Invasive Cutaneous Squamous Cell Carcinoma Research Articles

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.

Diagnosis of invasive cutaneous squamous cell carcinoma, imaging and staging.

The assessment of patients with a lesion raising the suspicion of an invasive cutaneous squamous cell carcinoma (cSCC) is a frequent clinical scenario. The management of patients with cSCC is a multistep approach, starting with the correct diagnosis. The two main diagnostic goals are to differentiate from other possible diagnoses and correctly recognize the lesion as cSCC, and then to determine the tumor spread (perform staging), that is if the patient has a common primary cSCC or a locally advanced cSCC, or a metastatic cSCC (with in-transit, regional lymph nodal, or rarely distant metastasis). The multistep diagnostic approach begins with the clinical characteristics of the primary cSCC, it is complemented with features with dermoscopy and, if available, reflectance confocal microscopy and is confirmed with histopathology. The tumor spread is assessed by physical examination and, in some cases, ultrasound and/or computed tomography or magnetic resonance imaging, mainly to investigate for regional lymph node metastasis or for local infiltration into deeper structures. In the last step, the clinical, histologic and radiologic findings are incorporated into staging systems.

Therapeutic and fluorescence evaluation of 20% 5-aminolevulinic acid-mediated photodynamic therapy in actinic keratosis

BackgroundActinic keratosis (AK) is a precancerous lesion that occurs in areas that are chronically exposed to sunlight and has the potential to develop into invasive cutaneous squamous cell carcinoma (cSCC). We investigated the efficacy of 20 % 5-aminolevulinic acid-photodynamic therapy (ALA-PDT) with LED red light for the treatment of AK in Chinese patients by examining changes in dermoscopic features, histopathology and fluorescence after treatment. MethodsTwenty-eight patients with fourty-six AK lesions from March 2022 to September 2023 were treated with 20 % ALA, and 3 h later, they were irradiated with LED red light (80–100 mW/cm2) for 20 min. A session of 20 % ALA-PDT was performed once a week for three consecutive weeks, and the dermoscopic, histopathological, fluorescent and photoaging outcomes were measured one week after the treatment. ResultsOne week after ALA-PDT, complete remission (CR) was reached in 53.6 % of patients. The CR of Grade I AK lesions was 100 %, that of Grade II lesions was 71.4 %, and that of Grade III lesions was 38.1 %. There was a significant improvement in the dermoscopic features, epidermal thickness and fluorescence of the AK lesions. The presence of red fluorescence decreased, and there was an association between CR and post-PDT fluorescence intensity. ALA-PDT also exhibited efficacy in treating photoaging, including fine lines, sallowness, mottled pigmentation, erythema, and telangiectasias, and improved the global score for photoaging. There were no serious adverse effects during or after ALA-PDT, and 82.1 % of the patients were satisfied with the treatment. ConclusionAK lesions can be safely and effectively treated with 20 % ALA-PDT with LED red light, which also alleviates photoaging in Chinese patients, including those with multiple AKs. This study highlights the possibility that fluorescence could be used to diagnose AK with peripheral field cancerization and evaluate the efficacy of ALA-PDT.

Advancements in elucidating the pathogenesis of actinic keratosis: present state and future prospects.

Solar keratosis, also known as actinic keratosis (AK), is becoming increasingly prevalent. It is a benign tumor that develops in the epidermis. Individuals with AK typically exhibit irregular, red, scaly bumps or patches as a result of prolonged exposure to UV rays. These growths primarily appear on sun-exposed areas of the skin such as the face, scalp, and hands. Presently, dermatologists are actively studying AK due to its rising incidence rate in the United States. However, the underlying causes of AK remain poorly understood. Previous research has indicated that the onset of AK involves various mechanisms including UV ray-induced inflammation, oxidative stress, complex mutagenesis, resulting immunosuppression, inhibited apoptosis, dysregulated cell cycle, altered cell proliferation, tissue remodeling, and human papillomavirus (HPV) infection. AK can develop in three ways: spontaneous regression, persistence, or progression into invasive cutaneous squamous cell carcinoma (cSCC). Multiple risk factors and diverse signaling pathways collectively contribute to its complex pathogenesis. To mitigate the risk of cancerous changes associated with long-term UV radiation exposure, prompt identification, management, and prevention of AK are crucial. The objective of this review is to elucidate the primary mechanisms underlying AK malignancy and identify potential treatment targets for dermatologists in clinical settings.

Intralesional Treatments for Invasive Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most frequent cancer in humans and has the potential to progress locally, metastasize, and cause death in a subset of patients. cSCC is especially common in the elderly, and it will probably represent a major health concern in the near future. Surgery is the standard treatment for cSCC, but intralesional therapies can sometimes be considered for certain patients and under certain circumstances. The choice of intralesional treatment depends on the patient's characteristics and the clinician's previous experience and expertise. Here we are reviewing intralesional treatments for cSCC and keratoacanthoma (KA). We have started with some classic drugs, such as methotrexate and 5-fluorouracil, bleomycin, interferon, and cryosurgery, but also comment on electrochemotherapy. Finally, we have focused on novel therapies, some of which are under development, and future perspectives, including intralesional immunotherapy and oncolytic viruses.

Cutaneous squamous cell carcinoma tumor accrual rates in immunosuppressed patients with autoimmune and inflammatory conditions: A retrospective cohort study

Immunosuppression is a known risk factor for the development of cutaneous squamous cell carcinoma (CSCC), especially in solid organ transplant recipients and chronic lymphocytic leukemia. However, this risk is less well defined in autoimmune and inflammatory conditions. Assess the impact that disease-type, duration of immunosuppression, and systemic medications have on CSCC accrual rates, defined as the number of CSCCs a patient develops per year, in autoimmune and inflammatory conditions. Retrospective review of 94 immunosuppressed (rheumatoid arthritis: 31[33.0%], inflammatory bowel disease: 17[18.1%], psoriasis: 11[11.7%], autoimmune other (AO): 24[25.5%], inflammatory other: 21[22.3%]) and 188 immunocompetent controls to identify all primary, invasive CSCCs diagnosed from 2010 to 2020. Immunosuppressed patients had higher CSCC accrual rates than immunocompetent controls (0.44±0.36): total cohort (0.82±0.95, P<.01), rheumatoid arthritis (0.88±1.10, P<.01), inflammatory bowel disease (0.94±0.88, P<.01), psoriasis (1.06±1.58, P<.01), AO (0.72±0.56, P<.01), and inflammatory other (0.72±0.61, P<.01). There was an association between increased tumor accrual rates and exposure to systemic medications including, immunomodulators, tumor necrosis factor-alpha inhibitors, non-tumor necrosis factor inhibitor biologics, and corticosteroids, but not with number of systemic medication class exposures or duration of immunosuppression. Retrospective, singlecenter study. Patients with autoimmune and inflammatory conditions accrue CSCCs at higher rates than immunocompetent patients.

Extensive Perineural Invasion vs Nerve Caliber to Assess Cutaneous Squamous Cell Carcinoma Prognosis

Perineural invasion (PNI) is an adverse risk feature in cutaneous squamous cell carcinoma (CSCC) that affects patient prognosis and disease management. However, research comparing different PNI patterns on patient outcomes is limited. To compare 4 assessments of PNI in CSCC, their associations with poor outcomes, and implications for their inclusion in the Brigham and Women's Hospital (BWH) staging system. This retrospective cohort study was performed at a single tertiary care institution and compared 4 PNI assessments: nerve caliber, number of involved nerves per section, PNI maximal depth, and PNI location with respect to tumor. Patients with primary, localized, invasive CSCC with PNI diagnosed between January 1, 2000, and December 31, 2017, were identified via an electronic in-house database. Available pathology slides were secondarily reviewed by study authors. Relevant patient and tumor characteristics and outcomes were abstracted from the medical record. Data analysis was performed between September 6 and October 20, 2022. Risks of recurrence, disease-specific death, and a composite end point (any poor outcome) were calculated via multivariable stepwise Fine and Gray competing-risks regression. Considered revisions to the BWH staging system were assessed via receiver operating characteristic curves and test characteristics. This study included 140 patients with CSCC, with a mean (SD) age of 75.1 (11.2) years. More than half of the patients were men (93 [66.4%]), and most identified as White (132 [94.3%]). Of the 4 PNI assessments studied, only involvement of multiple nerves was associated with poor outcomes. Perineural invasion of 5 or more distinct nerves (extensive PNI [ePNI]) was independently associated with local recurrence (subhazard ratio [SHR], 13.83 [95% CI, 3.50-54.62]; P < .001), disease-specific death (SHR, 6.20 [95% CI, 1.59-24.21]; P = .009), and any poor outcome (SHR, 10.21 [95% CI, 2.88-36.15]; P < .001). A revised BWH staging system with substitution of ePNI for large-caliber PNI resulted in improved area under the curve and test characteristics compared with current BWH staging criteria that use nerve caliber as the measure of PNI. The findings of this cohort study suggest that ePNI is the best prognostic measure of PNI. Because ePNI obviated the need for a micrometer and had superior prognostic capacity to nerve caliber in this cohort, ePNI should be considered for inclusion in CSCC tumor staging. Inclusion of ePNI as a high-risk factor in CSCC staging systems may optimize patient selection for primary treatment and adjuvant interventions.

Driver gene combinations dictate cutaneous squamous cell carcinoma disease continuum progression

The molecular basis of disease progression from UV-induced precancerous actinic keratosis (AK) to malignant invasive cutaneous squamous cell carcinoma (cSCC) and potentially lethal metastatic disease remains unclear. DNA sequencing studies have revealed a massive mutational burden but have yet to illuminate mechanisms of disease progression. Here we perform RNAseq transcriptomic profiling of 110 patient samples representing normal sun-exposed skin, AK, primary and metastatic cSCC and reveal a disease continuum from a differentiated to a progenitor-like state. This is accompanied by the orchestrated suppression of master regulators of epidermal differentiation, dynamic modulation of the epidermal differentiation complex, remodelling of the immune landscape and an increase in the preponderance of tumour specific keratinocytes. Comparative systems analysis of human cSCC coupled with the generation of genetically engineered murine models reveal that combinatorial sequential inactivation of the tumour suppressor genes Tgfbr2, Trp53, and Notch1 coupled with activation of Ras signalling progressively drives cSCC progression along a differentiated to progenitor axis. Taken together we provide a comprehensive map of the cSCC disease continuum and reveal potentially actionable events that promote and accompany disease progression.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma: Part 2. Treatment–Update 2023

In order to update recommendations on treatment, supportive care, education, and follow-up of patients with invasive cutaneous squamous cell carcinoma (cSCC), a multidisciplinary panel of 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 Organisation of Research and Treatment of Cancer (EORTC) was formed. Recommendations were based on an evidence-based literature review, guidelines, and expert consensus. Treatment recommendations are presented for common primary cSCC (low risk, high risk), locally advanced cSCC, regional metastatic cSCC (operable or inoperable), and distant metastatic cSCC. For common primary cSCC, the first-line treatment is surgical excision with postoperative margin assessment or micrographically controlled surgery. Achieving clear surgical margins is the most important treatment consideration for patients with cSCCs amenable to surgery. Regarding adjuvant radiotherapy for patients with high-risk localised cSCC with clear surgical margins, current evidence has not shown significant benefit for those with at least one high-risk factor. Radiotherapy should be considered as the primary treatment for non-surgical candidates/tumours. For cSCC with cytologically or histologically confirmed regional nodal metastasis, lymph node dissection is recommended. For patients with metastatic or locally advanced cSCC who are not candidates for curative surgery or radiotherapy, anti-PD-1 agents are the first-line systemic treatment, with cemiplimab being the first approved systemic agent for advanced cSCC by the Food and Drugs Administration/European Medicines Agency. Second-line systemic treatments for advanced cSCC, include epidermal growth factor receptor inhibitors (cetuximab) combined with chemotherapy or radiotherapy. Multidisciplinary board decisions are mandatory for all patients with advanced cSCC, considering the risks of toxicity, the age and frailty of patients, and co-morbidities, including immunosuppression. Patients should be engaged in informed, shared decision-making on management and be provided with the best supportive care to improve symptom management and quality of life. The frequency of follow-up visits and investigations for subsequent new cSCC depends on underlying risk characteristics.

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.

Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 transfection of guide RNA targeting on MMP9 as anti-cancer therapy in human cutaneous squamous cell carcinoma cell line A431.

Cutaneous squamous cell carcinoma (SCC) is the second most common form of skin malignancy, representing around 20% of all skin cancers. It is the main cause of death due to non-melanoma skin cancer every year. Metastatic cutaneous SCC is associated with poor prognosis in patients and warrants a more effective and specific approach such as disruption of genes associated with cancer metastasis. Matrix metalloproteinases (MMPs) are enzymes involved in cancer progression and are regarded as major oncotargets. Among others, MMP9 plays critical roles in tumour progression, angiogenesis, and invasion of cutaneous SCC. We aimed to determine whether the MMP9 gene is a suitable gene target for anti-cancer therapy for cutaneous SCC. We performed clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 transfection of guide RNA (gRNA) targeting the MMP9 gene into human cutaneous SCC cell line A431. Following CRISPR transfection treatment, the viability (p < 0.01) and migratory activities (p < 0.0001) of in vitro cutaneous SCC cells were found to be reduced significantly. The use of quantitative polymerase chain reaction (qPCR) also revealed downregulation of the mRNA expression levels of cancer-promoting genes TGF-β, FGF, PI3K, VEGF-A, and vimentin. Direct inhibition of the MMP9 gene was shown to decrease survivability and metastasis of cutaneous SCC cell line A431. Our findings provided direct evidence that MMP9 is important in the viability, proliferation, and metastasis of cutaneous SCC cells. It serves as a positive foundation for future CRISPR-based targeted anti-cancer therapies in treating skin cancer and other forms of malignancies that involve MMPs as the key determinants.

Seasonal variation in diagnosis of cutaneous invasive melanoma and cutaneous squamous cell carcinoma: A nationwide study in the Netherlands

BackgroundCurrently, there is no study that has reported on the seasonal trends of skin cancer in the Netherlands. This study aimed to investigate seasonal variation in diagnosis of cutaneous melanoma (CM) and cutaneous squamous cell carcinoma (cSCC) focusing on different subgroups. MethodsCM diagnosed from 2001 till 2019 and cSCCs from 2001 till 2015 were selected from the Netherlands Cancer Registry. The monthly distribution of CM and cSCC diagnoses were evaluated. Summer-to-winter ratios (SWRs) were calculated overall and stratified by patient and tumour characteristics. ResultsSignificant increases in melanoma incidence were noted over the summer months (SWR 1.39 (CI 1.37–1.40)). This increase was less apparent for cSCCs, as higher incidence rates were observed in the months September-November (SWR 1.13 (CI 1.12–1.14)). The seasonal variation of CM was greater in women and younger people, in superficial spreading melanoma and lentigo maligna melanoma, for the extremities, in thinner lesions, and for stage I at diagnosis. The seasonal variation of cSCC was similar for both sexes, most marked in patients 45‐69 and ≥ 70, and for the extremities. ConclusionsOur findings showed a pronounced seasonal variation in the diagnosis of CM with a peak in the summer months. For cSCC, no evident peak was observed, but an increase in diagnosis was noted in fall. Both CM and cSCC showed strong seasonal effects for the extremities.

From Bowen disease to cutaneous squamous cell carcinoma: eight markers were verified from transcriptomic and proteomic analyses

BackgroundBowen's disease is a cutaneous squamous cell carcinoma (CSCC) in situ. If left untreated, BD may progress to invasive CSCC. CSCC is one of the most common cutaneous carcinoma in the elderly and the advanced, metastasis CSCC usually have a poor outcomes. However, the mechanisms of invasion and metastasis from Bowen’s disease to CSCC is complicated and still unclear.ObjectivesThe aim of this study was to explore the biomarkers and molecular alterations in Bowen’s disease development process via analyzing the proteomics changes in tissues of CSCC, Bowen disease and healthy skin.MethodsA total of 7 individuals with CSCC (5 for proteomics study and 2 for validation), 7 individuals with Bowen disease (5 for proteomics study and 2 for validation) and 7 healthy controls (5 for proteomics study and 2 for validation) presented to the Department of Dermatology, Yijishan Hospital, the First Affiliated Hospital of Wannan Medical College between January 2021 and December 2021 were enrolled. The proteomics analysis was performed to screen differentially expressed proteins/gens (DEPs/DEGs) in the lesions of CSCC, Bowen disease and healthy skin tissues. The transcriptomic data (GSE32628) of CSCC was selected and downloaded from the GEO database. The common DEGs in our proteomics results and GSE32628 between CSCC and healthy skin tissues were selected. And then, the common DEGs which significantly up or down-regulated between CSCC and Bowen disease in our proteomics results were further screened to identify using Western blot methods in the validation group. CSCC A431 cells were transfected with SERPINB1 small interfering RNA (si-SERPINB1) or small interfering RNA negative control (si-NC). To explore the effect of SERPINB1 silencing on migration and invasion ability of A431 cells.ResultsA total of 501 proteins were differentially expressed between the CSCC and healthy skin tissues, with 332 up-regulated and 169 down-regulated at least 1.5-fold with a P value < 0.05. These DEPs involved multiple biological functions such as protein binding process, immune, inflammation, ribosome, protein digestion and absorption, ECM-receptor interaction, focal adhesion, PI3K-Akt signaling pathway and others. A total of 20 common DEGs (COL3A1, LUM, TNC, COL1A1, ALDH3A2, FSCN1, SERPINB4, SERPINB1, CD36, COL4A1, CSTB, GPX3, S100A7, ACTN1, SERPINB3, S100A8, RAB31, STAT1, SPRR1B, S100A9) between CSCC and healthy skin tissues in GSE32628 and our proteomics results were found. Besides, the proteins of TNC, FSCN1, SERPINB1, ACTN1 and RAB31 in CSCC were significantly up-regulated, while COL3A1, COL1A1 and CD36 were significantly down-regulated relative to Bowen disease in proteomics results. These proteins were mainly involved in multiple pathways, including Focal adhesion, ECM-receptor interaction, Human papillomavirus infection, PI3K-Akt signaling pathway, PPAR signaling pathway, AMPK signaling pathway and others. These eight proteins were selected for further validation. According to the Western blotting analysis, when compared with the Bowen disease and healthy skin tissues, we found that the relative expression levels of TNC, FSCN1, SERPINB1, ACTN1 and RAB31 in the CSCC were significantly increased, while COL1A1 and CD36 were significantly decreased, and the differences were statistically significant (P < 0.05). Furthermore, the relative expression levels of TNC, FSCN1, SERPINB1 in the Bowen disease were also significantly increased, while the COL3A1 were also significantly decreased relative to the healthy control. SERPINB1 siRNA inhibited the expression of SERPINB1 at mRNA and protein levels in the A431 cells. After interfering with the expression of SERPINB1, the migration and invasion ability in the A431 cells were significantly decreased (P < 0.05).ConclusionsThis study highlights that eight proteins, TNC, FSCN1, SERPINB1, ACTN1, RAB31, COL3A1, COL1A1, CD36, were significantly associated with the mechanisms of invasion and metastasis in Bowen’s disease.

Acitretin enhances the cytotoxic effect of 5-aminolevulinic acid photodynamic therapy on squamous cell carcinoma cells

The efficacy of 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) on invasive cutaneous squamous cell carcinoma (cSCC) remains to be improved due to the limited penetration of this treatment. Previous study showed that acitretin and ALA-PDT had synergistic effect on cSCC, but whether acitretin can enhance the cytotoxic effect of ALA-PDT on cSCC is unclear. ObjectiveTo investigate whether acitretin can enhance the cytotoxic effect of ALA-PDT on SCL-1 cells, as well as the possible mechanism involved. MethodsInverted microscopy, trypan blue exclusion assay, and flow cytometry were used to studied the morphology, viability and apoptosis of SCL-1 cells treated with acitretin, ALA-PDT and acitretin followed by ALA-PDT treatment, respectively. Confocal microscopy was applied to detect the ROS formation of SCL-1 cells treated with acitretin of four different concentrations. The ROS formation of SCL-I cells treated with acitretin of four different concentrations followed by ALA-PDT treatment was detected using confocal microscopy and flow cytometry. ResultsSCL-1 cells exhibited a significant morphological alteration when treated with acitretin followed by ALA-PDT. The combination of acitretin and ALA-PDT induced a higher cell death rate and apoptosis than that with acitretin or ALA-PDT treatment alone. ROS could be induced when incubated with acitretin at a concentration of 6.4 × 10−4mg /mL or above. However, a higher level of ROS formation was observed when SCL-1 cells were treated with acitretin followed by ALA-PDT than that with ALA-PDT or acitretin alone. ConclusionAcitretin can enhance the cytotoxic effect of ALA-PDT on SCL-1 cells, possibly via the ROS pathway.

Limited impact of COVID-19-related diagnostic delay on cutaneous melanoma and squamous cell carcinoma tumour characteristics: a nationwide pathology registry analysis.

BackgroundThe COVID‐19 pandemic reduced the number of skin cancer diagnoses, potentially causing a progression to unfavourable tumour stages.ObjectivesTo identify the impact of delayed diagnostics on primary invasive melanoma and cutaneous squamous cell carcinoma (cSCC) by comparing tumour (pT) stage, Breslow thickness and invasion depth from before to after the first and second lockdown periods.MethodsIn this population‐based cohort study, histopathology reports registered between 1 January 2018 and 22 July 2021 were obtained from the nationwide histopathology registry in the Netherlands. The Breslow thickness of melanomas, invasion depth of cSCCs, and pT stage for both tumour types were compared across five time periods: (i) pre‐COVID, (ii) first lockdown, (iii) between first and second lockdowns, (iv) second lockdown and (v) after second lockdown. Breslow thickness was compared using an independent t‐test. pT‐stage groups were compared using a χ2‐test. Outcomes were corrected for multiple testing using the false discovery rate.ResultsIn total, 20 434 primary invasive melanomas and 68 832 cSCCs were included in this study. The mean primary melanoma Breslow thickness of the prepandemic era (period i) and the following time periods (ii–v) showed no significant difference. A small shift was found towards unfavourable pT stages during the first lockdown compared with the pre‐COVID period: pT1 52·3% vs. 58·6%, pT2 18·9% vs. 17·8%, pT3 13·2% vs. 11·0%, pT4 9·1% vs. 7·3% (P = 0·001). No relevant changes were seen in subsequent periods. No significant change in pT stage distribution was observed between the pre‐COVID (i) and COVID‐affected periods (ii–v) for cSCCs.ConclusionsTo date, the diagnostic delay caused by COVID‐19 has not resulted in relatively more unfavourable primary tumour characteristics of melanoma or cSCC. Follow‐up studies in the coming years are needed to identify a potential impact on staging distribution and survival in the long term.

Risk of Invasive Cutaneous Squamous Cell Carcinoma After Different Treatments for Actinic Keratosis

Treatment of actinic keratosis (AK) aims to prevent cutaneous squamous cell carcinoma (cSCC). However, whether AK can progress into invasive cSCC is a matter of debate, and little is known about the effect of treatment on preventing cSCC. To evaluate the risk of invasive cSCC and factors that may contribute to increased risk in patients with multiple AKs. In this secondary analysis of a multicenter randomized clinical trial, 624 patients with a minimum of 5 AKs within an area of 25 to 100 cm2 on the head were recruited from the Department of Dermatology of 4 hospitals in the Netherlands. Long-term follow-up was performed from July 1, 2019, to December 31, 2020. Patients were randomized to treatment with 5% fluorouracil, 5% imiquimod cream, methylaminolevulinate photodynamic therapy, or 0.015% ingenol mebutate gel. The primary outcome was the proportion of patients with invasive cSCC in the target area during follow-up. Secondary outcomes were the associations between risk of invasive cSCC and a priori defined potential prognostic factors, including type of treatment, severity of AK (Olsen grade), history of nonmelanoma skin cancer, and additional treatment. Of the 624 patients (558 [89.4%] male; median age, 73 years [range, 48-94 years]) in the study, 26 were diagnosed with a histologically proven invasive cSCC in the target area during follow-up. The total 4-year risk of developing cSCC in a previously treated area of AK was 3.7% (95% CI, 2.4%-5.7%), varying from 2.2% (95% CI, 0.7%-6.6%) in patients treated with fluorouracil to 5.8% (95% CI, 2.9%-11.3%) in patients treated with imiquimod. In patients with severe AK (Olsen grade III), the risk was 20.9% (95% CI, 10.8%-38.1%), and the risk was especially high (33.5%; 95% CI, 18.2%-56.3%) in patients with severe AK who needed additional treatment. In this secondary analysis of a randomized clinical trial, risk of invasive cSCC was highest in patients with Olsen grade III AK and was substantially increased in patients who received additional treatment. These patients should be closely followed up after treatment. ClinicalTrials.gov Identifier: NCT02281682.

Digital Image Analysis-Based Evaluation of Claudin-1 and Claudin-7 Delocalization in Cutaneous Squamous Cell Carcinoma and in Its Precancerous State.

Accumulating evidence has revealed that delocalization of the transmembrane proteins, Claudin-1 and Claudin-7, to the cytoplasm and/or nucleus occurs in various tumors. However, their subcellular distribution in terms of the membrane, cytoplasm, and nucleus and relationship with signaling pathways have not been elucidated during carcinogenesis. We first determined the expression of these proteins in the membrane, cytoplasm, and nucleus using ImageJ software and automatically collected the immunohistochemical quantification of dysplasia (actinic keratosis (AK)), carcinoma in situ (CIS; Bowen's disease (BD)), and invasive cutaneous squamous cell carcinoma (SCC) for digital image analysis (DIA). The activity of p-ERK, p-AKT, and p-mTOR and their correlation with subcellular Claudin-1 and Claudin-7 were also performed. Finally, we validated Claudin-1 and Claudin-7 delocalization at the cytoplasm and nucleus in cultured human normal keratinocytes and cutaneous SCC cells. Claudin-1 and Claudin-7 were delocalized as revealed by membranous, cytoplasmic, and nuclear staining in sun-exposed skin, AK, BD, and SCC. In BD, both membranous and cytoplasmic Claudin-1 (nuclear Claudin-1 decrease but no significant difference) were higher than AK, while Claudin-7 almost had the opposite situation. In SCC, cytoplasmic and nuclear Claudin-1 (membranous Claudin-1 no significant difference) was lower than in AK and sun-exposed skin, while Claudin-7 had higher membranous and cytoplasmic but lower nuclear expression. Moreover, p-AKT and p-mTOR (but not p-ERK) were downregulated in the SCC. Subcellular Claudin-1 and Claudin-7 were not only correlated with each other, but also correlated with p-ERK in BD and p-AKT and p-mTOR in SCC. Together, these results imply the delocalization of Claudin-1 and Claudin-7 and their correlation with MAPK/ERK and PI3K-AKT-mTOR signaling pathways in tumorigenesis and infiltration in cutaneous SCC.

Aberrant epigenetic regulation of RARβ by TET2 is involved in cutaneous squamous cell carcinoma resistance to retinoic acid

With the growing incidence of cutaneous squamous cell carcinoma (CSCC), the treatment-resistant invasive CSCC should be taken seriously. Retinoic acid receptor β (RARβ) functions as a tumor suppressor gene and is associated with the proliferation inhibition to retinoic acid. Demethylase TET2 directed epigenetic landscape contributes to cell malignant transform and is involved in therapeutic resistance in tumors. Whether aberrant TET2 participated in the deficient RARβ remains largely unknown. Hereby, we identified the aberrant-TET2 directed epigenetic landscape contribute to the deficient RARβ in CSCC. The immunohistochemistry was used to detect the expression of RARβ and TET2. The bisulfite sequencing PCR was used to detect the RARβ promoter methylation. Plasmid transfection was used to upregulate TET2 in CSCC cells. Stable overxpressed TET2 cells were used to detect the effect of TET2 on RARβ and drug sensitivity in the CCSC. We observed RARβ decreased with promoter hypermethylation in CSCC and aberrant TET2 associated with deficient RARβ. We upregulated TET2 could reverse promoter hypermethylation and showed a significantly increased expression of RARβ, which enhanced the sensitivity of tumor cells to retinoic acid treatment. Aberrant TET2 leaded to the hypermethylation of RARβ promoter, which contributed to the deficient RARβ in CSCC. While reversing the hypermethylation of the RARβ promoter by recovering the TET2 could enhance tumor cells to be sensitive to retinoic acid.

A Review of Existing Therapies for Actinic Keratosis: Current Status and Future Directions.

Actinic keratosis (AK) is a chronic skin disease in which clinical and subclinical cutaneous lesions coexist on sun-exposed areas such as the head and neck region and the extremities. The high prevalence of AK means the disease burden is substantial, especially in middle-aged and elderly populations. Evidence indicates that AK may progress into invasive cutaneous squamous cell carcinoma, so the European guidelines recommend treatment of any AK regardless of clinical severity. Given the aging population and therefore the increasing incidence of AK and cutaneous field carcinogenesis, further updates on the long-term efficacy of current therapies and new investigational agents are critical to guide treatment choice. Patients often have difficulty adequately applying topical treatments and coping with adverse local skin reactions, leading to less than optimum treatment adherence. The development of associated local skin symptoms and cosmetic outcomes for the area of interest are also relevant to the choice of an appropriate therapeutic strategy. Treatment is always individually tailored according to the characteristics of both patients and lesions. This review focuses on the therapeutic approaches to AK and illustrates the currently available home-based and physician-managed treatments.

Neutrophil-to-lymphocyte ratio is associated with survival and sentinel lymph node positivity in invasive cutaneous squamous cell carcinoma: A retrospective study

The neutrophil-to-lymphocyte ratio (NLR) is a known prognostic biomarker for survival and is predictive of sentinel lymph node (SLN) positivity in some cancers. However, its usefulness as a prognostic biomarker for cutaneous squamous cell carcinoma (cSCC) has not been fully investigated. Our objective was to investigate the relationship between the NLR and the disease-specific survival and SLN positivity in patients with cSCC. In this single-center retrospective case series, we analyzed patients with cSCC who underwent blood tests prior to the initiation of treatment at our oncology hospital. The relationship between the patients' clinical characteristics (including the NLR) and the disease-specific survival and SLN positivity was evaluated using univariate and multivariate analyses. An elevated NLR was an independent prognostic factor for poor disease-specific survival and a predictive factor for SLN positivity. Limitations include the small number of participants and selection bias due to the large proportion of high-risk cases in our patient population. NLR is a useful biomarker in cSCC because it is simple to measure and can predict prognosis.