Spotlight on vismodegib in the treatment of basal cell carcinoma: an evidence-based review of its place in therapy

Treatment of locally advanced and metastatic basosquamous carcinoma, navigating among sonic hedgehog pathway inhibitors, immune checkpoint inhibitors, chemotherapy, and radiotherapy: A case series and literature review

Locally advanced (laBSCs) and metastatic basosquamous carcinomas (mBSCs) represent a therapeutic challenge. By definition, these forms are not amenable to surgery or radiotherapy, but according to literature reports, sonic hedgehog pathway inhibitors (HHIs), anti-programmed death 1 receptor antibodies (anti-PD-1), and other treatment approaches involving chemotherapy, surgery, and radiotherapy have been used. This work features 5 real-life cases of advanced BSCs, treated at the Dermato-Oncology Unit of Trieste (Maggiore Hospital, University of Trieste). In addition, a review of the current treatment options reported in the literature for laBSC and mBSC is provided, collecting a total of 17 patients. According to these preliminary data, HHIs such as sonidegib and vismodegib could represent a safe and effective first line of treatment, while the anti-PD-1 cemiplimab may be useful as a second-line option. Chemotherapy and combined approaches involving surgery and radiotherapy have been also reported to be suitable in some patients.

Basosquamous Carcinoma: Comprehensive Clinical and Histopathological Aspects, Novel Imaging Tools, and Therapeutic Approaches

Basosquamous carcinoma (BSC), an uncommon and aggressive nonmelanoma skin cancer exhibiting characteristics ranging from basal cell carcinoma (BCC) to squamous cell carcinoma (SCC), is a subject of controversy in terms of its classification, pathogenesis, histologic morphology, biologic behavior, prognosis, and management. This narrative review is based on an electronic search of English-language articles in PubMed that included the terms "basosquamous carcinoma" and/or "metatypical carcinoma of the skin" in their titles. The review aims to succinctly present and assess current data on the epidemiology, clinical presentation, dermoscopic, LC-OCT, and histopathologic characteristics, as well as the genetics and management of BSC, providing insight into this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies, and immunohistologic techniques should be applied in clinically suspicious lesions to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs' micrographic surgery, remain the treatment of choice. Finally, Hedgehog pathway inhibitors and checkpoint inhibitors, must be thoroughly investigated with large controlled trials, since they may offer an alternative solution to irresectable or difficult-to-treat locally advanced cases of basosquamous carcinoma.

Non-surgical Management of Locally Advanced Basal Cell Carcinoma of the Upper Extremity With Vismodegib

Basal cell carcinoma (BCC) is a common skin malignancy that can present reconstructive challenges in patients with locally advanced diseases of the extremities. This article highlights three cases of locally advanced BCC of the extremities managed with vismodegib (Erivedge, Genentech). Vismodegib is a sonic hedgehog pathway (Shh) inhibitor approved by the FDA for use in metastatic or recurrent BCC. All three patients in our case series demonstrated significant clinical responses with reductions in tumor size which obviated the need for complex reconstructive surgery or amputation.

Basosquamous Carcinoma: A Commentary

Simple Summary

Basosquamous carcinoma is a rare, aggressive non-melanoma skin cancer with features that lie between those of basal cell carcinoma and squamous cell carcinoma. A lot of controversy has been raised around the classification, pathogenesis, histologic morphology, biologic behavior, prognosis and management of this tumor. This is a narrative review based on articles published on PubMed in English language which had in their title the terms “basosquamous carcinoma” and/or “metatypical carcinoma of the skin”. The aim of this review was to summarize and evaluate the latest data of the English literature regarding epidemiology, clinical presentation, dermoscopic and histopathologic characteristics, as well as the genetics and management of BSC to better characterize basosquamous skin lesions.

Abstract

Basosquamous carcinoma is a rare, aggressive non-melanoma skin cancer with features that lie between those of basal cell carcinoma and squamous cell carcinoma. A lot of controversy has been raised around the classification, pathogenesis, histologic morphology, biologic behavior, prognosis and management of this tumor. This is a narrative review based on an electronic search of articles published in PubMed in English language which had in their title the terms “basosquamous carcinoma” and/or “metatypical carcinoma of the skin”. The aim of this review was to summarize and evaluate current data regarding epidemiology, clinical presentation, dermoscopic and histopathologic characteristics, as well as the genetics and management of BSC, in order to shed some more light onto this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies and immunohistologic techniques (Ber-EP4) should be applied in clinically suspicious lesions in order to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs’ micrographic surgery, remain the treatment of choice. Finally, vismodegib, a Hedgehog pathway inhibitor, must be thoroughly investigated, with large controlled trials, since it may offer an alternative solution to irresectable or difficult-to-treat, locally advanced cases of basosquamous carcinoma.

Real-World Experience of Vismodegib in Advanced Basal Cell Carcinoma at a Canadian Cancer Center

BACKGROUND

Vismodegib is a novel Hedgehog pathway inhibitor that has revolutionized the treatment of patients with advanced basal cell carcinoma (BCC) who are poor candidates for surgery or radiation. Few studies have explored the use of vismodegib to facilitate further surgery or radiotherapy, and the optimal treatment duration to balance outcomes with adverse effects.

OBJECTIVES

To characterize the disease response, progression, and recurrence outcomes of BCC patients, and to report the impact of subsequent therapies.

METHODS

We performed a retrospective study of 46 adult patients with advanced basal cell carcinoma (aBCC), including both locally advanced (laBCC) and metastatic (mBCC) disease, treated with vismodegib at a single center from 2012 to 2019.

RESULTS

Thirty-six had laBCC, and 10 had mBCC. Treatment was given over a mean of 21.9 months. Twenty-three (50%) had a complete response (CR), and 19 (41.3%) achieved partial response (PR). Median time to maximal response was 5.3 months. Eleven (23.9%) had resected disease at median 17.2 months, and 11 patients (23.9%) received radiotherapy. Thirty-two (69.6%) experienced progressive disease after achievement of CR or PR. Among 17 CR patients, who stopped treatment, 14 (82.3%) experienced subsequent relapse; 6 (85%) attained a repeat response. Twenty (43.5%) discontinued treatment at least once due to adverse effects.

CONCLUSIONS

With a response rate of 91%, London Regional Cancer Center's (LRCP)'s experience with vismodegib supports its effectiveness in treatment of aBCC. Moreover, a significant number of patients treated with vismodegib became amenable to surgery or radiotherapy. Toxicity remained an important factor that limited treatment duration.

Facial site distribution of basal cell carcinoma in Japanese

Basal cell carcinoma (BCC) occurs preferentially on the face. We retrospectively analyzed 200 cases of BCC treated at Nagoya City University Hospital from April 2004 to October 2015 and examined regional features based on modified facial aesthetic units. BCC occurred more frequently on the cheek, nasal and orbital areas. There was no significant difference between sides, and age was the only factor affecting tumor size.

Real-life data on basal cell carcinoma treatment: Insights on clinicians' therapeutic choices from an institutional hospital registry

Basal cell carcinoma (BCC) is the most common skin cancer in white skin individuals. The treatment of choice is surgical excision, but several other therapeutic choices are available and might also be efficient and cost-effective in selected cases of low-risk BCC or when surgery is complicate or contraindicated. The aim of the current study was to analyze the applied treatments for BCC in the real-life practice of a tertiary hospital, and investigate factors associated to the tumor and the patients that might influence the treatment selection of clinicians. Data on all BCCs treated from 1st January 2018 to 31st December 2019 were extracted. A total of 751 BCCs from 585 patients were included. The baseline characteristics of patients and tumors, the type of applied treatment and the histopathologic report when available were analyzed. Most tumors were located on the head/neck (64.2%). The most frequently applied treatment was surgical excision (580/751, 77.2%). In 22.8% of tumors a nonsurgical treatment was selected. The most frequently selected alternative treatments were, imiquimod, cryosurgery, their combination (immunocryosurgery), and vismodegib. A pretreatment diagnosis of superficial BCC was associated with a 12-fold increased probability of selecting a nonsurgical treatment except of vismodegib. Every added year of age increased the probability of selecting a nonsurgical treatment by 3-fold. Every added mm of diameter increased the possibility of vismodegib use by 4%. Surgery is the most frequently applied BCC treatment, but nonsurgical modalities do also have an essential role in real settings.

The Role of Anti-PD-1/PD-L1 in the Treatment of Skin Cancer

Skin cancers remain the most common group of cancers globally, and the incidence continues to rise. Although localized skin cancers tend to have excellent outcomes following surgical excisions, the less common cases that become surgically unresectable or metastatic have been associated with poor prognosis and suboptimal treatment responses to cytotoxic chemotherapy. Development of monoclonal antibodies to programmed cell death-1 receptor and its ligand (PD-1/PD-L1) have transformed the management of metastatic melanoma, squamous cell carcinoma, and Merkel cell carcinoma. These agents, as monotherapies, are associated with response rates of approximately 40-60%, many of which persist durably. Further efficacy is observed with combination immunotherapy in advanced melanoma. Early reports suggest similar activity in locally advanced or metastatic basal cell carcinoma. In this review, we describe common molecular features of skin cancers that may render them particularly susceptible to anti-PD-1/PD-L1 and detail results from key clinical trials of these agents across skin cancers. Overall, the superior response rates of skin cancer to anti-PD-1/PD-L1 compared with other solid tumor types are likely due, at least in part, to a high mutational burden and, in Merkel cell carcinoma, viral etiology. Although melanoma has been rigorously studied in the setting of anti-PD-1/PD-L1 treatment, more research is needed for the other skin cancer types to establish toxicity profiles, responses, and quality-of-life outcomes.

Treatment of periocular basal cell carcinoma with neoadjuvant vismodegib

Purpose

To report a case of a locally advanced periocular basal cell carcinoma treated with neoadjuvant Vismodegib therapy prior to surgery.

Observations

A 63-year-old female presented to the oculoplastics clinic with biopsy-proven basal cell carcinoma of the right periorbital region causing significant cicatricial ectropion of the right lower eyelid. The medial canthal lesion involved nearly the entire right lower eyelid with extension onto the cheek, the medial half of the right upper eyelid, the palpebral and bulbar conjunctiva, as well as the right lacrimal system. CT imaging was suggestive of involvement of the extraocular muscles and other post-septal tissues. Fortunately, the patient had no metastatic disease. The extent of the tumor would have necessitated aggressive resection to achieve surgical cure. However, the patient preferred to attempt globe-sparing therapy with a goal of preserving cosmesis as much as possible. Various treatment options were discussed with the patient, including the use of Vismodegib, and the patient elected to pursue this treatment strategy. The goal of Vismodegib treatment was to reduce the tumor size enough to permit surgical resection of all tumor without significantly affecting cosmesis. After 11 months of treatment with Vismodegib, the tumor size had reduced significantly to the point where surgical intervention with minimal disfigurement could be offered. The patient underwent multidisciplinary approach with Mohs micrographic excision of the tumor paired with oculoplastic reconstructive surgery resulting in negative margins and satisfactory cosmetic results.

Conclusions and importance

Although addition study is required regarding Vismodegib as a primary or adjuvant therapeutic approach to periorbital basal cell carcinoma, this case illustrates the potential usefulness of this drug as an option in this context. This case provides information that may help the comprehensive ophthalmologist or oculoplastic specialist in counseling patients with locally advanced periorbital basal cell carcinoma.

Safety and Tolerability of Sonic Hedgehog Pathway Inhibitors in Cancer

The hedgehog pathway, for which sonic hedgehog (Shh) is the most prominent ligand, is highly conserved and is tightly associated with embryonic development in a number of species. This pathway is also tightly associated with the development of several types of cancer, including basal cell carcinoma (BCC) and acute promyelocytic leukemia, among many others. Inactivating mutations in Patched-1 (PTCH1), leading to ligand-independent pathway activation, are frequent in several cancer types, but most prominent in BCC. This has led to the development of several compounds targeting this pathway as a cancer therapeutic. These compounds target the inducers of this pathway in Smoothened (SMO) and the GLI transcription factors, although targeting SMO has had the most success. Despite the many attempts at targeting this pathway, only three US FDA-approved drugs for cancers affect the Shh pathway. Two of these compounds, vismodegib and sonidegib, target SMO to suppress signaling from either PTCH1 or SMO mutations that lead to upregulation of the pathway. The other approved compound is arsenic trioxide, which can suppress this pathway at the level of the GLI proteins, although current evidence suggests it also has other targets. This review focuses on the safety and tolerability of these clinically approved drugs targeting the Shh pathway, along with a discussion on other Shh pathway inhibitors being developed.

Vismodegib: A Review in Advanced Basal Cell Carcinoma

Vismodegib (Erivedge^®) is the first-in-class, oral small molecule inhibitor of the Hedgehog (Hh) pathway, abnormal activation of which is associated with basal cell carcinoma (BCC). In the USA, vismodegib is indicated for the treatment of adults with metastatic BCC (mBCC) or with locally-advanced BCC (LaBCC) that has recurred following surgery or who are not candidates for surgery, and who are not candidates for radiation. Similarly, in the EU, vismodegib is indicated for the treatment of adult patients with symptomatic mBCC, or with laBCC inappropriate for surgery or radiotherapy. The full European approval of vismodegib was based on the results of two phase II, open-label, noncomparative, international trials (ERIVANCE BCC and STEVIE), both of which showed high rates of tumour control in the indicated patient populations, including individuals with or without Gorlin syndrome. These studies also showed that vismodegib has an acceptable and manageable tolerability profile characterized by a number of class-related treatment-emergent adverse events, including muscle spasms, taste disturbances, alopecia, weight loss and asthenia (fatigue). Primary and secondary resistance to vismodegib has been documented, albeit at a low rate compared with some other targeted therapies. Vismodegib is therefore an effective and generally well tolerated systemic therapy for patients with mBCC and laBCC that can no longer be suitably controlled with surgery and/or radiotherapy. Historically, it is the first member of a class of drugs (Hh pathway inhibitors) that are now considered to be first-line treatment options for such individuals.

Electrochemotherapy in the treatment of locally advanced or recurrent eyelid-periocular basal cell carcinomas

There is increasing evidence about the effectiveness of electrochemotherapy (ECT) in the treatment of basal cell carcinomas in the head and neck region, although its role in the management of eyelid-periocular skin tumors has to be clarified. The aim of the present study is to evaluate the results of ECT in the treatment of locally advanced primary and recurrent eyelid-periocular skin basal cell carcinomas. Twelve patients with basal cell carcinoma involving the eyelid-periocular skin region were treated with ECT. Three patients had locally advanced primary tumors, while 9 patients had recurrent tumors. All treatments were performed according to the ESOPE guidelines, using Cliniporator TM device. All patients received bleomycin based ECT. The route of administration was intratumoral in 3 patients and intravenous in 9 patients. Tumor response was evaluated using the RECIST 1.1. criteria. ECT resulted in complete response of the periocular skin tumors in all patients. Lower eyelid ectropion was developed in 3 patients which had to be corrected surgically. ECT can be used effectively in the treatment of locally advanced or recurrent basal cell carcinomas in the eyelid-periocular skin region. Excellent tumor control can be achieved with good functional and cosmetic results without systemic adverse events with short interval follow-up.

Sea turtle fibropapilloma tumors share genomic drivers and therapeutic vulnerabilities with human cancers

Wildlife populations are under intense anthropogenic pressures, with the geographic range of many species shrinking, dramatic reductions in population numbers and undisturbed habitats, and biodiversity loss. It is postulated that we are in the midst of a sixth (Anthropocene) mass extinction event, the first to be induced by human activity. Further, threatening vulnerable species is the increased rate of emerging diseases, another consequence of anthropogenic activities. Innovative approaches are required to help maintain healthy populations until the chronic underlying causes of these issues can be addressed. Fibropapillomatosis in sea turtles is one such wildlife disease. Here, we applied precision-medicine-based approaches to profile fibropapillomatosis tumors to better understand their biology, identify novel therapeutics, and gain insights into viral and environmental triggers for fibropapillomatosis. We show that fibropapillomatosis tumors share genetic vulnerabilities with human cancer types, revealing that they are amenable to treatment with human anti-cancer therapeutics.

David Duffy et al. use a precision-medicine-based approach to study fibropapillomatosis tumors in sea turtles to identify environmental triggers and potential therapeutics. They show that these tumors share genetic similarities with human cancer types, and may be treatable using human anti-cancer therapies.

Cutaneous Head and Neck Malignancies in the Elderly

Cutaneous malignancy of the head and neck affects a large proportion of elderly patients. The severity ranges from small, easily treatable lesions to large, invasive, potentially metastatic tumors. Surgical treatment is the primary treatment of most skin cancers; however, geriatric patients are more likely to have multiple comorbidities that increase the risk of surgery. Multiple treatment modalities exist, including surgical, radiation, and medical therapy. Recommendations and treatment options for basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, and melanoma are outlined and reviewed.