Systemic treatment of patients with advanced cutaneous squamous cell carcinoma: response rates and outcomes of the regimes used

Metastatic patterns and treatment options for head and neck cutaneous squamous cell carcinoma (Review)

According to current predictions, one-fifth of all Americans will develop skin cancer during their lifetime. Cutaneous squamous cell carcinoma (cSCC) most commonly occurs in the head and neck region, which is the area of the body with the highest level of sun exposure. High-risk head and neck cSCC (HNcSCC) is a broad category with numerous high-risk factors that are associated with unfavorable results. In cSCC staging systems, clinical and tumor traits that are likely to result in poor outcomes are identified. Metastasis occurs in ~2.5% of patients with cSCC, most often in the local lymph nodes, and there is some indication that lymph node metastasis has a distinct pattern based on the tumor site. Current findings on tumor molecular targets have suggested the use of systemic treatments, particularly immunotherapy (such as cemiplimab, pembrolizumab and nivolumab), over radiotherapy or chemotherapy for this type of metastasis. However, when used simultaneously with immunotherapy, radiotherapy may be beneficial in the treatment of metastatic HNcSCC by improving the efficacy of immunotherapy. The present review aims to assess the existing literature on metastatic HNcSCC pathways and treatment options, in order to define current and future directions. Notably, there is an urgent need to identify patients who may benefit from local or systemic cancer treatments. The treatment of lymph node metastasis presents a therapeutic challenge and requires comprehensive management.

Classic and new strategies for the treatment of advanced melanoma and non-melanoma skin cancer

Advanced melanoma and non-melanoma skin cancers (NMSCs) are burdened with a dismal prognosis. To improve the survival of these patients, studies on immunotherapy and target therapies in melanoma and NMSCs are rapidly increasing. BRAF and MEK inhibitors improve clinical outcomes, and anti-PD1 therapy demonstrates better results than chemotherapy or anti-CTLA4 therapy in terms of the survival of patients with advanced melanoma. In recent years, the combination therapy of nivolumab plus ipilimumab has gained ground in studies for its survival and response rate benefits in patients with advanced melanoma. In addition, neoadjuvant treatment for stages III and IV melanoma, either as monotherapy or combination therapy, has recently been discussed. Another promising strategy evaluated in recent studies is the triple combination of anti-PD-1/PD-L1 immunotherapy and anti-BRAF plus anti-MEK targeted therapy. On the contrary, in advanced and metastatic BCC, successful therapeutic strategies, such as vismodegib and sonidegib, are based on the inhibition of aberrant activation of the Hedgehog signaling pathway. In these patients, anti-PD-1 therapy with cemiplimab should be reserved as the second-line therapy in case of disease progression or poor response. In patients with locally advanced or metastatic SCC, who are not candidates for surgery or radiotherapy, anti-PD1 agents such as cemiplimab, pembrolizumab, and cosibelimab (CK-301) have shown significant results in terms of response rate. PD-1/PD-L1 inhibitors, such as avelumab, have also been used in Merkel carcinoma, achieving responses in half of the patients with advanced disease. The latest prospect emerging for MCC is the locoregional approach involving the injection of drugs that can stimulate the immune system. Two of the most promising molecules used in combination with immunotherapy are cavrotolimod (a Toll-like receptor 9 agonist) and a Toll-like receptor 7/8 agonist. Another area of study is cellular immunotherapy with natural killer cells stimulated with an IL-15 analog or CD4/CD8 cells stimulated with tumor neoantigens. Neoadjuvant treatment with cemiplimab in CSCCs and nivolumab in MCCs has shown promising results. Despite the successes of these new drugs, the new challenges ahead will be to select patients who will benefit from these treatments based on biomarkers and parameters of the tumor microenvironment.

A Hybrid Epithelial to Mesenchymal Transition in Ex Vivo Cutaneous Squamous Cell Carcinoma Tissues

While most cases of cutaneous squamous cell carcinoma (cSCC) are benign, invasive cSCC is associated with higher mortality and is often more difficult to treat. As such, understanding the factors that influence the progression of cSCC are important. Aggressive cancers metastasize through a series of evolutionary changes, collectively called the epithelial-to-mesenchymal transition (EMT). During EMT, epithelial cells transition to a highly mobile mesenchymal cell type with metastatic capacities. While changes in expression of TGF-β, ZEB1, SNAI1, MMPs, vimentin, and E-cadherin are hallmarks of an EMT process occurring within cancer cells, including cSCC cells, EMT within tissues is not an “all or none” process. Using patient-derived cSCC and adjacent normal tissues, we show that cells within individual cSCC tumors are undergoing a hybrid EMT process, where there is variation in expression of EMT markers by cells within a tumor mass that may be facilitating invasion. Interestingly, cells along the outer edges of a tumor mass exhibit a more mesenchymal phenotype, with reduced E-cadherin, β-catenin, and cytokeratin expression and increased vimentin expression. Conversely, cells in the center of a tumor mass retain a higher expression of the epithelial markers E-cadherin and cytokeratin and little to no expression of vimentin, a mesenchymal marker. We also detected inverse expression changes in the miR-200 family and the EMT-associated transcription factors ZEB1 and SNAI1, suggesting that cSCC EMT dynamics are regulated in a miRNA-dependent manner. These novel findings in cSCC tumors provide evidence of phenotypic plasticity of the EMT process occurring within patient tissues, and extend the characterization of a hybrid EMT program occurring within a tumor mass. This hybrid EMT program may be promoting both survival and invasiveness of the tumors. A better understanding of this hybrid EMT process may influence therapeutic strategies in more invasive disease.

Comparative efficacy analysis identifies immune checkpoint blockade as a new survival benchmark in advanced cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinoma is a common type of skin cancer that may progress to locally advanced or metastatic disease. Both disease stages are managed by a variety of treatment options, including immune checkpoint blockade (ICB), targeted therapy to epidermal growth factor, chemotherapy or treatment combinations. However, the comparative efficacy of such treatments is unclear.

METHODS

We performed a systematic literature search of Medline, Embase and Central to identify eligible studies reporting Kaplan-Meier curves or individual patient data for overall survival (OS) or progression-free survival (PFS). Kaplan-Meier curves were digitised using the "'WebPlotDigitizer" program. Individual patient data was subsequently remodelled and pooled for distinct treatment groups.

RESULTS

Overall, 22 independent studies were included of which n = 927 patients were evaluable for PFS and n = 1054 for OS. ICB showed the highest median PFS (mPFS 9.9 months (95% CI: 8.1-19.9)) and median OS (mOS not reached (95% CI: 31.5 months-not reached)) compared to chemotherapy (mPFS 3.0 months (95% CI: 2.2-4.8), mOS 12.6 months (95% CI: 9.6-15.8)), targeted therapy to epidermal growth factor (mPFS 4.9 months (95% CI: 4.4-5.6), mOS 12.7 months (95% CI: 11.9-14.9)) and combination therapies without ICB (mPFS 9.1 months (95% CI: 8.0-12.1), mOS 18.1 months (95% CI: 16.3-22.8)). The survival benchmark with ICB after 26 months for metastatic squamous cell carcinoma was 70.8% (95% CI: 61.5%-81.5%) versus 37.9% (95% CI: 29.5%-48.8%) for the combination group and 17.1% (95% CI: 9.5%-30.8%) for chemotherapy.

CONCLUSION

ICB is superior to other systemic treatments and sets a novel survival benchmark for advanced cutaneous squamous cell carcinoma.

Advanced or Metastatic Cutaneous Squamous Cell Carcinoma: The Current and Future Role of Radiation Therapy in the Era of Immunotherapy

Simple Summary

Nodal and distant metastases of cutaneous squamous cell carcinomas are very rare and lead to dismal prognoses. Immunotherapy is approved only for cutaneous squamous cell carcinoma patients not amenable to surgery or curative radiation therapy. Radiation therapy has a clear role as an adjuvant treatment for locally advanced disease. Radiation therapy may also have an important role in inoperable and metastatic disease. Oligometastatic disease is a condition that needs to be defined for this carcinoma. This review aims to offer to the readers a comprehensive overview of studies about the role of radiotherapy in the management of advanced or metastatic cutaneous squamous cell carcinomas, also assuming possible further developments in the light of the recent discoveries about tumor biology. The present paper has the merit of re-focusing great attention on the efficacy and cost-effectiveness of radiotherapy in these not yet properly explored scenarios.

Abstract

Radiation therapy (RT) is an effective therapeutic option for small localized cutaneous squamous cell carcinoma (cSCC) among patients who are not eligible for or refuse surgery. RT also has a defined role as an adjuvant treatment in cases of adverse features that predispose to tumor recurrence after local excision. Since the development of cSCC is often a late consequence of chronic sun exposure, its occurrence is more common among elderly patients whose comorbidities may contraindicate surgical procedures. These could be impeded not only by frail medical conditions but also by technical issues. Indeed, an aggressive locoregional behavior of cSCC may culminate in unresectability due to widespread invasion of neighboring tissues. Moreover, cSCC could develop distant metastases. Both locally advanced and metastatic cSCCs carry a poor prognosis. In these scenarios, recent discoveries of tumor molecular targets are promoting the use of promising systemic therapies, especially immunotherapy, over RT. However, the results from using immunotherapy and, even more so, of chemotherapy are still not optimal. By contrast, advances in radiation delivery equipment can safely treat even large and complex-shaped cSCC targets in challenging body sites. In addition, RT could also have a role in metastatic cSCC settings by enhancing the effectiveness of concomitant immunotherapy. The aim of this review is to summarize and comment on the body of literature about the use of radiotherapy for operable and inoperable locally advanced cSCCs and for metastatic ones in an attempt to define its current and future role.

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.

Advances in Targeting Cutaneous Melanoma

Simple Summary

Cutaneous Melanoma (CM), arising from pigment-producing melanocytes in the skin, is an aggressive cancer with high metastatic potential. While cutaneous melanoma represents only a fraction of all skin cancers (<5%), it accounts for most skin-cancer-related deaths worldwide. Immune checkpoint inhibition has been the first therapeutic approach to significantly benefit patient survival after treatment. Nevertheless, the immunosuppressive tumor microenvironment and the intrinsic and acquired treatment resistance of melanoma remain crucial challenges. Combining local and systemic treatment offers the potential to augment therapeutic response and overcome resistance, although, complex drug combinations can harbor an increased risk of immune-related adverse events. The aim of this review is to give current insight into studies combining systemic and local therapeutic approaches to overcome drug resistance, prime melanoma cells for therapy, and improve overall treatment response in CM patients.

Abstract

To date, the skin remains the most common cancer site among Caucasians in the western world. The complex, layered structure of human skin harbors a heterogenous population of specialized cells. Each cell type residing in the skin potentially gives rise to a variety of cancers, including non-melanoma skin cancer, sarcoma, and cutaneous melanoma. Cutaneous melanoma is known to exacerbate and metastasize if not detected at an early stage, with mutant melanomas tending to acquire treatment resistance over time. The intricacy of melanoma thus necessitates diverse and patient-centered targeted treatment options. In addition to classical treatment through surgical intervention and radio- or chemotherapy, several systemic and intratumoral immunomodulators, pharmacological agents (e.g., targeted therapies), and oncolytic viruses are trialed or have been recently approved. Moreover, utilizing combinations of immune checkpoint blockade with targeted, oncolytic, or anti-angiogenic approaches for patients with advanced disease progression are promising approaches currently under pre-clinical and clinical investigation. In this review, we summarize the current ‘state-of-the-art’ as well as discuss emerging agents and regimens in cutaneous melanoma treatment.

An online review of informational sources for advanced or high-risk cutaneous squamous cell carcinoma

OBJECTIVE

Cutaneous squamous cell carcinoma (cSCC) is one of the most prevalent non-melanoma skin cancers worldwide. While usually treatable, patients with high-risk or advanced disease have few treatment options and limited resources available. This review assesses what online information resources are available to patients and their families about either high-risk or advanced cSCC.

METHODS

Searches were run, via Google, using 8 terms such as 'advanced cutaneous squamous cell carcinoma patient information'. Advertisements were removed and the first 3 pages/30 results from each search were screened for duplicates and then against eligibility criteria. Websites needed to have been updated within the past 5 years, be freely accessible, designed specifically for patients and refer to the advanced disease or high-risk setting. Remaining results were assessed using the DISCERN tool.

RESULTS

Of the final 240 results, 121 were duplicates and 104 were ineligible. The remaining 15 sources were predominantly aimed at American audiences, used variable terminology and revealed differing treatment pathways. Only 3 sites were deemed as 'high'-quality information sources.

CONCLUSION

There is a lack of accessible online information on high-risk or advanced cSCC for patients. What is available is often too scientific or clinical and lacks clarity about the disease and treatment options.

PRACTICE IMPLICATIONS

Further work is needed to improve the integrity and accessibility of online sources and to signpost patients to the most reliable information. This should include elements of patient led research, clinical education and information development.

Anti-PD-1 antibody therapy for epithelial skin malignancies: An investigator-initiated, open-label, single-arm, multicenter, phase II clinical trial (NMSC-PD1 Study)

INTRODUCTION

Malignant cutaneous epithelial tumors comprise various skin malignancies originating from the cutaneous epithelium, including cutaneous squamous cell carcinoma, basal cell carcinoma, and malignant cutaneous adnexal tumors. Treatment options are limited, as the rarity of these tumors, especially among Asians, renders well-controlled clinical trials extremely challenging to conduct. Thus, we designed a clinical trial to evaluate the efficacy and safety of the anti-programmed cell death-1 (PD-1) monoclonal antibody nivolumab in patients with metastatic cutaneous squamous cell carcinomas and other rare metastatic cutaneous epithelial tumors.

METHODS AND ANALYSIS

This is an open-label, single-arm, multicenter, phase 2 clinical trial involving patients with metastatic malignant cutaneous epithelial tumors. Nivolumab (480 mg) will be administered intravenously every 4 weeks for a maximum of 26 doses. The primary outcome of the study will be the response rate based on response evaluation criteria in solid tumors, version 1.1. Assuming a null hypothesis of a response rate ≤5% and an alternative hypothesis of a 25% response rate, a minimum of 26 patients are required to achieve a 5% two-sided type I error and 80% power based on the exact binomial distribution. Finally, a target cohort size of 30 patients was determined as some patient dropout will be expected.

DISCUSSION

This is the first phase 2 clinical trial evaluating the efficacy and safety of the PD-1 inhibitor nivolumab in Asian patients with metastatic malignant cutaneous epithelial tumors. The findings of the study will contribute to the development of novel treatment approaches for patients with rare cutaneous malignancies, which remains an unmet clinical need.

TRIAL REGISTRATION

Registry number: jRCT 2031190048.