Update on Management Recommendations for Advanced Cutaneous Squamous Cell Carcinoma

Survival After Orbital Exenteration for Primary Cutaneous Squamous Cell Carcinoma: A Retrospective Cohort Study

BACKGROUND

Locally advanced periorbital cutaneous squamous cell carcinoma (cSCC) may require orbital exenteration, which is highly morbid. As immunotherapy develops, orbit preservation may become widespread, and data benchmarking survival with current standard-of-care surgery and radiotherapy are essential to the integration of this emerging method into modern treatment paradigms. This study aimed to determine the survival of patients after orbital exenteration for cSCC and investigate contributing factors. It was hypothesized that postoperative radiotherapy would be associated with improved survival.

METHODS

This was a retrospective cohort study of patients with T3 and T4 cSCC undergoing orbital exenteration. Survival analysis was performed using Cox proportional hazards.

RESULTS

The study enrolled 40 patients with a median age of 61.5 years who met the criteria. None of the patients had received preoperative radiotherapy. Age (hazard ratio [HR], 1.09; p = 0.019) and residual disease (HR, 9.00; p = 0.003) were associated with worse survival. Postoperative radiotherapy (HR, 0.003; p < 0.001) was associated with improved survival. Perineural, lymphovascular, and bony invasion and T and N stage were not associated with survival. Survival with postoperative radiotherapy was 94 % at 1 year, 87 % at 2 years, and 84 % at 5 years.

CONCLUSIONS

The oncologic outcomes of orbital exenteration with postoperative radiotherapy for locally advanced head and neck cSCC are good. However, amelioration of the morbidity caused by resection of the eye would be ideal. Data to support immunotherapy as a sole therapy are currently limited, but a combination of neoadjuvant immunotherapy and surgical treatment may facilitate orbit-preserving treatment in the future.

A population-based study using nomograms to predict overall and cancer-specific survival in HPV-associated CSCC

Constructing and validating two nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) in cutaneous squamous cell carcinoma (CSCC) correlated with human papillomavirus (HPV) infection was the main goal of this study. We constructed predictive models for OS and CSS incidence in HPV infection-associated CSCC using information from 2238 patients in the Surveillance, Epidemiology, and End Results (SEER) database and screened the variables by LASSO regression, Cox univariate regression, and Cox multifactorial regression models, which were calibrated and validated by internal and external cohorts. Finally, all patients were categorized into intermediate-risk, low-risk, and high-risk groups based on the optimal threshold calculated from the total score. Multivariate analysis showed that HPV infection status, marital status, tumor metastatic stage, surgical status, radiotherapy status, lymph node biopsy, local lymph node dissection, primary tumor status, and bone metastasis were risk factors for OS and CSS. The C index, the time-dependent area under the receiver-operating characteristic curve, and the column-line diagrams of the calibration plot were among the excellent-performance metrics that were effectively displayed. Moreover, the decision curve analysis of the two nomograms consistently revealed their favorable net benefits spanning 1, 2, and 3 years. In addition, the survival curves indicate that each of the two risk classification systems clearly differentiates high, medium, and low risk groups. These meticulously crafted nomograms stand poised to serve as indispensable instruments in clinical practice, empowering clinicians to adeptly communicate with patients regarding their prognostic outlook over the forthcoming 1, 2, and 3 years.

Outcomes With Radiation Therapy as Primary Treatment for Unresectable Cutaneous Head and Neck Squamous Cell Carcinoma

AIMS

Unresectable cutaneous squamous cell cancer of the head and neck (HNcSCC) poses treatment challenges in elderly and comorbid patients. Radiation therapy (RT) is often employed for locoregional control. This study aimed to determine progression-free survival (PFS) and overall survival (OS) outcomes achieved with upfront RT in unresectable HNcSCC. It also aimed to determine the impact of varying RT dose regimes on disease outcomes.

METHODS

A retrospective cohort study was conducted of patients with unresectable HNcSCC treated with first-line RT at a tertiary teaching hospital in Sydney, Australia between 2015-2024. Patient, disease, treatment and follow-up data were extracted from the electronic records.

RESULTS

Of 36 patients, 67% were male, median age was 81 years, and median Charlson Comorbidity Index was 6.5. Median follow-up was 21 months. 83% of RT courses were delivered via intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT). Objective response rate was 97%. Patients were grouped into low-dose RT receiving biologically equivalent dose (BED) <60Gy (n = 18) or high-dose RT (BED ≥ 60Gy, n = 18). Infield progression-free survival (PFS) at 6 months was 56% and 78%, respectively. Overall survival at 6 months was 83% and 89%, and by 24 months 31% and 65%, respectively.

CONCLUSION

RT is an efficacious treatment that can be tailored to individual patient contexts with unresectable HNcSCC. It has a high response rate overall, with higher doses producing longer disease control. Some patients with poorer functional status receiving low-dose RT can still achieve a sustained response. Future comparisons of outcomes and cost-effectiveness with emerging treatments such as immunotherapy will be important in guiding management for frail patients with unresectable disease.

Clinical and histopathological features of advanced cutaneous squamous cell carcinoma with varying responses to cemiplimab

BACKGROUND

Most patients with unresectable locally advanced cutaneous squamous cell carcinoma (cSCC) benefit from cemiplimab, but some do not respond. Our study aims to identify clinical and histopathological features predicting response to cemiplimab.

PATIENTS AND METHODS

We analyzed 15 patients treated with cemiplimab, assessing clinical, demographic, histopathological, and immunohistochemical characteristics and correlating them with treatment response. Furthermore, effectiveness and safety were evaluated in our cohort.

RESULTS

Our cohort included 12 males and 3 females, with a mean age of 78.1 years. The majority of tumors, accounting for 66.7%, were located in the head and neck region. Treatment was well-tolerated, with only one grade 3 colitis. There was no correlation between immune-related adverse events and treatment response. Non-responders were younger (69.4 vs. 82.5 years). A history of hematological malignancy correlated with poorer response. High mitotic rate, poor tumor differentiation, high vimentin and p53, and low E-cadherin expression were associated with worse response. Conversely, higher intratumoral inflammatory infiltrate density, presence of necrotic areas, and lower mismatch repair-protein staining correlated with better response.

CONCLUSIONS

Cemiplimab is a safe and effective therapy, particularly in elderly patients. Well-differentiated tumors with low proliferative index, intratumoral inflammatory infiltrate, and tumor necrosis may predict better clinical response.

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.

Pigmented Superficial Basal Cell Carcinoma of the Nipple-Areola Complex: A Case Report

Introduction

Basal cell carcinoma (BCC) is the most common type of skin malignancy, accounting for approximately 80% of all non-melanoma skin cancers (NMSCs). Ultraviolet (UV) exposure is a significant risk factor for BCC development, which typically occurs in sun-exposed areas. BCC arising in non-sun-exposed regions, such as the nipple-areola complex (NAC), is exceedingly rare, with fewer than 100 cases reported globally. This report describes a case of pigmented superficial BCC in the NAC of a 76-year-old Asian woman.

Case Presentation

A 76-year-old Asian female presented with a 5-year history of a slowly enlarging lesion on her left breast, with recent rapid growth. Physical examination revealed a 10 mm × 8 mm blue-gray, pearl-like plaque on the NAC. Histopathology confirmed pigmented superficial BCC. Preoperative imaging, including breast ultrasound, chest computed tomography (CT), SPECT-CT, and axillary lymph node ultrasound, showed no evidence of metastasis. The patient underwent standard surgical excision with a 10 mm margin, followed by pathologic evaluation, confirming clear margins. The patient was discharged on the second postoperative day and remained asymptomatic at a 3-month follow-up.

Conclusion

Pigmented superficial BCC of the NAC is an uncommon presentation due to the area's minimal sun exposure and lack of pilosebaceous units. This case underscores the importance of considering BCC in non-sun-exposed areas, particularly in elderly patients. While nonsurgical options such as photodynamic therapy may offer superior esthetic outcomes, the patient's financial constraints led to the selection of a cost-effective surgical excision, which successfully eliminated the tumor.

Tumour budding as a risk factor for lymph node metastases in cutaneous squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Current staging systems have limitations in stratifying high-risk cutaneous squamous cell carcinoma (cSCC). Tumour budding (TB) has emerged as a potential prognostic factor in various cancers.

OBJECTIVES

To evaluate the prognostic significance of TB in predicting lymph node metastases (NM) in cSCC.

METHODS

A comprehensive search of the PubMed, Web of Science, Embase and Cochrane databases was conducted. Studies investigating the association of TB using a 5-bud cutoff and NM in cSCC were included. A meta-analysis was performed using odds ratios (OR) to evaluate the association between TB and NM.

RESULTS

Six retrospective studies comprising 793 patients with cSCC were included. The random-effects analysis showed a significant association between high TB (≥ 5 buds) and NM (OR = 13.29, 95% confidence interval 5.55-31.86).

DISCUSSION

TB is a promising histopathological feature for predicting NM in cSCC. The results show a strong association between high TB and NM, supporting its utility as a risk factor for NM in cSCC. Its inclusion in clinical practice and cSCC staging might be helpful in the stratification of patients with high-risk cases and to guide optimal management strategies for each patient. However, further investigation is needed to determine standardized reporting guidelines for TB in cSCC.

Ultrasound in Skin Cancer: Why, How, and When to Use It?

BACKGROUND

Skin cancer is the most common cancer in human beings. Ultrasound is a powerful and non-invasive imaging technique that has expanded its use in dermatology, including in the skin cancer field. The full range of critical anatomical information provided by ultrasound cannot be deduced from a naked eye examination, palpation, or other imaging techniques such as dermoscopy, confocal microscopy, magnetic resonance imaging, or PET-CT (Positron Emission Tomography-Computed Tomography).

METHODS

This review practically analyzes the main ultrasonographic features of the most common types of skin cancers and the performance of the locoregional staging according to the literature, which is illustrated by state-of-the-art clinical and ultrasonographic correlations.

RESULTS

The most common types of skin cancer show recognizable ultrasonographic patterns.

CONCLUSIONS

Among the current radiological imaging techniques, ultrasound has the highest axial spatial resolution. Compared to other imaging techniques used in dermatology, it shows the great advantage of penetrating the soft tissues thoroughly, which allows us to detect and identify the most common skin types of skin cancer, including both the primary tumor and its locoregional metastases.

Patient-initiated follow-up for high-risk cutaneous squamous cell carcinoma: how we do it and 2 years of outcome data

BACKGROUND

For patients with high-risk cutaneous squamous cell carcinomas (cSCCs), current guidance suggests we should offer post-treatment follow-up appointments at regular intervals for 24 months. Is this to improve prognosis, provide psychological support or find the next cancer? Recent data confirm that recurrence and metastasis are rarer events, and that perhaps these intense follow-up schedules do not really lead to improved health outcomes.

OBJECTIVES

To question whether current follow-up practices are truly needed by introducing an option of patient-initiated follow-up (PIFU).

METHODS

We enrolled 476 patients with cSCC (January 2020-January 2023) who fulfilled the definition of high-risk cSCC based on guidelines in use at the time. Of the total, 59 did not fulful the inclusion criteria and were excluded; 250 (52.5%) did not recontact us during the 2-year period, with no clinical record of complications or recurrences; and 167 (35.1%) utilized the PIFU pathway, of which 119 patients required only one face-to-face appointment. Seven patients (1.5%) developed metastatic disease, 11 (2.3%) developed recurrence and 68 (14.3%) developed cSCC at another site. All lesions were identified by the patient via PIFU. We saved 1250 follow-up appointments from those who did not contact us (n = 250), financially equating to £181 462.50.

CONCLUSIONS

Our data imply that PIFU can be considered safe alternative practice for patients with cSCC. Patients independently identified the need for review without scheduled follow-up, making these appointments available to other patient cohorts. Although follow-up appointments may provide mental health support, they can be inconvenient and not the ideal use of our healthcare resources. Our findings support a call for revision of existing skin cancer health policies to cope with and subsequently improve our practices for better patient care.

Cutaneous Squamous Cell Carcinoma of the Head and Neck: Pathological Features and What They Mean for Prognosis and Treatment

Cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers worldwide, with an incidence that has increased over the past 30 years. Although usually curable with excision, cSCC can become widely metastatic and aggressive with poor outcomes. Whereas the clinical and radiographic extent of any cancer will always guide selection of treatment modality, pathological features of cSCC also play an important role in determining prognosis and, subsequently, the need for further therapy. Therefore, reviewing and summarizing the current literature regarding pathological prognostic indicators of cSCC is essential to improving clinical outcomes. The present literature review yielded depth of invasion, surgical margins, perineural invasion, extranodal extension, lymphovascular invasion, tumor grade, tumor subtype, premalignant lesions, and molecular markers as key prognostic indicators, all with varying recommendations for adjuvant therapy. Notably, some of these factors have not been incorporated into either the American Joint Committee on Cancer staging system (8th edition) or National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology for cSCC. This review highlights a need for further research into these prognostic indicators and their role in determining the need for adjuvant treatment in head and neck cSCC.

The Immunomodulatory Potential of Concurrent High-Dose Radiotherapy and Immune Checkpoint Inhibitor Cemiplimab in Advanced Cutaneous Squamous Cell Carcinoma: Initial Results

In this retrospective case series, we investigate the synergistic effect and the immunomodulatory potential of combination radiotherapy and immunotherapy on 11 patients affected by locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC), treated at our institution between 2020 and 2023. The primary endpoints of this study are objective tumor response, assessed by Immunotherapy Response Evaluation Criteria in Solid Tumors (iRECIST), and time to treatment failure (disease progression). In all patients, surgery was deemed not amenable, due to its potential functional and aesthetic impact. Therefore, upon multidisciplinary agreement, radiotherapy and immunotherapy with cemiplimab were alternatively administered. After 6 months, an early objective tumor response was observed in 9/11 patients, with 17/20 cutaneous lesions (85%) presenting either a complete or partial response. Only 2/11 patients, with a total of 3/20 cutaneous lesions (15%), had stable disease. These benefits persisted at a longer follow-up (21.4 ± 9.7 months), with no patients presenting disease progression. Despite the retrospective nature of this study and small sample size, our experience highlights the ability of concomitant radiotherapy and cemiplimab to promote an early objective response in patients with advanced CSCC. Moreover, in our population, the clinical benefits were also related to a longer progression-free survival, without any safety alert reported.

Use of Imaging in Cutaneous Squamous Cell Carcinoma to Detect High-Risk Tumor Features, Nodal Metastasis, and Distant Metastasis: A Systematic Review

BACKGROUND

Imaging has been shown to impact management and disease outcomes in cutaneous squamous cell carcinoma, but the literature on optimal modalities is lacking.

OBJECTIVE

To perform a systematic review evaluating the performance of various imaging studies for the detection of perineural spread, bony invasion, nodal metastasis (NM), and distant metastasis in cutaneous squamous cell carcinoma.

MATERIALS AND METHODS

Four databases were searched for relevant terms. Articles were included if they presented primary data on 5 or more subjects with cutaneous squamous cell carcinoma who underwent imaging to detect perineural spread, bony involvement, NM, or distant metastasis.

RESULTS

Thirty studies and 1,027 subjects were included in the pooled analysis. Magnetic resonance imaging had a 94.9% sensitivity in detecting perineural spread. Computed tomography (CT) demonstrated a sensitivity of 75.7% and specificity of 98.6% in detecting bony invasion. While ultrasound, positron emission tomography-computed tomography, and CT all performed reasonably well in detecting NM, CT demonstrated the highest sensitivity (96.4%) and specificity (100%). Imaging changed management in up to 33% of cases.

CONCLUSION

Imaging is useful in high-risk cutaneous squamous cell carcinoma. Magnetic resonance imaging performs best in the detection of perineural spread, and CT is the most accurate modality to detect bony invasion and NM.

Automated cutaneous squamous cell carcinoma grading using deep learning with transfer learning

INTRODUCTION

Histological grading of cutaneous squamous cell carcinoma (cSCC) is crucial for prognosis and treatment decisions, but manual grading is subjective and time-consuming.

AIM

This study aimed to develop and validate a deep learning (DL)-based model for automated cSCC grading, potentially improving diagnostic accuracy (ACC) and efficiency.

MATERIALS AND METHODS

Three deep neural networks (DNNs) with different architectures (AlexNet, GoogLeNet, ResNet-18) were trained using transfer learning on a dataset of 300 histopathological images of cSCC. The models were evaluated on their ACC, sensitivity (SN), specificity (SP), and area under the curve (AUC). Clinical validation was performed on 60 images, comparing the DNNs' predictions with those of a panel of pathologists.

RESULTS

The models achieved high performance metrics (ACC>85%, SN>85%, SP>92%, AUC>97%) demonstrating their potential for objective and efficient cSCC grading. The high agreement between the DNNs and pathologists, as well as among different network architectures, further supports the reliability and ACC of the DL models. The top-performing models are publicly available, facilitating further research and potential clinical implementation.

CONCLUSIONS

This study highlights the promising role of DL in enhancing cSCC diagnosis, ultimately improving patient care.

The role of micrometastasis in high-risk skin cancers

The propensity to metastasize is the most important prognostic indicator for solid cancers. New insights into the mechanisms of early carcinogenesis have revealed micrometastases are generated far earlier than previously thought. Evidence supports a synergistic relationship between vascular and lymphatic seeding which can occur before there is clinical evidence of a primary tumour. Early vascular seeding prepares distal sites for colonisation while regional lymphatics are co-opted to promote facilitative cancer cell mutations. In response, the host mounts a global inflammatory and immunomodulatory response towards these cells supporting the concept that cancer is a systemic disease. Cancer staging systems should be refined to better reflect cancer cell loads in various tissue compartments while clinical perspectives should be broadened to encompass this view when approaching high-risk cancers. Measured adjunctive therapies implemented earlier for low-volume, in-transit cancer offers the prospect of preventing advanced disease and the need for heroic therapeutic interventions. This review seeks to re-appraise how we view the metastatic process for solid cancers. It will explore in-transit metastasis in the context of high-risk skin cancer and how it dictates disease progression. It will also discuss how these implications will influence our current staging systems and its consequences on management.

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

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

A combined opposite targeting of p110δ PI3K and RhoA abrogates skin cancer

Malignant melanoma is the most aggressive and deadly skin cancer with an increasing incidence worldwide whereas SCC is the second most common non-melanoma human skin cancer with limited treatment options. Here we show that the development and metastasis of melanoma and SCC cancers can be blocked by a combined opposite targeting of RhoA and p110δ PI3K. We found that a targeted induction of RhoA activity into tumours by deletion of p190RhoGAP-a potent inhibitor of RhoA GTPase-in tumour cells together with adoptive macrophages transfer from δD910A/D910A mice in mice bearing tumours with active RhoA abrogated growth progression of melanoma and SCC tumours. Τhe efficacy of this combined treatment is the same in tumours lacking activating mutations in BRAF and in tumours harbouring the most frequent BRAF(V600E) mutation. Furthermore, the efficiency of this combined treatment is associated with decreased ATX expression in tumour cells and tumour stroma bypassing a positive feedback expression of ATX induced by direct ATX pharmacological inactivation. Together, our findings highlight the importance of targeting cancer cells and macrophages for skin cancer therapy, emerge a reverse link between ATX and RhoA and illustrate the benefit of p110δ PI3K inhibition as a combinatorial regimen for the treatment of skin cancers.

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.

Update on the Molecular Pathology of Cutaneous Squamous Cell Carcinoma

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

The long non-coding RNA PVT1 promotes tumorigenesis of cutaneous squamous cell carcinoma via interaction with 4EBP1

The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) plays an oncogenic role in multiple cancers due to its high expression. However, the expression and associated regulatory mechanisms of PVT1 in cutaneous squamous cell carcinoma (cSCC) remain unclear. Our results revealed that PVT1 was highly upregulated in cSCC tissues and cSCC cell lines. To determine the functional role of PVT1 in cSCC, we constructed a stable knockdown cell model of PVT1 in the A431 and COLO16 cell lines using a lentiviral approach. Xenograft tumor experiments of nude mice in vivo, and colony formation, CCK-8, and EdU assays in vitro demonstrated that knockdown of PVT1 could widely suppress cell proliferation in vivo and in vitro. In addition, PVT1 knockdown induced cell cycle arrest and promoted apoptosis, as detected by flow cytometry analysis. Wound healing and transwell assays revealed that PVT1 knockdown significantly inhibited the migration and invasion of CSCC cell lines. To gain insight into the tumorigenic mechanism and explore the potential target molecules of PVT1, we employed label-free quantitative proteomic analysis. The GO, KEGG enrichment, and protein-protein interaction (PPI) networks suggested that 4E-binding protein 1 (4EBP1) is the possible downstream target effector of PVT1, which was validated by western blot analysis. PVT1 silencing markedly decreased 4EBP1 protein expression levels and directly bound 4EBP1 in the cytoplasm of cSCC cells. 4EBP1 overexpression counteracted the effects of PVT1 knockdown on tumorigenesis in cSCC cells, including cell proliferation, apoptosis, migration, and invasion. Our findings provide strong evidence that PVT1 is an oncogene which plays a role in tumorigenesis of cSCC, that PVT1 may interact with 4EBP1 in the cytoplasm as an underlying mechanism in cSCC carcinogenesis, and that PVT1 combined with 4EBP1 may serve as a potential new therapeutic target for cSCC.

Recent Advances in Immunotherapy for Patients with Head and Neck Cutaneous Squamous Cell Carcinoma

Simple Summary

Cutaneous squamous cell cancer is a form of skin cancer, which is typically found in older fair-skinned individuals with frequent sun exposure. Most patients present with limited disease and can be treated with a combination of surgery and/or radiation with favorable outcomes. A small percentage of patients present with more aggressive, widespread disease. Immunotherapy has dramatically improved outcomes and has become the preferred treatment option for these patients. In this review article, the rationale for using immunotherapy in patients with squamous cell skin cancer is discussed. A summary of the new treatment options currently being explored is also provided.

Abstract

Cutaneous squamous cell carcinoma (CSCC) is the second most common non-melanoma skin cancer. A majority of patients present with localized disease, but some can present with locally advanced or metastatic disease. Most of these advanced cases occur in the anatomical head and neck region and are associated with more aggressive disease, necessitating prompt and effective treatment. Prior to the emergence of immunotherapy, systemic treatment options were limited to platinum-based chemotherapy and salvaged with targeted epidermal growth factor therapy. These therapies were associated with poor efficacy and increased toxicity in an often frail, older population. Immunotherapy has dramatically improved outcomes in this patient population due to its favorable side effect profile, durable treatment response, and improved overall outcomes. In this review, an overview of the recent advances of immunotherapy in the management of CSCC in the anatomical head and neck region is provided, with a focus on advanced presentations.

Whole genome analysis reveals the genomic complexity in metastatic cutaneous squamous cell carcinoma

Metastatic cutaneous squamous cell carcinoma (CSCC) is a highly morbid disease requiring radical surgery and adjuvant therapy, which is associated with a poor prognosis. Yet, compared to other advanced malignancies, relatively little is known of the genomic landscape of metastatic CSCC. We have previously reported the mutational signatures and mutational patterns of CCCTC-binding factor (CTCF) regions in metastatic CSCC. However, many other genomic components (indel signatures, non-coding drivers, and structural variants) of metastatic CSCC have not been reported. To this end, we performed whole genome sequencing on lymph node metastases and blood DNA from 25 CSCC patients with regional metastases of the head and neck. We designed a multifaceted computational analysis at the whole genome level to provide a more comprehensive perspective of the genomic landscape of metastatic CSCC. In the non-coding genome, 3′ untranslated region (3′UTR) regions of EVC (48% of specimens), PPP1R1A (48% of specimens), and ABCA4 (20% of specimens) along with the tumor-suppressing long non-coding RNA (lncRNA) LINC01003 (64% of specimens) were significantly functionally altered (Q-value < 0.05) and represent potential non-coding biomarkers of CSCC. Recurrent copy number loss in the tumor suppressor gene PTPRD was observed. Gene amplification was much less frequent, and few genes were recurrently amplified. Single nucleotide variants driver analyses from three tools confirmed TP53 and CDKN2A as recurrently mutated genes but also identified C9 as a potential novel driver in this disease. Furthermore, indel signature analysis highlighted the dominance of ID signature 13 (ID13) followed by ID8 and ID9. ID9 has previously been shown to have no association with skin melanoma, unlike ID13 and ID8, suggesting a novel pattern of indel variation in metastatic CSCC. The enrichment analysis of various genetically altered candidates shows enrichment of “TGF-beta regulation of extracellular matrix” and “cell cycle G1 to S check points.” These enriched terms are associated with genetic instability, cell proliferation, and migration as mechanisms of genomic drivers of metastatic CSCC.