Pharmacologic treatment options for advanced epithelial skin cancer

Optical coherence tomography-based non-invasive evaluation of premalignant lesions in SKH-1 mice

Non-invasively diagnosis of actinic keratoses (AK) is important for preventing cutaneous squamous cell carcinoma (cSCC). Optical coherence tomography (OCT) can be used to detect the cross-sectional skin micromorphology with sufficient resolution and imaging depth. It has the capability to reveal the changes in skin microstructure during the development of AK. Therefore, OCT can serve as a tool for diagnosing AK. This study explores the feasibility of OCT in evaluating the structural changes in mouse skin at the different stages following exposure to ultraviolet radiation. The performance of OCT is compared with histology, the gold standard in this context. The imaging results demonstrate that a wave-shaped irregular dermo-epidermal junction (DEJ), as well as the continuous thickening of the epidermis, are useful diagnostic parameters for diagnosing AK. Histological examinations confirm these observations. These findings emphasize the need for effective skin protection or medical treatment once changes in the DEJ and epidermis are detected. OCT shows strong potential for non-invasive evaluation of such changes and AK development, and can be used for the prevention of cSCC without the necessity of taking biopsies.

Anti-Proliferative and Genotoxic Activities of the Helichrysum petiolare Hilliard & B.L. Burtt

Helichrysum petiolare (Asteraceae family) is part of the Helichrysum genus which comprises of an estimated 600 species. Several parts of the plant have been used traditionally for the treatment of various ailments, such as cough, infection, asthma, chest problems, diabetes and wounds. Given its various chemical constituents with anticancer properties, there has been no scientific evidence of its usage for the treatment of cancer. This study aims to investigate the anti-proliferative and genotoxic activities of H. petiolare methanol extract. The cytotoxic effect and cell cycle analysis of mouse melanoma cells (B16F10) and human melanoma cells (MeWo) were assessed using the ImageXpress Micro XLS Widefield High-Content Analysis System. The genotoxic potential of the extract towards Vero cells was also assessed using the micronucleus assay. The extract displayed cytotoxicity towards B16F10 and MeWo skin melanoma cells, thereby showing a dose-dependent decrease in cell density. This was preceded by cell cycle arrest in B16F10 cells at the S phase and MeWo cell arrest at the early M phase with a significant increase in apoptosis in both cells. Furthermore, the extract displayed genotoxic potential at the tested concentrations (12.5–200 μg/mL). Overall, the results revealed that H. petiolare extract may have the potential to eradicate skin cancer.

Challenges and new perspectives in the treatment of advanced cutaneous squamous cell carcinoma

Despite the overall excellent survival rates in patients affected by early cutaneous squamous cell carcinoma (CSCC), advanced forms of CSCC are associated with high patient mortality. To date, only limited therapeutic modalities have been implemented, including chemotherapy and radiotherapy. Systemic therapy was enriched by the addition of epidermal growth factor receptor inhibitors (EGFRi) in the last years. Unfortunately, the overall outcome of all these therapeutic strategies remains poor, therefore important unmet clinical needs persist. Thanks to a better understanding of the biology of advanced CSCC, new treatment options are now available. This article presents the current definition of advanced CSCC along with actual therapeutic options and discusses the strengths and limitations of a new promising systemic approach, which involves the use of immune checkpoint inhibitors.

Advanced cutaneous squamous cell carcinoma: how is it defined and what new therapeutic approaches are available?

PURPOSE OF REVIEW

Despite the overall excellent survival rates in patients with cutaneous squamous cell carcinoma (cSCC), advanced cutaneous SCCs are associated with high patient morbidity and mortality. Therefore, important unmet clinical needs persist: identifying high risk patients and choosing optimal treatment approaches.

RECENT FINDINGS

In recent years, a better understanding of the biology of cSCC and its clinical progression have led to improved staging systems and new promising treatments for advanced disease. Such treatments include PD1 inhibitors, such as cemiplimab, which was recently approved for the treatment of cutaneous SCC, and pembrolizumab whose efficacy in the treatment cSCC is still being investigated. Other treatments, such as epidermal growth factor receptor inhibitors have also been used in the treatment of cSCC with moderate success. Several clinical and histological risk factors are considered key in estimating the risk or recurrence or metastasis in cSCCs and, therefore, influence the appropriate treatment choice and patient monitoring.

SUMMARY

The present study reviews the current definition of advanced cSCC and discusses the new systemic approaches, including checkpoint inhibitors.

In-vitro Anti-proliferative Effects of Ethanolic Extract of Vanilla Planifolia Leaf Extract against A431 Human Epidermoid Carcinoma Cells

Squamous cell carcinoma is the second largest among skin cancer diseases. The aim of the present study is to reveal the antiproliferative property of vanilla leaf extract against A431 cells. Antiproliferative property was assessed by MTT assay. Apoptotic property was assessed by DNA fragmentation assay. Antiproliferative property of extract was revealed in a dose dependent manner. IC50 of the extract against A431 cells was revealed at 31.2µg/ml. This study revealed the cancer suppression capability of vanilla leaf extract in skin cancer cell lines.

Programmed cell death 1 protein and programmed death-ligand 1 inhibitors in the treatment of nonmelanoma skin cancer: A systematic review

BACKGROUND

Immunotherapy using programmed cell death 1 protein (PD-1) or programmed death-ligand 1 (PD-L1) inhibitors has been increasingly reported in a variety of nonmelanoma skin cancers (NMSCs).

OBJECTIVE

To analyze the evidence of PD-1 and PD-L1 inhibitors in the treatment of NMSC.

METHODS

A primary literature search was conducted with the PubMed, Cochrane Library, EMBASE, Web of Science, and CINAHL databases through October 28, 2018, to include studies on the use of PD-1 or PD-L1 inhibitors in patients for NMSC. Two reviewers independently performed study selection, data extraction, and critical appraisal.

RESULTS

This systematic review included 51 articles. The most robust evidence was in the treatment of Merkel cell carcinoma and cutaneous squamous cell carcinomas, as supported by phase 1 and 2 clinical trials. Treatment of basal cell carcinoma, cutaneous sarcoma, sebaceous carcinoma, and malignant peripheral nerve sheath tumor also showed benefit with PD-1/PD-L1 inhibitors, but data are limited. There does not appear to be efficacy for PD-1/PD-L1 inhibitors in cutaneous lymphomas.

LIMITATIONS

More investigation is needed to determine the efficacy, tumor responsiveness, and the safety profile of PD-1 and PD-L1 inhibitors in NMSC.

CONCLUSION

PD-1 and PD-L1 inhibitors exhibit treatment efficacy in a variety of NMSCs.

Non-melanoma skin cancer: new and future synthetic drug treatments

INTRODUCTION

Non-melanoma skin cancers (NMSC) mainly comprise two different entities: basal cell carcinoma (BCC) and squamous cell carcinoma (SCC); beneath these two entities, Merkel cell carcinoma, adnexal tumors, dermatofibrosarcoma protuberans, angiosarcoma, and cutaneous lymphoma belong to NMSC. These rare skin tumors are not the topic of this review. BCC and SCC are the most common cancers diagnosed in humans. The preferred treatment is surgery, which in most cases is curative. Although a high recurrence rate is seen, these cancers rarely metastasize. Therefore, systemic treatments were not a priority for these patients. It is long known that the abnormal activation of Hedgehog and epidermal growth factor receptor pathways were involved in BCC and SCC. In the last decade, metastatic disease became an important area of research, mostly because new therapies that targeted components of these two pathways became available. Areas covered: Here we cover the available therapeutic options for patients diagnosed with BCC and SCC, focus on systemic and targeted therapies. Expert opinion: BCC and SCC are common cancers, with good prognosis. More than the metastatic disease, advanced local disease and recurrent disease pose clinicians a great challenge. Albeit there are promising results with targeted therapies, resistance development has already been described.

Basosquamous Carcinoma: Controversy, Advances, and Future Directions

BACKGROUND

Basosquamous carcinoma is a rare cutaneous neoplasm that has caused considerable controversy as to its classification, pathogenesis, and management.

OBJECTIVE

To review and summarize current literature on the definition, pathogenesis, incidence, and management of basosquamous carcinoma.

MATERIALS AND METHODS

Through December 2015, an electronic search of the Pubmed database was performed using combinations of basosquamous carcinoma and metatypical basal cell carcinoma as search terms.

RESULTS

A selection of 39 publications including case reports and series, retrospective studies, and systematic reviews of the literature were included. Descriptions of the definition of basosquamous carcinoma, clinical behavior, histopathological characteristics, current treatment therapies, and future advances are summarized.

CONCLUSION

This systematic review provides a comprehensive overview of the current understanding of basosquamous carcinoma. Further study is required to elucidate the mechanisms driving the formation of this aggressive tumor.

Can hair re-growth be considered an early clinical marker of treatment resistance to Hedgehog inhibitors in patients with advanced basal cell carcinoma? A report of two cases

INTRODUCTION

Basal cell carcinomas (BCCs) are the most common skin cancers in the Caucasian population. BCCs are in the majority of cases adequately managed with surgical excision, however a small subset of these tumours exhibit resistance to conventional therapies and progress to become locally advanced or even metastatic. Although Hedgehog inhibitors have been successfully used during the last few years in the treatment of locally advanced or metastatic BCCs, resistance to treatment remains an issue. Until this point, no biomarkers or clinical markers of drug resistance for Hedgehog inhibitors have been identified.

METHODS AND RESULTS

We report two patients, a female patient with Gorlin syndrome and a male patient with locally advanced BCC, which received treatment with the Hedgehog inhibitor Vismodegib. These patients responded adequately to treatment and they both developed Hedgehog inhibitor-induced alopecia as an adverse event. However, after 2.5 and 1.5 years of treatment, respectively, the patients exhibited progressive disease that was accompanied by reversal of the Hedgehog inhibitor-induced alopecia, although still under treatment with Vismodegib.

CONCLUSION

Although alopecia is a well-known adverse event associated with the administration of Hh inhibitors, data associated with the appearance and/or clinical severity of alopecia and the treatment efficacy of Hedgehog inhibitors are limited. The Hedgehog pathway plays an important role in the normal cycling of the hair follicles in adults and, therefore, the pathomechanism of Hedgehog inhibitor-induced alopecia is considered unique for this drug class. Based on the fact that Hh inhibitor resistance is associated with partial reactivation of the Hh pathway, it would not be illogical to suggest that reversal of Hh inhibitor-induced alopecia in patients under treatment with Hh inhibitors could serve as a clinical marker of drug resistance. However, this observation, as reported in this paper, is only limited in two patients and therefore more information is needed in order to assess its actual clinical importance.

Resistance of Nonmelanoma Skin Cancer to Nonsurgical Treatments. Part II: Photodynamic Therapy, Vismodegib, Cetuximab, Intralesional Methotrexate, and Radiotherapy

A wide range of treatments is now available for nonmelanoma skin cancer, including 5-fluorouracil, ingenol mebutate, imiquimod, diclofenac, photodynamic therapy, methotrexate, cetuximab, vismodegib, and radiotherapy. All are associated with high clinical and histologic response rates. However, some tumors do not respond due to resistance, which may be primary or acquired. Study of the resistance processes is a broad area of research that aims to increase our understanding of the nature of each tumor and the biologic features that make it resistant, as well as to facilitate the design of new therapies directed against these tumors. In this second article, having covered the topical treatments of nonmelanoma skin cancer, we review resistance to other nonsurgical treatments, such as monoclonal antibodies against basal and squamous cell carcinomas, intralesional chemotherapy, photodynamic therapy, and radiotherapy.