Immune Checkpoint Inhibitors for Treating Advanced Cutaneous Squamous Cell Carcinoma

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

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

Anti-PD-1 immunotherapy with adjuvant ablative fractional laser displays increased tumour clearance of squamous cell carcinoma, a murine study

PD-1 checkpoint inhibitors are used as systemic immunotherapy for locally advanced and metastatic cutaneous squamous cell carcinoma (SCC); however, improved treatment efficacy is urgently needed. In this study, we aimed to investigate the effect of combining systemic anti-PD-1 treatment with adjuvant ablative fractional laser (AFL) in a spontaneous SCC mouse model. Tumours induced by ultraviolet radiation in the strain C3.Cg-Hrhr /TifBomTac were divided into four groups: anti-PD-1-antibody+AFL (n = 33), AFL alone (n = 22) anti-PD-1-antibody alone (n = 31) and untreated controls (n = 46). AFL was given at Day 0 (100 mJ/mb, 5% density), while anti-PD-1-antibody (ip, 200 μg) at Days 0, 2, 4, 6 and 8. Response to treatment was evaluated by tumour growth, survival time and by dividing response to treatment into complete responders (clinically cleared tumours), partial responders (reduced tumour growth rate compared to untreated controls) and non-responders (no decrease in tumour growth rate compared to untreated controls). The strongest tumour response was observed following the combination of systemic anti-PD-1 treatment combined with laser exposure, resulting in the highest percentage of complete responders (24%) compared with untreated controls (0%, p < 0.01), AFL monotherapy (13%, p > 0.05) and anti-PD-1-antibody monotherapy (3%, p > 0.05). Moreover, all three treatment interventions demonstrated significantly reduced tumour growth rates compared with untreated controls (p < 0.01), and the mice had significantly longer survival times (p < 0.01). In conclusion, the combination treatment revealed an improved treatment effect that significantly enhanced the complete tumour clearance not observed with the monotherapies, indicating a possible additive effect of anti-PD-1 with adjuvant AFL in treatment of SCC.

NAD+ Metabolism-Related Gene Profile Can Be a Relevant Source of Squamous Cell Carcinoma Biomarkers

Poor survival rates of squamous cell carcinomas (SCCs) are associated with high recurrence, metastasis, and late diagnosis, due in part to a limited number of reliable biomarkers. Thus, the identification of signatures improving the diagnosis of different SCC types is mandatory. Considering the relevant role of NAD+ metabolism in SCC chemoprevention and therapy, the study aimed at identifying new biomarkers based on NAD+ metabolism-related gene (NMRG) expression. Gene expression of 18 NMRGs and clinical-pathological information for patients with head and neck SCC (HNSCC), lung SCC (LuSCC), and cervix SCC (CeSCC) from The Cancer Genome Atlas (TCGA) were analyzed by several bioinformatic tools. We identified a 16-NMRG profile discriminating 3 SCCs from 3 non-correlated tumors. We found several genes for HNSCC, LuSCC, and CeSCC with high diagnostic power. Notably, three NMRGs were SCC-type specific biomarkers. Furthermore, specific signatures displayed high diagnostic power for several clinical-pathological characteristics. Analyzing tumor-infiltrating immune cell profiles and PD-1/PD-L1 levels, we found that NMRG expression was associated with suppressive immune microenvironment mainly in HNSCC. Finally, the evaluation of patient survival identified specific genes for HNSCC, LuSCC, and CeSCC with potential prognostic power. Therefore, our analyses indicate NAD+ metabolism as an important source of SCC biomarkers and potential therapeutic targets.

Basosquamous Carcinoma: Comprehensive Clinical and Histopathological Aspects, Novel Imaging Tools, and Therapeutic Approaches

Basosquamous carcinoma (BSC), an uncommon and aggressive nonmelanoma skin cancer exhibiting characteristics ranging from basal cell carcinoma (BCC) to squamous cell carcinoma (SCC), is a subject of controversy in terms of its classification, pathogenesis, histologic morphology, biologic behavior, prognosis, and management. This narrative review is based on an electronic search of English-language articles in PubMed that included the terms "basosquamous carcinoma" and/or "metatypical carcinoma of the skin" in their titles. The review aims to succinctly present and assess current data on the epidemiology, clinical presentation, dermoscopic, LC-OCT, and histopathologic characteristics, as well as the genetics and management of BSC, providing insight into this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies, and immunohistologic techniques should be applied in clinically suspicious lesions to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs' micrographic surgery, remain the treatment of choice. Finally, Hedgehog pathway inhibitors and checkpoint inhibitors, must be thoroughly investigated with large controlled trials, since they may offer an alternative solution to irresectable or difficult-to-treat locally advanced cases of basosquamous carcinoma.

Efficacy and safety of cosibelimab, an anti-PD-L1 antibody, in metastatic cutaneous squamous cell carcinoma

BACKGROUND

Programmed cell death receptor-1 (PD-1)-blocking antibodies are approved to treat metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) cases ineligible for curative surgery or radiation. Notwithstanding, some patients experience inadequate responses or severe immune-related adverse events (AEs), indicating the need for improved therapies. Cosibelimab is a high-affinity programmed cell death-ligand 1 (PD-L1)-blocking antibody that activates innate and adaptive immunity by blocking PD-L1 interaction with PD-1 and B7-1 receptors. It is an unmodified immunoglobulin G1 subtype with a functional Fc domain capable of inducing antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Here, we present results of the pivotal study of patients with metastatic CSCC from an open-label, multicenter, multiregional, multicohort, phase 1 trial of cosibelimab.

METHODS

In this trial, participants with metastatic CSCC received cosibelimab 800 mg intravenously every 2 weeks. Primary endpoint was objective response rate (ORR) by independent central review using Response Evaluation Criteria in Solid Tumors, V.1.1. Secondary endpoints included duration of response (DOR) and safety.

RESULTS

Objective response was observed in 37 of 78 participants (47.4% (95% CI: 36.0% to 59.1%)), with median follow-up of 15.4 months (range: 0.4 to 40.5) as of data cut-off. Median DOR was not reached (range: 1.4+ to 34.1+ months), with response ongoing in 73.0% of participants. Common treatment-emergent AEs (≥15%) were fatigue (26.9%), rash (16.7%), and anemia (15.4%). Eighteen participants (23.1%) experienced immune-related AEs (grade 3: n=2 (2.6%); no grade 4/5). No treatment-related deaths were reported.

CONCLUSIONS

Cosibelimab demonstrated clinically meaningful ORR and DOR and was associated with a manageable safety profile.

TRIAL REGISTRATION NUMBER

NCT03212404.

The Distinctive Features behind the Aggressiveness of Oral and Cutaneous Squamous Cell Carcinomas

Squamous cell carcinomas arise from stratified squamous epithelia. Here, a comparative analysis based on recent studies defining the genetic alterations and composition of the stroma of oral and cutaneous squamous cell carcinomas (OSCC and CSCC, respectively) was performed. Both carcinomas share some but not all histological and genetic features. This review was focused on how mutations in tumor suppressor genes and protooncogenes cooperate to determine the differentiation, aggressiveness, and metastatic potential of OSCC and CSCC. In fact, driver mutations in tumor suppressor genes are more frequently observed in OSCC than CSCC. These include mutations in TP53 (encoding pP53 protein), CDKN2A (encoding cyclin dependent kinase inhibitor 2A), FAT1 (encoding FAT atypical cadherin 1), and KMT2D (encoding lysine methyltransferase 2D), with the exception of NOTCH (encoding Notch receptor 1), whose mutation frequency is lower in OSCC compared to CSCC. Finally, we describe the differential composition of the tumor microenvironment and how this influences the aggressiveness of each tumor type. Although both OSCC and CSCC tumors are highly infiltrated by immune cells, high levels of tumor-infiltrating lymphocytes (TILs) have been more frequently reported as predictors of better outcomes in OSCC than CSCC. In conclusion, OSCC and CSCC partially share genetic alterations and possess different causal factors triggering their development. The tumor microenvironment plays a key role determining the outcome of the disease.

Serine and one-carbon metabolism sustain non-melanoma skin cancer progression

Non-melanoma skin cancer (NMSC) is a tumor that arises from human keratinocytes, showing abnormal control of cell proliferation and aberrant stratification. Cutaneous basal cell carcinoma (cBCC) and cutaneous squamous cell carcinoma (cSCC) are the most common sub-types of NMSC. From a molecular point of view, we are still far from fully understanding the molecular mechanisms behind the onset and progression of NMSC and to unravel targetable vulnerabilities to leverage for their treatment, which is still essentially based on surgery. Under this assumption, it is still not elucidated how the central cellular metabolism, a potential therapeutical target, is involved in NMSC progression. Therefore, our work is based on the characterization of the serine anabolism/catabolism and/or one-carbon metabolism (OCM) role in NMSC pathogenesis. Expression and protein analysis of normal skin and NMSC samples show the alteration of the expression of two enzymes involved in the serine metabolism and OCM, the Serine Hydroxy-Methyl Transferase 2 (SHMT2) and Methylen-ThetraHydroFolate dehydrogenase/cyclohydrolase 2 (MTHFD2). Tissues analysis shows that these two enzymes are mainly expressed in the proliferative areas of cBCC and in the poorly differentiated areas of cSCC, suggesting their role in tumor proliferation maintenance. Moreover, in vitro silencing of SHMT2 and MTHFD2 impairs the proliferation of epidermoid cancer cell line. Taken together these data allow us to link the central cellular metabolism (serine and/or OCM) and NMSC proliferation and progression, offering the opportunity to modulate pharmacologically the involved enzymes activity against this type of human cancer.

Cutaneous Squamous Cell Carcinoma: The Frontier of Cancer Immunoprevention

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer, with its incidence rising steeply. Immunosuppression is a well-established risk factor for cSCC, and this risk factor highlights the critical role of the immune system in regulating cSCC development and progression. Further highlighting the nature of cSCC as an immunological disorder, substantial evidence demonstrates a tight association between cSCC risk and age-related immunosenescence. Besides the proven efficacy of immune checkpoint blockade therapy for advanced cSCC, novel immunotherapy that targets cSCC precursor lesions has shown efficacy for cSCC prevention. Furthermore, the appreciation of the interplay between keratinocytes, commensal papillomaviruses, and the immune system has revealed the possibility for the development of a preventive cSCC vaccine. cSCC shares fundamental aspects of its origin and pathogenesis with mucosal SCCs. Therefore, advances in the field of cSCC immunoprevention will inform our approach to the management of mucosal SCCs and potentially other epithelial cancers.

Treatment of Cutaneous Squamous Cell Carcinoma with Immune Checkpoint Inhibitors in Special Populations

Cutaneous squamous cell carcinoma (cSCC) may develop in patients with dysregulated immune activation (pre-existing autoimmune diseases or immunosuppression due to hematopoietic/solid organ transplant recipients), patients with a compromised immune function (long-term immunosuppression), and patients carrying chronic viral infections, or those affected by lymphoproliferative diseases. It should be also considered that patients presenting with immunosuppression have a high incidence of cSCC (65-250-times higher than general population), highlighting the central role played by the immune system in the development of cSCC. All these cases must be considered as "special populations" for treatment with immune checkpoint inhibitors (ICIs), as the safety and activity of these drugs have not been studied on these specific cases, since these patients were excluded from clinical trials leading to approval of ICIs. It is therefore important to gain as much information as possible from the analysis of real-life data, to derive an indication to be adopted in everyday clinical setting. Moreover, therapeutic alternatives other than ICIs are scarce, mainly consisting in chemotherapy and anti-EGFR agents, whose activity is lower than immunotherapy and whose toxicity (particularly with chemotherapy) are not sustainable by this frail population. Here, we describe the current evidence of treatment with ICIs in special populations and conclude that it is necessary to find a balance between treatment risks (toxicities) and benefits (efficacy), as well as engaging a multidisciplinary team of experts to thoroughly manage and treat these patients.

An evaluation of prognostic factors, oncologic outcomes, and management for primary and recurrent squamous cell carcinoma of the vulva

OBJECTIVE

To evaluate prognostic factors, outcomes, and management patterns of patients treated for squamous cell carcinoma of the vulva.

METHODS

One hundred sixty-four women were retrospectively identified with primary squamous cell carcinoma of the vulva treated at our institution between 1/1996-12/2018. Descriptive statistics were performed on patient, tumor, and treatment characteristics. The χ² tests and t-tests were used to compare categorical variables and continuous variables, respectively. Recurrence free survival (RFS), overall survival (OS), and disease-specific survival (DSS) were analyzed with Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards.

RESULTS

Median follow-up was 52.5 months. Five-year RFS was 67.9%, 60.0%, 42.1%, and 20.0% for stage I-IV, respectively. Five-year DSS was 86.2%, 81.6%, 65.0%, and 42.9% for stage I-IV, respectively. On multivariate analysis, positive margins predicted overall RFS (hazard ratio [HR]=3.55; 95% confidence interval [CI]=1.18-10.73; p=0.025), while presence of lichen sclerosus on pathology (HR=2.78; 95% CI=1.30-5.91; p=0.008) predicted local RFS. OS was predicted by nodal involvement (HR=2.51; 95% CI=1.02-6.13; p=0.043) and positive margins (HR=5.19; 95% CI=2.03-13.26; p=0.001). Adjuvant radiotherapy significantly improved RFS (p=0.016) and DSS (p=0.012) in node-positive patients. Median survival after treatment of local, groin, and pelvic/distant recurrence was 52, 8, and 5 months, respectively.

CONCLUSION

For primary treatment, more conservative surgical approaches can be considered with escalation of treatment in patients with concurrent precursor lesions, positive margins, and/or nodal involvement. Further studies are warranted to improve risk stratification in order to optimize treatment paradigms for vulvar cancer patients.

Cemiplimab for the treatment of advanced cutaneous squamous cell carcinoma

INTRODUCTION

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent malignant skin cancer, with an increasing worldwide incidence. Cemiplimab is a human monoclonal antibody directed against programmed cell death-1 receptor that acts by blocking T-cell inactivation. It is the first drug approved for the treatment of adult patients with metastatic or locally advanced cutaneous squamous cell carcinoma who are not candidates for curative surgery or curative radiation.

AREAS COVERED

The aim of this review is to analyze the mechanism of action, including pharmacokinetic and pharmacodynamic properties, clinical efficacy, safety, and tolerability of cemiplimab for squamous cell carcinoma.

EXPERT OPINION

The introduction of immune checkpoint inhibitors has revolutionized the therapeutic scenario of advanced skin cancers. Many challenges regarding the use of cemiplimab for locally advanced and metastatic CSCC still exist. The use of combination treatments, including the association of different immune checkpoint inhibitors, could be a strategy to increase treatment response, reducing the possibility of therapeutic failure. Also, different schemes of treatment or dose adjustments should be considered in order to reduce toxicity, avoiding treatment discontinuation and increasing patient´s quality of life.

Sentinel lymph node biopsy in high-risk cutaneous squamous cell carcinoma of the head and neck

INTRODUCTION

Cutaneous squamous cell carcinoma (cSCC) shows malignant behaviour in 3-4% of patients with locoregional metastases and a poor prognosis, metastases that are difficult to predict clinically. Therefore, sentinel lymph node biopsy (SLNB) has been assessed, with contradictory findings thus far. We aimed to clarify the prognostic value of SLNB in high-risk cSCC patients.

PATIENTS AND METHODS

We completed a retrospective clinical study amongst 63 patients, preoperatively classified as N0 with a high-risk primary cSCC of the head and neck who underwent SLNB between 2001 and 2014 at Helsinki University Hospital (Finland). Considered high risk, the inclusion criteria comprised at least two of the following characteristics: tumour diameter ≥10 mm and/or thickness ≥4 mm and a specific tumour location, such as the lips, ear, scalp and central face. Patients were followed-up postoperatively for a median of 4.1 years (0.2-13.8 years).

RESULTS

Only four (6.3%) patients had positive sentinel nodes. One of these patients died of cSCC, while the other three ultimately survived their disease. Five (7.9%) patients showed a negative SLNB, but developed recurrence within one year postoperatively. Recurrence appeared in the neck lymph nodes concurrently with locoregional soft-tissue invasion in all patients. Amongst these patients, three died for cSCC and the remaining two from other causes. Comparing the SLNB-positive and SLNB-negative groups with recurrence, we identified no significant differences in terms of patient or tumour characteristics.

CONCLUSIONS

SLNB appears to carry no prognostic value for identifying recurrent disease amongst high-risk cSCC in the head and neck area.

Immunotherapy for the Treatment of Cutaneous Squamous Cell Carcinoma

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

Adjuvant therapy for high-risk cutaneous squamous cell carcinoma: 10-year review

Standard of care for high-risk cutaneous squamous cell carcinoma (cSCC) is surgical excision of the primary lesion with clear margins when possible, and additional resection of positive margins when feasible. Even with negative margins, certain high-risk factors warrant consideration of adjuvant therapy. However, which patients might benefit from adjuvant therapy is unclear, and supporting evidence is conflicting and limited to mostly small retrospective cohorts. Here, we review literature from the last decade regarding adjuvant radiation therapy and systemic therapy in high-risk cSCC, including recent and current trials and the role of immune checkpoint inhibitors. We demonstrate evidence gaps in adjuvant therapy for high-risk cSCC and the need for prognostic tools, such as gene expression profiling, to guide patient selection. More large-cohort clinical studies are needed for collecting high-quality, evidence-based data for determining which patients with high-risk cSCC may benefit from adjuvant therapy and which therapy is most appropriate for patient management.

Integrated care pathways and the hub-and-spoke model for the management of non-melanoma skin cancer: A proposal of the Italian Association of Hospital Dermatologists (ADOI)

The term non-melanoma skin cancer (NMSC) refers to skin cancer different from melanoma, and it is usually restricted to basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and their pre-cancerous lesions, e.g., actinic keratosis. These conditions represent the most frequent tumors in Caucasians and are characterized by an increasing incidence worldwide and a high socio-economic impact. The term Integrated Care Pathway (ICP) refers to "a complex intervention for the mutual decision making and organization of care processes for a well-defined group of patients during a well-defined period". The purpose of this paper is to present a proposal from the Italian Association of Hospital Dermatologists (ADOI) for an ICP organization of care of NMSC, considering the hub-and-spoke model in the different geographical areas. This proposal is based on the most recent literature and on documents from the Italian Association of Medical Oncology (AIOM), the European consensus-based interdisciplinary guidelines from the European Association of Dermato- Oncology (EADO), and the National Comprehensive Cancer Network (NCCN). We initially discuss the NMSC outpatient clinic, the role of the multidisciplinary working groups, and the hub-and-spoke model regarding this topic. Then, we define the ICP processes specific for BCC and SCC. The ICP for NMSC is an innovative strategy to guarantee the highest possible quality of health care while the hub-andspoke model is crucial for the organization of different health care structures. Considering the importance on this topic, it is essential to create a valid ICP together with an efficient organization within the different geographical areas.

Differences in the mitochondrial microsatellite instability of Keratoacanthoma and cutaneous squamous cell carcinoma

Keratoacanthoma (KA) is a common cutaneous neoplasm which often resembles typical squamous cell carcinoma (SCC) in both its clinical and historical presentation. Several studies have attempted to identify methods for distinguishing between KA and SCC, however, none of these have proven to play any obvious roles in these tumors. Given this we went on to evaluate mitochondrial microsatellite instability (mtMSI) in KA and SCC in an effort to understand these tumors better. DNA was isolated from paired normal and tumoral tissues donated by 57 KA patients and 43 SCC patients. MtMSI was then analyzed using eight microsatellite markers and was observed in 2 (3.5%) of the 57 KA patients and 8 (18.6%) of the 43 SCC patients, respectively. MtMSI was also shown to affect different locations depending on tumor type. In KA patients, mtMSI was detected at mitochondrial D514 D-loop and presented with (CA) n repeats, in contrast, all of the SCC patient experienced mtMSI at the D310 with (C)n repeats of the D-loop region. These differences in location were found to be significant, which may support the hypothesis that KA and SCC have different pathogenetic pathways. Our results also suggest that mtMSI may be a candidate for developing novel differential diagnostic methods for KA and SCC.

Targeting the PD-1/PD-L1 pathway in glioblastoma multiforme: Preclinical evidence and clinical interventions

Glioblastoma multiforme (GBM), as one of the immunosuppressive and common intrinsic brain tumors in adults, remains an intractable malignancy to manage. Since the standard of care for treatment, which includes surgery and chemoradiation, has not provided a sustainable and durable response in affected patients, seeking novel therapeutic approaches to treat GBM seems imperative. Immunotherapy, a breakthrough for cancer treatment, has become an attractive tool for combating cancer with the potential to access the blood-brain-barrier (BBB). In this regard, programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1), as major immunological checkpoints, have drawn considerable interest due to their effectiveness in a spectrum of highly-aggressive neoplasms through negative regulation of the T-cell-mediated immune response. Nevertheless, due to the immunosuppressive microenvironment of GBM, the efficacy of these immune checkpoint inhibitors (ICIs), when used as monotherapy, has been unfavorable and lacks sufficient beneficial outcomes for GBM patients. A variety of clinical studies are attempting to evaluate the combination of ICIs (neoadjuvant/adjuvant) and existing treatment guidelines to strengthen their effectiveness; however, the exact mechanism of this signaling axis affects the consequences of immune therapy remains elusive. This review provides an overview of the PD-1/PD-L1 pathway, currently approved ICIs for clinical use, preclinical and clinical trials of PD-1/PD-L1 as monotherapy, and when used concomitantly with other GBM treatments.

Cutaneous Squamous Cell Carcinoma: From Pathophysiology to Novel Therapeutic Approaches

Cutaneous squamous cell carcinoma (cSCC), a non-melanoma skin cancer, is a keratinocyte carcinoma representing one of the most common cancers with an increasing incidence. cSCC could be in situ (e.g., Bowen's disease) or an invasive form. A significant cSCC risk factor is advanced age, together with cumulative sun exposure, fair skin, prolonged immunosuppression, and previous skin cancer diagnoses. Although most cSCCs can be treated by surgery, a fraction of them recur and metastasize, leading to death. cSCC could arise de novo or be the result of a progression of the actinic keratosis, an in situ carcinoma. The multistage process of cSCC development and progression is characterized by mutations in the genes involved in epidermal homeostasis and by several alterations, such as epigenetic modifications, viral infections, or microenvironmental changes. Thus, cSCC development is a gradual process with several histological- and pathological-defined stages. Dermoscopy and reflectance confocal microscopy enhanced the diagnostic accuracy of cSCC. Surgical excision is the first-line treatment for invasive cSCC. Moreover, radiotherapy may be considered as a primary treatment in patients not candidates for surgery. Extensive studies of cSCC pathogenic mechanisms identified several pharmaceutical targets and allowed the development of new systemic therapies, including immunotherapy with immune checkpoint inhibitors, such as Cemiplimab, and epidermal growth factor receptor inhibitors for metastatic and locally advanced cSCC. Furthermore, the implementation of prevention measures has been useful in patient management.

Cemiplimab for locally advanced cutaneous squamous cell carcinoma: safety, efficacy, and position in therapy panel

INTRODUCTION

Locally advanced cutaneous squamous cell carcinoma (lacSCC) is rare. Approximately one-fourth of the cases are observed among immunocompromised patients, in particular in solid organ transplant recipients (OTRs). LacSCC has a very poor prognosis. Surgery with or without radiotherapy remains the golden standard of treatment for cSCC. However, in advanced cases, there is a medical need for alternative treatment options. Classic systemic treatments include chemotherapy and/or EGFR inhibitors. Recently the effectiveness of programmed cell death protein-1 (PD-1) inhibitors has been demonstrated for lacSCC. Cemiplimab is a recombinant IgG4 human monoclonal antibody against the PD-1 protein for the intravenous treatment of lacSCC.

AREAS COVERED

The principal studies evaluating the efficacy and safety of cemiplimab for lacSCC are presented.

EXPERT OPINION

Cemiplimab is the first anti-PD-1 antibody that was FDA (2018) and EMA (2019) approved as a systemic treatment for lacSCC and/or metastatic cSCC when curative surgery or radiotherapy is no longer amenable. For this situation, experts currently recommend cemiplimab as a first-line systemic alternative. As cemiplimab therapy is potentially associated with a risk of organ graft rejection, pros and cons should be evaluated for every individual OTR patient with lacSCC.

Survival after parotid gland metastases of cutaneous squamous cell carcinoma of the head and neck

Purpose

Malignant tumours in the parotid gland can originate either from the gland itself or as a result of metastatic spread of other tumours, such as cutaneous squamous cell carcinomas (CSCC) of the head and neck area. The aim of this study was to analyse and compare the clinical behaviour of primary as well as CSCC metastatic parotid cancers with special emphasis on therapy and oncologic outcome.

Methods

Clinical and histopathological data of 342 patients with parotid gland malignomas surgically treated in a tertiary referral centre between 1987 and 2015 were retrospectively assessed. Oncologic outcomes of all cases with CSCC metastasis of the parotid gland (n = 49) were compared to those of primary parotid gland carcinomas (n = 293).

Results

Mean age at diagnosis was 72.3 years for CSCC patients versus 56.8 years in patients with primary parotid carcinoma. A total of 83.7% of CSCC patients were male, compared to 48.8% in the group of primary carcinomas. Forty-five out of 49 CSCC patients underwent total parotidectomy and neck dissection (91.8%). A total of 93.9% out of all CSCC patients received adjuvant radiotherapy. Five-year overall survival (OS) was 32.6% in CSCC patients versus 77.2% in primary parotid carcinoma patients.

Conclusion

As compared to primary parotid cancers, we could show that patients suffering from CSCC metastases to the parotid gland presented with significantly higher age and worse survival.

Deciphering the Molecular Landscape of Cutaneous Squamous Cell Carcinoma for Better Diagnosis and Treatment

Cutaneous squamous cell carcinoma (cSCC) is a common type of neoplasia, representing a terrible burden on patients' life and clinical management. Although it seldom metastasizes, and most cases can be effectively treated with surgical intervention, once metastatic cSCC displays considerable aggressiveness leading to the death of affected individuals. No consensus has been reached as to which features better characterize the aggressive behavior of cSCC, an achievement hindered by the high mutational burden caused by chronic ultraviolet light exposure. Even though some subtypes have been recognized as high risk variants, depending on certain tumor features, cSCC that are normally thought of as low risk could pose an increased danger to the patients. In light of this, specific genetic and epigenetic markers for cutaneous SCC, which could serve as reliable diagnostic markers and possible targets for novel treatment development, have been searched for. This review aims to give an overview of the mutational landscape of cSCC, pointing out established biomarkers, as well as novel candidates, and future possible molecular therapies for cSCC.

Identification of responders to immune checkpoint therapy: which biomarkers have the highest value?

Evasion of immune recognition by the innate and acquired immune system is a major principle of tumour cells and belongs to the hallmarks of cancer. Immune checkpoint inhibitor-based cancer therapies targeting the co-inhibitory receptors CTLA-4 or PD-1 have received enormous scientific and clinical attention during the last few years, because of promising clinical results observed in the treatment of different cancer entities including melanoma and cutaneous squamous cell carcinoma. However, the enthusiasm about the effects of the immune checkpoint inhibitors is muted as only a subfraction of patients shows a stable clinical response. To predefine the patient cohorts that may benefit from immune checkpoint therapy, rigorous biomarker analyses, which predict the response to these novel therapies, need to be performed. In addition, combination of immune checkpoint therapy with classical DNA-damaging chemotherapy or radiotherapy, which positively affects tumour neo-antigen presentation, appears to be a promising approach in optimizing patients' response. In this review, we briefly summarize important biomarkers for patient stratification and discuss the current limitations of these biomarkers in defining responders vs. non-responders to immune checkpoint therapy.

[Classification of cutaneous squamous cell carcinoma : How do I recognise my high-risk patient?]

Cutaneous squamous cell carcinomas are the second most common malignant tumours of the skin. In most cases, they are primarily treatable by surgery. Various risk factors for local recurrence as well as metastasis and tumor-specific death have been described. Various classification systems are available for risk stratification. Tumour thickness is the strongest risk factor for the development of local recurrences, but also for metastasis and tumour-specific death. In addition, the immune status of patients, location and histological factors such as growth patterns and differentiation play an important role in the assessment of the individual risk. According to these parameters, patients should be included in a risk-adapted follow-up regimen. The risk of local recurrence and metastasis is highest in the first few years after excision, which is why follow-up care should be more intensive during this time.