High-risk cutaneous squamous cell carcinoma (CSCC): Challenges and emerging therapies

Lymph node metastasis development in external ear squamous cell carcinoma follow-up: the role of T stage, tumor grade, and anatomical subsites

PURPOSE

Lymph node metastasis (LNM) significantly impacts prognosis in external ear squamous cell carcinoma (SCC). Identifying high-risk patients remains a challenge due to the lack of standardized criteria for elective neck dissection (END). This study aims to evaluate predictive factors for LNM in external ear SCC.

METHODS

a retrospective analysis of 176 patients with T1-T3, N0 external ear SCC who underwent surgical excision between 2015 and 2019 was conducted. Patients were stratified by tumour subsite (auricle, external auditory canal, retroauricular, and preauricular regions). Histopathological parameters, including tumor size (T), depth of invasion (DOI), perineural invasion (PNI), perivascular invasion (PVI), cartilage invasion, and tumor grade, were analysed for association with LNM. Statistical analyses included univariate and multivariate logistic regression models.

RESULTS

LNM occurred in 5.7% (n = 10) of patients, with metastases appearing within an average of 7.1 months post-surgery. T3 tumours had a significantly higher LNM rate (p < 0.05). The preauricular region was the most frequent metastatic subsite (p = 0.001). Poorly differentiated tumours (G3/G4) were strongly associated with LNM (p = 0.001). DOI and cartilage invasion were not independent predictors. The Brigham and Women's Hospital (BWH) classification system demonstrated superior risk stratification compared to NCCN and AJCC-8.

CONCLUSION

T3 stage, preauricular location, and high tumour grade are significant predictors of LNM in external ear SCC. The findings support the need for individualised risk stratification, with consideration of END in high-risk cases. Future studies should incorporate molecular markers to refine metastatic risk assessment.

Management Approaches for High-Risk Cutaneous Squamous Cell Carcinoma with Perineural Invasion: An Updated Review

Cutaneous squamous cell carcinoma (cSCC) stands as the second most prevalent non-melanoma skin cancer worldwide, comprising approximately 20% of all cutaneous malignancies. Determining its precise incidence poses challenges; however, reports indicate a global increase in its prevalence. At the time of diagnosis, the majority of cSCCs are localized, resulting in favorable 5-year cure rates surpassing 90%. Nevertheless, a subset of patients (3-7%) encounters locally advanced or metastatic cSCC, leading to substantial morbidity and mortality. The risk of metastasis ranges from 0.1% to 9.9%, carrying an associated mortality risk of 2.8%. Factors influencing recurrence, metastasis, and disease-specific mortality underscore the significance of perineural invasion (PNI) as a key indicator. Patients with PNI may manifest clinical symptoms and/or radiologic signs of PNI, while the majority remain asymptomatic, and PNI is frequently identified upon histologic examination. Despite its lower frequency compared to other cancer types, PNI serves as a recognized adverse prognostic factor for cSCC. Surgery is the elective treatment for these patients, while the role of adjuvant radiotherapy (ART) is yet contentious and have not been conclusively assessed, particularly in clear surgical margin. Prospective comparative studies are required to comprehensively evaluate the benefit and the risks of ART for cSCC and PNI patients.

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.

Aberrant expression of B7-H4 and B7-H5 contributes to the development of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most common malignant tumor of the skin. B7 homolog 4 (B7-H4) and B7-H5 (B7 homolog 5) are associated with a variety of tumors. Investigate the potential role of B7-H4 and B7-H5 in regulating the tumorigenesis and progression of CSCC. B7-H4 and B7-H5 transcriptome data were collected from GEO and TCGA databases and subjected to bioinformatical analysis by protein-protein interaction (PPI) network, functional enrichment analysis, immune analysis, and drug-gene interaction prediction analysis. We characterized the expression of B7-H4 and B7-H5 in carcinoma tissues of CSCC patients by immunohistochemistry. Meanwhile, the clinical correlation of B7-H4 and B7-H5 in CSCC was explored by statistical analysis. B7-H4 and B7-H5 genes were under-expressed in CSCC and correlated with tumor staging. According to GO and KEGG Pathway enrichment analysis, B7-H4, and B7-H5 can regulate the proliferation and activation of T cells, lymphocytes, and monocytes, and the expression of cytokines, such as IL-6 and IL-10, in CSCC. B7-H4 and B7-H5 are also jointly involved in the occurrence and development of CSCC via the JAK-STAT and Notch signaling pathways. We found that B7-H4 and B7-H5 proteins were abnormally highly expressed in CSCC tissue and correlated with tumor size and stage. Our findings offer new insights into the pathogenesis of CSCC and suggest that B7-H4 and B7-H5 are novel tissue biomarkers and promising therapeutic targets for CSCC.

GBP1 promotes cutaneous squamous cell carcinoma proliferation and invasion through activation of STAT3 by SP1

Cutaneous squamous cell carcinoma (cSCC) ranks as the second most prevalent skin tumour (excluding melanoma). However, the molecular mechanisms driving cSCC progression remain elusive. This study aimed to investigate GBP1 expression in cSCC and elucidate its potential molecular mechanisms underlying cSCC development. GBP1 expression was assessed across public databases, cell lines and tissue samples. Various assays, including clone formation, CCK8 and EdU were employed to evaluate cell proliferation, while wound healing and transwell assays determined cell migration and invasion. Subcutaneous tumour assays were conducted to assess in vivo tumour proliferation, and molecular mechanisms were explored through western blotting, immunofluorescence and immunoprecipitation. Results identified GBP1 as an oncogene in cSCC, with elevated expression in both tumour tissues and cells, strongly correlating with tumour stage and grade. In vitro and in vivo investigations revealed that increased GBP1 expression significantly enhanced cSCC cell proliferation, migration and invasion. Mechanistically, GBP1 interaction with SP1 promoted STAT3 activation, contributing to malignant behaviours. In conclusion, the study highlights the crucial role of the GBP1/SP1/STAT3 signalling axis in regulating tumour progression in cSCC. These findings provide valuable insights into the molecular mechanisms of cSCC development and offer potential therapeutic targets for interventions against cSCC.

Treatment of nasal squamous cell carcinoma with combination of surgery and photodynamic therapy

Cutaneous squamous cell carcinoma (cSCC) is a common malignant skin tumor. Some invasive cSCC can cause severe cosmetic damage; therefore, comprehensive measures should be taken. Here, we present a case of a 48-year-old male patient with invasive cSCC on the nose. The lesion recurred twice after excision in the other hospital. After admission, the patient underwent surgical excision; however, the tumor remained because of its deep infiltration, and we left the wound exposed without repair. During the period of open-wound, the patient received 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) to completely clear the residual tumors, and multipoint biopsies were performed to monitor the tumor remission process. We reconstructed the defect by using bilateral flaps after complete remission. The tumor did not recur in 63 months of follow-up after reconstruction. Open-wound treatment should be considered for tumors that occur at high-risk sites such as the nose. Surgery combined with PDT may be an efficient method for treating cSCC.

Antitumor Effect of Poplar Propolis on Human Cutaneous Squamous Cell Carcinoma A431 Cells

Propolis is a gelatinous substance processed by western worker bees from the resin of plant buds and mixed with the secretions of the maxillary glands and beeswax. Propolis has extensive biological activities and antitumor effects. There have been few reports about the antitumor effect of propolis against human cutaneous squamous cell carcinoma (CSCC) A431 cells and its potential mechanism. CCK-8 assays, label-free proteomics, RT-PCR, and a xenograft tumor model were employed to explore this possibility. The results showed that the inhibition rate of A431 cell proliferation by the ethanol extract of propolis (EEP) was dose-dependent, with an IC50 of 39.17 μg/mL. There were 193 differentially expressed proteins in the EEP group compared with the control group (p < 0.05), of which 103 proteins (53.37%) were upregulated, and 90 proteins (46.63%) were downregulated. The main three activated and suppressed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were extracellular matrix (ECM)-receptor interaction, amoebiasis, cell adhesion molecules (CAMs), nonalcoholic fatty liver disease (NAFLD), retrograde endocannabinoid signaling, and Alzheimer's disease. The tumor volume of the 100 mg/kg EEP group was significantly different from that of the control group (p < 0.05). These results provide a theoretical basis for the potential treatment of human CSCC A431 cell tumors using propolis.

Phytochemical Profiling and Biological Activities of Quercus sp. Galls (Oak Galls): A Systematic Review of Studies Published in the Last 5 Years

Quercus species have been widely used in traditional medicine, and recently, researchers' attention has focused on galls of the genus Quercus as a source of health-promoting phytochemicals. This review presents a summary of the most recent findings on the phytochemistry and bioactivity of oak galls, following the screening of scientific papers published in two relevant databases, PubMed and Embase, between January 2018 and June 2023. The oak galls are rich in active compounds, mostly gallotannins and phenolic acids. Due to these secondary metabolites, the reviewed studies have demonstrated a wide range of biological activities, including antioxidant and anti-inflammatory actions, antimicrobial properties, tissue-protective effects, and antitumor, anti-aging, and hypoglycemic potential. Thus, oak galls are a promising natural matrix, to be considered in obtaining pharmaceutical and cosmetic preparations used in anti-aging strategies and, together with medications, in the management of age-related diseases. In further evaluations, the valuable functional properties of oak galls, reported mostly in preclinical studies, should be confirmed with clinical studies that would also take into account the potential health risks of their use.

Neoadjuvant cemiplimab and surgery for stage II-IV cutaneous squamous-cell carcinoma: follow-up and survival outcomes of a single-arm, multicentre, phase 2 study

BACKGROUND

We previously reported rates of pathological complete responses (51% [95% CI 39-62] per independent central review, the primary endpoint) and major pathological responses (13% per independent central review, a secondary endpoint) to neoadjuvant cemiplimab (an anti-PD-1 inhibitor) among 79 patients with locoregionally advanced, resectable cutaneous squamous cell carcinoma. Here, we present follow-up data, including event-free, disease-free, and overall survival.

METHODS

This single-arm, multicentre, phase 2 study included patients aged 18 years or older with resectable stage II-IV (M0) cutaneous squamous cell carcinoma and Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received up to four planned doses of neoadjuvant cemiplimab 350 mg intravenously every 3 weeks followed by curative-intent surgery. After surgery, per investigator discretion, patients received either adjuvant cemiplimab for up to 48 weeks, radiotherapy, or observation alone. Secondary endpoints included in this follow-up analysis are event-free survival, disease-free survival, and overall survival, all summarised using the Kaplan-Meier method. Activity and safety endpoints were analysed for all enrolled patients who received at least one dose of neoadjuvant cemiplimab. In this report, safety data are reported for all patients who received at least one dose of adjuvant cemiplimab. This trial is registered with ClinicalTrials.gov, NCT04154943, has completed enrolment and follow-up is ongoing.

FINDINGS

Between March 20, 2020, and July 8, 2021, 79 patients were enrolled. Median age was 73 years (IQR 66-81), 67 (85%) patients were male, 12 (15%) were female, 69 (87%) were White, one was Asian (1%), one was other race (1%), and race was not reported for eight (10%). As of data cutoff (Dec 1, 2022), median follow-up was 18·7 months (IQR 15·6-22·1) for all 79 patients. Among 70 patients who had surgery, 65 (93%) had post-surgical management data: 32 (49%) of 65 were observed postoperatively, 16 (25%) received adjuvant cemiplimab, and 17 (26%) received adjuvant radiotherapy. 11 (14%) of 79 patients had event-free survival events, with an estimated 12-month event-free survival of 89% (95% CI 79-94) for all patients. None of 40 patients who had a pathological complete response and one (10%) of ten patients with major pathological response had recurrence. Six (9%) of 70 patients who completed surgery had a disease-free survival event, with an estimated 12-month disease-free survival of 92% (95% CI 82-97). Nine (11%) of 79 patients died, with an estimated 12-month overall survival for all patients of 92% (95% CI 83-96). Four (25%) of 16 patients who received adjuvant cemiplimab treatment had grade 3 adverse events, including one (6%) who had increased blood potassium, one (6%) who had traumatic limb amputation, and two who had serious adverse events (one [6%] cardiomyopathy and one [6%] hypophysitis). There were no grade 4 adverse events or treatment-related deaths.

INTERPRETATION

For patients with resectable stage II-IV cutaneous squamous cell carcinoma, neoadjuvant cemiplimab followed by surgery might be a potential treatment option, addressing a substantial unmet need.

FUNDING

Regeneron Pharmaceuticals and Sanofi.

ENO1 Binds to ApoC3 and Impairs the Proliferation of T Cells via IL-8/STAT3 Pathway in OSCC

Lymph node metastasis is associated with poor prognosis of oral squamous cell carcinoma (OSCC), and few studies have explored the relevance of postoperative lymphatic drainage (PLD) in metastatic OSCC. Alpha-enolase (ENO1) is a metabolic enzyme, which is related to lymphatic metastasis of OSCC. However, the role of ENO1 in PLD in metastatic OSCC has not been elucidated. Herein, we collected lymphatic drainage after lymphadenectomy between metastatic and non-metastatic lymph nodes in OSCC patients to investigate the relationship between ENO1 expression and metastasis, and to identify the proteins which interacted with ENO1 in PLD of patients with metastatic OSCC by MS/GST pulldown assay. Results revealed that the metabolic protein apolipoprotein C-III (ApoC3) was a novel partner of ENO1. The ENO1 bound to ApoC3 in OSCC cells and elicited the production of interleukin (IL)-8, as demonstrated through a cytokine antibody assay. We also studied the function of IL-8 on Jurkat T cells co-cultured with OSCC cells in vitro. Western blot analysis was applied to quantitate STAT3 (signal transducer and activator of transcription 3) and p-STAT3 levels. Mechanistically, OSCC cells activated the STAT3 signaling pathway on Jurkat T cells through IL-8 secretion, promoted apoptosis, and inhibited the proliferation of Jurkat T cells. Collectively, these findings illuminate the molecular mechanisms underlying the function of ENO1 in metastasis OSCC and provide new strategies for targeting ENO1 for OSCC treatment.