role of rare variants.

Case Report: Dostarlimab for treatment of aggressive cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy with the aggressive cSCC subtype being especially worrisome due to its higher metastatic and mortality rate. An 80-year-old immunocompetent Caucasian man presented with a locally advanced and recurrent cSCC for which he underwent six Mohs surgeries, radiation therapy, and standard immunotherapy treatments. Throughout treatment, the patient's cancer continued to progress across different regions of the face. Biopsy and analysis were performed and showed that the cSCCs had a high mutational burden and oncogenes known to be present in tumors with aggressive nature. After the algorithmically applied standard of care failed to cure or control the progressing disease, the genetic analysis favored dostarlimab as a suitable option. With only three doses of 500 mg dostarlimab q3 weeks, the patient showed a fast response with macroscopic resolution of clinically discernible disease of, the previously noted, locally advanced cSCC on his right forehead, as well as other primary keratinocyte carcinomas on his left contralateral face, nose, left leg, and neck. This remarkable case can present an option for complex patients with locally advanced and recurrent cSCC who failed the current standard of care. Moreover, it warrants a proper clinical trial to assess efficacy and potential indication of dostarlimab in such patients. Of note is the presence of a KMT2D mutation and its well-identified correlation with mismatch repair deficiency (dMMR) and poor prognosis, which can play an informative role in clinical decision making and precision therapeutic choice at the point of care.

Tumour Recurrence, Depth of Invasion, and Temple Location as Independent Prognostic Parameters of Lymph Node Metastases of Head and Neck Cutaneous Squamous Cell Carcinomas

The excellent survival rate of cutaneous squamous cell carcinoma (cSCC) exceeding 90% is reduced by the presence of nodal metastases by over 50%. We analysed various risk parameters of cSCC to predict the incidence of nodal metastases. A total of 118 patients with the head cSCC were included in a single-institution retrospective study covering the period from 2008 to 2020. Tumour recurrence, temple location, and tumour infiltration depth were found to be independent predictors of nodal metastases (increasing the probability of metastases by 8.0, 8.1, and 4.3 times, respectively). Furthermore, univariate analysis shows that the tumour size and T stage are significant factors increasing the risk of metastases. Several independent risk factors for the development of metastases in the head cSCC have been confirmed. These findings might help identify at-risk patients who require additional attention for adequate radical treatment and close follow-up. In contrast, elective treatment of lymph nodes is not recommended due to the low incidence of regional metastases.

Hypertrophic Lichen Planus: A Precursor Lesion for Squamous Cell Carcinoma

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

Medical thoracoscopy with cryobiopsy as diagnostic tool for pleural metastatic in cutaneous squamous cell carcinoma: a rare case report

Introduction

Distance metastasis of cutaneous squamous cell carcinoma (cSCC) to pleural is rarely reported, and meets difficulties in diagnosing due to quality of pleural biopsy sample. This case presented a novel technique by using cryobiopsy to obtain adequate sample and was first conducted in our hospital.

Case presentation

A 62-years-old man admitted to hospital with dyspnoea due to massive right pleural effusion. Lung multi-sliced computed tomography showed right lung pleural effusion with compression atelectasis as well as collapse of medial lobe and upper lobe, multiple solitary nodules on mediastinal, costal antero-posterior and right diaphragm pleural part. Medical thoracoscopy was performed to obtain pleural samples by using cryobiopsy and forceps biopsy. Pathological analysis with Immunohistochemistry (IHC) revealed metastatic squamous cell carcinoma.

Discussion

Recurrence rate of cSCC remains high even after treatment, with worse prognosis. Distant metastasis to pleural is rarely reported. Clinical approach for malignant pleural effusion by using medical thoracoscopy has 80% sensitivity with minimal complication. Pleural cryobiopsy is a novel technique used for obtaining sample from pleural biopsy with significant larger size of the specimen, less crush artefacts, fragmented and better tissue integrity, although the diagnostic yield and bleeding severity between cryobiopsy and conventional forceps biopsy are not significant.

Conclusion

Medical thoracoscopy with cryobiopsy should be considered as a preferrable diagnostic tool for obtaining better sample specimen, especially for pleural metastatic.

Association between lifetime smoking and cutaneous squamous cell carcinoma: A 2-sample Mendelian randomization study

Background/Purpose

Cutaneous squamous cell carcinoma (cSCC) is one of the most common malignancies worldwide. While several environmental risk factors for cSCC are well established, there is conflicting evidence on cigarette smoking (and its potential causal effect) and cSCC risk. Furthermore, it is unclear if these potential associations represent causal, modifiable risk factors for cSCC development. This study aims to assess the nature of the associations between cigarette smoking traits (smoking initiation, amount smoked, and lifetime smoking exposure) and cSCC risk using two-sample Mendelian randomization analyses.

Methods

Genetic instruments, based on common genetic variants associated with cigarette smoking traits (P < 5 × 10-8), were derived from published genome-wide association studies (GWASs). For cSCC, we used GWAS summary statistics from the Kaiser Permanente GERA cohort (7701 cSCC cases and 60,167 controls; all non-Hispanic Whites).

Results

We found modest evidence that genetically determined lifetime smoking was associated with cSCC (inverse-variance weighted method: OR[95% CI] = 1.47[1.09-1.98]; P = .012), suggesting it may be a causal risk factor for cSCC. We did not detect any evidence of association between genetically determined smoking initiation or amount smoked and cSCC risk.

Conclusion

Study findings highlight the importance of smoking prevention and may support risk-stratified cSCC screening strategies based on carcinogen exposure and other genetic and clinical information.

Molecular targeted therapies for cutaneous squamous cell carcinoma: recent developments and clinical implications

Cutaneous Squamous Cell Carcinoma (cSCC) is a common and potentially fatal type of skin cancer that poses a significant threat to public health and has a high prevalence rate. Exposure to ultraviolet radiation on the skin surface increases the risk of cSCC, especially in those with genetic syndromes like xerodermapigmentosum and epidermolysis bullosa. Therefore, understanding the molecular pathogenesis of cSCC is critical for developing personalized treatment approaches that are effective in cSCC. This article provides a comprehensive overview of current knowledge of cSCC pathogenesis, emphasizing dysregulated signaling pathways and the significance of molecular profiling. Several limitations and challenges associated with conventional therapies, however, are identified, stressing the need for novel therapeutic strategies. The article further discusses molecular targets and therapeutic approaches, i.e., epidermal growth factor receptor inhibitors, hedgehog pathway inhibitors, and PI3K/AKT/mTOR pathway inhibitors, as well as emerging molecular targets and therapeutic agents. The manuscript explores resistance mechanisms to molecularly targeted therapies and proposes methods to overcome them, including combination strategies, rational design, and optimization. The clinical implications and patient outcomes of molecular-targeted treatments are assessed, including response rates and survival outcomes. The management of adverse events and toxicities in molecular-targeted therapies is crucial and requires careful monitoring and control. The paper further discusses future directions for therapeutic advancement and research in this area, as well as the difficulties and constraints associated with conventional therapies.

miR-184 represses β-catenin and behaves as a skin tumor suppressor

miR-184-knockout mice display perturbed epidermal stem cell differentiation. However, the potential role of miR-184 in skin pathology is unclear. Here, we report that miR-184 controls epidermal stem cell dynamics and that miR-184 ablation enhances skin carcinogenesis in mice. In agreement, repression of miR-184 in human squamous cell carcinoma (SCC) enhances neoplastic hallmarks of human SCC cells in vitro and tumor development in vivo. Characterization of miR-184-regulatory network, suggests that miR-184 inhibits pro-oncogenic pathways, cell proliferation, and epithelial to mesenchymal transformation. Of note, depletion of miR-184 enhances the levels of β-catenin under homeostasis and following experimental skin carcinogenesis. Finally, the repression of β-catenin by miR-184, inhibits the neoplastic phenotype of SCC cells. Taken together, miR-184 behaves as an epidermal tumor suppressor, and may provide a potentially useful target for skin SCC therapy.

Pathophysiology, Histopathology, and Differential Diagnostics of Basal Cell Carcinoma and Cutaneous Squamous Cell Carcinoma-An Update from the Pathologist's Point of View

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are the most frequently occurring non-melanocytic skin cancers. The objective of our study is to present the pathophysiology of BCC and cSCC and its direct relationship with the histopathological diagnostics and the differential diagnostics of these types of cancer, based on the morphological characteristics, immunohistochemical profile, and genetic alterations. The qualitative study was based on emphasizing the morphological characteristics and immunohistochemistry profiles of BCC and cSCC and the differential diagnostics based on the tissue samples from the Clinical Pathology Department of Mures Clinical County Hospital between 2020 and 2022. We analyzed the histopathological appearances and immunohistochemical profiles of BCC and cSCC in comparison with those of Bowen disease, keratoacanthoma, hyperkeratotic squamous papilloma, metatypical carcinoma, pilomatricoma, trichoblastoma, Merkel cell carcinoma, pleomorphic dermal sarcoma (PDS), and melanoma. Our study showed the importance of the correct histopathological diagnosis, which has a direct impact on the appropriate treatment and outcome for each patient. The study highlighted the histopathological and morphological characteristics of NMSCs and the precursor lesions in HE and the immunohistochemical profile for lesions that may make the differential diagnosis difficult to establish.

Nanotechnology as a Promising Method in the Treatment of Skin Cancer

The incidence of skin cancer continues to grow. There are an estimated 1.5 million new cases each year, of which nearly 350,000 are melanoma, which is often fatal. Treatment is challenging and often ineffective, with conventional chemotherapy playing a limited role in this context. These disadvantages can be overcome by the use of nanoparticles and may allow for the early detection and monitoring of neoplastic changes and determining the effectiveness of treatment. This article briefly reviews the present understanding of the characteristics of skin cancers, their epidemiology, and risk factors. It also outlines the possibilities of using nanotechnology, especially nanoparticles, for the transport of medicinal substances. Research over the previous decade on carriers of active substances indicates that drugs can be delivered more accurately to the tumor site, resulting in higher therapeutic efficacy. The article describes the application of liposomes, carbon nanotubes, metal nanoparticles, and polymer nanoparticles in existing therapies. It discusses the challenges encountered in nanoparticle therapy and the possibilities of improving their performance. Undoubtedly, the use of nanoparticles is a promising method that can help in the fight against skin cancer.

Ovine papillomaviruses: Diversity, pathogenicity, and evolution

The family Papillomaviridae includes a plethora of viral species infecting virtually all vertebrates excluding amphibians, with astonishing impact on human and animal health. Although more than 250 species have been described in humans, the total number of papillomaviruses (PVs) discovered in animals does not reach up to this number. In animals, PV infections are mostly asymptomatic or can cause variable clinical conditions ranging from self-limiting papillomas and other cutaneous and mucosal benign lesions to cancer. Most of animal PV types have been discovered in cattle, dogs, horses, and cats with other farm host species remaining overlooked. In particular, the number of PV types so far identified in sheep is limited. This paper comprehensively reviews ovine PVs features, including viral taxonomy and evolution; genome organization; viral tropism and pathogenesis; macroscopical features and histopathological patterns, as well as available diagnostics tools. Data are critically presented and discussed in terms of impact on veterinary and public health. The development of future dedicated research is also discussed.

Non-Habit-Related Oral Squamous Cell Carcinoma: A Review

Oral squamous cell carcinoma (OSCC) is a serious and potentially life-threatening condition that can have a profound impact on an individual's health and well-being. Its etiology is commonly known to be habit induced, such as tobacco consumption, smoking, or alcohol abuse. Apart from these etiologies, certain factors that lead to OSCC are also present but are less frequently encountered in hospitals and clinics. However, these non-habitual factors, with their pathogenesis, can lead to OSCC, which may be confusing to certain medical practitioners. This article discusses the various non-habitual causes that can lead to OSCC, as well as their pathophysiology, molecular expression, and related indicators and prognostic factors.

A Panel of Potential Serum Markers Related to Angiogenesis, Antioxidant Defense and Hypoxia for Differentiating Cutaneous Squamous Cell Carcinomas from Actinic Keratoses

Cutaneous squamous cell carcinoma (cSCC) arising from the malignant proliferation of epidermal keratinocytes is the second most common skin cancer. Actinic keratosis (AK), which is considered cSCC in situ, may progress into invasive tumors. Currently, there are no serum markers that can differentiate cSCC from AK. The aim of our study was to assess angiogenesis and oxidative stress in patients with cSCC and patients with AK and find reliable serum markers useful in the diagnosis of cSCC. We have determined the serum levels of a group of proangiogenic factors (MMP-2, MMP-9, VEGF, FGF2), the total antioxidative status/capacity (TAS/TAC), ImAnOx, a marker of oxidative stress, and HIF-1 alpha, an indicator of hypoxia. We have identified higher serum levels of MMP-2. MMP-9, VEGF, FGF2 and HIF-1 alpha and lower levels of ImAnOx in cSCC patients compared to AK patients and controls. There were no statistically significant differences between AK patients and controls. We have found positive correlations between proangiogenic markers and HIF-1 alpha and negative correlations between proangiogenic markers and ImAnOx. Our results suggest that MMP-2, MMP-9, VEGF, FGF2, ImAnOx and HIF-1 may be promising markers for differentiating AK from cSCC, and there is a link between angiogenesis, oxidative stress and hypoxia.

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.

Cutaneous Squamous Cell Carcinoma: Clinico-Dermoscopic and Histological Correlation: About 72 Cases

INTRODUCTION

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, accounting for 20% of malignant skin tumors. Dermoscopy is a very useful tool for diagnosing cSCC, and its findings are confirmed through histopathological studies.

OBJECTIVES

to describe the different dermoscopic structures of invasive cSCC and investigate their association with the clinical form and histopathological grade of differentiation.

METHODS

We conducted a cross-sectional study, collecting all patients diagnosed with squamous cell carcinoma over a period of 5 years. The study population was divided into two groups based on histological differentiation (well-differentiated and non-well-differentiated) and clinical form ( nodulo-ulcerative and nodular). Various dermoscopic parameters were compared between these groups.

RESULTS

Out of 72 invasive cSCC, 81.9% were well-differentiated, while 18.1% were non-well-differentiated. The clinical form of cSCC was nodulo-ulcerative in 83.3% of cases and nodular in 16.7%. Well-differentiated tumors showed dotted, glomerular and hairpin vessels, along with a predominant white pattern characterized by centrally distributed keratin as well as white circles, and whitish perivascular halo (P < 0.05). The distribution of these white structures was radial in nodulo-ulcerarive lesions, whereas in nodular lesions, their distribution, as well as that of keratin, was more diffuse (P < 0.05). Non-well-differentiated tumors showed a combined white-red pattern with the predominance of arborizing vessels (P < 0.05).

CONCLUSIONS

Our results show the reliability of dermoscopy as a tool for distinguishing between well- and poorly differentiated cSCC. This distinction is characterized by an increase in predominantly arborizing vessels and a corresponding decrease in white structures as the tumor progresses from a well-differentiated to a poorly differentiated state. Additionally, the nodulo-ulcerative form exhibits a central distribution of keratin, while the nodular form displays a diffuse distribution.

Competing-risks analysis for evaluating the prognosis of patients with microinvasive cutaneous squamous cell carcinoma based on the SEER database

BACKGROUND

Utilizing the traditional Cox regression model to identify the factors affecting the risk of mortality due to microinvasive cutaneous squamous cell carcinoma (micSCC) may produce skewed results. Since cause-specific mortality can guide clinical decision-making, this study employed the Fine-Gray model based on the Surveillance, Epidemiology, and End Results (SEER) database to identify significant predictive variables for the risk of micSCC-related mortality.

METHODS

This study used the information of patients with micSCC who were listed in the SEER database during 2000-2015. Cox regression and Fine-Gray models were utilized for the multivariable analysis, and Gray's test and the cumulative incidence function were used for the univariable analyses.

RESULTS

There were 100 patients who died from other reasons and 38 who died from micSCC among the 1259 qualified patients with micSCC. Most were female, white, married, had localized metastasis, etc. According to the univariable Gray's test (P < 0.05), the cumulative incidence rate for events of interest was strongly associated with age, sex, marital status, American Joint Committee on Cancer staging, radiation status, summary stage, chemotherapy status, surgery status, and tumor size. Multivariable Cox regression analysis and multivariable competing-risks analysis indicated that age, tumor size, and income were independent risk variables for the prognosis of patients with micSCC. In both age and tumor size variables, the competing-risks model showed a slight decrease in the hazard ratio and a slight narrowing of the 95% confidence interval compared with the Cox regression model. However, this pattern is not evident in the income variable.

CONCLUSIONS

This study established a Fine-Gray model for identifying the independent risk factors that influence the risk of mortality among patients with micSCC. This study uncovers that, in the context of competing risks, age, tumor size, and income serve as independent risk factors influencing the risk of mortality due to micSCC among patients. Our findings have the potential to provide more accurate risk assessments for patient outcomes and contribute to the development of individualized treatment plans.

Photodynamic therapy with hematoporphyrin derivative for recurrent plantar cutaneous squamous cell carcinoma: A case report

Cutaneous squamous cell carcinoma (cSCC) is a prevalent malignant tumor typically treated through surgical removal. However, when the lesion is situated in specific areas like the hands, feet, or lips, particularly if it's sizable, surgical interventions can adversely impact appearance and function. In such cases, non-surgical treatments are preferable to preserve both aesthetics and functionality. We present a case of recurrent cSCC on the plantar region post-surgery. Given the extensive lesion area, deep infiltration, and the patient's reliance on foot function, hematoporphyrin derivative-photodynamic therapy (HpD-PDT) was chosen over traditional surgery. The lesion was successfully treated, and while a minor recurrence was observed after 20 months, it was localized and amenable to non-surgical intervention. We posit that HpD-PDT is a viable treatment for cSCC, especially in unique locations, with extensive lesions, and postoperative recurrence.

Selective adhesion inhibition and hyaluronan envelope reduction of dermal tumor cells by cold plasma-activated medium

The sensitivity to cold plasma is specific to tumor cells while leaving normal tissue cells unaffected. This is the desired challenge in cancer therapy. Therefore, the focus of this work was a comparative study concerning the plasma sensitivity of dermal tumor cells (A-431) versus non-tumorigenic dermal cells (HaCaT) regarding their adhesion capacity. We found a selective inhibiting effect of plasma-activated medium on the adhesion of tumor cells while hardly affecting normal cells. We attributed this to a lower basal gene expression for the adhesion-relevant components CD44, hyaluronan synthase 2 (HAS2), HAS3, and the hyaluronidases in A431. Noteworthy, after plasma exposure, we revealed a significantly higher expression and synthesis of the hyaluronan envelope, the HAS3 gene, and the transmembrane adhesion receptors in non-tumorigenic HaCaTs.

Health-Related Quality of Life with Pembrolizumab in Patients with Locally Advanced or Recurrent or Metastatic Cutaneous Squamous Cell Carcinoma: KEYNOTE-629

INTRODUCTION

At first interim analysis of KEYNOTE-629, health-related quality of life (HRQoL) with pembrolizumab was stable or improved over 48 weeks in recurrent or metastatic (R/M) cutaneous squamous cell carcinoma (cSCC). HRQoL results from the second interim analysis in R/M or locally advanced (LA) cSCC are presented.

METHODS

Patients received pembrolizumab 200 mg every 3 weeks for ≤ 2 years. Change in EORTC Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and EQ-5D-5L scores were exploratory end points. Primary analysis was performed at week 12 to ensure adequate completion/compliance. Descriptive analyses were also conducted through weeks 48 and 75 for the LA and R/M cohorts, respectively.

RESULTS

At data cutoff (29 July 2020), mean scores in the LA cohort (n = 47) were stable from baseline to week 12 for EORTC QLQ-C30 global health status (GHS)/quality of life (QoL) (-0.27 points [95% confidence interval (CI) -10.93 to 10.39]), physical functioning (-1.29 points [95% CI  -8.77 to 6.19]), and EQ-5D-5L visual analog scale (2.06 [95% CI -7.70 to 11.82]). HRQoL remained stable through week 48 in the LA cohort; 76.6% and 74.5% of patients had improved or stable GHS/QoL and physical functioning scores, respectively. HRQoL continued to show stability or improvement through week 75 in the R/M cohort (n = 99); 71.7% and 64.6% of patients had improved or stable GHS/QoL and physical functioning scores, respectively.

CONCLUSIONS

Pembrolizumab has demonstrated antitumor activity and manageable safety. The current analysis shows pembrolizumab treatment preserved HRQoL. Collectively, these results support pembrolizumab as standard of care for LA or R/M cSCC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03284424-September 15, 2017.

Influence of environmental risk factors on the development of wounds associated with squamous cell carcinoma

The incidence of squamous cell carcinoma (SCC) is on the rise, making it a significant global health concern. Environmental risk factors are crucial to the development of SCC. This study sought to examine comprehensively the impact of these factors on the onset of SCC. We conducted a cross-sectional study involving 480 participants at Beijing tertiary care hospital. Utilizing structured questionnaires, data on demographics, environmental exposures, medical history and clinical characteristics were collected. The cohort was composed of 272 men (56.67%) and 208 women (43.33%). The majority (44.38%) were between ages of 41 and 60, and Type III skin predominated (34.79%). Most of the participants belonged to the middle socioeconomic class (60.83%). 'Vegetarian' dietary habits (46.67%) were prevalent, as was the 'Sedentary' lifestyle (49.79%). Regarding environmental exposures, moderate sun exposure of 3 to 5 h per day (54.58%) and UV protective eyewear (30.83%) were prevalent. The majority (69.58%) of respondents indicated 'Never' exposure to carcinogens. A variety of wound characteristics were observed, with 'non-smokers' (64.17%) dominating. Most SCC lesions were located on the extremities (40.21%), lasted less than 6 months (44.38%) and measured 1-3 cm (39.79%). The majority (54.58%) did not have a history of cutaneous injuries. Our research uncovered substantial relationships between SCC and numerous environmental variables, gender, Fitzpatrick skin type, occupation, duration of sun exposure, exposure to carcinogens, dietary practices, history of skin wounds, wound location, duration, size and depth were significantly associated with the onset of SCC. These results highlighted the complexity of SCC aetiology and need for individualized prevention and treatment strategies.

Knockdown of Simulated-Solar-Radiation-Sensitive miR-205-5p Does Not Induce Progression of Cutaneous Squamous Cell Carcinoma In Vitro

Solar radiation is the main risk factor for cSCC development, yet it is unclear whether the progression of cSCC is promoted by solar radiation in the same way as initial tumorigenesis. Additionally, the role of miRNAs, which exert crucial functions in various tumors, needs to be further elucidated in the context of cSCC progression and connection to solar radiation. Thus, we chronically irradiated five cSCC cell lines (Met-1, Met-4, SCC-12, SCC-13, SCL-II) with a custom-built irradiation device mimicking the solar spectrum (UVB, UVA, visible light (VIS), and near-infrared (IRA)). Subsequently, miRNA expression of 51 cancer-associated miRNAs was scrutinized using a flow cytometric multiplex quantification assay (FirePlex®, Abcam). In total, nine miRNAs were differentially expressed in cell-type-specific as well as universal manners. miR-205-5p was the only miRNA downregulated after SSR-irradiation in agreement with previously gathered data in tissue samples. However, inhibition of miR-205-5p with an antagomir did not affect cell cycle, cell growth, apoptosis, or migration in vitro despite transient upregulation of oncogenic target genes after miR-205-5p knockdown. These results render miR-205-5p an unlikely intracellular effector in cSCC progression. Thus, effects on intercellular communication in cSCC or the simultaneous examination of complementary miRNA sets should be investigated.

Microplastics exposure promotes the proliferation of skin cancer cells but inhibits the growth of normal skin cells by regulating the inflammatory process

Cutaneous squamous cell carcinoma (CSCC) is one of the most common malignant tumors of the skin, occurring primarily in the elderly population. CSCC is the second most common nonmelanoma skin malignancy in humans. The development of cutaneous squamous cell carcinoma is closely linked to environmental factors. Microplastics, as a new pollutant, are currently being intensively studied for their potential health effects. However, the effect of microplastics on skin cancer is not yet known and is an important scientific question that needs to be addressed. To this end, in the current study, two skin squamous cell carcinoma cell lines (SCL-1 and A431) were utilized to investigate the effects of microplastics on skin cancer, and cell behavior experiments showed that microplastics were internalized into the skin squamous cell carcinoma cell line in a time- and dose-dependent manner. Further experiments showed that microplastics promoted the proliferation of skin cancer cells by MTT, flow cytometry, laser confocal microscopy, Western blotting and other experimental techniques. Mechanistic studies showed that microplastics could lead to increased mitochondrial ROS in skin cancer cells, which in turn caused a change in mitochondrial membrane potential, thus opening mPTP, which in turn caused the release of mt-DNA from mitochondria into the cytoplasm, thus activating NLRP3 and ultimately causing skin cancer cell proliferation. We further evaluated the effect of microplastics on HaCaT cells in a normal skin cell model and showed that microplastics caused damage to normal skin cells through NLRP3-mediated inflammation and scorch death. The current study suggests that microplastics, as a new contaminant, may promote tumor cell proliferation while causing damage to normal skin.

Large Cutaneous Squamous Cell Carcinoma: A Consequence of Elective Surgery Deferment During the COVID-19 Pandemic

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer that can be treated effectively with limited morbidity if caught and treated early with elective surgical procedures. The COVID-19 pandemic caused most healthcare facilities to delay or defer elective surgeries as they allocated workforce and resources to treating significant increases of critically ill patients. This care delay has increased morbidity and mortality of many conditions treated with surgery. A few case reports exist on delayed elective surgeries' effects on patients and healthcare facilities. We report a case of cSCC enlarging and locally spreading due to elective surgery delay during the COVID-19 pandemic.

Functionally distinct cancer-associated fibroblast subpopulations establish a tumor promoting environment in squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a serious public health problem due to its high incidence and metastatic potential. It may progress from actinic keratosis (AK), a precancerous lesion, or the in situ carcinoma, Bowen's disease (BD). During this progression, malignant keratinocytes activate dermal fibroblasts into tumor promoting cancer-associated fibroblasts (CAFs), whose origin and emergence remain largely unknown. Here, we generate and analyze >115,000 single-cell transcriptomes from healthy skin, BD and cSCC of male donors. Our results reveal immunoregulatory and matrix-remodeling CAF subtypes that may derive from pro-inflammatory and mesenchymal fibroblasts, respectively. These CAF subtypes are largely absent in AK and interact with different cell types to establish a pro-tumorigenic microenvironment. These findings are cSCC-specific and could not be recapitulated in basal cell carcinomas. Our study provides important insights into the potential origin and functionalities of dermal CAFs that will be highly beneficial for the specific targeting of the cSCC microenvironment.

Nivolumab for locally advanced and metastatic cutaneous squamous cell carcinoma (NIVOSQUACS study)-Phase II data covering impact of concomitant haematological malignancies

BACKGROUND

Monoclonal antibodies, such as cemiplimab and pembrolizumab, against the programmed death receptor (PD)-1 have become the current standard of care and first-line treatment of advanced cutaneous squamous cell carcinoma (cSCC), proving remarkable clinical benefit and acceptable safety.

OBJECTIVES

To assess efficacy and safety of the anti-PD-1 antibody nivolumab in patients with locally advanced and metastatic cSCC.

METHODS

Patients received open-label nivolumab 240 mg intravenously every 2 weeks for up to 24 months. Patients with concomitant haematological malignancies (CHMs), either non-progressing or stable under active therapy, were eligible for inclusion.

RESULTS

Of 31 patients with a median age of 80 years, 22.6% of patients achieved an investigator assessed complete response, resulting in an objective response rate (ORR) of 61.3% and a disease control rate (DCR) of 64.5%. Progression-free survival (PFS) was 11.1 months, and the median overall survival (OS) was not reached after 24 weeks of therapy. Median follow-up was 23.82 months. Subgroup analysis of the CHM cohort (n = 11; 35%) revealed an ORR of 45.5%, a DCR of 54.5%, a median PFS of 10.9 months, and median OS of 20.7 months. Treatment related adverse events were reported in 58.1% of all patients (19.4% grade 3, the remaining grade 1 or 2). PD-L1 expression and CD-8+ T-cell infiltration did not significantly correlate with clinical response, although a trend towards a shorter PFS of 5.6 months was observed with PD-L1 negativity and low CD8+ intratumoral infiltration.

CONCLUSION

This study demonstrated robust clinical efficacy of nivolumab in patients with locally advanced and metastatic cSCCs and a tolerability comparable to data of other anti-PD-1 antibodies. Favourable outcomes were obtained despite involving the oldest hitherto reported study cohort for anti-PD-1 antibodies and a significant proportion of CHM patients prone to high risk tumours and an aggressive course otherwise typically excluded from clinical trials.

Nano-based formulations of curcumin: elucidating the potential benefits and future prospects in skin cancer

Skin cancer refers to any malignant lesions that occur in the skin and are observed predominantly in populations of European descent. Conventional treatment modalities such as excision biopsy, chemotherapy, radiotherapy, immunotherapy, electrodesiccation, and photodynamic therapy (PDT) induce several unintended side effects which affect a patient's quality of life and physical well-being. Therefore, spice-derived nutraceuticals like curcumin, which are well tolerated, less expensive, and relatively safe, have been considered a promising agent for skin cancer treatment. Curcumin, a chemical constituent extracted from the Indian spice, turmeric, and its analogues has been used in various mammalian cancers including skin cancer. Curcumin has anti-neoplastic activity by triggering the process of apoptosis and preventing the multiplication and infiltration of the cancer cells by inhibiting some signaling pathways and thus subsequently preventing the process of carcinogenesis. Curcumin is also a photosensitizer and has been used in PDT. The major limitations associated with curcumin are poor bioavailability, instability, limited permeation into the skin, and lack of solubility in water. This will constrain the use of curcumin in clinical settings. Hence, developing a proper formulation that can ideally release curcumin to its targeted site is important. So, several nanoformulations based on curcumin have been established such as nanogels, nanoemulsions, nanofibers, nanopatterned films, nanoliposomes and nanoniosomes, nanodisks, and cyclodextrins. The present review mainly focuses on curcumin and its analogues as therapeutic agents for treating different types of skin cancers. The significance of using various nanoformulations as well non-nanoformulations loaded with curcumin as an effective treatment modality for skin cancer is also emphasized.

Small intestinal perforation secondary to metastasis from skin squamous cell carcinoma: A case report and literature review

INTRODUCTION AND IMPORTANCE

Primary and metastatic carcinoma of the small intestine are rare. While most of these malignancies are adenocarcinomas, squamous cell carcinoma (SCC) of the gastrointestinal tract is uncommon. We present a case report of a rare occurrence of skin SCC metastasizing to the ileum, highlighting diagnostic challenges and clinical implications.

CASE PRESENTATION

An 83-year-old female had a history of cutaneous SCC excision in the right temporal region two years prior to the current emergency department visit, followed by metastatic recurrence in a right intra-parotid lymph node treated with radiotherapy. The patient exhibited septic shock and an acute abdomen, and an abdominal computed tomography scan revealed signs of intestinal perforation. Emergency exploratory laparotomy confirmed purulent peritonitis and perforation of the terminal ileum. Subsequently, a 20 cm intestinal resection was performed. Histopathological examination of the resected specimen revealed a 4 cm perforated SCC of the small intestine (pT4 pN0 L0 V1 Pn0 R0).

CLINICAL DISCUSSION

Metastases of the small intestine are rare. The primary sites for these metastases are typically the uterus, cervix, colon, lung, breast, or melanoma. SCC of the small intestine is particularly rare and poses challenges in diagnosis owing to non-specific symptoms. The prognosis for SCC of the small intestine is generally poor, and the potentially aggressive behavior of some skin SCC emphasizes the need for increased awareness and vigilance in managing such cases.

CONCLUSION

This case report underscores the importance of considering metastatic disease in the small bowel of patients with a history of skin SCC who present with new-onset abdominal symptoms.

CD271 activation prevents low to high-risk progression of cutaneous squamous cell carcinoma and improves therapy outcomes

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is the second most prevalent form of skin cancer, showing a rapid increasing incidence worldwide. Although most cSCC can be cured by surgery, a sizeable number of cases are diagnosed at advanced stages, with local invasion and distant metastatic lesions. In the skin, neurotrophins (NTs) and their receptors (CD271 and Trk) form a complex network regulating epidermal homeostasis. Recently, several works suggested a significant implication of NT receptors in cancer. However, CD271 functions in epithelial tumors are controversial and its precise role in cSCC is still to be defined.

METHODS

Spheroids from cSCC patients with low-risk (In situ or Well-Differentiated cSCC) or high-risk tumors (Moderately/Poorly Differentiated cSCC), were established to explore histological features, proliferation, invasion abilities, and molecular pathways modulated in response to CD271 overexpression or activation in vitro. The effect of CD271 activities on the response to therapeutics was also investigated. The impact on the metastatic process and inflammation was explored in vivo and in vitro, by using zebrafish xenograft and 2D/3D models.

RESULTS

Our data proved that CD271 is upregulated in Well-Differentiated tumors as compared to the more aggressive Moderately/Poorly Differentiated cSCC, both in vivo and in vitro. We demonstrated that CD271 activities reduce proliferation and malignancy marker expression in patient-derived cSCC spheroids at each tumor grade, by increasing neoplastic cell differentiation. CD271 overexpression significantly increases cSCC spheroid mass density, while it reduces their weight and diameter, and promotes a major fold-enrichment in differentiation and keratinization genes. Moreover, both CD271 overexpression and activation decrease cSCC cell invasiveness in vitro. A significant inhibition of the metastatic process by CD271 was observed in a newly established zebrafish cSCC model. We found that the recruitment of leucocytes by CD271-overexpressing cells directly correlates with tumor killing and this finding was further highlighted by monocyte infiltration in a THP-1-SCC13 3D model. Finally, CD271 activity synergizes with Trk receptor inhibition, by reducing spheroid viability, and significantly improves the outcome of photodynamic therapy (PTD) or chemotherapy in spheroids and zebrafish.

CONCLUSION

Our study provides evidence that CD271 could prevent the switch between low to high-risk cSCC tumors. Because CD271 contributes to maintaining active differentiative paths and favors the response to therapies, it might be a promising target for future pharmaceutical development.

COVID-19 and Cutaneous Squamous Cell Carcinoma-Impact of the Pandemic on Unequal Access to Healthcare

Most skin tumors are not fatal, but if not treated in a timely manner, they can lead to significant morbidity. Due to the COVID-19 pandemic and in order to create more capacities for the treatment of COVID-19-positive patients as well as to contain the spread of the virus, the healthcare system was reorganized worldwide, leading to decreased access to preventive screening programs. The aim of this study was to evaluate the impact of the pandemic on healthcare accessibility to cutaneous squamous cell carcinoma patients in Serbia. This retrospective study was conducted at the Clinic for Burns, Plastic, and Reconstructive Surgery, University Clinical Center of Serbia in Belgrade. Patient demographics and pathohistological findings of tumors of patients living in and outside the capital in the period before, during, and after the pandemic were compared. The two groups did not show any differences regarding the largest tumor diameter prior and during the pandemic; however, this difference became extremely noticeable after the pandemic (15 mm vs. 27 mm; p < 0.001). While cSCCs are commonly slow-growing tumors, the impact of the COVID-19 pandemic is not negligible. This study found a population at a significant risk of cSCC metastasis, with additional evidence likely to emerge in the upcoming years.

Systemic Photoprotection in Melanoma and Non-Melanoma Skin Cancer

Non-melanoma skin cancers (NMSCs), which include basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and actinic keratosis (AK), are the most common cancer diseases in the Caucasian race. If diagnosed late and improperly treated, BCC and SCC can become locally advanced and metastasize. Malignant melanoma (MM) is less frequent but more lethal than NMSC. Given the individual and social burdens of skin cancers, performing an adequate prevention is needed. Ultraviolet (UV) ray exposure is one of the main risk factors for skin cancer. Thus, the first-choice prevention strategy is represented by photoprotection that can be both topical and systemic. The latter consists of the oral administration of molecules which protect human skin against the damaging effects of UV rays, acting through antioxidant, anti-inflammatory, or immunomodulator mechanisms. Although several compounds are commonly used for photoprotection, only a few molecules have demonstrated their effectiveness in clinical trials and have been included in international guidelines for NMSC prevention (i.e., nicotinamide and retinoids). Moreover, none of them have been demonstrated as able to prevent MM. Clinical and preclinical data regarding the most common compounds used for systemic photoprotection are reported in this review, with a focus on the main mechanisms involved in their photoprotective properties.

Involvement of necroptosis in the selective toxicity of the natural compound (±) gossypol on squamous skin cancer cells in vitro

Cutaneous basal and squamous cell carcinoma reflect the first and second most common type of non-melanoma skin cancer, respectively. Especially cutaneous squamous cell carcinoma has the tendency to metastasize, finally resulting in a rather poor prognosis. Therapeutic options comprise surgery, radiation therapy, and a systemic or targeted chemotherapy. There are some good treatment results, but overall, the response rate of newly developed drugs is still modest. Drug repurposing represents an alternative approach where already available and clinically approved substances are used, which originally intended for other clinical benefits. In this context, we tested the effect of the naturally occurring polyphenolic aldehyde (±) gossypol with concentrations between 1 and 5 µM on the invasive squamous cell carcinoma cell line SCL-1 and normal human epidermal keratinocytes. Gossypol treatment up to 96 h resulted in a selective cytotoxicity of SCL-1 cells (IC50: 1.7 µM, 96 h) compared with normal keratinocytes (IC50: ≥ 5.4 µM, 96 h) which is mediated by mitochondrial dysfunction and finally leading to necroptotic cell death. Taken together, gossypol shows a high potential as an alternative anticancer drug for the treatment of cutaneous squamous cell carcinoma.

Endoglin and squamous cell carcinomas

Despite the fact that the role of endoglin on endothelial cells has been extensively described, its expression and biological role on (epithelial) cancer cells is still debatable. Especially its function on squamous cell carcinoma (SCC) cells is largely unknown. Therefore, we investigated SCC endoglin expression and function in three types of SCCs; head and neck (HNSCC), esophageal (ESCC) and vulvar (VSCC) cancers. Endoglin expression was evaluated in tumor specimens and 14 patient-derived cell lines. Next to being expressed on angiogenic endothelial cells, endoglin is selectively expressed by individual SCC cells in tumor nests. Patient derived HNSCC, ESCC and VSCC cell lines express varying levels of endoglin with high interpatient variation. To assess the function of endoglin in signaling of TGF-β ligands, endoglin was overexpressed or knocked out or the signaling was blocked using TRC105, an endoglin neutralizing antibody. The endoglin ligand BMP-9 induced strong phosphorylation of SMAD1 independent of expression of the type-I receptor ALK1. Interestingly, we observed that endoglin overexpression leads to strongly increased soluble endoglin levels, which in turn decreases BMP-9 signaling. On the functional level, endoglin, both in a ligand dependent and independent manner, did not influence proliferation or migration of the SCC cells. In conclusion, these data show endoglin expression on individual cells in the tumor nests in SCCs and a role for (soluble) endoglin in paracrine signaling, without directly affecting proliferation or migration in an autocrine manner.

Comparative Study of Digital Squamous Cell Carcinoma in Giant, Standard, and Miniature Schnauzers

In schnauzers, a breed predisposition to squamous cell carcinoma of the digit (dSCC) is well known. The aim of this study was to compare the clinical and macroscopic findings of dSCCs in giant (GSs), standard (SSs), and miniature schnauzers (MSs).

METHODS

Pathology reports of 478 dSCCs from 417 schnauzers (227 GSs, 174 SSs, and 16 MSs) were retrospectively evaluated.

RESULTS

The MSs were older than the SSs and GSs (p ≤ 0.01). The male GSs were predisposed to dSCC (p < 0.05). In the GSs, the nodular dSCCs were larger than in the MSs (p ≤ 0.05) and SSs (p ≤ 0.001). The digital SCCs were mostly diagnosed at the forelimbs, especially at digits 1, 2, and 5. At the hindlimbs, the affected toes differed between the GSs and SSs. Multiple dSCCs were more common in SSs than in GSs (p = 0.003). If dSCC was the cause of death, the survival time was shorter than in dogs dying from other diseases (p = 0.004). Metastases occurred in 20% of the cases and led to a significantly shorter survival time in both the GSs and SSs (p < 0.001).

CONCLUSIONS

The results showed various differences in the dSCC depending on the size variant of the schnauzer.

Non-Melanoma Skin Cancer and Vitamin D: The "Lost Sunlight" Paradox and the Oxidative Stress Explanation

UV radiation (UVR) is responsible for inducing both harmful and beneficial effects on skin health. Specifically, it has been reported to disrupt oxidant and antioxidant levels, leading to oxidative stress conditions in skin tissue. This phenomenon might trigger photo-carcinogenesis, resulting in melanoma, NMSC (non-melanoma skin cancer), such as BCC (basal cell carcinoma) and SCC (squamous cell carcinoma), and actinic keratosis. On the other hand, UVR is essential for the production of adequate vitamin D levels, a hormone with important antioxidant, anticancer and immunomodulatory properties. The exact mechanisms implicated in this two-fold action are not well understood, as there still no clear relation established between skin cancer and vitamin D status. Oxidative stress seems to be a neglected aspect of this complex relation, despite its role in both skin cancer development and vitamin D deficiency. Therefore, the aim of the present study is to examine the correlation between vitamin D and oxidative stress in skin cancer patients. A total of 100 subjects (25 with SCC, 26 with BCC, 23 with actinic keratosis, and 27 controls) were assessed in terms of 25-hydroxyvitamin D (25(OH) D) and redox markers such as thiobarbituric acid reactive substances (TBARS), protein carbonyls, total antioxidant capacity (TAC) in plasma, glutathione (GSH) levels and catalase activity in erythrocytes. The majority of our patients revealed low vitamin D levels; 37% of the subjects showed deficiency (<20 ng/mL) and 35% insufficiency (21-29 ng/mL). The mean 25(OH) D level of the NMSC patients (20.87 ng/mL) was also found to be significantly lower (p = 0.004) than that of the non-cancer patients (28.14 ng/mL). Furthermore, higher vitamin D levels were also correlated with lower oxidative stress (positive correlation with GSH, catalase activity TAC index and negative correlation with TBARS and CARBS indices). NMSC patients diagnosed with SCC showed lower catalase activity values compared to non-cancer patients (p < 0.001), with the lowest values occurring in patients with a chronic cancer diagnosis (p < 0.001) and vitamin D deficiency (p < 0.001). Higher GSH levels (p = 0.001) and lower TBARS levels (p = 0.016) were found in the control group compared to the NMSC group, and to patients with actinic keratosis. Higher levels of CARBS were observed in patients with SCC (p < 0.001). Non-cancer patients with vitamin D sufficiency showed higher TAC values compared to non-cancer patients with vitamin D deficiency (p = 0.023) and to NMSC patients (p = 0.036). The above-mentioned results indicate that NMSC patients reveal increased levels of oxidative damage markers compared to control levels, while vitamin D status plays a critical role in the determination of individuals' oxidative status.

Network Biology-Inspired Machine Learning Features Predict Cancer Gene Targets and Reveal Target Coordinating Mechanisms

Anticipating and understanding cancers' need for specific gene activities is key for novel therapeutic development. Here we utilized DepMap, a cancer gene dependency screen, to demonstrate that machine learning combined with network biology can produce robust algorithms that both predict what genes a cancer is dependent on and what network features coordinate such gene dependencies. Using network topology and biological annotations, we constructed four groups of novel engineered machine learning features that produced high accuracies when predicting binary gene dependencies. We found that in all examined cancer types, F1 scores were greater than 0.90, and model accuracy remained robust under multiple hyperparameter tests. We then deconstructed these models to identify tumor type-specific coordinators of gene dependency and identified that in certain cancers, such as thyroid and kidney, tumors' dependencies are highly predicted by gene connectivity. In contrast, other histologies relied on pathway-based features such as lung, where gene dependencies were highly predictive by associations with cell death pathway genes. In sum, we show that biologically informed network features can be a valuable and robust addition to predictive pharmacology models while simultaneously providing mechanistic insights.

Inguinal Squamous Cell Carcinoma Presenting as a Marjolin Ulcer in the Absence of Mesh Infection: A Case Report

Inguinal hernias are the most common type of hernias, and most are repaired surgically with mesh placement to prevent future reoccurrence. Mesh infection and hernia recurrence are some of the rare complications of mesh placement, and chronic mesh infections increase the risk of squamous cell carcinoma at the site. Squamous cell carcinoma (SCC) in the setting of a mesh infection presents in a similar manner to a Marjolin ulcer and is treated with the removal of the tumor and degraded infected mesh. However, in this case, the patient presented atypically with an absence of mesh involvement. This report aims to explore the etiology of SCC due to mesh infections as well as describe the perplexing case of inguinal SCC in the absence of mesh involvement.