Systemic Therapy in Advanced Cutaneous Squamous Cell Carcinoma (CSCC): The Roswell Park Experience and a Review of the Literature

Immunotherapy followed by cetuximab in locally advanced/metastatic cutaneous squamous cell carcinomas: the I-TACKLE trial

BACKGROUND

Immunotherapy with pembrolizumab and cemiplimab achieves an overall response rate (ORR) of 34-51 % in locally advanced/metastatic (LA/M) cSCC, but primary and acquired resistance remains a challenge. This study evaluates whether adding cetuximab to pembrolizumab can overcome resistance by reducing immune escape.

PATIENTS AND METHODS

I-TACKLE is a phase II, open-label trial conducted at three Italian centers. Patients received intravenous pembrolizumab 200 mg every 3 weeks, and cetuximab was added in cases of stable disease or progression. The primary endpoint was cumulative ORR by a single agent or by combination strategy. Secondary endpoints included safety, progression-free survival (PFS), overall survival (OS), and response duration.

RESULTS

From May 2019 to April 2021, 43 patients were enrolled and treated with pembrolizumab, and 23 received combination therapy. Median treatment durations were 3 months (pembrolizumab) and 4 months (combination). Cumulative ORR was 63 % [95 % CI 48-77], with 19/43 (44 %) responding to pembrolizumab and 8/21 (38 %) responding to the combination after resistance. Both patients experiencing an acquired resistance to pembrolizumab obtained partial response when cetuximab was introduced. Overall, 10/23 (44 %) responded to the combination. One-year PFS was 51 % with pembrolizumab and 42 % with combination therapy. Grade 3-4 treatment-related adverse events occurred in 7/43 (16 %) during pembrolizumab and 8/23 (35 %) during combination therapy, primarily dermatitis (30 %).

CONCLUSIONS

In LA/M cSCC, the addition of cetuximab to pembrolizumab reverts primary and acquired resistance with manageable toxicities. This sequential approach warrants further study.

Access to systemic treatment of non-melanoma skin cancer in Spain: a survey analysis

BACKGROUND

Novel and highly effective drugs for non-melanoma skin cancer (NMSC) improve patient outcomes, but their high cost strains healthcare systems. Spain's decentralized public health system, managed by 17 autonomous communities (AaCc), raises concerns about equitable access.

METHODS

A cross-sectional survey (July-September 2023) was sent to Spanish Multidisciplinary Melanoma Group (GEM Group) members to assess access to new drugs.

FINDINGS

Fifty physicians from 15 Spanish AaCc responded to the survey. Access for drug with approved public reimbursement, Hedgehog inhibitors in basal-cell carcinoma and anti PD-L1 antibody in Merkel carcinoma, was observed in 84% and 86% of centers, respectively. For other EMA-approved treatments, but without reimbursement in Spain access decreased to 78% of centers. Heterogeneity in access was mainly observed intra regions.

CONCLUSION

Unequal financial support for drugs for NMSC with creates a patchwork of access across Spanish hospitals, with variations even within the same AaCc.

Global research trends in the treatment of squamous cell carcinoma over the past decade: A bibliometric analysis

Objective

This study aims to identify research trends and hot spots in the treatment of Squamous Cell Carcinoma (SCC) over the past decade using bibliometric analysis.

Methods

Data were extracted from the Web of Science Core Collection, including Science Citation Index Expanded (SCI-Expanded), Social Sciences Citation Index (SSCI), and Emerging Sources Citation Index (ESCI). The data underwent manual cleaning to remove inaccuracies and irrelevancies, followed by transformation into an analyzable format via the VOSviewer software. This tool facilitated the visualization of co-occurrence networks and keyword maps, highlighting the relationships and the prominence of research themes.

Results

A total of 46448 authors from 7374 institutions across 108 countries contributed to the literature, reflecting a broad international effort. The study documented a consistent increase in SCC-related publications up to 2020, with some variability in subsequent years. Notably, the United States, Germany, China, the United Kingdom, and France were predominant in this research area. The University of Texas MD Anderson Cancer Center and the University of Pittsburgh were leading contributors in terms of publication volume and citation impact. Key journals included 'Oral Oncology' and 'Clinical Cancer Research', which were central to the dissemination of high-impact research. Our keyword analysis identified three major research clusters focused on molecular mechanisms, clinical treatment strategies, and emerging interests in immunotherapeutic approaches.

Conclusions

The extensive collaboration and the increasing publication trend underscore the growing global commitment to advancing SCC treatment. The high level of engagement from top institutions and the concentration of research in influential journals reflect the field's dynamic evolution towards innovative and effective treatment modalities. This study provides a valuable overview for researchers, guiding future studies towards areas of high impact and emerging trends in SCC treatment. The findings advocate for enhanced focus on personalized medicine and combination therapies, which are poised to improve outcomes for SCC patients.

Current Advances and Challenges in the Management of Cutaneous Squamous Cell Carcinoma in Immunosuppressed Patients

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin malignancy and poses a significant risk to immunosuppressed patients, such as solid organ transplant recipients and those with hematopoietic malignancies, who are up to 100 times more likely to develop cSCC compared with the general population. This review summarizes the current state of treatment for cSCC in immunosuppressed patients, focusing on prevention, prophylaxis, surgical and non-surgical treatments, and emerging therapies. Preventative measures, including high-SPF sunscreen and prophylactic retinoids, are crucial for reducing cSCC incidence in these patients. Adjusting immunosuppressive regimens, particularly favoring mTOR inhibitors over calcineurin inhibitors, has been shown to lower cSCC risk. Surgical excision and Mohs micrographic surgery remain the primary treatments, with adjuvant radiation therapy recommended for high-risk cases. Traditional chemotherapy and targeted therapies like EGFR inhibitors have been utilized, though their efficacy varies. Immunotherapy, particularly with agents like cemiplimab and pembrolizumab, has shown promise, but its use in immunosuppressed patients requires further investigation due to potential risks of organ rejection and exacerbation of underlying conditions. Treatment of cSCC in immunosuppressed patients is multifaceted, involving preventive strategies, tailored surgical approaches, and cautious use of systemic therapies. While immunotherapy has emerged as a promising option, its application in immunosuppressed populations necessitates further research to optimize safety and efficacy. Future studies should focus on the integration of personalized medicine and combination therapies to improve outcomes for this vulnerable patient group.

Overexpression of CCL-20 and CXCL-8 genes enhances tumor escape and resistance to cemiplimab, a programmed cell death protein-1 (PD-1) inhibitor, in patients with locally advanced and metastatic cutaneous squamous cell carcinoma

Cemiplimab has demonstrated relevant clinical activity in cutaneous squamous cell carcinoma (cSCC) but mechanisms of primary and acquired resistance to immunotherapy are still unknown. We collected clinical data from locally advanced and/or metastatic cSSC patients treated with cemiplimab in two Italian University centers. In addition, gene expression analysis by using Nanostring Technologies platform to evaluate 770 cancer- and immune-related genes on 20 tumor tissue samples (9 responders and 11 non-responders to cemiplimab) was performed. We enrolled 81 patients with a median age of 82 years. After 16.4 months of median follow-up, 12- and 24-months PFS were 53% and 42%, respectively; while 12- and 24-months OS were 71% and 61%, respectively. Treatment was well tolerated. Overall response rate (ORR) was 58%, with a disease control rate (DCR) of 77.8%. The difference between genes expressed in responder versus non-responder patient samples was substantial, particularly for genes involved in immune system regulation. Cemiplimab-resistant tumors were associated with over-expression of CCL-20 and CXCL-8. Cemiplimab confirmed efficacy and safety data in real-life cSCC patients. Overexpression of CCL-20 and CXCL-8 could represent biomarkers of lack of response to immunotherapy.

The hidden Australian skin cancer epidemic, high-risk cutaneous squamous cell carcinoma: a narrative review

Deaths from non-melanoma skin cancers (NMSCs) have almost doubled in Australia in recent years. Cutaneous squamous cell carcinoma (cSCC) constitutes approximately 20% of NMSCs, but is responsible for most of the deaths. Most skin cancers are easy to diagnose and treat and therefore cSCC are often trivialised; however, there is a high-risk subgroup of cSCC (HRcSCC) that is associated with a high risk of metastasis and death. The definition of early HRcSCC and our ability to identify them is evolving. Many significant prognostic factors have been identified, but a universally accepted prognostic index does not exist. Guidelines for workup, treatment, and follow-up leave many important decisions open to broad interpretation by the treating physician or multidisciplinary team. Some of the treatments used for metastatic cSCC are not supported by robust evidence and the prognosis of metastatic cSCC is guarded. In this review, we highlight the rapid rise in NMSC deaths and discuss some of the deficiencies in our knowledge of how to define, diagnose, stage, and manage HRcSCC.

A Food Odorant, α-Ionone, Inhibits Skin Cancer Tumorigenesis by Activation of OR10A6

SCOPE

This study aims to investigate the anticancer properties of α-ionone in squamous cell carcinoma (SCC).

METHODS AND RESULTS

The expression of OR10A6 together with olfactory receptor signaling components is demonstrated in A431 human SCC cells via RT-PCR and qRT-PCR analysis. OR10A6 activation in A431 cells using the ligand α-ionone inhibits proliferation and migration but induces apoptosis which is confirmed by proliferation assay, colony formation, and western blotting. The mechanism involves the core proteins of the Hippo pathway, where the phosphorylation of large tumor suppressor kinase (LATS), yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ) is confirmed by western blotting. However, the anticancer effects of α-ionone are abrogated in A431 cells with OR10A6 gene knockdown. In A431 xenograft mouse model, the injection of α-ionone suppresses tumor growth, induces apoptosis, and increases phosphorylation of the LATS-YAP-TAZ signaling axis in the Hippo pathway. None of these effects are observed in xenografted tumors with OR10A6 gene knockdown.

CONCLUSION

These findings collectively demonstrate that activation of ectopic OR OR10A6 by α-ionone in SCC cells stimulates the Hippo pathway and suppresses tumorigenesis both in vitro and in vivo, suggesting a novel therapeutic candidate for the treatment of SCC.

Real-World Treatment Patterns and Outcomes of Cemiplimab in Patients with Advanced Cutaneous Squamous Cell Carcinoma Treated in US Oncology Practices

Background

Prior to the Food and Drug Administration approval of cemiplimab in 2018, the median overall survival (OS) for adult patients with advanced CSCC receiving systemic therapy was approximately 8 to 15 months. Limited real-world data are available on cemiplimab for this indication in the US.

Patients and Methods

This retrospective cohort study included US patients with advanced CSCC initiating cemiplimab monotherapy in a real-world database (2018-2021). A clinical trial-like sub-cohort was identified using select criteria. Time to treatment discontinuation (TTD), time to next treatment (TTNT), and OS were estimated using Kaplan-Meier methods. Cox proportional hazard models were used to examine prognostic factors associated with OS in the main cohort.

Results

The main cohort included 622 patients (n = 240 in the trial-like cohort). In the main cohort, the median age was 78 years, 77.8% were male, 21.4% were immunocompromised/immunosuppressed, and 63.8% had metastatic CSCC. Median (95% CI) TTD and TTNT were 8.0 (6.6-9.0) months and 16.4 (13.3-21.0) months, respectively, in the main cohort. Median (95% CI) OS was 24.8 (21.8-29.1) months in the main cohort (not reached in the trial-like cohort). In multivariable analyses, age <60 years (hazard ratio [HR], 0.37), Eastern Cooperative Oncology Group performance status <3-4 (HR range, 0.13-0.57), and primary CSCC location in the head and neck only versus extremities only (HR, 0.59) were associated with better OS. Similar OS was observed between patients who had immunosuppressing/immunocompromising conditions and those without.

Conclusion

These findings confirm the effectiveness of cemiplimab among a heterogenous, real-world advanced CSCC patient population and substantiate the efficacy of cemiplimab observed in clinical trials.

Cutaneous Squamous Cell Carcinoma: An Updated Review

Representing the second most common skin cancer, the incidence and disease burden of cutaneous squamous cell carcinoma (cSCC) continues to increase. Surgical excision of the primary site effectively cures the majority of cSCC cases. However, an aggressive subset of cSCC persists with clinicopathological features that are indicative of higher recurrence, metastasis, and mortality risks. Acceleration of these features is driven by a combination of genetic and environmental factors. The past several years have seen remarkable progress in shaping the treatment landscape for advanced cSCC. Risk stratification and clinical management is a top priority. This review provides an overview of the current perspectives on cSCC with a focus on staging, treatment, and maintenance strategies, along with future research directions.

Guidelines for the diagnosis and treatment of cutaneous squamous cell carcinoma: a GRADE approach for evidence evaluation and recommendations by the Italian Association of Medical Oncology

Cutaneous squamous cell carcinoma (CSCC) accounts for ∼20%-25% of all skin tumors. Its precise incidence is often challenging to determine due to limited statistics and its incorporation with mucosal forms. While most cases have a favorable prognosis, challenges arise in patients presenting with locally advanced or metastatic forms, mainly appearing in immunocompromised patients, solid organ transplantation recipients, or those facing social difficulties. Traditionally, chemotherapy and targeted therapy were the mainstays for advanced cases, but recent approvals of immunotherapeutic agents like cemiplimab and pembrolizumab have revolutionized treatment options. These guidelines, developed by the Italian Association of Medical Oncologists (AIOM) using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach, aim to guide clinicians in diagnosing, treating, and monitoring patients with CSCC, covering key aspects from primitive tumors to advanced stages, selected by a panel of experts selected by AIOM and other national scientific societies. The incorporation of these guidelines into clinical practice is expected to enhance patient care and address the evolving landscape of CSCC management.

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.

A Sub-Group of Kidney-Transplant Recipients with Highly Aggressive Squamous Cell Carcinoma Expressing Phosphorylated Serine392p53

Cutaneous squamous cell carcinomas in kidney-transplant recipients are frequent, with an increasing incidence linked to long immunosuppression durations and exposure to ultraviolet radiation. p53 is at the cornerstone of ultraviolet-induced DNA damage, but the role of p53 post-translational modifications in this context is not yet deciphered. Here, we investigated the phosphorylation status of p53 at Serine 392 in 25 cutaneous squamous cell carcinomas in kidney-transplant recipients, compared with 22 non-transplanted patients. Cutaneous squamous cell carcinomas in transplanted patients occurred after a median period of 19 years of immunosuppression, with a median number of 15 cutaneous squamous cell carcinomas and more aggressive histological and clinical characteristics. There was no significant difference between Ki67, p53, and pSer392p53 expression in the two groups. Using principal component analysis, we identified a cluster of exclusively transplanted patients with a median of 23 years of immunosuppression duration, significantly more aggressive biological characteristics, and higher pSer392p53 expression. pSer392p53 was expressed in the whole tumor, suggesting an early carcinogenic event in the course of prolonged immunosuppression. This high, diffuse pSer392p53 expression, corresponding to a high level of DNA damage, might be useful to identify aggressive cutaneous squamous cell carcinomas in kidney-transplant recipients to treat them more aggressively.

Atypical Site of Presentation of a Rare Type of SMARCA4-Positive Cutaneous Squamous Cell Carcinoma of the Skin: Case Report and Review of the Literature

Cutaneous squamous cell carcinoma (cSCC) comprises 20% of cases of nonmelanoma skin cancers in the United States. In total, 3% to 5% of squamous cell carcinoma (SCC) are metastatic at the time of presentation, associated with significant mortality due to a lack of standardized treatment options. In total, 95% of these tumors are amenable to the initial standard of treatment, which is surgical resection. However, a small percentage of them require systemic therapy as they are either locally advanced to regional lymph nodes or have distant metastasis. The common sites of presentation of cSCC are the scalp and the face with predictable spread to the intra-parotid, upper jugular, and perifacial lymph nodes. In our case report, however, our patient had a large lump lesion on the upper back, an unusual site of presentation of cSCC, with locally advanced metastasis to the left axillary lymph nodes. Subsequently, the tumor marker study revealed a positive SMARCA4 variant (the essential ATPase subunit of the Switch (SWI)/Sucrose Nonfermenting (SNF) chromatin-remodeling complex) that is even rarer in the context of cSCC. Furthermore, abnormalities in SWI/SNF chromatin-remodeling complex subunits have shown promising results as a target therapy for immune checkpoint inhibitor (ICI) therapy. We present an atypical presentation site of locally advanced rare variant SMARCA4-positive cSCC in a patient who received treatment with chemoradiation and systemic therapy with ICI after primary surgical resection. To date, only 2 cases of SMARCA4-positive cSCC were found in the literature with no details of the treatment received. Our case is unique in its atypical site of presentation as well as showing partial response to radiotherapy (RT) and systemic therapy with ICI.

5-aminolevulinic acid sonodynamic therapy for cutaneous squamous cell carcinoma

BACKGROUND

The treatment of deep-invasive cutaneous squamous cell carcinoma (cSCC) is difficult. Sonodynamic therapy (SDT) has showed advantages in large penetration depth, small trauma, good repeatability, high targeting selectivity and effective protection for intact structure and function of tissues and organs.

OBJECTIVE

To study the efficacy and safety of 5-aminolevulinic acid SDT (ALA-SDT) in the treatment of cSCC.

METHODS

The absorption and transformation of ALA after co-incubation with cSCC were detected by UV-Vis and fluorescence absorption. The production of reactive oxygen species (ROS) when protoporphyrin IX (PpIX) excited with ultrasound was detected by ROS detection probe. Cytotoxicity of ALA-SDT to cSCC was detected with cytotoxicity indicators. The tumor volume changes and tumor weight of mice after ALA-SDT were detected. The effects of ALA-SDT on the growth of mice were evaluated through the changes in body weight of mice. Biosafety of treatment was further evaluated by histopathology to determine whether the tissues and organs of mice were affected after ALA-SDT.

RESULTS

ALA can be absorbed and converted into PpIX when incubated with cSCC cells and produces ROS with ultrasound irradiation. ALA-SDT showed a significant cytotoxicity on cSCC cells. With one session of ALA-SDT in vivo, tumor growth was slowed but not stopped and would proceed once treatment was ended. ALA-SDT had no significant effect on body weight changes and major tissues and organs of the mice.

CONCLUSION

ALA-SDT could safely and reduce cSCC cells growth both in vitro and in vivo.

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

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

Immunotherapy and Hypofractionated Radiotherapy in Older Patients with Locally Advanced Cutaneous Squamous-Cell Carcinoma of the Head and Neck: A Proposed Paradigm by the International Geriatric Radiotherapy Group

Cutaneous skin carcinoma is a disease of older patients. The prevalence of cutaneous squamous-cell carcinoma (cSCC) increases with age. The head and neck region is a frequent place of occurrence due to exposure to ultraviolet light. Surgical resection with adjuvant radiotherapy is frequently advocated for locally advanced disease to decrease the risk of loco-regional recurrence. However, older cancer patients may not be candidates for surgery due to frailty and/or increased risk of complications. Radiotherapy is usually advocated for unresectable patients. Compared to basal-cell carcinoma, locally advanced cSCC tends to recur locally and/or can metastasize, especially in patients with high-risk features such as poorly differentiated histology and perineural invasion. Thus, a new algorithm needs to be developed for older patients with locally advanced head and neck cutaneous squamous-cell carcinoma to improve their survival and conserve their quality of life. Recently, immunotherapy with checkpoint inhibitors (CPIs) has attracted much attention due to the high prevalence of program death ligand 1 (PD-L1) in cSCC. A high response rate was observed following CPI administration with acceptable toxicity. Those with residual disease may be treated with hypofractionated radiotherapy to minimize the risk of recurrence, as radiotherapy may enhance the effect of immunotherapy. We propose a protocol combining CPIs and hypofractionated radiotherapy for older patients with locally advanced cutaneous head and neck cancer who are not candidates for surgery. Prospective studies should be performed to verify this hypothesis.

Treatment of metastatic squamous cell carcinoma arising in sacrococcygeal pilonidal sinus: a case report series

Background

Squamous cell carcinoma (SCC) arising in a sacrococcygeal pilonidal sinus is rare, with cases of metastatic disease being even rarer. Among published cases, almost none have reported on systemic treatment.

Objective

This disease has a poorer prognosis than other forms of cutaneous SCC; therefore, our objective is to shed some light on the treatment of metastatic disease.

Methods

We present a series of nine cases treated at a single center, four of whom received systemic treatment. Additionally, other previously reported cases of metastatic disease are included in an attempt to draw stronger conclusions.

Results

Four patients were treated under several treatment regimens, with a median progression-free survival of only 2 months and two instances of partial response (18%). The best result was achieved with cemiplimab. Across all the cases, there was a trend toward a benefit of the use of systemic treatment (HR 0.41, 95% CI 0.15-1.12, p = 0.083; median overall survival 13 vs. 8 months).

Limitations

Limitations include the significant lack of information on previously published cases and the extremely heterogeneous nature of the existing information.

Conclusion

The initial systemic treatment should be an anti-PD-1, as with other SCCs. After progression on anti-PD-1, there is no strong evidence to support the recommendation of a specific treatment or sequence: options include cetuximab and/or chemotherapy (platinum, paclitaxel, 5-fluorouracyl).

PD-1 Inhibitors in Elderly and Immunocompromised Patients with Advanced or Metastatic Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) of the skin is the second most common form of skin cancer, with aging and prolonged exposure to ultraviolet rays being the main causes of the disease. Cemiplimab and pembrolizumab recently gained regulatory approval for the treatment of locally advanced and metastatic cSCC-conditions that are not treatable by surgical resection and/or radiotherapy. Although the results from the clinical trials have been promising, these studies have not included immunosuppressed, elderly patients. In this study, we included all immunocompromised and immunocompetent patients over the age of 75 years diagnosed with locally advanced or metastatic cSCC and treated with cemiplimab or pembrolizumab. The median duration of follow-up from cSCC diagnosis was 35.6 months, 82.9% of patients were male, and the median age was 83 years old. The median progression-free survival was 8.94 months. The incidence of treatment-related adverse events was 85.6%, the majority of which were grades 1 or 2. The disease control rate was 91.4%, the complete response rate was 17.1%, the partial response rate was 51.4%, the stable disease rate was 23%, and the progressive disease rate was 8.7%. Based on this study, cemiplimab and pembrolizumab for the treatment of locally advanced or metastatic cSCC in elderly, immunocompromised patients are efficacious, with acceptable safety profiles.

Advancing Cancer Research: Current Knowledge on Cutaneous Neoplasia

Skin cancers require a multidisciplinary approach. The updated guidelines introduce new insights into the management of these diseases. Melanoma (MM), the third most common skin cancer, a malignant melanocytic tumor, which is classified into four major histological subtypes, continues to have the potential to be a lethal disease. The mortality-incidence ratio is higher in Eastern European countries compared to Western European countries, which shows the need for better prevention and early detection in Eastern European countries. Basal cell carcinoma (BCC) and squamous cell carcinoma (cSCC) remain the top two skin cancers, and their incidence continues to grow. The gold standard in establishing the diagnosis and establishing the histopathological subtype in BCC and SCC is a skin biopsy. Sebaceous carcinoma (SeC) is an uncommon and potentially aggressive cutaneous malignancy showing sebaceous differentiation. It accounts for 0.7% of skin cancers and 3-6.7% of cancer-related deaths. Due to the rapid extension to the regional lymph nodes, SeC requires early treatment. The main treatment for sebaceous carcinoma is surgical treatment, including Mohs micrographic surgery, which has the advantage of complete margin evaluation and low recurrence rates. Primary cutaneous lymphomas (PCLs) are a heterogeneous group of lymphoproliferative diseases, with no evidence of extracutaneous determination at the moment of the diagnosis. PCLs have usually a very different evolution, prognosis, and treatment compared to the lymphomas that may secondarily involve the skin. The aim of our review is to summarize the important changes in the approach to treating melanoma, non-melanoma skin, cutaneous T and B cell lymphomas, and other types of skin cancers. For all skin cancers, optimal patient management requires a multidisciplinary approach including dermatology, medical oncology, and radiation oncology.

Immunotherapy for keratinocyte cancers. Part I: Immune-related epidemiology, risk factors, pathogenesis, and immunotherapy management of keratinocyte cancers

The important role of the immune system in the surveillance and control of keratinocyte cancers (KCs), namely squamous and basal cell carcinomas, is increasingly appreciated, as new immunotherapies have recently become available. As the field of immunotherapy is rapidly evolving, this review synthesizes key concepts and highlights important cellular components within the immune system responsible for attacking KCs. We review the most current data on the epidemiology, risk factors, and immunotherapy management for KCs. Patients will seek advice from dermatologists to help explain why immunotherapies work for KCs and whether they might be appropriate for different clinical scenarios. Collaboration with medical colleagues across different disciplines to evaluate KCs for response to immunotherapy and early recognition of immune-related adverse events will help to optimize patient outcomes.

New and emerging drugs for the treatment of advanced cutaneous squamous cell carcinoma

INTRODUCTION

Cutaneous squamous cell carcinoma (CSCC) is the second most common form of human cancer. Treatment of locally advanced and/or recurrent CSCC is often challenging. A subset of patients are not candidates for curative-intent therapies due to extent of loco-regional disease, refractoriness to prior local therapy, or presence of distant metastasis.

AREAS COVERED

Traditionally, CSCC has been treated with surgery and/or radiotherapy, but in some instances, local therapies can lead to significant functional morbidity or are no longer feasible. Until 2018, systemic therapy options to treat patients with advanced CSCC were limited. Recently, clinical studies have shown activity of Immune Checkpoint Inhibitors (ICI) in patients with advanced CSCC. This article reviews the current systemic therapy options for CSCC with a focus on ICI and emerging promising therapies in the treatment of this challenging disease.

EXPERT OPINION

ICI is currently the most effective and tolerable systemic therapy in the treatment of non-immunosuppressed advanced CSCC and can lead to cure in a subset of patients. Combinatorial therapies to overcome resistance to ICI may further increase the proportion of patients who will benefit from ICI and may help improve the quantity and quality of life of patients affected by this disease.

Monoclonal antibodies for the treatment of squamous cell carcinoma: A literature review

BACKGROUND

Squamous cell carcinoma (SCC) is a relatively common and heterogenous malignancy of different organs, such as the skin, esophagus, and lungs. Although most cases experience good survival with surgical methods, management of advanced types of the disease remains challenging. Several modalities, including different chemotherapy regimens and immunotherapies, have been investigated in this matter, among which Monoclonal antibodies (Mabs) are one of the most promising ones. Since the development of Mabs, they have been widely used to treat different diseases. Mabs have shown significant efficacy with high specificity along with acceptable safety, which makes them a favorable option in cancer therapy. In this article, we aimed to review the different aspects of using Mabs in SCC therapy.

RECENT FINDINGS

We found that treating with different Mabs has shown excellent efficacy accompanied by acceptable safety in treating SCC of different organs. Therefore, Mabs are considered great options in the treatment of SCC, especially in advanced cases. Overall, two highly potent types of Mabs in SCC therapy are anti-EGFR Mabs and checkpoint inhibitors, especially Cetuximab, Nimotuzumab, and PD-1 inhibitors. Bevacizumab is also a promising option as adjuvant therapy to other modalities.

CONCLUSION

Although some Mabs have shown promising outcomes in SCC therapy, their application as a part of cancer treatment depends on further investigations regarding cost-effectiveness and predictors of response. FDA has approved several Mabs in SCC therapies, and Mabs may have a crucial role in this era in the near future, especially in treating head and neck and esophageal SCC and metastatic lung cancer.

The Current Treatment Landscape of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers (NMSCs) are the most common form of skin cancer worldwide. The global incidence of cutaneous squamous cell carcinoma (CSCC) is rising, with an estimated 2.4 million cases diagnosed in 2019. Chronic exposure to ultraviolet (UV) radiation is a major risk factor for developing CSCC. Most early-stage CSCCs are treated successfully with surgery or radiotherapy; however, locally advanced or metastatic disease can be associated with significant morbidity or mortality. Recently, the treatment paradigm for advanced CSCC has been revolutionised by the introduction of immunotherapy, which can achieve a response rate of approximately 50% with durable cancer control, and significant improvement in quality of life. With the regulatory approval of programmed death-1 (PD-1)-targeting drugs since 2018, immunotherapy is now recognised as the standard of care for first-line systemic therapy in advanced or metastatic CSCC.

Immune checkpoint inhibitors in advanced cutaneous squamous cell carcinoma: A systemic review and meta-analysis

BACKGROUND

To evaluate the immune checkpoint inhibitors (CPI) for the treatment of patients with advanced cutaneous squamous cell carcinoma (CSCC).

MATERIALS AND METHODS

A meta-analysis was conducted, and the efficacy and safety of CPI were assessed.

RESULTS

A total of 13 studies with 980 patients were included. The pooled objective response rate (ORR) and disease control rate were 47.2% and 64.4%, separately. In addition, patients with primary tumor located in head and neck (odds ratio [OR]: 0.374, 95% confidence interval [CI]: 0.219-0.640, p < 0.001) and positive expression of programmed death ligand 1 (OR: 0.364, 95% CI: 0.158-0.842, P = 0.018) had superior ORR during CPI treatment. The incidence of progression free survival at 6 and 12 months was 59.3% and 52.8%, and 80.6% and 76.4% for overall survival. As for safety, the overall incidence of adverse events with all grades and 3-4 grade was 76.9% and 20.2%.

CONCLUSIONS

Our systematic review confirmed the satisfying efficacy and acceptable toxicity of CPI for advanced CSCC.

A phase 2 study of first-line nivolumab in patients with locally advanced or metastatic cutaneous squamous-cell carcinoma

BACKGROUND

Cutaneous squamous-cell carcinoma (CSCC) is among the most frequent malignancies worldwide. For those not amenable to treatment with curative intent, immune checkpoint inhibition (ICI) with anti-programmed death receptor 1 (PD-1) antibodies has emerged as a novel therapeutic option. In this study, the authors sought to investigate the activity of the anti-PD-1 agent nivolumab in patients with advanced CSCC (aCSCC).

METHODS

CA209-9JC was an open-label, single-arm, phase 2 study to evaluate the safety and/or efficacy of nivolumab in systemic treatment-naive patients with aCSCC. Nivolumab (3 mg/kg) was administered every 2 weeks until disease progression, unacceptable toxicity, or 12 months of treatment. The primary end point was the best objective response rate (BORR) as per RECIST 1.1 criteria. Secondary end points included safety, progression-free survival (PFS), and overall survival (OS).

RESULTS

Twenty-four patients with aCSCC were enrolled with a median age of 74 years (range, 48-93). Among the 24 patients evaluable for response, the BORR was 58.3% (14/24); there were no complete responses. With a median follow-up of 17.6 months, median duration of response has not been reached, and the estimated median PFS and OS were 12.7 and 20.7 months, respectively. Prior exposure to radiotherapy was associated with worse outcomes (p = .035, univariate analysis). Treatment-related adverse events of any grade and grade ≥ 3 occurred in 21 (87.5%) and six (25%) patients, respectively, and one patient discontinued nivolumab due to toxicities.

CONCLUSIONS

Nivolumab resulted in robust antitumor activity, sustained responses, and good tolerability in systemic treatment-naive patients with aCSCC. These data provide further evidence to support the use of ICI as the standard treatment of aCSCC.

Update in the treatment of non-melanoma skin cancers: the use of PD-1 inhibitors in basal cell carcinoma and cutaneous squamous-cell carcinoma

Non-melanoma skin cancer (NMSC) includes a wide range of cutaneous tumors, the most frequent of which are basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (CSCC). Although NMSC is usually cured by surgical resection, in rare cases it can progress to locally advanced and metastatic disease. Risk factors for advanced disease include comorbidities, neglect, and immunosuppression. Advanced NMSC may require systemic treatment if surgery and radiation are not feasible. Chemotherapy, epidermal growth factor receptor (EGFR) inhibitors in CSCC, and hedgehog inhibitors in BCC have been used but are generally of limited benefit, with responses often short-lived and toxicity issues. Given the high mutational burden of NMSC, the use of immunotherapy has been investigated and two anti-PD-1 antibodies, cemiplimab and pembrolizumab, are approved for the treatment of advanced CSCC not curable by surgery or radiation. Both have shown durable responses with good tolerability in patients in phase II trials and anti-PD-1 therapy is now the standard of care for locally advanced and metastatic CSCC. PD-1 blockade is also approved as second-line therapy in advanced BCC, with frequent and durable responses after failure on hedgehog inhibitor therapy. PD-1 checkpoint inhibition is being assessed for NMSC in combination with other modalities, including oncolytic viruses and EGFR inhibitors. Adjuvant and neoadjuvant use of cemiplimab and pembrolizumab is also being investigated with several ongoing trials. Further clinical trials of immunotherapy must be prioritized in NMSC for further improvement in outcomes.

Skeletal Mets From Squamous Cell Carcinoma of the Lower Limb: A Case Report

Squamous cell carcinoma (SCC) is the second most common non-melanoma skin cancer worldwide and one of the most capable of metastasis. The bone is a common metastatic site of cancers, which is a major cause of morbidity, with an estimated 350,000 people dying yearly from bone metastases. However, bone metastasis from an SCC in the lower limb is rarely reported in the literature and the role of systemic chemotherapy is not well established. We report a case of a 72-year-old gentleman with an SCC metastasis of the bone. This patient received six cycles of platinum-based chemotherapy with no surgical or radiation intervention.

Benchmarking Survival Outcomes Following Surgical Management of pT3 and pT4 Cutaneous Squamous Cell Carcinoma of the Head and Neck

Background

pT3/4 head and neck cutaneous squamous cell carcinomas (HNcSCCs) are associated with poor outcomes, including local recurrence, metastasis and death. Whilst surgery remains the standard treatment for advanced HNcSCC, novel systemic therapies, such as immunotherapy, are being used earlier in the treatment paradigm. It is imperative that the clinical outcomes of surgery are clearly described so that conventional and emerging treatment modalities can be better integrated and sequenced in the management of pT3/4 HNcSCC.

Methods

Patients with confirmed pT3/4 HNcSCC undergoing curative surgical resection between 2014-2020 were identified retrospectively from a prospectively maintained research database. The primary outcomes of interest were locoregional control (LRC), disease-specific survival (DSS), and overall survival (OS). The secondary outcome was surgical complication rate.

Results

A total of 104 patients (median age 74, range 41–94 years) were included, 90% of which had pT3 tumors; 36.5% received adjuvant radiotherapy. Median follow-up was 24.3 (range 1.0–84.3) months. LRC at 5 years was 62.0%, DSS at 5 years was 83.7%, and OS at 5 years was 71.9%. Median time to recurrence was 8.4 months. LRC was reduced in the presence of margin involvement and previous treatment (radiotherapy/surgery). The major surgical complication rate was 9.6%.

Conclusions

More than 60% of patients treated surgically for pT3/4 head and neck cSCC were alive and free of disease at 5 years posttreatment. High-risk features such as margin involvement and having had previous treatment (radiotherapy/surgery) should be used to guide adjuvant therapy.

Real-world outcomes of systemic therapy in locally advanced, recurrent or metastatic cutaneous squamous cell carcinoma

Aim: Real-world treatment patterns and clinical outcomes in advanced cutaneous squamous cell carcinoma were evaluated. Methods: Adults receiving their first systemic therapy for unresectable, locally advanced or recurrent/metastatic cutaneous squamous cell carcinoma from 4 September 2014, to 30 June 2017, were evaluated. The primary end point was real-world overall response rate per Response Evaluation Criteria in Solid Tumors or physician assessment. Time-to-event outcomes were assessed using the Kaplan-Meier method. Results: Of 51 eligible patients, the median age was 76 years, 80% were male and 65% had an Eastern Cooperative Oncology Group score of 0-1. The most common regimens were cetuximab (51%) and carboplatin + paclitaxel (22%). Median real-world overall response rate ranged from 9.8% per Response Evaluation Criteria in Solid Tumors to 43.1% when supplemented by physician assessment. Median overall survival was 10.7 months, and median time to next treatment was 7.5 months. Conclusion: Survival in advanced cutaneous squamous cell carcinoma was short. Real-world overall response rate was lower with Response Evaluation Criteria in Solid Tumors than physician assessment.

Immunotherapy for the treatment of perineural spread in cutaneous head and neck squamous cell carcinoma: Time to rethink treatment paradigms

BACKGROUND

Immune checkpoint inhibitors have shown promising antitumour activity. Application in head and neck cutaneous squamous cell carcinoma (cSCC) large nerve perineural spread (PNS) is limited.

METHODS

Retrospective review of 13 patients with PNS receiving anti-PD-1 therapy from September 2017 to May 2021 is presented. Primary endpoints were objective response (complete or partial response) and median time to progression, determined by Head and Neck Multi-Disciplinary Team (MDT) and independent radiology review of magnetic resonance imaging (MRI) and/or computed tomography/positron emission tomography (CT/PET).

RESULTS

Objective response was observed in 9/13 patients (69%), with complete response in 6 (46%) and partial response in 3 patients (23%). Median time to response was 2.1 months (IQR 1.8-2.7 months). There were 3 (23%) patients with progressive disease, with median time to progression of 3.5 months. There were no grade 3-4 treatment related adverse events.

CONCLUSIONS

This case series supports developing evidence for anti-PD-1 checkpoint inhibitor therapy for perineural spread, supporting future prospective clinical trials in this patient population.

Management of elderly patients with advanced cutaneous squamous cell carcinoma

The incidence of cutaneous squamous cell carcinoma has been increasing rapidly in recent years, especially among the elderly. The purpose of this review article is to summarize the findings of studies on systemic therapy for advanced cutaneous squamous cell carcinoma, to review geriatric screening tools, which can assess frailty and predict treatment outcomes, and discuss the indications of their use in advanced cases. A literature review revealed that studies on systemic therapy for advanced cutaneous squamous cell carcinoma often included relatively older patients. However, there has been little research on the safety and efficacy of systemic therapy for advanced disease that takes older age and frailty into account. Notably, studies on geriatric screening for skin cancer have been conducted in recent years, mainly to detect early-stage resectable cases. The Geriatric 8 screening tool is considered the most useful for predicting post-operative complications in patients with early-stage cancer, as it can evaluate comorbidities, polypharmacy and cognition, has appropriate measurement properties, can be quickly executed and is clinically relevant, easily understandable and interpretable. This geriatric screening tool may also be applicable in advanced-stage cancer. In conclusion, despite the fact that advanced cutaneous squamous cell carcinoma occurs mainly in the elderly, the importance of geriatric screening has not yet been fully appreciated by dermato-oncologists. In the future, geriatric screening tools should be actively used in clinical trials for the appropriate assessment of drug efficacy and toxicity in elderly patients with advanced cutaneous squamous cell carcinoma.

Immunotherapy for Cutaneous Squamous Cell Carcinoma: Results and Perspectives

Although initial surgical excision cures 95% of patients, a minority of cutaneous squamous cell carcinomas (cSCCs) are judged to be unresectable, either locally advanced or with unresectable regional lymph nodes or distant metastases. These patients are offered systemic treatments. Response rate to chemotherapy is relatively low and not durable, as well as the results obtained with epidermal growth factor inhibitors (EGFRi). Like other cutaneous tumors, cSCCs have high immunogenicity, driven by the high mutational burden, the ultraviolet signature, and the overexpressed tumor antigens. Two checkpoint inhibitors, cemiplimab and pembrolizumab, achieved high response rate and survival with fewer toxicities than other available systemic agents. These promising results prompted to investigate new combination strategies of systemic therapy and surgery or radiotherapy. Subgroup analysis showed promising role of immunotherapy to facilitate surgery in locally advanced cSCC and, in a small group of patients, long-term survivals without resection. However, some cSCCs treated with immunotherapy develop either early or late resistance, so new drugs and new combinations are in a clinical study to overcome the mechanism underpinning these resistances. The present review focuses on the progress with immunotherapy to date and on new therapeutic strategies for cSCC.

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.

Identifying candidates for immunotherapy with cemiplimab to treat advanced cutaneous squamous cell carcinoma: an expert opinion

Cutaneous squamous cell carcinoma (CSCC) is the second most common skin malignancy in white-skinned populations. Only a minority of patients (<5%) develop advanced disease, but this is often difficult to treat and characterised by a poor prognosis. Cemiplimab, a fully human IgG4 monoclonal antibody against programmed cell death-1 receptor, is indicated for advanced (i.e. locally advanced or metastatic) CSCC. Although the definition of metastatic CSCC is clear, there is currently no agreed definition of locally advanced CSCC. In recent guidelines, locally advanced CSCC was described as non-metastatic CSCC that is unlikely to be cured with surgery, radiotherapy or combination treatment. A multi-disciplinary advisory group of Italian CSCC experts was convened to develop criteria to assist in identifying appropriate candidates for cemiplimab therapy in advanced CSCC, based on the literature and clinical experience. In locally advanced CSCC, absolute, or mandatory, criteria for the use of cemiplimab are deep invasion, multiple lesions without defined margins, inadequate surgical excision margins and multiple recurrences, whereas relative criteria include large lesions, in critical or functionally significant areas and that are surgically complex. In addition, physicians should consider patient willingness/preferences (an absolute criterion), and their age and health status/comorbidities (relative criteria). It is hoped that these proposed absolute and relative criteria will help guide rational identification of patients who will receive maximum benefit from immunotherapy, while more clinical data accumulate.

The Multidisciplinary Management of Cutaneous Squamous Cell Carcinoma: A Comprehensive Review and Clinical Recommendations by a Panel of Experts

Cutaneous squamous cell carcinomas (CSCC) account for about 20% of all keratinocyte carcinomas, which are the most common form of cancer. Heterogeneity of treatments and low mortality are a challenge in obtaining accurate incidence data and consistent registration in cancer registries. Indeed, CSCC mostly presents as an indolent, low-risk lesion, with five-year cure rates greater than 90% after surgical excision, and only few tumors are associated with a high-risk of local or distant relapse; therefore, it is particularly relevant to identify high-risk lesions among all other low-risk CSCCs for the proper diagnostic and therapeutic management. Chemotherapy achieves mostly short-lived responses that do not lead to a curative effect and are associated with severe toxicities. Due to an etiopathogenesis largely relying on chronic UV radiation exposure, CSCC is among the tumors with the highest rate of somatic mutations, which are associated with increased response rates to immunotherapy. Thanks to such strong pre-clinical rationale, clinical trials led to the approval of anti-PD-1 cemiplimab by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), and anti-PD-1 pembrolizumab by the FDA only. Here, we provide a literature review and clinical recommendations by a panel of experts regarding the diagnosis, treatment, and follow-up of CSCC.

NCCN Guidelines® Insights: Squamous Cell Skin Cancer, Version 1.2022

The NCCN Guidelines for Squamous Cell Skin Cancer provide recommendations for diagnostic workup, clinical stage, and treatment options for patients with cutaneous squamous cell carcinoma. The NCCN panel meets annually to discuss updates to the guidelines based on comments from panel members and the Institutional Review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new surgical recommendation terminology (peripheral and deep en face margin assessment), as well as recent updates on topical prophylaxis, immunotherapy for regional and metastatic disease, and radiation therapy.

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.

Non-Surgical Treatments for Keratinocyte Carcinomas

Skin cancer is the most common malignancy worldwide, comprising approximately 30% of all human tumors. In recent decades, the incidence of keratinocyte carcinomas, which include basal cell carcinoma and cutaneous squamous cell carcinoma, has been steadily increasing globally (Rogers et al. in JAMA Dermatol 151(10):1081-1086. https://doi.org/10.1001/jamadermatol.2015.1187 , 2015; Nehal and Bichakjian in N Engl J Med 379(4):363-374. https://doi.org/10.1056/nejmra1708701 , 2018). Most tumors are cured with surgical excision; however, some tumors are best treated with non-surgical approaches. Superficial tumors can often be cured with non-surgical methods whereas more advanced stage tumors may not be amenable to surgery. Additionally, surgical treatment may not be available for all populations depending on geographic location and accessibility to care. This article reviews commonly utilized nonsurgical options such as cryotherapy, photodynamic therapy, topical treatments, and radiation as well as systemic treatments including immunotherapies and chemotherapies.

Real-world Treatment Patterns and Outcomes with Systemic Therapies in Unresectable Locally Advanced and Metastatic Cutaneous Squamous Cell Carcinoma in Germany

Advanced cutaneous squamous cell carcinoma is a challenge to treat. Conventional systemic treatment options include chemotherapy and epidermal growth factor receptor-inhibitors. The aim of this study was to assess clinical outcomes with systemic treatments in advanced cutaneous squamous cell carcinoma. Patients receiving systemic treatment at the Tübingen Dermato-Oncology centre between 2007 and 2017 were identified (n = 59). Median age was 76 years (interquartile range (IQR) 71-80 years), 83.1% of patients were male, 72.9% had metastatic cutaneous squamous cell carcinoma, and 27.1% had unresectable locally advanced cutaneous squamous cell carcinoma. During median follow-up of 52 weeks (IQR 27-97 weeks), overall response rate was 14.3%, and disease control rate was 53.6%. Median progression-free survival was 15 weeks (IQR 8-42 weeks), and median overall survival was 52 weeks (IQR 27-97 weeks). Patients receiving chemoradiation vs chemo-therapy alone showed better overall survival (hazard ratio 0.41, p = 0.014,) and progression-free survival (hazard ratio 0.42, p = 0.009); no differences were observed for metastatic cutaneous squamous cell carcinoma vs locally advanced cutaneous squamous cell carcinoma patients. Although chemotherapy and/or cetuximab showed limited outcomes in advanced cutaneous squamous cell carcinoma, such therapy may still be an option when anti-PD-1 treatment is contraindicated.

Cemiplimab in an Elderly Frail Population of Patients With Locally Advanced or Metastatic Cutaneous Squamous Cell Carcinoma: A Single-Center Real-Life Experience From Italy

Background

Cutaneous squamous cell carcinoma (CSCC) is the second most common skin cancer whose incidence is growing parallel to the lengthening of the average lifespan. Cemiplimab, an antiPD-1 monoclonal antibody, is the first approved immunotherapy for patients with locally advanced CSCC (laCSCC) or metastatic CSCC (mCSCC) thanks to phase I and II studies showing high antitumor activity and good tolerability. Nevertheless, at present, very few data are available regarding cemiplimab in real-life experience and in frail, elderly, and immunosuppressed patients as well as regarding biomarkers able to predict response so as to guide therapeutic choices.

Patients and Methods

We built a retroprospective cohort study including 30 non-selected patients with laCSCC (25) and mCSCC (five) treated with cemiplimab from August 2019 to November 2020. Clinical outcomes, toxicity profile, and correlations with disease, patients, and peripheral blood parameters are explored.

Results

The median age was 81 years (range, 36-95), with 24 males and five patients having an immunosuppressive condition, while the frailty prevalence was 83% based on index derived from age, Eastern Cooperative Oncology Group performance status, and Charlson Comorbidity Index. We reported 23 responses (76.7%) with nine complete responses (30%). A statistically significant higher response rate was observed in head and neck primary tumors and in patients with hemoglobin level >12 g/dl. No difference was observed with respect to frailty, median age, sex, and body mass index. The baseline low neuthophil/lymphocyte ratio and low platelet/lymphocyte ratio resulted to be also correlated with a better response. Moreover, lymphocyte, neutrophil, and monocyte behaviors had an opposite trend in responders and non-responders. An overall response was reported in four of five immunosuppressed patients. Seventeen patients (57.6%) have an ongoing response and are still alive. Six responders had interrupted treatment (two for toxicity and four for personal choice) but maintained their response. The treatment was well tolerated by the majority of patients. The most common adverse events were fatigue in seven patients (23.3%) and skin toxicity in 10 patients (33.3%), including pruritus in six patients, rash in three patients, and bullous erythema in one patient.

Conclusions

In our real-life experience, cemiplimab showed a high antitumor activity with acceptable safety profile similar to those in trials with selected patients. Moreover, its antitumor activity resulted to be not impaired in very elderly patients and in those with immunocompromised status.

Biology and Treatment Advances in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most common skin cancer diagnosed worldwide. CSCC is generally localized and managed with local therapies such as excision and/or radiotherapy. For patients with unresectable or metastatic disease, recent improvements in our understanding of the underlying biology have led to significant advancements in treatment approaches-including the use of immune checkpoint inhibition (ICI)-which have resulted in substantial gains in response and survival compared to traditional cytotoxic approaches. However, there is a lack of understanding of the biology underpinning CSCC in immunocompromised patients, in whom the risk of developing CSCC is hundreds of times higher compared to immunocompetent patients. Furthermore, current ICI approaches are associated with significant risk of graft rejection in organ transplant recipients who make up a significant proportion of immunocompromised patients. Ongoing scientific and clinical research efforts are needed in order to maintain momentum to increase our understanding and refine our therapeutic approaches for patients with CSCC.

Cemiplimab in advanced cutaneous squamous cell carcinoma

Cemiplimab, a high-affinity, highly potent human monoclonal antibody that binds to the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) receptor, is the only drug to attain Food and Drug Administration (FDA) approval and marketing authorization from the European Commission for use in patients with metastatic and locally advanced cutaneous squamous cell carcinoma (CSCC) who are not candidates for curative surgery or curative radiation therapy as a first- or later-line treatment. In pivotal phase II clinical testing, cemiplimab showed rapid and substantial antitumor efficacy and acceptable safety. This systematic review was aimed at evaluating the efficacy and safety of cemiplimab in patients with advanced CSCC. To this end, I reviewed EMBASE, MEDLINE, PubMed, and clinical trial registries/databases by using the following keywords alone or in combination: "cemiplimab," "Libtayo," "cutaneous squamous cell carcinoma," "REGN2810," and "SER439684." Cemiplimab showed clinical efficacy and considerable safety and was associated with low rates of treatment discontinuation (7%) and death (3%). However, the current recommendation is primarily based on only phase II clinical testing due to the absence of an approved comparator agent.

Immune Checkpoint Inhibitors for Advanced Cutaneous Squamous Cell Carcinoma: A Systematic Review with Meta-Analysis

BACKGROUND

Results of early trials led to FDA approval of immune checkpoint inhibitors (ICIs) for advanced and recurrent/metastatic (R/M) cutaneous squamous cell carcinoma (CSCC). Updated data from these trials are pending and extent of survival outcomes is undetermined.

OBJECTIVE

The aim of this study was to assess the efficacy of ICIs in advanced CSCC, comprising locally advanced (LA), locoregionally advanced (LR), and recurrent or metastatic (R/M) disease.

PATIENTS AND METHODS

A systematic review of four databases (PubMed, Scopus, OVID, Cochrane) and meta-analysis of proportions was performed. Phase I and II prospective clinical trials were included.

RESULTS

Six trials evaluating cemiplimab (n = 3) and pembrolizumab (n = 3) were eligible for inclusion. Overall survival (OS) was not reached at data-cutoff. Pooled analysis of 392 patients demonstrated that ICIs conferred an objective response rate (ORR) of 42.43% (95% CI 37.53-47.45) and disease control rate (DCR) of 58.05% (95% CI 53.04-62.95). Patients with LR or distant metastatic lesions achieved equivalent ORRs and DCRs. Duration of response (DOR) was not reached in all trials and 92% of all responders continued to have therapeutic response at data cut-off. Tolerability was favorable, with only 27.12% (95% CI 10.89-47.38) of patients experiencing grade ≥ 3 adverse events.

CONCLUSION

Surgical treatment of CSCC remains the guideline-based standard of care for curative intent of local, LA, and LR disease. ICIs demonstrate promising results for LA, LR, and R/M CSCC not amenable to surgery. Endpoints assessing survival and durability of response have not been reached, warranting additional trials exploring neoadjuvant or adjuvant therapy in combination with local treatment.

Treatment of advanced cutaneous squamous cell carcinoma: a Mohs surgery and dermatologic oncology perspective

Locally advanced or metastatic cutaneous squamous cell carcinoma no longer amenable to surgical resection or primary radiation therapy requires an alternative approach to treatment. Until 2018, management consisted of limited systemic chemotherapies, which carried marginal clinical benefit. The introduction of immunotherapy with anti-PD-1 antibodies resulted in alternative treatment options for advanced cutaneous squamous cell carcinoma with substantial antitumor activity, durable response and acceptable safety profile. The field of immunotherapeutics continues to expand with adjuvant, neoadjuvant and intralesional studies currently in progress. Herein, the authors discuss their approach for the treatment of advanced cutaneous squamous cell carcinoma from the perspective of a Mohs surgeon and a dermatologic oncologist.

Systematic Review of PD-1/PD-L1 Inhibitors in Oncology: From Personalized Medicine to Public Health

BACKGROUND

To review and summarize all U.S. Food and Drug Administration (FDA) approvals of programmed death (PD)-1 and PD-ligand 1 blocking antibodies (collectively referred to as PD-[L]1 inhibitors) over a 6-year period and corresponding companion/complementary diagnostic assays.

MATERIALS AND METHODS

To determine the indications and pivotal trials eligible for inclusion, approval letters and package inserts available on Drugs@FDA were evaluated for approved PD-[L]1 inhibitors to identify all new indications granted from the first approval of a PD-[L]1 inhibitor on September 4, 2014, through September 3, 2020. The corresponding FDA drug and device reviews from the marketing applications for the approved indications were identified through FDA internal records. Two reviewers independently extracted information for the endpoints, efficacy data, basis for approval, type of regulatory approval, and corresponding in vitro diagnostic device test. The results were organized by organ system and tumor type.

RESULTS

Of 70 Biologic Licensing Application or supplement approvals that resulted in new indications, 32 (46%) were granted based on response rate (ORR) and durability of response, 26 (37%) on overall survival, 9 (13%) on progression-free survival, 2 (3%) on recurrence-free survival, and 1 (1%) on complete response rate. Most ORR-based approvals were granted under the accelerated approval provisions and were supported with prolonged duration of response. Overall, 21% of approvals were granted with a companion diagnostic. Efficacy results according to tumor type are discussed.

CONCLUSION

PD-[L]1 inhibitors are an effective anticancer therapy in a subset of patients. This class of drugs has provided new treatment options for patients with unmet need across a wide variety of cancer types. Yet, the modest response rates in several tumor types signal a lack of understanding of the biology of these diseases. Further preclinical and clinical investigation may be required to identify a more appropriate patient population, particularly as drug development continues and additional treatment alternatives become available.

IMPLICATIONS FOR PRACTICE

The number of PD-[L]1 inhibitors in drug development and the associated companion and complementary diagnostics have led to regulatory challenges and questions regarding generalizability of trial results. The interchangeability of PD-L1 immunohistochemical assays between PD-1/PD-L1 drugs is unclear. Furthermore, robust responses in some patients with low levels of PD-L1 expression have limited the use of PD-L1 as a predictive biomarker across all cancers, particularly in the setting of diseases with few alternative treatment options. This review summarizes the biomarker thresholds and assays approved as complementary and companion diagnostics and provides regulatory perspective on the role of biomarkers in oncology drug development.

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.

Cost-effectiveness analysis of cemiplimab vs pembrolizumab for treatment of advanced cutaneous squamous cell carcinoma

BACKGROUND: Most cutaneous squamous cell carcinomas (CSCCs) can be treated with surgical excision or radiation; however, approximately 1% of patients develop advanced disease. In 2018, the FDA approved cemiplimab-rwlc as the first programmed cell death-1 (PD-1) monoclonal antibody for the treatment of patients with metastatic CSCC or locally advanced CSCC who are not candidates for curative surgery or curative radiation. In June 2020, pembrolizumab, another PD-1 monoclonal antibody, was approved for the treatment of patients with recurrent or metastatic CSCC who are not candidates for curative surgery or radiation. We previously reported on the cost-effectiveness of cemiplimab vs historical standard of care for the treatment of advanced CSCC from a US perspective. OBJECTIVE: To estimate the cost-effectiveness of cemiplimab vs pembrolizumab for patients with advanced CSCC in the United States. METHODS: A "partitioned survival" framework was used to assess the cost-effectiveness of cemiplimab vs pembrolizumab. Clinical inputs were based on the most recent data cut of the phase 2 trials for cemiplimab (EMPOWER-CSCC-1; NCT02760498) and pembrolizumab (KEYNOTE-629). Progression-free survival and overall survival were extrapolated using parametric models until all patients had progressed or died. Health state utilities were derived from data collected in the EMPOWER-CSCC-1 trial. Costs included drug acquisition, drug administration, disease management, terminal care, and adverse events and were based on published 2020 US list prices. To assess model uncertainty, 1-way sensitivity and probabilistic sensitivity analyses (PSA) were conducted, alongside scenario analyses evaluating key modeling assumptions. RESULTS: In the base case, cemiplimab resulted in an incremental gain of 3.44 life-years (discounted) and incremental cost-effectiveness ratio (ICER) of $130,329 per quality-adjusted life-year (QALY) vs pembrolizumab. At a willingness-to-pay threshold of $150,000/QALY, PSA indicated a 71% probability that cemiplimab is cost-effective when compared with pembrolizumab. Scenario analysis resulted in ICERs ranging from $115,909 to $187,374. CONCLUSIONS: Findings suggest that cemiplimab is a cost-effective treatment for patients with advanced CSCC, compared with pembrolizumab. These results should be interpreted cautiously in the absence of head-to-head trials; however, in the absence of such data, these results can be used to inform health care decisions over resource allocation. DISCLOSURES: This study was supported by Regeneron Pharmaceuticals, Inc., and Sanofi. Paul, Cope, Keeping, Mojebi, and Ayers are employees of PRECISIONheor, which received funding to produce this work. Chen, Kuznik, and Xu are employees and stockholders of Regeneron Pharmaceuticals, Inc. Sasane is an employee and stockholder of Sanofi, Inc. Konidaris, Atsou, and Guyot are employees of Sanofi, Inc. The authors were responsible for all content and editorial decisions and received no honoraria related to the development of this publication.

Pembrolizumab in Patients with Refractory Cutaneous Squamous Cell Carcinoma: A Phase II Trial

INTRODUCTION

Patients with advanced cutaneous squamous cell carcinoma (CSCC) have a poor prognosis. Blocking the PD-1-PD-L1 axis has shown promising activity in this patient population. We assessed the safety and antitumor activity of PD-1 inhibitor pembrolizumab in patients with refractory advanced CSCC.

METHODS

This was a prespecified subgroup analysis of patients with advanced CSCC who enrolled in an open-label, phase II clinical trial for pembrolizumab in patients with refractory rare cancers during 2016-2018. Patients received pembrolizumab 200 mg intravenously every 21 days until progressive disease, unacceptable adverse event, or completion of 24 months of treatment. The primary endpoint was nonprogression rate (NPR) at 27 weeks; secondary endpoints included safety, objective response rate (ORR) per irRECIST, clinical benefit rate (CBR), progression-free survival, and overall survival.

RESULTS

Twenty patients with refractory CSCC enrolled; 19 were evaluable for efficacy. Median follow-up time was 44.1 months. The NPR at 27 weeks was 37% (95% CI 0.16-0.62). Three patients had a complete response (CR), three had a partial response, and one had stable disease, for an ORR of 32% and a CBR of 37%; median duration of response was 27.3 months. All three patients with a CR remained free of recurrence at the time of writing. Severe treatment-related adverse events (grade ≥ 3) occurred in 10% of patients (2/20). PD-L1 expression was not correlated with response to pembrolizumab.

CONCLUSION

A long-term follow-up confirms pembrolizumab's antitumor activity and safety profile in patients with refractory CSCC. Patients with a CR may experience cure.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02721732, Registered March 29, 2016.

Cutaneous Malignancies of the Head and Neck

Cutaneous malignancies (CMs), or skin cancers, are the most common cancer worldwide, with a quarter million cases diagnosed annually in the United States alone. The best described risk factor for CM is ultraviolet radiation from sunlight, and therefore most of these cancers develop in sun-exposed skin, including the head and neck. Beginning with melanoma, immunotherapy has increasingly been used over the past decade for treatment of unresectable CM, and immune checkpoint inhibitors are now Food and Drug Administration-approved for first-line treatment of unresectable melanoma, Merkel cell carcinoma, and cutaneous squamous cell carcinoma, and second-line for basal cell carcinoma.