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

Cetuximab plus 5-fluorouracil in patients with advanced cutaneous squamous cell carcinoma: a retrospective cohort study

BACKGROUND

For patients with locally advanced (la) or metastatic (m) cutaneous squamous cell carcinoma (cSCC) who are not candidates for curative surgery/radiation or systemic anti-PD1 therapy, anti-EGFR in combination with chemotherapy is a rational treatment option.

PATIENTS AND METHODS

We analyzed data from 20 patients with cSCC in this monocentric, retrospective study. 4/20 patients had laSCC and 16/20 patients had mSCC. Patients received combined cetuximab and 5-FU between 2015 and 2023. Nine patients received cetuximab + 5-FU as second-line therapy (8 patients after anti-PD-1, 1 patient after radiochemotherapy).

RESULTS

One patient had partial response (PR) and 9/20 (45.0%) had stable disease (SD). Disease control rate (PR + SD) was 50%. No complete remissions were observed. One of the non-responders suffered from laSCC, nine patients had mSCC with distant metastases (including parotid) and locoregional lymph node metastases. Treatment was well tolerated, with a median PFS of 3 months (95% confidence interval [CI] 2 months to not assessable [NA]) and median overall survival (OS) of 29 months (95% CI 11-NA). The most common adverse event was acne-like rash in 40.0% of patients.

CONCLUSIONS

For patients with advanced cSCC who are contraindicated to or have progressed on first-line cemiplimab, combination of cetuximab and 5-FU is a well-tolerated but limited treatment option.

WITHDRAWN: Cancer and Hidradenitis Suppurativa

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.clindermatol.2025.05.011. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies-and-standards/article-withdrawal.

Cancer and hidradenitis suppurativa

Patients with hidradenitis suppurativa (HS) have an increased risk of developing cancer. This includes not only hematologic malignancies and solid tumors but also cutaneous squamous cell carcinoma (SCC) originating within the HS lesions. The development of SCC is most commonly associated with Caucasian men who smoke and have severe gluteal or perianal lesions of more than 25 years. Other factors that have occasionally been associated with HS-related SCC include treatment with a tumor necrosis factor-alpha inhibitor (such as infliximab and adalimumab), genodermatoses (such as keratitis-ichthyosis-deafness syndrome and Dowling-Degos disease), and paraneoplastic syndromes (such as hypercalcemia, hypercalcemia-leukocytosis, and paraneoplastic neuropathy). The tumor may demonstrate the presence of human papillomavirus; even after treatment, patients have a poor prognosis because cancer metastasis, recurrence, or both commonly occur. The potential role of human papillomavirus vaccination for cancer prevention and early treatment of SCC with targeted therapy (with an epidermal growth factor inhibitor such as cetuximab) and/or checkpoint inhibitor immunotherapy (such as cemiplimab and pembrolizumab) remains to be determined. Rarely, HS lesions have mimicked cutaneous metastases in patients with visceral malignancy by demonstrating an increased uptake of fluorine-18 fluorodeoxyglucose on positron emission tomography and/or computed tomography scans. Primary cancers (such as cutaneous SCC and mucinous adenocarcinoma) and breast cancer skin metastases can masquerade as HS lesions. When a lesion is located at a current or earlier site of HS that is new or rapidly growing and/or does not respond to HS-directed therapy, prompt evaluation to establish or exclude the diagnosis of cancer should be considered.

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.

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

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

Epidermal growth factor receptor inhibitors in advanced cutaneous squamous cell carcinoma: A systematic review and meta-analysis

Patients with advanced cutaneous squamous cell carcinoma (cSCC) who are not eligible for or who fail to respond to anti-PD1 immunotherapy have few treatment options. Epidermal growth factor receptor (EGFR) inhibitors have been investigated as a therapeutic option for advanced cSCC; however, data are limited to small single-arm trials or retrospective studies. A systematic review and meta-analysis was conducted to PRISMA guidelines (CRD42023394300). Studies reporting on outcomes of EGFR inhibition in advanced cSCC were identified. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and adverse event (AE) rate were pooled using a random effects model and the inverse variance method. Twelve studies (six prospective, six retrospective) were identified, representing 324 patients. Pooled ORR was 26% (95% confidence interval [CI] 18-36), median PFS was 4.8 months (95% CI 3.9-6.6) and median OS was 11.7 months (95% CI 9.2-14.1). Any grade AEs occurred in 93% of patients (95% CI 85-97) while grade 3 and higher AEs occurred in 30% (95% CI 14-54). These results were similar between anti-EGFR monoclonal antibodies (MAbs) and tyrosine kinase inhibitors (TKIs). EGFR inhibitors can be considered in patients with advanced cSCC who are contraindicated for or progress on first-line anti-PD1 immunotherapy. Future studies should evaluate their activity and safety following anti-PD1, identify predictive biomarkers for their efficacy and explore combination approaches.

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.

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.