The Impact of Neoadjuvant Hedgehog Inhibitor Therapy on the Surgical Treatment of Extensive Basal Cell Carcinoma

Risk Factors for Orbital Invasion in Malignant Eyelid Tumors, Is Orbital Exenteration Still Necessary?

Basal cell carcinoma is the most common malignant skin tumor of the eyelids in Caucasians, followed by squamous cell carcinoma and sebaceous gland carcinoma. The primary treatment for these tumors is radical excision. In cases where malignant eyelid tumors are advanced and have invaded the orbit, orbital exenteration is necessary. In this retrospective study, we aimed to determine the correlation between the risk of orbital infiltration and various factors like tumor location, size, histological type, and patient age. This study revealed that tumors in multiple regions increased the risk of orbital infiltration by 3.75 times. Tumors with a diameter of 21-30 mm raised the likelihood of requiring exenteration by 15.5 times compared to smaller tumors (up to 10 mm). Age was also associated with the likelihood of orbital invasion in periocular tumors. Interestingly, no correlation was found between the histological type of the tumor and the risk of orbital infiltration. Notably, the conjunctiva of the eyeball was the most commonly infiltrated orbital structure, followed by the orbital fat. Timely treatment and well-planned procedures are crucial for patients with malignant periocular skin tumors to avoid multiple reoperations and the potential need for orbital exenteration.

The initial rate of tumour response to vismodegib treatment, can predict a complete response outcome for periocular LA-BCC

PURPOSE

To establish a model to predict treatment outcome of periocular locally advanced basal cell carcinoma (POLA BCC) based on initial response to treatment with vismodegib (ErivedgeTM), a sonic hedgehog inhibitor.

DESIGN

Subgroup analysis of data from the STEVIE study database.

METHODS

Analysis of medical history, treatment protocol, and treatment outcome of POLA BCC tumours in a STEVIE study population of 244 POLA BCC patients treated with ≥1 dose of vismodegib.

RESULTS

A predictive model for complete response (CR) was established based on the initial treatment response. A cutoff value of 20% reduction in tumour size at 3 months of treatment identified the patients with a high probability (82.76%) to achieve CR. A second cutoff value of 67.7% reduction in tumour size at 6 months of treatment improved the prediction to a 95.42% probability of a CR outcome.

CONCLUSIONS

A treatment model was constructed based on the prediction of a CR outcome and the initial response to vismodegib treatment at 3 and 6 months. The study result provide significant new insights can facilitate decision-making on treatment management according to tumour response in patients with POLA BCC.

The current clinical approach to difficult-to-treat basal cell carcinomas

INTRODUCTION

Basal cell carcinoma (BCC) is the most common malignant tumor in adult white populations. If BCCs are not treated for years, if they cause massive destruction of the surrounding tissues, if they are considered unresectable or not eligible for radiotherapy they become progressively 'locally advanced' (laBCC) or metastatic (mBCC). These tumors are defined as 'difficult-to-treat BCC.'

AREAS COVERED

A comprehensive search on PubMed was conducted to identify relevant literature about the several approved and recommended treatment options for the management of difficult-to-treat BCC published from January 2012 to July 2022. Surgical options, radiotherapy, hedgehog inhibitors, immunotherapy, and combined treatments are discussed. The keywords used were basal cell carcinoma; difficult-to-treat BCC; management of difficult-to-treat BCC; surgical therapy; radiotherapy; hedgehog inhibitors; immunotherapy.

EXPERT OPINION

Identifying the best approach to DTT BCCs is one of the main challenges for the dermato-oncologist. The introduction of HHI for the treatment of advanced BCCs has revolutionized the clinical management of DTT BCCs. The immune checkpoint inhibitor cemiplimab has been approved for the treatment of locally advanced or metastatic BCC refractory to HHI therapy or in patients intolerant to HHI therapy. Multidisciplinary teams (MDTs) play a key role in managing these complex patients.

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.

Advanced basal cell carcinoma: What dermatologists need to know about treatment

The treatment of advanced basal cell carcinoma (BCC) often requires therapies beyond local surgical excision or radiation due to the invasiveness of the tumor. Historically, cytotoxic chemotherapy was used to treat advanced BCC, but with limited data, no standard regimens were established. The discovery of cyclopamine, a natural inhibitor in the Hedgehog pathway, led to the development of the 2 currently approved Hedgehog inhibitors, vismodegib and sonidegib. Both agents are indicated for locally advanced BCC, while vismodegib is also indicated for metastatic BCC. In patients who progress on hedgehog inhibitors or cannot tolerate hedgehog inhibitors, the programmed cell death protein 1 inhibitor cemiplimab can be used to treat locally advanced or metastatic disease. Complex cases of locally advanced or metastatic BCC may be best discussed through a multidisciplinary approach in order to determine the optimal treatment approach for the individual patient.

Outcomes of adjunctive therapies post hedgehog inhibitors in the management of locally advanced basal cell carcinoma: A systematic review and pooled analysis

Management of patients with locally advanced basal cell carcinoma (laBCC) with traditional strategies has yielded suboptimal outcomes. Targeted treatments including hedgehog inhibitor therapy (HHIT) present limitations when utilized as monotherapy. Herein, we report evidence-based outcomes from available literature on multimodality treatments adjuvant to HHIT in laBCC management. Utilizing a systematic search strategy in PubMed, we identified studies published from inception to April 15, 2020, screened for definitive inclusion/exclusion criteria, and performed individual study quality assessment and pooled analysis to assess impact of adjunctive treatment-based responses post-HHIT on clinical response and recurrence outcomes. Twenty-nine studies (n = 103) were included. Primary findings include a complete response (CR) rate of 90.5%, the median follow-up of 12 months post-HHIT completion. The recurrence rate was 10.8% with 12-month median time to recurrence. Mohs micrographic surgery (MMS) had 100% CR post-HHIT, while no difference was observed between surgery and radiation therapy (RT). MMS and surgery had comparable 2-year recurrence free rates (RFR) at 87% and 86% respectively, while RT had the lower 2-year RFR at 67%. Male gender portended a more advanced stage at diagnosis and worse outcomes. In a subset analysis, periorbital laBCCs with orbital involvement had a CR rate of 81.8% versus 100% in those without orbital involvement, with similar rates of recurrence. Limited available quantitative data and possible publication bias were limitations. Pooled analysis of observational data supports use of adjunctive therapies post-HHIT to improve treatment response in patients with laBCC. Longer-term follow-up is needed to study recurrence rates after combination therapy.

Switching Hedgehog inhibitors and other strategies to address resistance when treating advanced basal cell carcinoma

Although basal cell carcinoma (BCC) is often managed successfully with surgery, patients with locally advanced BCC (laBCC) or metastatic BCC (mBCC) who are not candidates for surgery or radiotherapy have limited treatment options. Most BCCs result from aberrant Hedgehog pathway activation in keratinocyte tumor cells, caused by sporadic or inherited mutations. Mutations in the patched homologue 1 gene that remove its inhibitory regulation of Smoothened homologue (SMO) or mutations in SMO that make it constitutively active, lead to Hedgehog pathway dysregulation and downstream activation of GLI1/2 transcription factors, promoting cell differentiation and proliferation. Hedgehog inhibitors (HHIs) block overactive signaling of this pathway by inhibiting SMO and are currently the only approved treatments for advanced BCC. Two small-molecule SMO inhibitors, vismodegib and sonidegib, have shown efficacy and safety in clinical trials of advanced BCC patients. Although these agents are effective and tolerable for many patients, HHI resistance occurs in some patients. Mechanisms of resistance include mutations in SMO, noncanonical cell identity switching leading to tumor cell resistance, and non-canonical pathway crosstalk causing Hedgehog pathway activation. Approaches to managing HHI resistance include switching HHIs, HHI and radiotherapy combination therapy, photodynamic therapy, and targeting Hedgehog pathway downstream effectors. Increasing understanding of the control of downstream effectors has identified new therapy targets and potential agents for evaluation in BCC. Identification of biomarkers of resistance or response is needed to optimize HHI use in patients with advanced BCC. This review examines HHI resistance, its underlying mechanisms, and methods of management for patients with advanced BCC.

High-Risk Recurrence Basal Cell Carcinoma: Focus on Hedgehog Pathway Inhibitors and Review of the Literature

Basal cell carcinoma is the most common skin tumour, with the majority of the cases occurring on the head and neck district, where cosmetic and functional results are crucial. It can be locally destructive if not diagnosed early and treated appropriately. Surgery is the treatment of choice for most lesions, but aggressive, recurrent, or unresectable tumours can be challenging to manage. Advanced basal cell carcinoma includes high recurrence risk subtypes, in which standard therapies demonstrate lack of efficacy. This led to a need for investigating more deeply the pathogenesis of the disease and to the discovery of the implication of the hedgehog pathway. The development of systemic inhibitors of this pathway provides new treatment options for patients with advanced disease, resulting in survival improvement. Food and Drug Administration, before, and European Medicines Agency later approved 2 Hedgehog pathway inhibitors for the treatment of advanced basal cell carcinomas, vismodegib and sonidegib. Here, we present a review of the current English language literature trying to analyze differences in the 2 drugs as a head-to-head comparison between them has not already been documented in a randomized controlled clinical trial. Although vismodegib and sonidegib showed similar efficacy and safety profiles, in an indirect comparison scenario, sonidegib has shown slightly better outcomes in locally advanced basal cell carcinoma than vismodegib. They present different molecular structures, as they bind different residues on their targets and develop resistance for different mutations. In a future scenario, clinical trials comparing the 2 drugs are needed, as well as expanding data on discontinuation of therapy and/or consequential administration of them, with the aim to improve our clinical practise.

Diagnosis and Treatment of Basal Cell Carcinoma in Specialized Dermatology Units: A Clinical Practice Guideline

BACKGROUND AND OBJECTIVE

Basal cell carcinoma (BCC) is the most common skin cancer in the general population. BCC is managed in a variety of ways, and available international guidelines are difficult to put into practice in Spain. This guideline aims to improve the management of BCC based on current evidence and provide a point of reference for Spanish dermatologists.

MATERIAL AND METHODS

Members of the Spanish Oncologic Dermatology and Surgery Group (GEDOC) with experience treating BCC were invited to participate in drafting this guideline. The drafters used the ADAPTE collaboration process to develop the new guideline based on existing ones, first summarizing the care pathway and posing relevant clinical questions. They then searched for guidelines, assessed them with the AGREEII (Appraisal of Guidelines for Research and Evaluation) tool, and searched the selected guidelines for answers to the clinical questions. Finally, the recommendations were drafted and submitted for external review.

RESULTS

The highest-scoring guidelines were from the Association of Dermatologists, the National Comprehensive Cancer Network, the European Dermatology Forum, and the European Academy of Dermatology and Venereology. A total of 11 clinical questions were answered.

CONCLUSIONS

This new guideline answers the working group's clinical questions about the routine management of BCC in Spain. It provides dermatologists with a tool they can use for decision-making while taking into consideration the resources available and patient preferences.

Neoadjuvant Vismodegib and Mohs Micrographic Surgery for Locally Advanced Periocular Basal Cell Carcinoma

INTRODUCTION

Vismodegib has shown a significant response rate in locally advanced periocular basal cell carcinoma. Long-term monotherapy is very difficult to accomplish due to primary or secondary resistance and side effects that limit the length of treatment. The use of Vismodegib as neoadjuvant followed by Mohs micrographic surgery is an option.

PURPOSE

To report the use of neoadjuvant Vismodegib as an option for operable locally advanced basal cell carcinoma followed by Mohs surgery.

PATIENTS AND METHODS

The authors treated 8 locally advanced periocular basal cell carcinomas. Mean age was 76, and 6 of 8 were women. Mean size was 18 mm (12-30). Three were recurrent after surgery. Maximal clinical response was obtained at 4.8 months. Patients were operated at the mean time of 7.3 months.

RESULTS

Seven patients (87.5%) had a complete response and 1 (12.5%) progressed. Mohs micrographic surgery allowed to confirm a complete histologic response in 5 of 6 (83.3%) cases, and 1 patient refused surgery. All 7 patients are disease free after a mean follow-up of 12.4 months. All patients experienced adverse events. The most common included dysgeusia (100%) and muscle spasms (100%). Weight loss was present in 75% of the patients with a mean loss of 12.6 pounds and hair loss was seen in 50%. Only 1 (12.5%) patient withdraw from treatment because of intolerable muscle spasms.

CONCLUSIONS

The authors believe there is a clear role for Vismodegib as neoadjuvant in locally advanced periocular basal cell carcinoma, even in operable cases. Specific indications beyond those already approved should be further discussed. Prospective studies to assess the combination of neoadjuvant Vismodegib followed by Mohs micrographic surgery in locally advanced periocular basal cell carcinoma with long-term follow-up are needed.

Hedgehog Pathway Inhibitors and Their Utility in Basal Cell Carcinoma: A Comprehensive Review of Current Evidence

Basal cell carcinoma (BCC) is the most commonly diagnosed malignancy in humans, and as such it poses a significant healthcare burden. The majority of BCC cases are amenable to cure by surgical extirpation. However, until recently there have been no good treatment options for a significant minority of advanced BCC cases, including locally advanced BCC and metastatic BCC. The introduction of a novel class of drugs, the Hedgehog pathway inhibitors, into clinical practice has ushered in a new treatment algorithm for the treatment of difficult BCC cases. In this review we present the latest available evidence and discuss areas for further research in this rapidly evolving field.

Small Molecule Inhibitors of the Hedgehog Pathway in the Treatment of Basal Cell Carcinoma of the Skin

Basal cell carcinoma (BCC) is the most common type of skin cancer, with rising incidence rates primarily attributed to an aging population and ultraviolet radiation exposure. While the majority of BCCs are localized and respond to standard therapies, a very small minority of these tumors become locally destructive or metastasize. These advanced BCCs may not be amenable to localized treatment with surgery and/or radiation therapy. Most BCCs result from mutations in key receptors in the Hedgehog (HH) signaling pathway. As a result, identification of drugs that inhibit the receptor Smoothened (SMO) in the HH pathway has resulted in novel therapeutic approaches to treating patients with advanced BCC. These HH-pathway inhibiting medications have shown efficacy in clinical trials, and two medications, vismodegib and sonidegib, have received FDA approval. However, several limitations of these drugs have been identified, including treatment-limiting adverse events, drug resistance, and the formation of additional malignancies. This paper aims to summarize the clinical trials leading to the approval of SMO inhibitors, as well as reviewing potential mechanisms driving tumor resistance and the formation of cutaneous squamous cell carcinomas. Strategies to overcome some of these challenges, including the development of drugs that inhibit other downstream targets in the HH pathway, are the subject of ongoing clinical trials.

Basal Cell Carcinoma Surgery: Simple Undermining Approach in Two Patients with Different Tumour Locations

Basal cell carcinoma (BCC) is the most common human malignancy, accounting for the majority of all non-melanoma skin cancers (NMSC). In the past several decades the worldwide incidence of BCC has constantly been increasing. Even though it is a slow growing tumour that, left untreated, rarely metastasizes, it has a distinctive invasive growth pattern, posing a considerable risk for local invasion and destruction of underlying tissues, such as muscle, cartilage, bone or vital structures. Advanced BCCs include such locally invasive or metastatic tumours. Complete surgical excision is the standard therapy for most uncomplicated BCC cases with good prognosis and cure rates. Treatment of advanced forms of BCCs poses significant therapeutic challenges, most often requiring complicated surgery, radiotherapy, and/or targeted therapies directed towards the sonic hedgehog signalling pathway (SHH). We present two cases of large BCCs located on the scalp and posterior thorax, which underwent surgical excision with clear margins, followed by reconstruction of the defect after extensive undermining of the skin.