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

Epidemiological and clinical analysis of exposure-related factors in non-melanoma skin cancer: A retrospective cohort study

BACKGROUND

The incidence of non-melanoma skin cancers (NMSCs) increased over last decades, probably due to environmental concerns or to the increase of frail patients with age related comorbidities. Currently, the relationship of increasing global skin cancer rates with increased ultraviolet radiations (UVRs) resulting from stratospheric ozone depletion, global warming, and air pollution from fossil-fuel combustion.

AIMS

We conducted a retrospective epidemiological study including 546 NMSC patients managed at the Dermatology Unit of the Tor Vergata Hospital to highlight different trends of sun exposure or different comorbidities.

METHODS

Descriptive and inferential statistical analyses were performed to evidence differences between continous variable and Spearman rank test for dicotomical variables. Charlson Comorbidity Index was calculated to obtain the 10-years survival rate in order to identify the mean comorbidity burden of our patients.

RESULTS

Considering patients with comorbidities (73.81%), actinic keratoses (AKs) was the most frequent lesion. In patients with a history of previous melanoma, basal cell carcinoma (BCC) was predominant (ANOVA test, p < 0.05) with a statistically significant correlation (rho = 0.453; p < 0.01). Squamous cell carcinoma (SCC) showed a higher rate in arterial hypertension patients, followed by the chronic heart failure and hematologic neoplasms (60%, 29.7% and 32.1%, respectively) groups. Men were more affected than women, representing 61.54% of patients. Chronic sun exposure is directly correlated with SCC rho = 0.561; p < 0.01), whereas BCC correlated with a history of sunburns (rho = 0.312; p < 0.05).

CONCLUSIONS

History of photo-exposition had an important role on NMSC development especially for work or recreational reasons. Sex, age, and presence of comorbidities influenced different NMSC types. BCC was more frequent in younger patients, associated with melanoma and sunburns. The presence of SCC is associated with older patients and the hypertension group. AKs were diagnosed predominantly in oldest men, with a chronic sun-exposure history, and hematologic neoplasms group.

Review of Targeted Therapy, Vismodegib, for the Treatment of Periocular Basal Cell Carcinoma

PURPOSE

Periocular locally advanced basal cell carcinoma (POLA-BCC) is characterized by orbital involvement and/or extensive invasion of periocular structures. Hedgehog pathway inhibitors have been used for POLA-BCC with promising outcomes.

METHODS

The authors reviewed 11 articles published in English literature from January 2012 to July 2022 and reported the outcomes of patients with POLA-BCC who were treated with vismodegib.

RESULTS

A total of 384 patients were treated with vismodegib. The mean age was 72 years, and the median treatment duration was 9 months. The overall response rate was 75% with a median follow-up time of 14.4 months. Following vismodegib treatment, the median number of patients who required adjuvant surgery was 43% with a median time to surgery of 6.5 months. The exenteration rate was 6% (overall 8 patients). In total 93.7% of patients experienced grade I adverse events, 26.7% to 37.5% grade II, 8.8% to 10% grade III-IV, and 0.8% to 4.8% grade V. Major side effects included dysgeusia (30-100%), muscle spasm (15-100%), alopecia (47-75%), weight loss (23-83%), and decreased appetite (19-42%). The median percentage of patients who discontinued treatment due to toxicity was 29% with a median interval of 5 months before the development of side effects. The median recurrence rate following discontinuation of vismodegib was 7.8% with a median recurrence duration of 20 months.

CONCLUSIONS

In patients with POLA-BCC, vismodegib, a hedgehog pathway inhibitor, provided high rates of orbital preservation, reducing exenteration rates to 6%. Neoadjuvant therapy with vismodegib can also be suggested for patients with POLA-BCC. While extremely effective, side effects lead to temporary or permanent discontinuation of vismodegib in small numbers of patients.

Pharmacokinetics and pharmacodynamics of Hedgehog pathway inhibitors used in the treatment of advanced or treatment-refractory basal cell carcinoma

INTRODUCTION

Sonidegib and vismodegib are currently the only US Food and Drug Administration and European Medicines Agency-approved small-molecule Hedgehog pathway inhibitors (HHIs)for treating adults with advanced or refractory basal cell carcinoma (BCC) that is not amenable to conventional surgery or radiotherapy. At this time, there are no head-to-head clinical trials comparing these two HHIs for efficacy and safety to assist clinicians with determining which HHI may be best suited for their patients.

AREAS COVERED

This review briefly describes the pathogenesis of BCC, provides a detailed overview of the key pharmacokinetic profile differences between sonidegib and vismodegib, explains their pharmacodynamics, and highlights the therapeutic considerations when either HHI is used to treat special patient populations.

EXPERT OPINION

Although both HHIs act at the same molecular target in the Hedgehog pathway, there are significant differences in their pharmacokinetic profiles that may play a potential role in their efficacy and safety. Evidence-based recommendations serve to inform clinicians until direct comparative clinical trials of sonidegib versus vismodegib are conducted to determine the clinical relevance of the reported differences in their pharmacokinetic properties.

Mechanisms of hedgehog, calcium and retinoic acid signalling pathway inhibitors: Plausible modes of action along the MLL-EZH2-p53 axis in cellular growth control

Understanding the molecular mechanism(s) of small compounds in cellular growth control are essential for using those against the disease(s). Oral cancers exhibit a very high mortality rate due to higher metastatic potential. Aberrant EGFR, RAR, HH signalling, enhanced [Ca²⁺] and oxidative stress are some of the important characteristics of oral cancer. So, we target these for our study. Herein, we tested the effect of fendiline hydrochloride (FH) as an LTCC Ca²⁺-channel inhibitor, erismodegib (a SMO inhibitor of HH-signalling) and all-trans retinoic acid (RA) inducer of RAR signalling that causes cellular differentiation. OCT4 activating compound (OAC1) counters differentiation and induces stemness properties. Cytosine β-D arabinofuranoside (Cyto-BDA), a DNA replication inhibitor was used to reduce high proliferative capacity. Treatment of FaDu cells with OAC1, Cyto-BDA and FH increase G0/G1 population by 3%, 20% and 7% respectively, and lead to reduction of cyclin D1, CDK4/6 levels. Erismodegib arrests the cells in S-phase with reduced cyclin-E1&A1 levels, whereas RA-treatment causes G2/M phase arrest with reduced cyclin-B1. There was a decrease in the expression of EGFR and mesenchymal markers, Snail/Slug/Vim/Zeb/Twist, and increased E-cadherin expression in all the drug treatments, indicating a reduction in proliferative signal and EMT. Enhanced MLL2 (Mll4) and reduced EZH2 expression associated overexpression of p53 and p21 were traced out. We conclude that these drugs impact expression of epigenetic modifiers by modulating signalling pathways and the epigenetic modifiers then controls the expression of cell cycle control genes, including p53 and p21.

Lower lip basal cell and squamous cell carcinomas: a reappraisal of the similarities and differences in clinical presentation and management

Basal cell carcinoma and squamous cell carcinoma are the two most common types of carcinomas, affecting a total of 5.4 million people each year in the United States. Sun-exposed areas, especially the face and nose, are most affected given the strong association between these carcinomas and ultraviolet radiation. Less research has been done surrounding carcinomas of the lip, despite the significant aesthetic and functional importance of this area. Although lip carcinomas tend to follow a classic, unique distribution pattern that favors basal cell carcinoma on the upper lip and squamous cell carcinoma on the lower lip, more cases of lower lip basal cell carcinoma are being reported, warranting further educational awareness to differentiate carcinomas of the lower lip. In this article, we provide an updated overview of the risk factors, presentations, differential diagnoses, metastatic risks, evaluation, management guidelines, and outcomes of lower lip carcinoma. Of note, recent advances in imaging modalities are beginning to show promise as a non-invasive, affordable, and rapid way to detect and stage tumors. We conclude that increased clinical awareness and investigation of lower lip carcinoma is needed to improve early intervention, as a delayed diagnosis can rapidly alter the management and outcomes of lip carcinomas.

A Sonic Hedgehog Pathway Score to Predict the Outcome of Resected Non-Small Cell Lung Cancer Patients

BACKGROUND

Mutations and deregulations in components of the Hedgehog (Hh) pathway have been associated with cancer onset and tumor growth in different malignancies, but their role in non-small cell lung cancer (NSCLC) remains unclear. This study aims to investigate the expression pattern of the main components of the Hh pathway in tumor and adjacent normal tissue biopsies of resected NSCLC patients.

METHODS

The relative expression of GLI1, PTCH1, SHH, and SMO was analyzed by quantitative polymerase chain reaction (PCR) in a cohort of 245 NSCLC patients. Results were validated in an independent cohort of NSCLC patients from The Cancer Genome Atlas (TCGA).

RESULTS

We found that SMO and GLI1 were overexpressed in the tumor compared with normal-paired tissue, whereas PTCH1 and SHH were underexpressed. In addition, patients with higher expression levels of PTCH1 presented better outcomes. A gene expression score, called the Hedgehog Score, was calculated using a multivariable model including analyzed components of the Hh signaling pathway. NSCLC patients with a high Hedgehog Score had significantly shorter relapse-free survival (RFS) and overall survival (OS) than patients with a low score, especially at stage I of the disease. Similarly, patients in the adenocarcinoma (ADC) subcohort had shorter RFS and OS. Multivariate Cox analysis exhibited that the Hedgehog Score is an independent prognostic biomarker for OS in both the entire training cohort and the ADC subcohort. The Hedgehog Score was validated in an independent cohort of NSCLC patients from TCGA, which confirmed its prognostic value.

CONCLUSIONS

Our results provide relevant prognostic data for NSCLC patients and support further studies on the Hh pathway.

Non-melanoma skin cancers: physio-pathology and role of lipid delivery systems in new chemotherapeutic treatments

Non-melanoma carcinoma has high incidence rates and has two most common subtypes: basal cell carcinoma and squamous cell carcinoma. This type of carcinoma is usually not fatal; however, it can destroy sensory organs such as the nose, ears, and lips. The treatment of these injuries using non-invasive methods is thus strongly recommended. Some treatments for non-melanoma carcinoma are already well defined, such as surgery, cryosurgery, curettage and electrode section, and radiotherapy; however, these conventional treatments cause inflammation and scarring. In the non-surgical treatment of non-melanoma carcinoma, the topical administration of chemotherapeutic drugs contributes for an effective treatment with reduced side effects. However, the penetration of anticancer drugs in the deeper layers of the skin is required. Lipid delivery systems (liposomes, solid lipid nanoparticles, nanostructured lipid carriers) have been developed to overcome epidermal barrier of the skin and to allow the drugs to reach tumor cells. These lipid nanoparticles contribute to control the release profile of the loaded chemotherapeutic drugs, maintaining their stability and increasing death of tumor cells. In this review, the characteristics of non-melanoma carcinoma will be discussed, describing the main existing treatments, together with the contribution of lipid delivery systems as an innovative approach to increase the effectiveness of topical therapies for non-melanoma carcinomas.

Patidegib in Dermatology: A Current Review

Background: Basal cell carcinoma is one of the most common types of non-melanoma skin cancers, which can be locally destructive despite low-rate metastasis. Surgery is the treatment of choice, but it lacks of efficacy on advanced cases. Hedgehog pathway inhibitors are a class of drugs providing a new therapeutic option for patients affected by advanced disease. Besides systemic therapy, such as vismodegib and sonidegib, also topical inhibitors have been developed. Patidegib is able to decrease tumor burden, reducing the adverse effects induced by systemic targeted therapies. Methods: We performed comprehensive research to summarize the use of patidegib in advanced and recurrent aggressive basal cell carcinomas. Only English language human studies were included in the search. Results: Seven trials reported the application of patidegib. Both topical and systemic patidegib demonstrated safety, tolerability, and efficacy in naïve patients with stage II and III basal cell carcinomas, while stage IV disease and not-naïve patients did not show any benefit. Conclusion: Unlike systemic Hedgehog pathway inhibitors, patidegib 2% gel is not associated with systemic adverse effects and allows a better patient management. Considering the multidisciplinary management of neoplasia, in the era of precision medicine, it is mandatory to confide in pharmacogenomics to obtain personalized combined or sequential therapies.

Review of the Molecular Genetics of Basal Cell Carcinoma; Inherited Susceptibility, Somatic Mutations, and Targeted Therapeutics

Simple Summary

Basal cell carcinoma is the most common human cancer worldwide. The molecular basis of BCC involves an interplay of inherited genetic susceptibility and somatic mutations, commonly induced by exposure to UV radiation. In this review, we outline the currently known germline and somatic mutations implicated in the pathogenesis of BCC with particular attention paid toward affected molecular pathways. We also discuss polymorphisms and associated phenotypic traits in addition to active areas of BCC research. We finally provide a brief overview of existing non-surgical treatments and emerging targeted therapeutics for BCC such as Hedgehog pathway inhibitors, immune modulators, and histone deacetylase inhibitors.

Abstract

Basal cell carcinoma (BCC) is a significant public health concern, with more than 3 million cases occurring each year in the United States, and with an increasing incidence. The molecular basis of BCC is complex, involving an interplay of inherited genetic susceptibility, including single nucleotide polymorphisms and genetic syndromes, and sporadic somatic mutations, often induced by carcinogenic exposure to UV radiation. This review outlines the currently known germline and somatic mutations implicated in the pathogenesis of BCC, including the key molecular pathways affected by these mutations, which drive oncogenesis. With advances in next generation sequencing and our understanding of the molecular genetics of BCC, established and emerging targeted therapeutics are offering new avenues for the non-surgical treatment of BCC. These agents, including Hedgehog pathway inhibitors, immune modulators, and histone deacetylase inhibitors, will also be discussed.

Rapid and exceptional response to Sonidegib in a patient with multiple locally advanced basal cell carcinomas

Locally advanced basal cell carcinoma (laBCC) represents a rare but possible occurrence in the vast scenario of dermatological diseases. It is well known that most BCC has a pathological activation of the hedgehog pathway, making them susceptible to targeted therapy with selective inhibitors. Sonidegib, approved for the treatment of laBCC on the basis of the results of the basal cell carcinoma outcomes with LDE225 treatment study, demonstrated rapid efficacy and a manageable safety profile. Here, we describe the case of a patient affected by multiple laBCC treated with Sonidegib. The patient experienced an important regression of tumors after only 2 months of therapy, with few side effects. This result confirms the role of Sonidegib as a valid and well-tolerated therapeutic option for laBCC.

Gorlin Syndrome: Recent Advances in Genetic Testing and Molecular and Cellular Biological Research

Gorlin syndrome is a skeletal disorder caused by a gain of function mutation in Hedgehog (Hh) signaling. The Hh family comprises of many signaling mediators, which, through complex mechanisms, play several important roles in various stages of development. The Hh information pathway is essential for bone tissue development. It is also the major driver gene in the development of basal cell carcinoma and medulloblastoma. In this review, we first present the recent advances in Gorlin syndrome research, in particular, the signaling mediators of the Hh pathway and their functions at the genetic level. Then, we discuss the phenotypes of mutant mice and Hh signaling-related molecules in humans revealed by studies using induced pluripotent stem cells.