Basal cell carcinoma of the skin (part 1): epidemiology, pathology and genetic syndromes

New graphene-containing pharmaceutical formulations for infrared lamps-based phototherapy of skin cancer: In vitro validation and ex-vivo human skin permeation

Basal cell carcinoma (BCC) is the most common form of human cancer, and treatment usually involves surgery, with alternative strategies being needed. We propose the use of carbopol hydrogels (HG) for topical administration of nanographene oxide (GOn) and partially-reduced nanographene oxide (p-rGOn) for photothermal therapy (PTT) of BCC. GOn and p-rGOn incorporated into the HG present lateral sizes ∼200 nm, being stable for 8 months. After 20 min irradiation with an infrared (IR) photothermal therapy lamp (15.70 mW cm-2), GOn-HG increased temperature to 44.7 °C, while p-rGOn-HG reached 47.0 °C. Human skin fibroblasts (HFF-1) cultured with both hydrogels (250 μg mL-1) maintained their morphology and viability. After 20 min IR irradiation, p-rGOn HG (250 μg mL-1) completely eradicated skin cancer cells (A-431). Ex vivo human skin permeability tests showed that the materials can successfully achieve therapeutic concentrations (250 μg mL-1) inside the skin, in 2.0 h for GO HG or 0.5 h for p-rGOn HG.

Advancements in nanoparticle-based treatment approaches for skin cancer therapy

Skin cancer has emerged as the fifth most commonly reported cancer in the world, causing a burden on global health and the economy. The enormously rising environmental changes, industrialization, and genetic modification have further exacerbated skin cancer statistics. Current treatment modalities such as surgery, radiotherapy, conventional chemotherapy, targeted therapy, and immunotherapy are facing several issues related to cost, toxicity, and bioavailability thereby leading to declined anti-skin cancer therapeutic efficacy and poor patient compliance. In the context of overcoming this limitation, several nanotechnological advancements have been witnessed so far. Among various nanomaterials, nanoparticles have endowed exorbitant advantages by acting as both therapeutic agents and drug carriers for the remarkable treatment of skin cancer. The small size and large surface area to volume ratio of nanoparticles escalate the skin tumor uptake through their leaky vasculature resulting in enhanced therapeutic efficacy. In this context, the present review provides up to date information about different types and pathology of skin cancer, followed by their current treatment modalities and associated drawbacks. Furthermore, it meticulously discusses the role of numerous inorganic, polymer, and lipid-based nanoparticles in skin cancer therapy with subsequent descriptions of their patents and clinical trials.

Does the histopathological subtype of primary basal cell carcinoma predict the subtype of secondary tumours? What role do genetic mutations play?

Background

Basal cell carcinoma (BCC) is one of the most common malignancies in the world. The frequency of histopathological subtypes and the distribution on the body of BCC has been well documented. Less has been written on the nature of secondary tumours. The genetics of BCC is starting to be understood, particularly with the advent of newer medical treatments (hedgehog inhibitors).

Objectives

To determine if primary basal cell carcinoma histopathological subtype predicts secondary tumour subtype, as well as their anatomical distribution.

Methods

A retrospective case series of patients over the age of 18 was performed from 2009 to 2014, with at least two separate diagnoses of BCC.

Results

In 394 identified patients, a total of 1355 BCCs arose in the cohort over the 6-year study period. The number of secondary BCCs per patient ranged from 2 to 19 tumours. Nodular BCC was the most likely to reoccur in secondary tumours (53.3%), followed by mixed subtypes (45.7%).

Conclusions

Within our study, we did find a predisposition for secondary BCCs to be of the same histopathological subtype as the primary, particularly with respect to nodular and mixed tumours. Furthermore, we found that secondary tumours were also more likely to occur on the same anatomical site as the primary tumour. We are only just beginning to under the genetic mutations involved in subtype formation.

Non-surgical treatments for basal cell skin cancer

Basal cell carcinoma is the most common nonmelanoma skin cancer. It originates from undifferentiated cells in the basal cell layer of the epidermis or from the outer root sheath of the hair follicle. The most important factor in development of basalioma is ultraviolet radiation. Surgery is considered the gold standard of treatment for basal cell cancer. However, nonsurgical options are available for individuals who are unsuitable for surgery. The purpose of this review is to summarize the efficacy and indications of alternative, nonsurgical treatments that can be used in the management of basal cell cancer Effective nonsurgical treatments include destructive methods (eg, curettage and electrodessication, cryosurgery, laser), photodynamic therapy, topical medications, hedgehog pathway inhibitors. Nonsurgical therapeutic alternatives are safe and effective for the treatment of BCC. Factors such as tumor location, size, and histopathological subtype should be taken into consideration when selecting optimal treatment, cosmetic results and patient preference should be considered too. To search for the necessary literature, the PubMed, MedLine, Web of Science and RSCI databases were used.

Modern understanding of the pathogenesis of basal cell skin cancer

The incidence of basal cell skin cancer is increasing worldwide. The initiation and progression of basal cell skin cancer is due to the interaction of environmental factors and the patient's genetic characteristics. Aberrant activation of the transmission of the Hedgehog signaling pathway is the main pathogenetic pathway of carcinogenesis. Since basal cell skin cancer is manifested by significant variability of morphological structure, aggressiveness and response to treatment, the disclosure of the molecular genetics of pathogenesis will become the basis for developing new approaches and increasing the effectiveness of treatment, as well as overcoming tumor resistance to treatment. To search for the necessary literature, the PubMed, MedLine, Web of Science and RSCI databases were used.

TERTp mutations and p53 expression in head and neck cutaneous basal cell carcinomas with different aggressive features

Cutaneous basal cell carcinoma (cBCC) is an economic burden to health services, due to its great morbidity and increasing incidence in old people. Infiltrative cBCCs and cBCCs with micronodular pattern are considered as more aggressive. The role of p53 expression and TERTp mutation on cBCC behavior remains to be clarified. We aimed to assess TERTp mutations and p53 expression in relation to the cBCC histological subtype in a cohort of patients referred to an ENT Department of a tertiary Hospital of Northern Portugal. We performed a retrospective clinicopathological and histological review of the head and neck cBCCs followed-up at the otorhinolaryngology department of Trás-os-Montes e Alto Douro hospital (January 2007–June 2018). We assessed TERTp mutations in 142 cBCCs and p53 protein expression, through immunohistochemistry, in 157 cBCCs. We detected TERTp mutations in 43.7% of cBCCs and p53 overexpression in 60.5% of cBCCs. We spotted association of p53 overexpression and TERTp mutation with necrosis. In the infitrative-growth pattern cBCCs, there was no significant association with the clinical and histological features evaluated, except for necrosis. In the indolent-growth cBCCs, we identified a significant association of TERTp mutation status with female sex, necrosis, multiple cBCCs, and p53 positive expression. Our results suggest that TERTp mutation may be useful to identify more aggressive features in the indolent-growth pattern cBCCs (nodular and superficial subtypes). Further studies with larger cohorts are warranted to clarify the relevance of TERTp mutation in cBCCs.

Topical photodynamic therapy combined with ablative "light needles" against basal cell carcinoma

Basal cell carcinoma (BCC), a non-melanoma cancer with high morbidity in the elders, is a type of limited skin cancer with a projected appearance. Traditional treatments such as oral or injection administration are likely to result in serious side effects. Here, we developed a strategy that combined photodynamic therapy (PDT) with ablative light "needles" (carbon-dioxide laser) for the treatment of BCC, involving β-Tetra-(4-carboxyl-phenoxy)-zinc phthalocyanine (ZnPC₄) cubic phases with high drug loading, easy preparation, long local retention, good spreading ability and little toxicity. A model of nude mice with BCC was established for the study of pharmacodynamics. The light needles of low energy (53 mJ/cm²) used here could promote transdermal absorption of ZnPC₄ cubic phases while those of high energy (238 mJ/cm²) alone could completely kill tumor cells with no recurrence. However, ZnPC₄ cubic phases alone could not completely inhibit tumor growth, for it was distributed mainly at the topical administration site in the absence of any adjuvant technology. Therefore, the combination of photodynamics and light needles offered a good solution. Especially, the combined use of light needles with high energy and ZnPC₄ cubic phases can treat BCC efficiently with no recurrence. This approach is expected to be a novel and promising medication against BCC.

Basal Cell Carcinoma: From Pathophysiology to Novel Therapeutic Approaches

Basal cell carcinoma (BCC) is the most common human cancer worldwide, and is a subtype of nonmelanoma skin cancer, characterized by a constantly increasing incidence due to an aging population and widespread sun exposure. Although the mortality from BCC is negligible, this tumor can be associated with significant morbidity and cost. This review presents a literature overview of BCC from pathophysiology to novel therapeutic approaches. Several histopathological BCC subtypes with different prognostic values have been described. Dermoscopy and, more recently, reflectance confocal microscopy have largely improved BCC diagnosis. Although surgery is the first-line treatment for localized BCC, other nonsurgical local treatment options are available. BCC pathogenesis depends on the interaction between environmental and genetic characteristics of the patient. Specifically, an aberrant activation of Hedgehog signaling pathway is implicated in its pathogenesis. Notably, Hedgehog signaling inhibitors, such as vismodegib and sonidegib, are successfully used as targeted treatment for advanced or metastatic BCC. Furthermore, the implementation of prevention measures has demonstrated to be useful in the patient management.

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.

Mediterranean diet, Dietary Approaches to Stop Hypertension, and Pro-vegetarian dietary pattern in relation to the risk of basal cell carcinoma: a nested case-control study within the Seguimiento Universidad de Navarra (SUN) cohort

BACKGROUND

The association of dietary pattern with the risk of basal cell carcinoma (BCC) is little understood and has scarcely been investigated.

OBJECTIVES

We assessed the association of several complete dietary patterns [Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Pro-vegetarian dietary pattern] with the risk of BCC, conducting a nested case-control study (4 controls for each case).

METHODS

Cases and controls were selected from the SUN (Seguimiento Universidad de Navarra) cohort using risk set sampling. Cases were identified among subjects free of skin cancer at baseline but who later reported a physician-made BCC diagnosis during the follow-up period. In the cohort we identified 101 incident cases of BCC.

RESULTS

In multivariable-adjusted conditional logistic regression analyses, better adherence to the Mediterranean diet (highest compared with lowest quintile) was associated with a 72% relative reduction in the odds of BCC (OR: 0.28; 95% CI: 0.10, 0.77; Ptrend = 0.014); the DASH diet was associated with a 68% RR reduction (OR: 0.32; 95% CI: 0.14, 0.76; Ptrend = 0.013) for the comparison between extreme quintiles. No association was found between a Pro-vegetarian dietary pattern and BCC. Higher fruit consumption (highest compared with lowest quintile, OR: 0.27; 95% CI: 0.11, 0.64; Ptrend < 0.001) and low-fat dairy products (OR: 0.39; 95% CI: 0.16, 0.92; Ptrend = 0.014) were associated with a lower BCC risk.

CONCLUSIONS

Our results suggest that Mediterranean and DASH dietary patterns may be associated with a lower risk of BCC, but confirmatory studies are required.

Non-Melanoma Skin Cancers: Biological and Clinical Features

Non-melanoma skin cancers (NMSCs) include basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and Merkel cell carcinoma (MCC). These neoplasms are highly diverse in their clinical presentation, as well as in their biological evolution. While the deregulation of the Hedgehog pathway is commonly observed in BCC, SCC and MCC are characterized by a strikingly elevated mutational and neoantigen burden. As result of our improved understanding of the biology of non-melanoma skin cancers, innovative treatment options including inhibitors of the Hedgehog pathway and immunotherapeutic agents have been recently investigated against these malignancies, leading to their approval by regulatory authorities. Herein, we review the most relevant biological and clinical features of NMSC, focusing on innovative treatment approaches.

SHARPIN regulates cell proliferation of cutaneous basal cell carcinoma via inactivation of the transcriptional factors GLI2 and c‑JUN

SHANK‑associated RH domain‑interacting protein (SHARPIN) is a component of the linear ubiquitin chain assembly complex that can enhance the NF‑κB and JNK signaling pathways, acting as a tumor‑associated protein in a variety of cancer types. The present study investigated the role of SHARPIN in cutaneous basal cell carcinoma (BCC). Human BCC (n=26) and normal skin (n=5) tissues, and BCC (TE354.T) and normal skin (HaCaT) cell lines were used to evaluate SHARPIN expression level using immunohistochemistry and western blotting, respectively. A lentivirus carrying SHARPIN‑targeting or negative control short hairpin RNA was infected into TE354.T cells, and the infected stable cells were assayed to analyze tumor cell proliferation, cell cycle, apoptosis, migration and invasion by Cell Counting Kit‑8 and 5‑ethynyl‑2'‑deoxyuridine incorporation assays, flow cytometry and Transwell assays. Western blotting was performed to assess the protein expression levels of gene signaling in SHARPIN‑silenced BCC cells. SHARPIN protein expression levels were downregulated or absent in BCC cancer nests and precancerous lesions compared with normal skin samples. In addition, SHARPIN expression levels were lower in TE354.T cells compared with HaCaT cells. SHARPIN shRNA enhanced tumor cell proliferation and the S phase of the cell cycle, whereas BCC cell apoptotic rates, and migratory and invasive abilities were not significantly altered. The expression levels of cyclin D1, cyclin‑dependent kinase 4, phosphorylated‑c‑JUN and GLI family zinc finger 2 proteins were increased, whereas Patched 1 (PTCH1) and PTCH2 were decreased in the SHARPIN‑shRNA‑infected BCC cells. Therefore, the present results suggested that SHARPIN may act as a tumor suppressor during BCC development.

Incongruent radiographic indication of calvarial metastatic diploic space invasion with absent histologic findings in a patient with basal cell carcinoma of the scalp

BACKGROUND

Radiographic imaging is often used to determine basal cell carcinoma (BCC) extension and invasion and to define a surgical plan. However, imaging modalities may overestimate tumor invasion and lead to unnecessarily aggressive treatment.

METHODS

A 77-year-old woman was seen with a growing BCC of the scalp with MRI imaging indicative of calvarial diploic space invasion. The patient underwent Mohs surgery followed by a parietal craniectomy.

RESULTS

Contrary to the MRI findings, histological evaluation of the cortical parietal calvarium and the diploic space did not demonstrate BCC.

CONCLUSIONS

Surgeons should be wary of diploic space changes in the absence of cortical erosion demonstrated in MRI as it may not explicitly indicate tumor invasion. Biopsy of the diploe is necessary in such cases to determine the surgical course and to avoid morbidity associated with calvarium removal.

Emerging Perspective: Role of Increased ROS and Redox Imbalance in Skin Carcinogenesis

Strategies to battle malignant tumors have always been a dynamic research endeavour. Although various vehicles (e.g., chemotherapeutic therapy, radiotherapy, surgical resection, etc.) are used for skin cancer management, they mostly remain unsatisfactory due to the complex mechanism of carcinogenesis. Increasing evidence indicates that redox imbalance and aberrant reactive oxygen species (ROS) are closely implicated in the oncogenesis of skin cancer. When ROS production goes beyond their clearance, excessive or accumulated ROS could disrupt redox balance, induce oxidative stress, and activate the altered ROS signals. These would damage cellular DNA, proteins, and lipids, further leading to gene mutation, cell hyperproliferation, and fatal lesions in cells that contribute to carcinogenesis in the skin. It has been known that ROS-mediated skin carcinogenesis involves multiple ways, including modulating related signaling pathways, changing cell metabolism, and causing the instability of the genome and epigenome. Nevertheless, the exact role of ROS in skin cancer has not been thoroughly elucidated. In spite of ROS inducing skin carcinogenesis, toxic-dose ROS could trigger cell death/apoptosis and, therefore, may be an efficient therapeutic tool to battle skin cancer. Considering the dual role of ROS in the carcinogenesis and treatment of skin cancer, it would be essential to clarify the relationship between ROS and skin cancer. Thus, in this review, we get the related data together to seek the connection between ROS and skin carcinogenesis. Besides, strategies basing on ROS to fight skin cancer are discussed.

Head and neck cutaneous basal cell carcinoma: what should the otorhinolaryngology head and neck surgeon care about?

Cutaneous basal cell carcinoma (cBCC) is the most common malignancy diagnosed in the human population. cBCC presents an increasing incidence which, in the near future, will be higher than all other cancers combined. The majority of cBCC are located in the head and the neck. A diversity of management modalities is currently available; nonetheless, surgical excision remains the main modality of treatment. cBCC rarely metastasises and presents a low mortality rate. cBCC morbidity is influenced by local invasion and destruction, especially in the face, where function and aesthetics are major issues. Easy accessibility to the face and skin on the neck makes cBCC an important issue for otorhinolaryngology head and neck surgeons who must be aware and committed in its management, as the main modality of treatment continues to be surgical. The aim of this review is to present a brief and practical overview of head and neck cBCC management for ear, nose and throat (ENT) surgeons, discussing key issues about its epidemiology, risk factors, diagnosis and pathogenesis.

Clinical Characteristics of Basal Cell Carcinoma in African Americans: A 10-Year Retrospective Review at a Single Academic Institution

BACKGROUND

Basal cell carcinoma (BCC) is an uncommon diagnosis in African Americans, and as a result, there is a limited amount of data available.

OBJECTIVE

We sought to describe the clinical characteristics of BCC in African Americans treated with Mohs micrographic surgery (MMS).

METHODS

We performed a retrospective case series in an ambulatory referral center at a single academic institution from 2007 to 2017 to characterize BCCs in African Americans treated with MMS.

RESULTS

A total of 17 patients, who identified as black or African American, with 18 BCCs were included for analysis. Patients were predominantly female (82%) with a mean age at diagnosis of 61 years. Seventy-eight percent of tumors were located in the head and neck region with 50% of BCCs located in high-risk areas. The average preoperative and postoperative defect size was 1.78 and 5.90 cm, respectively, with a mean number of 2.2 Mohs stages required for tumor clearance. One patient had Gorlin syndrome.

CONCLUSION

The presented retrospective review adds to limited available reported studies regarding BCC in African Americans to potentially aid in early recognition of these tumors.

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.

Complexing Methylene Blue with Phosphorus Dendrimers to Increase Photodynamic Activity

The efficiency of photodynamic therapy is limited mainly due to low selectivity, unfavorable biodistribution of photosensitizers, and long-lasting skin sensitivity to light. However, drug delivery systems based on nanoparticles may overcome the limitations mentioned above. Among others, dendrimers are particularly attractive as carriers, because of their globular architecture and high loading capacity. The goal of the study was to check whether an anionic phosphorus dendrimer is suitable as a carrier of a photosensitizer-methylene blue (MB). As a biological model, basal cell carcinoma cell lines were used. We checked the influence of the MB complexation on its singlet oxygen production ability using a commercial fluorescence probe. Next, cellular uptake, phototoxicity, reactive oxygen species (ROS) generation, and cell death were investigated. The MB-anionic dendrimer complex (MB-1an) was found to generate less singlet oxygen; however, the complex showed higher cellular uptake and phototoxicity against basal cell carcinoma cell lines, which was accompanied with enhanced ROS production. Owing to the obtained results, we conclude that the photodynamic activity of MB complexed with an anionic dendrimer is higher than free MB against basal cell carcinoma cell lines.