Update on Keratinocyte Carcinomas

Applications and challenges of photodynamic therapy in the treatment of skin malignancies

Photodynamic Therapy (PDT), as a minimally invasive treatment method, has demonstrated its distinct advantages in the management of skin malignant tumors. This article examines the current application status of PDT, assesses its successful cases and challenges in clinical treatment, and anticipates its future development trends. PDT utilizes photosensitizers to interact with light of specific wavelengths to generate reactive oxygen species that selectively eradicate cancer cells. Despite PDT's exceptional performance in enhancing patients' quality of life and prognosis, the limitation of treatment depth and the side effects of photosensitizers remain unresolved issues. With the advancement of novel photosensitizers and innovative treatment technology, the application prospects of PDT are increasingly expansive. This article delves into the mechanism of PDT, its application in various skin malignancies, its advantages and limitations, and envisions its future development. We believe that through continuous technological enhancements and integration with other treatment technologies, PDT has the potential to assume a more pivotal role in the treatment of skin malignancies.

A phase 2 open-label study of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (EMPOWER-CSCC-1): Final long-term analysis of groups 1, 2, and 3, and primary analysis of fixed-dose treatment group 6

BACKGROUND

In the phase 2 EMPOWER-CSCC-1 study (NCT02760498), cemiplimab demonstrated antitumor activity against metastatic cutaneous squamous cell carcinoma (mCSCC) and locally advanced cutaneous squamous cell carcinoma (laCSCC).

OBJECTIVES

To report final analysis of weight-based cemiplimab in mCSCC and laCSCC (groups 1 and 2), fixed-dose cemiplimab in mCSCC (group 3), and primary analysis of fixed-dose cemiplimab in mCSCC/laCSCC (group 6).

METHODS

Patients received cemiplimab (3 mg/kg intravenously every 2 weeks [groups 1 and 2]) or cemiplimab (350 mg intravenously [groups 3 and 6]) every 3 weeks. The primary end point was objective response rate (ORR). Duration of response (DOR) and progression-free survival (PFS) are presented per protocol, according to post-hoc sensitivity analyses that only include the period of protocol-mandated imaging assessments.

RESULTS

At 42.5 months, ORR for groups 1-3 (n = 193) was 47.2%, estimated 12-month DOR was 88.3%, and median PFS was 26.0 months. At 8.7 months, ORR for group 6 (n = 165 patients) was 44.8%; median DOR and median PFS were not reached. Serious treatment-emergent adverse event rates (grade ≥3) were groups 1-3: 31.1% and group 6: 34.5%.

LIMITATIONS

Nonrandomized study, nonsurvival primary end point.

CONCLUSION

EMPOWER-CSCC-1 provides the largest prospective data on long-term efficacy and safety for anti-programmed cell death-1 therapy in advanced CSCC.

Prospective Randomized Study on the Use of Sentinel Node Biopsy for High-risk Cutaneous Squamous Cell Carcinomas of the Head and Neck

Background

The use of sentinel lymph node biopsy (SLNB) for high-risk cutaneous squamous cell carcinoma (CSCC) is not yet clearly documented, especially for the head and neck area, due to its rich and cross-branching lymphatic system. We present the first prospective randomized study on the use of SLNB in high-risk CSCCs of the head and neck.

Methods

Seventy-six patients with high-risk CSCCs of the head and neck were randomly divided into two groups: A (n = 38) and B (n = 38). In group A, SLNB was performed additionally to the excision of squamous cell carcinoma, whereas in group B, only excision of the lesion was performed. The patients were followed up for 5 years postoperatively, and local recurrences, regional metastases (regional lymph nodes), and mortality were documented.

Results

One patient of group A, who never attended any follow-up, was excluded. Both groups had similar characteristics regarding Breslow thickness, perineurial invasion, peripheral limits, differentiation, size, previous incomplete excision, age, sex, education, sun exposure, Fitzpatrick score, previous incomplete excision, previous skin cancer, and smoking. Two patients had a positive sentinel lymph node and were submitted to regional lymphadenectomy. We documented deaths (three in group A and two in group B; P = 0.674), local recurrence (seven in group A and six in group B; P = 0.768), and regional metastasis (zero in group A and two in group B; P = 0.159).

Conclusion

There is no clear benefit on the use of SLNB in high-risk CSCCs of the head and neck regarding metastasis, mortality, or local recurrence control.

Genetic evolution of keratinocytes to cutaneous squamous cell carcinoma

We performed multi-omic profiling of epidermal keratinocytes, precancerous actinic keratoses, and squamous cell carcinomas to understand the molecular transitions during skin carcinogenesis. Single-cell mutational analyses showed that most keratinocytes in normal skin had lower mutation burdens than melanocytes and fibroblasts, however keratinocytes with TP53 or NOTCH1 mutations had substantially higher mutation burdens, suggesting that these mutations prime keratinocytes for transformation by increasing their mutation rate. Mutational profiling and spatial transcriptomics on squamous cell carcinomas adjacent to actinic keratoses revealed TERT promoter and CDKN2A mutations emerging in actinic keratoses, whereas additional mutations inactivating ARID2 and activating the MAPK-pathway delineated the transition to squamous cell carcinomas. Spatial variation in gene expression patterns was common in both tumor and immune cells, with high expression of checkpoint molecules at the invasive front of tumors. In conclusion, this study documents key events during the evolution of cutaneous squamous cell carcinoma.

Emerging Indications for Neoadjuvant Systemic Therapies in Cutaneous Malignancies

Patients with cutaneous malignancies and locoregional involvement represent a high-risk population for disease recurrence, even if they receive optimal surgery and adjuvant treatment. Here, we discuss how neoadjuvant therapy has the potential to offer significant advantages over adjuvant treatment, further improving outcomes in some patients with skin cancers, including melanoma, Merkel cell carcinoma, and cutaneous squamous-cell carcinoma. Both preclinical studies and in vivo trials have demonstrated that exposure to immunotherapy prior to surgical resection can trigger a broader and more robust immune response, resulting in increased tumor cell antigen presentation and improved targeting by immune cells, potentially resulting in superior outcomes. In addition, neoadjuvant approaches hold the possibility of providing a platform for evaluating pathological responses in the resected lesion, optimizing the prognosis and enabling personalized adaptive management, in addition to expedited drug development. However, more data are still needed to determine the ideal patient selection and the best treatment framework and to identify reliable biomarkers of treatment responses. Although there are ongoing questions regarding neoadjuvant treatment, current data support a paradigm shift toward considering neoadjuvant therapy as the standard approach for selecting patients with high-risk skin tumors.

Clustering of RNA co-expression network identifies novel long non-coding RNA biomarkers in squamous cell carcinoma

Long non-coding RNAs (lncRNAs) have emerged as important players in cancer progression. Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer with increasing incidence worldwide. The prognosis of the metastatic cSCC is poor, and currently there are no established biomarkers to predict metastasis risk or specific therapeutic targets for advanced or metastatic cSCC. To elucidate the role of lncRNAs in cSCC, RNA sequencing of patient derived cSCC cell lines and normal human epidermal keratinocytes was performed. The correlation analysis of differentially expressed lncRNAs and protein-coding genes revealed six distinct gene clusters with one of the upregulated clusters featuring genes associated with cell motility. Upregulation of the expression of lncRNAs linked to cSCC cell motility in cSCC and head and neck SCC (HNSCC) cells was confirmed using qRT-PCR. Elevated expression of HOTTIP and LINC00543 was also noted in SCC tumors in vivo and was associated with poorer prognosis in HNSCC and lung SCC cohorts within TCGA data, respectively. Altogether, these findings uncover a novel set of lncRNAs implicated in cSCC cell locomotion. These lncRNAs may serve as potential novel biomarkers and as putative therapeutic targets for locally advanced and metastatic cSCC.

PTGES2 and RNASET2 identified as novel potential biomarkers and therapeutic targets for basal cell carcinoma: insights from proteome-wide mendelian randomization, colocalization, and MR-PheWAS analyses

Introduction

Basal cell carcinoma (BCC) is the most common skin cancer, lacking reliable biomarkers or therapeutic targets for effective treatment. Genome-wide association studies (GWAS) can aid in identifying drug targets, repurposing existing drugs, predicting clinical trial side effects, and reclassifying patients in clinical utility. Hence, the present study investigates the association between plasma proteins and skin cancer to identify effective biomarkers and therapeutic targets for BCC.

Methods

Proteome-wide mendelian randomization was performed using inverse-variance-weight and Wald Ratio methods, leveraging 1 Mb cis protein quantitative trait loci (cis-pQTLs) in the UK Biobank Pharma Proteomics Project (UKB-PPP) and the deCODE Health Study, to determine the causal relationship between plasma proteins and skin cancer and its subtypes in the FinnGen R10 study and the SAIGE database of Lee lab. Significant association with skin cancer and its subtypes was defined as a false discovery rate (FDR) < 0.05. pQTL to GWAS colocalization analysis was executed using a Bayesian model to evaluate five exclusive hypotheses. Strong colocalization evidence was defined as a posterior probability for shared causal variants (PP.H4) of ≥0.85. Mendelian randomization-Phenome-wide association studies (MR-PheWAS) were used to evaluate potential biomarkers and therapeutic targets for skin cancer and its subtypes within a phenome-wide human disease category.

Results

PTGES2, RNASET2, SF3B4, STX8, ENO2, and HS3ST3B1 (besides RNASET2, five other plasma proteins were previously unknown in expression quantitative trait loci (eQTL) and methylation quantitative trait loci (mQTL)) were significantly associated with BCC after FDR correction in the UKB-PPP and deCODE studies. Reverse MR showed no association between BCC and these proteins. PTGES2 and RNASET2 exhibited strong evidence of colocalization with BCC based on a posterior probability PP.H4 >0.92. Furthermore, MR-PheWAS analysis showed that BCC was the most significant phenotype associated with PTGES2 and RNASET2 among 2,408 phenotypes in the FinnGen R10 study. Therefore, PTGES2 and RNASET2 are highlighted as effective biomarkers and therapeutic targets for BCC within the phenome-wide human disease category.

Conclusion

The study identifies PTGES2 and RNASET2 plasma proteins as novel, reliable biomarkers and therapeutic targets for BCC, suggesting more effective clinical application strategies for patients.

Multidisciplinary patient-centered approach to the management of skin cancer

In recent years, new approaches for optimal patient management of cancer have focused on patient-centered care, with integration of tumour-directed treatment and patient-directed supportive and palliative care throughout the disease journey from prevention through screening, diagnosis, treatment, and follow-up. In 2022, at the International Forum of Dermatology (IFD), a scientific session was entirely dedicated to highlight recent developments on patient-centered approaches in skin cancer. An international panel of different groups of participants involved in a patient's journey on the management of skin cancer presented and discussed challenges and barriers that persist in the field of skin cancer prevention and care pathways. Although primary prevention remains a crucial step in the prevention of melanoma, the different surveys performed during the last 20 years demonstrate that the use of sunscreen increases very slowly. Secondary prevention that includes skin screening and diagnostic measures may benefit from the development of digital tools. To improve adherence, patients need accurate, reliable information about their disease and the treatment options, and this type of content that can also be made available on digital tools. Shared decision-making is a hallmark of a patient-centered approach and requires health care providers who can communicate well to patients and their families, underscoring the pivotal role of health care professionals all through the patient journey. Health care providers have a crucial role in supporting patients through their journey in skin cancer. They will benefit from mobile apps and technologies that have been developed recently to address challenges in skin cancer prevention, detection and care, including those that are primarily directed to the patient. However, more peer-reviewed studies are needed as well as regulations to ensure that apps are accurate, reliable, and up to date.

Phase II, Single-Arm Trial of Induction and Concurrent Vismodegib With Curative-Intent Radiation Therapy for Locally Advanced, Unresectable Basal Cell Carcinoma

PURPOSE

Locally advanced, unresectable basal cell carcinoma (LA BCC) can be treated with radiation therapy (RT), but locoregional control (LRC) rates are unsatisfactory. Vismodegib is a hedgehog pathway inhibitor (HPI) active in BCC that may radiosensitize BCC. We evaluated the combination of vismodegib and RT for patients with LA BCC.

METHODS

In this multicenter, single-arm, phase II study, patients with unresectable LA BCC received 12 weeks of induction vismodegib, followed by 7 weeks of concurrent vismodegib and RT. The primary end point was LRC rate at 1 year after the end of treatment. Secondary end points included objective response, progression-free survival (PFS), overall survival (OS), safety, and patient-reported quality of life (PRQOL).

RESULTS

Twenty-four patients received vismodegib; five were unable to complete 12 weeks of induction therapy. LRC was achieved in 91% (95% CI, 68 to 98) of patients at 1 year. The response rate was 63% (95% CI, 38 to 84) after induction vismodegib and 83% (95% CI, 59 to 96) after concurrent vismodegib and RT. With a median follow-up of 5.7 years, 1-year PFS and OS rates were 100% and 96%, and at 5 years PFS and OS rates were 78% and 83%, respectively. Distant metastasis or BCC-related death has not been observed. The most frequent treatment-related adverse events (AEs) were dysgeusia, fatigue, and myalgias occurring in 83%, 75%, and 75% of patients. No grade 4 to 5 treatment-related AEs occurred. PRQOL demonstrated clinically meaningful improvements in all subscales, with emotions and functioning improvements persisting for a year after the end of treatment.

CONCLUSION

In patients with unresectable LA BCC, the combination of vismodegib and RT yielded high rates of LRC and PFS and durable improvements in PRQOL.

Multidisciplinary Approach to Melanoma: A Case Report on Below-Knee Amputation and Lymph Node Dissection

A 65-year-old male presented with progressive swelling and difficulty in walking due to a right foot sprain. Initial treatments were conducted in Chandrapur, followed by referral to Acharya Vinoba Bhave Rural Hospital for further evaluation and management. The patient, a known case of diabetes mellitus and hypertension, reported an insidious onset of right foot swelling over two months. A physical examination revealed stable vital signs; no significant abnormalities were observed during the systemic examination. Laboratory investigations indicated mild anemia and slightly elevated liver enzymes. Imaging studies, including MRI and CT scan, identified an ill-defined lesion on the medial aspect of the right foot, consistent with dermatofibroma. The patient underwent a below-knee amputation with inguinal lymph node dissection on 31st May 2024. The procedure, performed under spinal and epidural anesthesia, involved meticulous dissection and ligation, with the posterior flap sutured using Ethilon 2-0 (Ethicon, Cincinnati, OH, USA). Post-operative management included IV antibiotics and supportive care. The patient's postoperative course was uneventful, with a healthy suture line and stable vitals upon discharge. Histopathological evaluation of the resected specimen confirmed melanoma, with immunohistochemistry revealing HMB-45 and S-100 negativity. The patient was discharged with advice on local hygiene, physiotherapy, dietary recommendations, and a follow-up schedule. This case highlights the importance of comprehensive multidisciplinary management in treating malignancies complicated by chronic conditions. Early diagnosis, appropriate surgical intervention, and diligent post-operative care are crucial for favorable outcomes in complex oncological cases.

Neoadjuvant Immunotherapy in Non-melanoma Skin Cancers of the Head and Neck

OPINION STATEMENT

Neoadjuvant immunotherapy will change the standard of care for advanced resectable cutaneous squamous cell carcinoma (cSCC) and possibly other non-melanoma skin cancers. With pathological complete response rates around 50% for cSCC in early studies, neoadjuvant therapy allows patients the possibility of significant reduction in tumor size, de-escalation of adjuvant therapy, and improved long-term outcomes. Patients must be carefully selected to ensure that there is a margin of safety with respect to resectability, such that if a tumor progresses on neoadjuvant therapy, there remains a curative surgical option that is acceptable to the patient. The optimal treatment paradigm is an area of active research, with many researchers questioning whether adjuvant therapy, or even local therapy, is necessary in patients who seem to have a complete response. The ability to predict who will respond will become even more critical to answer, as a significant number of patients do not want to risk their disease progressing, especially in cosmetically sensitive areas of the head and neck. Recent studies in melanoma show promise for improved response rates using combination therapies, and these strategies may apply to cSCC as well. The use of LAG-3 inhibitors or mRNA vaccine technology may further improve the utility of neoadjuvant strategies.

Cancer cell plasticity defines response to immunotherapy in cutaneous squamous cell carcinoma

Immune checkpoint blockade (ICB) approaches have changed the therapeutic landscape for many tumor types. However, half of cutaneous squamous cell carcinoma (cSCC) patients remain unresponsive or develop resistance. Here, we show that, during cSCC progression in male mice, cancer cells acquire epithelial/mesenchymal plasticity and change their immune checkpoint (IC) ligand profile according to their features, dictating the IC pathways involved in immune evasion. Epithelial cancer cells, through the PD-1/PD-L1 pathway, and mesenchymal cancer cells, through the CTLA-4/CD80 and TIGIT/CD155 pathways, differentially block antitumor immune responses and determine the response to ICB therapies. Accordingly, the anti-PD-L1/TIGIT combination is the most effective strategy for blocking the growth of cSCCs that contain both epithelial and mesenchymal cancer cells. The expression of E-cadherin/Vimentin/CD80/CD155 proteins in cSCC, HNSCC and melanoma patient samples predicts response to anti-PD-1/PD-L1 therapy. Collectively, our findings indicate that the selection of ICB therapies should take into account the epithelial/mesenchymal features of cancer cells.

C1s targeting antibodies inhibit the growth of cutaneous squamous carcinoma cells

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer. The incidence of cSCC is increasing globally and the prognosis of metastatic disease is poor. Currently there are no specific targeted therapies for advanced or metastatic cSCC. We have previously shown abundant expression of the complement classical pathway C1 complex components, serine proteases C1r and C1s in tumor cells in invasive cSCCs in vivo, whereas the expression of C1r and C1s was lower in cSCCs in situ, actinic keratoses and in normal skin. We have also shown that knockdown of C1s expression results in decreased viability and growth of cSCC cells by promoting apoptosis both in culture and in vivo. Here, we have studied the effect of specific IgG2a mouse monoclonal antibodies TNT003 and TNT005 targeting human C1s in five primary non-metastatic and three metastatic cSCC cell lines that show intracellular expression of C1s and secretion of C1s into the cell culture media. Treatment of cSCC cells with TNT003 and TNT005 significantly inhibited their growth and viability and promoted apoptosis of cSCC cells. These data indicate that TNT003 and TNT005 inhibit cSCC cell growth in culture and warrant further investigation of C1s targeted inhibition in additional in vitro and in vivo models of cSCC.

Neoadjuvant Photodynamic Therapy: An Updated Therapeutic Approach for Non-Melanoma Skin Cancers

OPINION STATEMENT

Non-melanoma skin cancers (NMSCs) are the most common malignancy and surgical excision is considered treatment of choice for the majority of cases. However, surgery can be very extensive in cases of large, multiple, or cosmetic-sensitive tumors located on areas such as scalp and face or genital region, leading to significant functional and cosmetic deficit. Aminolaevulinic acid photodynamic therapy (ALA-PDT) has emerged as a widely used approach in a variety of skin diseases, demonstrating remarkable efficacy in treatment of actinic keratosis, Bowen disease and basal cell carcinoma. Besides, when employed as a preoperative intervention, ALA-PDT effectively reduces tumor size and minimizes subsequent local surgical morbidity. With its minimally invasive nature and proven effectiveness, ALA-PDT holds significant promise as a neoadjuvant treatment option for NMSCs. In cases where the tumor is large, invasive, multiple, or located in cosmetically and functionally sensitive areas, or when considering patient factors such as age, comorbidity, willingness to undergo surgery, and post-operative quality-of-life, surgical intervention or radiotherapy alone may be impracticable or unacceptable. In such scenarios, neoadjuvant ALA-PDT can offer remarkable outcomes. In order to further ensure the maximum benefit of patients from neoadjuvant PDT, collaboration with multidisciplinary teams and whole-process management may be in need.

European consensus-based interdisciplinary guideline for diagnosis, treatment and prevention of actinic keratoses, epithelial UV-induced dysplasia and field cancerization on behalf of European Association of Dermato-Oncology, European Dermatology Forum, European Academy of Dermatology and Venereology and Union of Medical Specialists (Union Européenne des Médecins Spécialistes)

A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology, the European Dermatology Forum, the European Academy of Dermatology and Venereology, and the European Union of Medical Specialists was formed to develop European recommendations on AK diagnosis and treatment, based on current literature and expert consensus. This guideline addresses the epidemiology, diagnostics, risk stratification and treatments in immunocompetent as well as immunosuppressed patients. Actinic keratoses (AK) are potential precursors of cutaneous squamous cell carcinoma (cSCC) and display typical histopathologic and immunohistochemical features of this malignancy in an early stage. They can develop into cSSC in situ and become invasive in a low percentage of cases. AK is the most frequent neoplasia in white populations, frequently occurring within a cancerous field induced by ultraviolet radiation. Since it cannot be predicted, which lesion will progress to cSCC and when treatment is usually recommended. The diagnosis of AK and field cancerization is made by clinical examination. Dermatoscopy, confocal microscopy, optical coherence tomography or line-field confocal-OCT can help in the differential diagnosis of AK and other skin neoplasms. A biopsy is indicated in clinically and/or dermatoscopically suspicious and/or treatment-refractory lesions. The choice of treatment depends on patients' and lesion characteristics. For single non-hyperkeratotic lesions, the treatment can be started upon patient's request with destructive treatments or topical treatments. For multiple lesions, field cancerization treatment is advised with topical treatments and photodynamic therapy. Preventive measures such as sun protection, self-examination and repeated field cancerization treatments of previously affected skin areas in high-risk patients are advised.

Changes in mouse epidermal DNA methylation during development of squamous cell carcinoma in response to UVR

Squamous cell carcinoma (SCC) is a common skin cancer, often caused by exposure to ultraviolet radiation (UVR). Recent studies have shown that changes in DNA methylation play a crucial role in the development of cancers. However, methylation patterns of SCC are not well characterised. Identifying biomarkers for the risk of developing SCC could be helpful for early detection and diagnosis and can potentially improve treatment and prevention strategies. This study aimed to investigate methylation changes in the epidermis of mice exposed to UVR for 24 weeks. We examined the DNA methylation levels of 260 199 CpGs using the Illumina Infinium Mouse Methylation BeadChip and studied the epidermis of UVR-exposed and unexposed mice every 4 weeks for 24 weeks (n = 39). We identified CpGs with large differences in methylation levels (β-values) between UVR-exposed and unexposed mice. We also observed differences in the epigenetic age of these mice. We identified CpGs in Rev, Ipmk, Rad51b, Fgfr2, Fgfr3 and Ctnnb1 that may serve as potential biomarkers for SCC risk and could be helpful for the early detection and prevention of SCC. Further investigations are necessary to determine the biological functions and clinical significance of these CpGs.

Personalized treatment concepts in extraocular cancer

Background

The periocular skin is neoplasms-prone to various benign and malignant. Periocular malignancies are more aggressive and challenging to cure and repair than those in other skin areas. In recent decades, immunotherapy has significantly advanced oncology, allowing the autoimmune system to target and destroy malignant cells. Skin malignancies, especially periocular tumors, are particularly sensitive to immunotherapy. This technique has dramatically impacted the successful treatment of challenging tumors.

Main text

Extraocular cancers, including eyelid (basal cell carcinoma, squamous cell carcinoma, melanoma, merkel cell carcinoma), conjunctival tumors (conjunctival melanoma, ocular surface squamous neoplasia) and other rare tumors, are unique and challenging clinical situations. Several genetic alterations associated with the pathogenesis of these diseases have been identified, and molecular mechanism are essential for the development of the immunotherapy agents, such as Hedgehog pathway inhibitors (vismodegib and sonidegib) for basal cell carcinoma, BRAF/MEK inhibitors (vemurafenib, dabrafenib, and encorafenib) for melanoma, and immune checkpoint inhibitors (Avelumab, pembrolizumab) for Merkel cell carcinoma.

Conclusions

The optimal treatment for periocular skin cancer depends on the type and size of the tumor and whether it involves orbital and adnexal structures. Adjuvant and neoadjuvant therapy with chemotherapy-targeted therapies and immune checkpoint inhibitors should be considered based on tumor type, tumor molecular profile, expected response rate, and candidacy for systemic treatment.

Patient-Orientated Evaluation of Treatment of Non-Melanoma Skin Cancer with Rhenium-188 Compared to Surgery

BACKGROUND

Non-melanoma skin cancers (NMSCs) are responsible for up to one-third of all human malignancies. Surgery is usually the treatment of choice, but patients often experience pain during the procedure. Topical rhenium-188 resin skin cancer treatment (RSCT) may be a valid therapeutic alternative.

METHODS

In this monocentric pilot study, 19 patients suffering from NMSC were treated with RSCT. Most of these patients had also experienced surgery, either because they developed a new NMSC in aftercare, or they had suffered previously from NMSC. Three RSCT-treated patients, who had no exposure to surgery so far, were paired with three matched patients, who had received surgery. We sought to evaluate and compare the patients' experience with both treatments. A questionnaire assessed patients' perceptions regarding side effects, aesthetic outcomes, wound care, fear of complications, and personal treatment preferences. Patients evaluated the different parameters of their either RSCT- or surgery-treated lesions on a scale from 0-10.

RESULTS

Patients were more afraid of complications before surgery than before RSCT (p = 0.04). Treatment with RSCT caused significantly less pain on treatment day (mean 0.56) than surgery (mean 2.32) (0 no pain, 10 maximum pain) (p = 0.02) and 14 days after the procedure (mean 0.89 versus mean 2.47) (p = 0.02). On day 14, RSCT-treated lesions were also significantly less itchy (mean 0.34) than after surgery (mean 1.50). Most patients were very satisfied with the aesthetic outcome after both RSCT (mean 8.42) and surgery (mean 8.31) (p = 0.89). In the case of a new NMSC, the majority of patients who experienced both treatments would rather be treated primarily with RSCT (44%) or would consider both options (31%); only 19% preferred surgery.

CONCLUSION

Patients evaluated RSCT as less painful than surgery. The aesthetic outcomes of both treatments were comparable. For pain-sensitive patients, RSCT might be a preferable treatment option.

Efficacy of Combinational Treatment versus Nicotinamide Monotherapy in the Prevention of Ultraviolet Radiation-Induced Skin Cancer

INTRODUCTION

Ultraviolet radiation (UVR) is the primary risk factor for keratinocyte carcinomas. Oral supplementation with nicotinamide (NAM) is reported to reduce the formation of new keratinocyte carcinomas. NAM's photoprotection is mediated by enhanced DNA repair. We wanted to explore whether NAM in combination with antiproliferative (metformin [Met]) or antioxidant (phloroglucinol [PG]) compounds could potentially enhance its photoprotective effects.

METHODS

Hairless mice (C3.Cg-Hrhr/TifBomTac) were treated orally with either a standard dose of NAM monotherapy (NAM-mono; 600 mg/kg) or NAM (400 mg/kg) combined with Met (200 mg/kg) (NAM-Met) or PG (75 mg/kg) (NAM-PG). Mice were irradiated with 3.5 standard erythema doses of UVR three times per week to induce tumour development. Photoprotective effects were based on (i) tumour onset of the first three tumours, (ii) skin photodamage, and (iii) DNA damage (cyclobutane pyrimidine dimers [CPDs] and pyrimidine-pyrimidone (6-4) photoproducts [6-4PPs]).

RESULTS

All mice treated with NAM demonstrated a delay in tumour onset and reduced tumour burden compared to the UV control group (NAM, NAM-Met, NAM-PG vs. UV control: p ≤ 0.015). NAM-mono and NAM-PG increased time until all three tumours with no difference between them, indicating a similar degree of photoprotection. NAM-mono had no effect on DNA damage compared to the UV control group (p > 0.05), whereas NAM-PG reduced 6-4PP lesions (p < 0.01) but not CPDs (p > 0.05) compared to NAM-mono. NAM-Met delayed the onset of the third tumour compared to the UV control but demonstrated a quicker onset compared to NAM-mono, suggesting inferior photoprotection compared to nicotinamide monotherapy.

CONCLUSION

NAM-PG was as effective in delaying UVR-induced tumour onset as NAM-mono. The reduction in 6-4PP lesions may indicate that the mechanism of NAM-PG is better suited for photoprotection than NAM-mono. NAM-mono was superior to NAM-Met, indicating a dose dependency of NAM's photoprotection. These results highlight the potential for combining photoprotective compounds to enhance photoprotection.

Transglutaminase 3 regulates cutaneous squamous carcinoma differentiation and inhibits progression via PI3K-AKT signaling pathway-mediated Keratin 14 degradation

Cutaneous squamous carcinoma is the second most common epithelial malignancy, associated with significant morbidity, mortality, and economic burden. However, the mechanisms underlying cSCC remain poorly understood. In this study, we identified TGM3 as a novel cSCC tumor suppressor that acts via the PI3K-AKT axis. RT-qPCR, IHC and western blotting were employed to assess TGM3 levels. TGM3-overexpression/knockdown cSCC cell lines were utilized to detect TGM3's impact on epithelial differentiation as well as tumor cell proliferation, migration, and invasion in vitro. Additionally, subcutaneous xenograft tumor models were employed to examine the effect of TGM3 knockdown on tumor growth in vivo. Finally, molecular and biochemical approaches were employed to gain insight into the tumor-suppressing mechanisms of TGM3. TGM3 expression was increased in well-differentiated cSCC tumors, whereas it was decreased in poor-differentiated cSCC tumors. Loss of TGM3 is associated with poor differentiation and a high recurrence rate in patients with cSCC. TGM3 exhibited tumor-suppressing activity by regulating cell proliferation, migration, and invasion both in vitro and in vivo. As a novel cSCC tumor differentiation marker, TGM3 expression was positively correlated with cell differentiation. In addition, our results demonstrated an interaction between TGM3 and KRT14 that aids in the degradation of KRT14. TGM3 deficiency disrupts keratinocytes differentiation, and ultimately leads to tumorigenesis. Furthermore, RNA-sequence analysis revealed that loss of TGM3 enhanced EMT via the PI3K-AKT signaling pathway. Deguelin, a PI3K-AKT inhibitor, blocked cSCC tumor growth induced by TGM3 knockdown in vivo. Taken together, TGM3 inhibits cSCC tumor growth via PI3K-AKT signaling, which could also serve as a tumor differentiation marker and a potential therapeutic target for cSCC. Proposed model depicted the mechanism by which TGM3 suppress cSCC development. TGM3 reduces the phosphorylation level of AKT and degrades KRT14. In the epithelial cell layer, TGM3 exhibits a characteristic pattern of increasing expression from bottom to top, while KRT14 and pAKT are the opposite. Loss of TGM3 leads to reduced degradation of KRT14 and activation of pAKT, disrupting keratinocyte differentiation, and eventually resulting in the occurrence of low-differentiated cSCC.

Head and neck nonmelanoma skin cancers: surgical management and debated issues

PURPOSE OF REVIEW

This review critically assesses the current literature and guidelines, aiming to clarify some of the most important factors that impact surgical strategies of head and neck nonmelanoma skin cancers (NMSCs), focusing on squamous, basal, and Merkel cell carcinomas.

RECENT FINDINGS

Recent developments underscore the complexity of treatment for NMSC, particularly in the head and neck region. There is a lack of high-level evidence for the management of these tumors, especially in advanced stages. The need to tailor the extent of surgical margins and parotid/neck management to different histotypes, considering the varying risk factors for recurrence, is beginning to emerge in the literature. Moreover, the role of immunotherapy and targeted therapies for locally advanced disease, alongside traditional treatment options, is progressively growing.

SUMMARY

NMSCs represent a heterogeneous group of malignancies with varying treatment complexities and prognoses. Management of NMSC is evolving towards an increasingly personalized strategy within a multidisciplinary therapeutic framework.

Nanotechnology strategies to address challenges in topical and cellular delivery of siRNAs in skin disease therapy

Gene therapy is one of the most advanced therapies in current medicine. In particular, interference RNA-based therapy by small interfering RNA (siRNA) has gained attention in recent years as it is a highly versatile, selective and specific therapy. In dermatological conditions, topical delivery of siRNA offers numerous therapeutic advantages, mainly by inhibiting the expression of target transcripts directly in the skin. However, crossing the stratum corneum and overcoming intracellular barriers is an inherent challenge. Substantial efforts by scientists have moved towards the use of multimodal and multifunctional nanoparticles to overcome these barriers and achieve greater bioavailability in their site of action, the cytoplasm. In this review the most innovative strategies based on nanoparticle and physical methods are presented, as well as the design principles and the main factors that contribute to the performance of these systems. This review also highlights the synergistic contributions of medicine, nanotechnology, and molecular biology to advancing translational research into siRNA-based therapeutics for skin diseases.

A Comprehensive Review of Various Therapeutic Strategies for the Management of Skin Cancer

Skin cancer (SC) poses a global threat to the healthcare system and is expected to increase significantly over the next two decades if not diagnosed at an early stage. Early diagnosis is crucial for successful treatment, as the disease becomes more challenging to cure as it progresses. However, identifying new drugs, achieving clinical success, and overcoming drug resistance remain significant challenges. To overcome these obstacles and provide effective treatment, it is crucial to understand the causes of skin cancer, how cells grow and divide, factors that affect cell growth, and how drug resistance occurs. In this review, we have explained various therapeutic approaches for SC treatment via ligands, targeted photosensitizers, natural and synthetic drugs for the treatment of SC, an epigenetic approach for management of melanoma, photodynamic therapy, and targeted therapy for BRAF-mutated melanoma. This article also provides a detailed summary of the various natural drugs that are effective in managing melanoma and reducing the occurrence of skin cancer at early stages and focuses on the current status and future prospects of various therapies available for the management of skin cancer.

Management of periocular keratinocyte carcinomas with Mohs micrographic surgery and predictors of complex reconstruction: a retrospective study

BACKGROUND

Skin cancer is the most frequent cancer worldwide and the most frequent periocular tumor. Keratinocyte Carcinomas (KC) located in periorificial areas, such as periocular tumors, are considered high-risk tumors. Mohs Micrographic Surgery (MMS) is considered the first line for the treatment of high-risk KC, providing a lower recurrence rate than conventional wide excision.

OBJECTIVE

To describe the clinical-pathological features of periocular KC treated with MMS in a tertiary university center in Chile.

METHODS

A single-center, retrospective study of patients with KC located on the periocular area, that underwent MMS between 2017‒2022. MMS details were recorded.

RESULTS

One hundred thirteen patients with periocular carcinomas were included. The mean age was 59 ± 13 years; 52% were women. The most frequent location was the medial canthus (53%), followed by the lower eyelid (30.1%). The most frequent BCC histology was the nodular variant (59.3%). Regarding MMS, the average number of stages was 1.5 ± 0.7, and 54% of the cases required only 1 stage to achieve clear margins. To date, no recurrence has been reported. Tumors larger than 8.5 mm in largest diameter or 43.5 mm2 were more likely to require complex reconstruction.

STUDY LIMITATIONS

Retrospective design and a relatively low number of patients in the SCC group. Possible selection bias, as larger or more complex cases, may have been referred to oculoplastic surgeons directly.

CONCLUSION

The present study confirms the role of MMS for the treatment of periocular KCs. Periocular KCs larger than 8.5 mm might require complex reconstruction. These results can be used to counsel patients during pre-surgical visits.

Long noncoding RNA plasmacytoma variant translocation 1 is overexpressed in cutaneous squamous cell carcinoma and exon 2 is critical for its oncogenicity

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is one of the most common and fastest increasing forms of cancer worldwide with metastatic potential. Long noncoding RNAs (lncRNAs) are a group of RNA molecules with essential regulatory functions in both physiological and pathological processes.

OBJECTIVES

To investigate the function and mode of action of lncRNA plasmacytoma variant translocation 1 (PVT1) in cSCC.

METHODS

Quantitative reverse transcriptase polymerase chain reaction and single-molecule in situ hybridization were used to quantify the expression level of PVT1 in normal skin, premalignant skin lesions, actinic keratosis (AK) and primary and metastatic cSCCs. The function of PVT1 in cSCC was investigated both in vivo (tumour xenografts) and in vitro (competitive cell growth assay, 5-ethynyl-2'-deoxyuridine incorporation assay, colony formation assay and tumour spheroid formation assay) upon CRISPR-Cas9-mediated knockout of the entire PVT1 locus, the knockout of exon 2 of PVT1, and locked nucleic acid (LNA) gapmer-mediated PVT1 knockdown. RNA sequencing analysis was conducted to identify genes and processes regulated by PVT1.

RESULTS

We identified PVT1 as a lncRNA upregulated in cSCC in situ and cSCC, associated with the malignant phenotype of cSCC. We showed that the expression of PVT1 in cSCC was regulated by MYC. Both CRISPR-Cas9 deletion of the entire PVT1 locus and LNA gapmer-mediated knockdown of PVT1 transcript impaired the malignant behaviour of cSCC cells, suggesting that PVT1 is an oncogenic transcript in cSCC. Furthermore, knockout of PVT1 exon 2 inhibited cSCC tumour growth both in vivo and in vitro, demonstrating that exon 2 is a critical element for the oncogenic role of PVT1. Mechanistically, we showed that PVT1 was localized in the cell nucleus and its deletion resulted in cellular senescence, increased cyclin-dependent kinase inhibitor 1 (p21/CDKN1A) expression and cell cycle arrest.

CONCLUSIONS

Our study revealed a previously unrecognized role for exon 2 of PVT1 in its oncogenic role and that PVT1 suppresses cellular senescence in cSCC. PVT1 may be a potential biomarker and therapeutic target in cSCC.

Exploring the Functions of Mutant p53 through TP53 Knockout in HaCaT Keratinocytes

Approximately 50% of tumors carry mutations in TP53; thus, evaluation of the features of mutant p53 is crucial to understanding the mechanisms underlying cell transformation and tumor progression. HaCaT keratinocytes represent a valuable model for research in this area since they are considered normal, although they bear two gain-of-function mutations in TP53. In the present study, transcriptomic and proteomic profiling were employed to examine the functions of mutant p53 and to investigate the impact of its complete abolishment. Our findings indicate that CRISPR-mediated TP53 knockout results in significant changes at the transcriptomic and proteomic levels. The knockout of TP53 significantly increased the migration rate and altered the expression of genes associated with invasion, migration, and EMT but suppressed the epidermal differentiation program. These outcomes suggest that, despite being dysfunctional, p53 may still possess oncosuppressive functions. However, despite being considered normal keratinocytes, HaCaT cells exhibit oncogenic properties.

Favorable efficacy of S-1 treatment for locoregionally advanced cutaneous squamous cell carcinoma in the head and neck region

Cutaneous squamous cell carcinoma is usually treated with surgery; however, locoregionally advanced cutaneous squamous cell carcinoma can be difficult to resect. Although recent guidelines from Western countries recommend using anti-programmed cell death protein 1 (PD-1) antibodies, including cemiplimab and pembrolizumab, there are no approved anti-PD-1 antibodies for locoregional cutaneous squamous cell carcinoma in Asian countries. S-1 is an oral drug with a low incidence of severe toxicity that can be used for head and neck cancers, including head and neck locoregional cutaneous squamous cell carcinoma, in Japan. We retrospectively evaluated patients with head and neck locoregional cutaneous squamous cell carcinoma treated with S-1 at two Japanese institutions (2008-2022). The initial dosage was determined by the body surface area (<1.25 m2 : 80 mg/day, 1.25-1.5 m2 : 100 mg/day, ≥1.5 m2: 120 mg/day) for 28 consecutive days. The outcome measures were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). Fourteen patients were included. The ORR was 78%, and the complete response (CR) rate was 64.3%. The median PFS and OS were not reached (NR) (95% confidence interval [CI], 5.9 months-NR) and NR (95% CI, 13.8 months-NR), respectively. The 12-month PFS and OS rates were 51% and 85%, respectively. Six of the nine patients who achieved CR showed no recurrence during the follow-up period (median follow-up, 24.7 months). After CR, three patients experienced recurrence. Among these, two resumed S-1 treatment and subsequently underwent salvage surgery, resulting in a sustained absence of recurrence. One patient developed lung metastasis and died, although S-1 therapy was resumed. Only one patient (7.1%) developed grade 3 anemia. S-1 showed favorable efficacy and low toxicity in patients with head and neck locoregionally advanced cutaneous squamous cell carcinoma. S-1 may be a good alternative to the anti-PD-1 antibody for treating head and neck locoregionally advanced squamous cell carcinoma.

Targeting tumor-associated macrophages: Novel insights into immunotherapy of skin cancer

BACKGROUND

The incidence of skin cancer is currently increasing, and conventional treatment options inadequately address the demands of disease management. Fortunately, the recent rapid advancement of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has ushered in a new era for numerous cancer patients. However, the efficacy of immunotherapy remains suboptimal due to the impact of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs), a major component of the TME, play crucial roles in tumor invasion, metastasis, angiogenesis, and immune evasion, significantly impacting tumor development. Consequently, TAMs have gained considerable attention in recent years, and their roles have been extensively studied in various tumors. However, the specific roles of TAMs and their regulatory mechanisms in skin cancer remain unclear.

AIM OF REVIEW

This paper aims to elucidate the origin and classification of TAMs, investigate the interactions between TAMs and various immune cells, comprehensively understand the precise mechanisms by which TAMs contribute to the pathogenesis of different types of skin cancer, and finally discuss current strategies for targeting TAMs in the treatment of skin cancer.

KEY SCIENTIFIC CONCEPTS OF OVERVIEW

With a specific emphasis on the interrelationship between TAMs and skin cancer, this paper posits that therapeutic modalities centered on TAMs hold promise in augmenting and harmonizing with prevailing clinical interventions for skin cancer, thereby charting a novel trajectory for advancing the landscape of immunotherapeutic approaches for skin cancer.

Blood-based microRNAs as Potential Diagnostic Biomarkers for Melanoma: A Meta-Analysis

INTRODUCTION

Circulating microRNAs (miRNAs) serve as noninvasive diagnostic markers in many cancers. This meta-analysis aims to evaluate the diagnostic efficacy of circulating microRNAs for melanoma.

MATERIALS AND METHODS

The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and ROC curve were evaluated using the Meta-Disc V.1.4 and Comprehensive Meta-Analysis V.3.3 software packages. To investigate the heterogeneity, the I2 and Chi-square tests were used. The publishing bias was evaluated using Begg's rank correlation and Egger regression asymmetry tests.

RESULTS

A total of 9 articles covering 13 studies (more than 50 miRs individually and in combination) were included, containing 1,355 participants (878 cases and 477 controls). The overall pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and AUC were 0.78 (95% CI: 0.76-0.81), 0.80 (95% CI: 0.77-0.83), 4.32 (95% CI: 3.21-5.82), 0.17 (95% CI: 0.09-0.32), 28.0 (95% CI: 15.34-51.09), and 0.91, respectively. According to Begg's and Egger's tests, there was no publication bias (Begg's p = 0.160 and Egger's p = 0.289).

CONCLUSION

Circulating miRNAs can serve as fair and non-invasive diagnostic biomarkers for melanoma. Additionally, specific miRNAs still need to be discovered for diagnosing melanoma.

Advancements in Basal Cell Carcinoma Diagnosis: Non-Invasive Imaging and Multimodal Approach

(1) Background: The aim of this study was to correlate the diagnostic criteria described in dermatoscopy, ultrasonography (US), ex vivo confocal microscopy, and histology to the most common subtypes of basal cell carcinoma (BCC). (2) Methods: We conducted a prospective study including 46 BCC cases, which were analyzed with dermatoscopy using the Delta 30 dermatoscope and Vidix 4.0 videodermoscope, with US using a high-resolution 20 MHz linear probe, with confocal microscopy, along with histopathological analysis. (3) Results: This study categorized BCC by histological subtype, with nodular being the most common (84.8%) and various other subtypes represented. US measurements of tumor thickness correlated strongly with the histopathological depth of invasion index (DI). Dermatoscopy analysis revealed significant associations between specific features and BCC subtypes. The DI was directly related to arborized vessels but inversely related to short, fine telangiectasias, maple-leaf-like areas, and spoke-wheel areas. The presence of ulceration was directly related to the DI. Confocal microscopy images exhibited several characteristics, including fluorescence, nuclear crowding, peripheral palisading, clefting, increased nuclear-cytoplasmic (N/C) ratio, and a "cauliflower-like" appearance. (4) Conclusion: The advanced detection of BCC through imagistic techniques like dermatoscopy, confocal microscopy, and ultrasound improves the diagnosis and may offer valuable insights for treatment in the future by evaluating lesion characteristics.

Targeting Fatty Acid Amide Hydrolase Counteracts the Epithelial-to-Mesenchymal Transition in Keratinocyte-Derived Tumors

The endocannabinoid system regulates physiological processes, and the modulation of endogenous endocannabinoid (eCB) levels is an attractive tool to contrast the development of pathological skin conditions including cancers. Inhibiting FAAH (fatty acid amide hydrolase), the degradation enzyme of the endocannabinoid anandamide (AEA) leads to the increase in AEA levels, thus enhancing its biological effects. Here, we evaluated the anticancer property of the FAAH inhibitor URB597, investigating its potential to counteract epithelial-to-mesenchymal transition (EMT), a process crucially involved in tumor progression. The effects of the compound were determined in primary human keratinocytes, ex vivo skin explants, and the squamous carcinoma cell line A431. Our results demonstrate that URB597 is able to hinder the EMT process by downregulating mesenchymal markers and reducing migratory potential. These effects are associated with the dampening of the AKT/STAT3 signal pathways and reduced release of pro-inflammatory cytokines and tumorigenic lipid species. The ability of URB597 to contrast the EMT process provides insight into effective approaches that may also include the use of FAAH inhibitors for the treatment of skin cancers.

Quality of Life Before and After Radiation Therapy for Early-Stage Keratinocyte Carcinoma: A Longitudinal Analysis

PURPOSE

Little is known about patient-reported quality of life (QOL) before and after radiotherapy (RT) for early keratinocyte carcinoma (KC). The present study tested the hypothesis that QOL is hypothesized to deteriorate soon after RT, with subsequent improvement of a magnitude similar to other KC treatments.

METHODS AND MATERIALS

This observational study assessed prospectively collected longitudinal patient-reported QOL data at a single center. Patients undergoing external beam RT for early-stage (T0-2, <4 cm) KC that completed the Skindex-16 (S16) or Skin Cancer Index (SCI) before and at least once after RT were included. These indices include subscales of symptoms, emotions, and functioning for S16 and emotional, social, and appearance for SCI.

RESULTS

81 patients (median age 79 years) were treated for early KC, most being basal cell carcinomas (87%) on the face (80%) an average of 1.3 cm in diameter. Composite S16 scores and total SCI scores showed significant, clinically meaningful improvements at 3 months and 6 weeks after RT, respectively. QOL declined at 6 weeks after treatment on the S16 symptoms subscale. Concurrently, S16 and SCI emotional subscales significantly improved, and this trend persisted for 2+ years. Improvements in S16 functioning and SCI social and appearance QOL occurred after RT. The magnitude of improvement in QOL 3-12 months after RT was comparable to what has been previously reported after other types of KC treatments, like surgery.

CONCLUSIONS

QOL related to symptoms deteriorates during the first 6 weeks after RT for early KC, but it improves by 3 months. QOL related to emotions, functioning, social, and appearance all improve after RT. These changes in QOL are similar to those observed after other treatments of early KC.

Skin cancer prevention - Recent advances and unmet challenges

Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy in the world. Among many identified risk factors, immunosuppression is a major factor that contributes to cSCC development. Organ transplant recipients (OTRs) are at markedly increased risk of developing multiple cSCCs with a propensity for advanced metastatic disease, leading to significant morbidity and mortality. The severity of the cSCC phenotype in OTRs highlights the urgent need to identify effective preventive modalities in this population. Despite recent advances in skin cancer prevention (e.g., nicotinamide) and treatment (e.g., immune checkpoint blockade), these modalities have limited utility in OTRs due to the lack of efficacy or significant side effect. Topical treatments against precancerous skin lesions, actinic keratosis (AK), remain the primary strategy to prevent cSCC in OTRs, which also have significant deficiencies in this population. Herein, we review the epidemiology, risk factors, and current cSCC prevention strategies. We highlight the gaps and future clinical strategies to address cSCC risk in high-risk populations.

Inter-rater concordance of basal cell carcinoma subtypes: influences on reporting format and opportunities for further classification modifications

Diagnosis of basal cell carcinoma (BCC) higher risk subtypes influences management strategies because of their propensity to recur locally. Subtyping is prone to inter-observer variability, and subtyping definitions are inconsistently applied. This study sought to compare the interobserver reproducibility of individual BCC subtypes using the 4th edition World Health Organization (WHO) Classification of Skin Tumours (CoST) definitions, with classification into lower and higher risk histological subtype groups. Ninety-one BCC cases were rated by seven pathologists, noting the presence of BCC subtype(s), and providing a higher or lower risk subtype grouping per case. Raters were provided with definitions as per the 4th edition WHO CoST for 10 listed BCC subtypes. Surgical specimen type was noted. Subgroup analysis was performed to exclude cases when the tumour deep front was not well visualised, or there was tangential sectioning (n = 6). Light's kappa was used to assess inter-rater reliability. From the total group (n = 91), five BCC subtypes showed a sufficient number of ratings for computing a κ statistic. From these five subtypes, superficial subtype showed substantial inter-rater agreement (κ = 0.64), and the other four subtypes showed moderate inter-rater agreement [nodular (κ = 0.45), sclerosing/morphoeic (κ = 0.45), infiltrating (κ = 0.49) and micronodular (κ = 0.57)]. Two-tiered rating into either higher or lower risk subtype showed substantial inter-rater agreement (κ = 0.72). Our results suggest a need to more precisely define BCC subtypes. We suggest reporting BCC subtype using a two-tiered risk grouping, followed by specific subtypes present. Further studies examining the inter-rater reliability of less common BCC subtypes are required.

Topical 188Re Ionizing Radiation Therapy Exerts High Efficacy in Curing Nonmelanoma Skin Cancer

PURPOSE OF THE REPORT

Nonmelanoma skin cancer (NMSC) is the most frequent malignancy. Surgical intervention is the common treatment but may lead to disappointing results; alternative treatment options are needed.

METHODS

In this monocentric pilot study, topical 188Re resin was investigated as a treatment for invasive NMSC up to 3-mm thickness. Twenty-two patients with 40 histologically confirmed NMSCs with a median size of 1.25 cm2 (range, 0.04-16.8 cm2) and a median tumor thickness of 0.35 mm (range, 0.1-2.1 mm) were included. Patients were treated once with 188Re resin with a targeted dose of 50 Gy. The median applied activity was 111.4 MBq (range, 21.0-168.0 MBq), and the median treatment time was 89 minutes (range, 38-175 minutes). The response rate, adverse events, and cosmetic outcome were assessed at 14 days, 4 months, and 12 months.

RESULTS

Response rate at 12 months was 97.5%, with 95% complete responses (clinically or histologically proven in case of clinical doubt). Most adverse events were reported at 14 days, with 20% itching and 12.5% mostly minor pain. Forty-nine percent of the lesions showed hypopigmentation only at 12 months. Forty-one percent of the lesions were graded as cosmetically superior to the expected result after surgery and 51.3% as comparable to successful surgery. The cosmetic outcome on the head and face was superior compared with the trunk and leg (P = 0.003).

CONCLUSION

188Re resin is a highly effective treatment for NMSC up to 3-mm thickness and a valid alternative to surgery, specifically for tumors located on sensitive areas such as nose or ear.

Squamous carcinogenesis: potential truncal mutations

Squamous carcinogenesis is incompletely understood, but more recent genetic studies support that the order of acquired mutations is important. This paper will review more recent genetic studies with an emphasis on the potential truncal mutations, mutations critical to the trunk of the cancer evolutionary tree, in actinic keratosis, squamous cell carcinoma in situ, cutaneous squamous cell carcinoma, keratoacanthoma, and keratoacanthoma-like squamous proliferation.

Sunscreens - another endangered species?

Skin cancer continues to increase in incidence year-on-year and represents the most common form of cancer across the globe. Every human undergoes premature ageing, particularly on the face, neck and hands. Both phenomena are driven primarily by chronic, daily exposure to solar ultraviolet radiation (UVR). While sunscreen products play a primary role in the prevention of UVR skin damage, the active ingredients, i.e., UVR filters, are facing unprecedented challenges in the coming 10 years and their future is by no means certain. This article, therefore, reviews afresh the facts around photoprotection and the role of sunscreen products in the prevention of acute (sunburn) and chronic (cancer, photoageing) skin damage and compares/contrasts these with various emerging questions and opinions around UVR filter technology. We present a passionate defence of this remarkable technology, but also attempt to imagine a world without it.

Cumulative thiopurine dosing and keratinocyte skin cancer in inflammatory bowel disease: a case-control study

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) treated with thiopurines are at increased risk of keratinocyte skin cancer (KSC). Most international guidelines recommend yearly dermatological screening of thiopurine-treated patients. Whether the association between the development of KSC and the use of thiopurines is dose-dependent remains unclear. The aim of this study was to investigate the association between the cumulative thiopurine dose and KSC development in patients with IBD which can be helpful to assist in further skin cancer risk stratification and personalization of screening recommendations in patients with IBD.

METHODS

We performed a single-center case-control study, including patients with IBD with and without a history of KSC (cases and controls, respectively). The primary outcome was the association of cumulative azathioprine, mercaptopurine and thioguanine dose with KSC development. Univariable and multivariable logistic regression analyses were performed, the latter corrected for age and smoking, known risk factors of KSC.

RESULTS

We included 50 cases and 150 controls, predominantly white population. Age and current azathioprine use were univariably significantly associated with KSC development. In multivariable logistic regression analyses, age at inclusion remained significantly associated. Cumulative doses of thiopurines (separate or combined) or duration of thiopurine use did not impact KSC risk, also after correcting for age and smoking.

CONCLUSION

Cumulative thiopurine dose and duration did not show an association with KSC development. Future KSC risk stratification, based on all available KSC risk factors, may aid in selecting individuals who can benefit most from dermatologic screening programs.

Looking into the Skin in Health and Disease: From Microscopy Imaging Techniques to Molecular Analysis

The skin is a complex organ that includes a wide variety of tissue types with different embryological origins [...].

Staging System Performance and Clinical Outcomes for Cutaneous Squamous Cell Carcinoma of the Ear: A Single-Center Retrospective Study

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) of the ear is associated with poor outcomes. No studies have evaluated current staging system performance in this specific location.

OBJECTIVE

Describe clinicopathologic characteristics and outcomes of ear cSCC and evaluate the performance of current staging systems.

METHODS

Retrospective study including cases diagnosed and treated at a cancer center from January 2000 to December 2014. Demographic, clinical, and pathologic data were collected from clinical records. Biopsy slides were rereviewed and patients were staged according to the American Joint Committee on Cancer (AJCC) seventh, eighth, and Brigham Women's Hospital (BWH) staging.

RESULTS

Of 125 patients, the mean age at diagnosis was 71.9 years (SD 12.5), with most men (89.6%, n = 112). Median follow-up was 22.3 months. Local recurrence and survival risk factors were similar to cSCC outside the ear. The Akaike's Information Criterion (AIC) estimates showed that the BWH system better predicted outcomes than the AJCC seventh, and the AJCC eighth, with AIC values of 189.9, 270.5, and 274.1, respectively. Limitations of the study include retrospective design, single center study, and no control group.

CONCLUSION

Current staging systems perform well at stratifying risk in ear cSCC.

Cutaneous squamous cell carcinoma-derived extracellular vesicles exert an oncogenic role by activating cancer-associated fibroblasts

Cutaneous squamous cell carcinoma (cSCC) is a fast-increasing cancer with metastatic potential. Extracellular vesicles (EVs) are small membrane-bound vesicles that play important roles in intercellular communication, particularly in the tumor microenvironment (TME). Here we report that cSCC cells secrete an increased number of EVs relative to normal human epidermal keratinocytes (NHEKs) and that interfering with the capacity of cSCC to secrete EVs inhibits tumor growth in vivo in a xenograft model of human cSCC. Transcriptome analysis of tumor xenografts by RNA-sequencing enabling the simultaneous quantification of both the human and the mouse transcripts revealed that impaired EV-production of cSCC cells prominently altered the phenotype of stromal cells, in particular genes related to extracellular matrix (ECM)-formation and epithelial-mesenchymal transition (EMT). In line with these results, co-culturing of human dermal fibroblasts (HDFs) with cSCC cells, but not with normal keratinocytes in vitro resulted in acquisition of cancer-associated fibroblast (CAF) phenotype. Interestingly, EVs derived from metastatic cSCC cells, but not primary cSCCs or NHEKs, were efficient in converting HDFs to CAFs. Multiplex bead-based flow cytometry assay and mass-spectrometry (MS)-based proteomic analyses revealed the heterogenous cargo of cSCC-derived EVs and that especially EVs derived from metastatic cSCCs carry proteins associated with EV-biogenesis, EMT, and cell migration. Mechanistically, EVs from metastatic cSCC cells result in the activation of TGFβ signaling in HDFs. Altogether, our study suggests that cSCC-derived EVs mediate cancer-stroma communication, in particular the conversion of fibroblasts to CAFs, which eventually contribute to cSCC progression.

Mohs micrographic surgery for keratinocyte carcinomas: clinicopathological predictors of the number of stages

Background

The number of Mohs stages needed to remove a keratinocyte carcinoma affects resource use, expenses, and repair complexity. This study aimed to identify clinicopathological predictors associated with increased or decreased stages and areas for further research.

Methods

A retrospective review was conducted from a single private practice with two Mohs surgeons of 2788 consecutive Mohs cases between January 2017 and December 2021, analyzing the average number of stages taken versus national norms (P = 0.21) and subgroups using unpaired t tests (*<0.05).

Results

Several tumor features were significantly associated with fewer stages: squamous cell carcinomas, Mohs appropriate use criteria score of 7 or 8, preoperative size <0.25 cm2, tumors on the lips and extremities (including hands/fingers), and smoking. Clinicopathological features significantly associated with more stages included Mohs appropriate use criteria score of 9, recurrent skin cancers, basal cell carcinomas, tumor size of 2.25-3.99 cm2, cancers on ears, solid organ transplant patients, treatment delays >180 days, and patients ≥90 years old.

Conclusions

Significant predictors exist for both increased and decreased numbers of Mohs micrographic surgery stages required to eradicate a tumor, which may help Mohs surgeons facilitate, plan, and allocate resources more effectively. Areas for further research in Mohs micrographic surgery are identified.

Surgery in the Era of Immunotherapy for Advanced Head and Neck Non-melanoma Skin Cancer

PURPOSE OF REVIEW

Surgery remains the mainstay of treatment for non-melanoma skin cancer (NMSC). Immunotherapy (IO) has emerged as an alternative option. This review provides a contemporary summary of how to incorporate IO into the management of advanced NMSC. Evidence-based outcomes and recent clinical trials are provided with emphasis on the three most common NMSC diagnoses: cutaneous squamous cell carcinoma (cSCC), basal cell carcinoma (BCC), and merkel cell carcinoma (MCC).

RECENT FINDINGS

Surgical resection while preserving form and function remains the standard of care for the majority of NMSCs. In recalcitrant cases failing traditional surgery and/or primary radiation, patient ineligible for such treatments, or unresectable disease, IO has emerged as a promising alternative. In the majority of cases, it is a supplanting primary chemotherapy. Surgery remains the standard of care for NMSC. Immunotherapy has emerged as an alternative option for non-surgical candidates and as a neoadjuvant means to minimize morbidity.

A Multicenter Prospective Trial of Electronic Skin Surface Brachytherapy for Keratinocyte Carcinoma: Early Cosmesis, Quality of Life, and Adverse Events

PURPOSE

Keratinocyte carcinomas are amenable to many treatments, including radiation therapy (RT). Electronic skin surface brachytherapy (ESSB) enables the precise delivery of radiation without radioisotopes. In this prospective multicenter clinical trial, we characterized early outcomes of ESSB prospectively through both patient- and clinician-reported measures. To corroborate the cosmesis observations, we also assessed patient-reported quality of life (QoL) and adverse events.

METHODS AND MATERIALS

Patients ≥60 years old with stage T1N0M0 keratinocyte carcinoma were treated with ESSB. At 2-, 6-, and 12-weeks post-treatment, cosmesis from ESSB was assessed by both the patient and a clinician study investigator as either "good," "fair," or "bad." The Skindex-16 and the Skin Cancer Index (SCI) were used to assess patient QoL before and after treatment. Adverse events were assessed using the Common Toxicity Criteria for Adverse Events, version 4.0.

RESULTS

Cosmesis and QoL were collected at 97% (99/102) of possible patient follow-up times. By 12 weeks post-treatment, 93.9% (31/33) of patient-reported and 96.9% (31/32) of clinician-reported cosmesis outcomes were "good." Compared with baseline, total Skindex-16 score significantly deteriorated at 2 weeks post-treatment (10.5 vs 24.5, P <.001), but significantly improved at 6 weeks (10.5 vs 4.7, P = .014) and 12 weeks (10.5 vs 2.1, P = .001) post-treatment. The total SCI score significantly improved from baseline to 6 weeks (78.4 vs 89.0, P = .001) post-treatment. The most frequent adverse events were radiation dermatitis, skin pain, and pruritus. All adverse events resolved to Grade ≤1 by 12 weeks post-treatment.

CONCLUSIONS

This prospective, multicenter study demonstrated that ESSB is associated with a high rate of "good" early patient-reported cosmesis and increasing QoL and satisfaction with time. Validated assessments demonstrated a significant improvement in quality of life and resolution of moderate early adverse events by 6 to 12 weeks after treatment and corroborate the observation of favorable cosmesis.

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.

Ectopically Expressed Meiosis-Specific Cancer Testis Antigen HORMAD1 Promotes Genomic Instability in Squamous Cell Carcinomas

Genomic instability is a prominent hallmark of cancer, however the mechanisms that drive and sustain this process remain elusive. Research demonstrates that numerous cancers with increased levels of genomic instability ectopically express meiosis-specific genes and undergo meiomitosis, the clash of mitotic and meiotic processes. These meiotic genes may represent novel therapeutic targets for the treatment of cancer. We studied the relationship between the expression of the meiosis protein HORMAD1 and genomic instability in squamous cell carcinomas (SCCs). First, we assessed markers of DNA damage and genomic instability following knockdown and overexpression of HORMAD1 in different cell lines representing SCCs and epithelial cancers. shRNA-mediated depletion of HORMAD1 expression resulted in increased genomic instability, DNA damage, increased sensitivity to etoposide, and decreased expression of DNA damage response/repair genes. Conversely, overexpression of HORMAD1 exhibited protective effects leading to decreased DNA damage, enhanced survival and decreased sensitivity to etoposide. Furthermore, we identified a meiotic molecular pathway that regulates HORMAD1 expression by targeting the upstream meiosis transcription factor STRA8. Our results highlight a specific relationship between HORMAD1 and genomic instability in SCCs, suggesting that selectively inhibiting HORMAD1, possibly, through STRA8 signaling, may provide a new paradigm of treatment options for HORMAD1-expressing SCCs.

Advances in cutaneous squamous cell carcinoma

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.