Multiple familial and pigmented basal cell carcinomas in early childhood - Bazex-Dupré-Christol syndrome

ARP-T1-associated Bazex-Dupré-Christol syndrome is an inherited basal cell cancer with ciliary defects characteristic of ciliopathies

Actin-Related Protein-Testis1 (ARP-T1)/ACTRT1 gene mutations cause the Bazex-Dupré-Christol Syndrome (BDCS) characterized by follicular atrophoderma, hypotrichosis, and basal cell cancer. Here, we report an ARP-T1 interactome (PXD016557) that includes proteins involved in ciliogenesis, endosomal recycling, and septin ring formation. In agreement, ARP-T1 localizes to the midbody during cytokinesis and the basal body of primary cilia in interphase. Tissue samples from ARP-T1-associated BDCS patients have reduced ciliary length. The severity of the shortened cilia significantly correlates with the ARP-T1 levels, which was further validated by ACTRT1 knockdown in culture cells. Thus, we propose that ARP-T1 participates in the regulation of cilia length and that ARP-T1-associated BDCS is a case of skin cancer with ciliopathy characteristics.

Park et al. characterise the interactome, localisation and function of Actin-Related Protein-Testis1 protein (ARP-T1), encoded by the ACTRT1 gene, associated with inherited basal cell cancer. They find that ARP-T1 is localised to the primary cilia basal body in epidermal cells, interacts with the cilia machinery, and is needed for proper ciliogenesis.

Basal cell carcinoma: Epidemiology; pathophysiology; clinical and histological subtypes; and disease associations

As the most common human cancer worldwide and continuing to increase in incidence, basal cell carcinoma is associated with significant morbidity and cost. Continued advances in research have refined both our insight and approach to this seemingly ubiquitous disease. This 2-part continuing medical education article will provide a comprehensive and contemporary review of basal cell carcinoma. The first article in this series describes our current understanding of this disease regarding epidemiology, cost, clinical and histopathologic presentations, carcinogenesis, natural history, and disease associations.

Genetic diseases associated with an increased risk of skin cancer development in childhood

PURPOSE OF REVIEW

Childhood skin cancers are relatively rare and may indicate an underlying genetic disorder. The increasing elucidation of genetic pathways is changing the diagnosis and management of genetic skin cancer susceptibility syndromes. In this review, we provide an overview of genetic conditions that predispose to skin cancer development in childhood and signs that providers should assess when evaluating affected individuals.

RECENT FINDINGS

In basal cell nevus syndrome (BCNS), the patched2 (PTCH2) and suppressor of fused (SUFU) genes have been implicated in disease pathogenesis. The sonic hedgehog (SHH) pathway inhibitor vismodegib was shown in a placebo-controlled phase III randomized trial to reduce the tumor burden in patients with BCNS. Epidermolysis bullosa (EB) has been classified into four major types and more than 30 subtypes based partly on specific mutations, and best clinical practice guidelines for the management of cutaneous squamous cell carcinoma in EB have been developed. Oculocutaneous albinism (OCA) has been associated with new mutations in genes named OCA5, OCA6, and OCA7, bringing to the total number of culprit genes to seven (OCA1-OCA7).

SUMMARY

Advances in our understanding of genetic conditions that predispose to childhood skin cancer include new disease classification systems, management guidelines, and treatment options.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Nevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome)

Nevoid basal cell carcinoma syndrome, or basal cell nevus syndrome (Gorlin syndrome), is a rare autosomal dominantly inherited disorder that is characterized by development of basal cell carcinomas from a young age. Other distinguishing clinical features are seen in a majority of patients, and include keratocystic odontogenic tumors (formerly odontogenic keratocysts) as well as dyskeratotic palmar and plantar pitting. A range of skeletal and other developmental abnormalities are also often seen. The disorder is caused by defects in hedgehog signaling which result in constitutive pathway activity and tumor cell proliferation. As sporadic basal cell carcinomas also commonly harbor hedgehog pathway aberrations, therapeutic agents targeting key signaling constituents have been developed and tested against advanced sporadically occurring tumors or syndromic disease, leading in 2013 to FDA approval of the first hedgehog pathway-targeted small molecule, vismodegib. The elucidation of the molecular pathogenesis of nevoid basal cell carcinoma syndrome has resulted in further understanding of the most common human malignancy.

[Genodermatoses with malignant skin tumors]

Cutaneous malignancies can manifest as isolated and sporadic tumors as well as multiple and disseminated tumors. In the latter case they often point to a genetic disease, which either can be restricted to the skin exclusively or also involve extracutaneous organs in the context of a hereditary tumor syndrome. Such hereditary tumor syndromes are clinically and genetically very heterogeneous. Therefore, the prevailing specific skin tumors play an important diagnostic role in the case of complex symptom constellations. Elucidation of the genetic basis of rare monogenetically inherited disorders and syndromes can contribute to a better understanding of the pathogenesis of frequently occurring cutaneous malignancies because the mutated genes often encode proteins, which have a key position in metabolic signaling pathways that are of high significance for the development of targeted therapies. Here we provide an overview of genodermatoses, which are associated with basal cell carcinomas, sebaceous carcinomas, keratoacanthomas, squamous cell carcinomas and malignant melanomas.

Hereditary nonmelanoma skin cancer

Cutaneous basal and squamous cell carcinomas are among the most frequent malignancies in the white population, with the annual incidence estimates ranging from 1 million to 3.5 million cases in the United States. These tumors can occur either sporadically or in the context of hereditary genodermatoses with cancer predisposition, such as basal cell nevus syndrome, xeroderma pigmentosum, epidermolysis bullosa, or oculocutaneous albinism. Different genes and signaling pathways have been shown to play a central role in the development and growth of these tumors. This article overviews the clinical features, diagnostic criteria, and the most recent data on genetic routes of the major hereditary syndromes predisposed to the development of nonmelanoma skin cancer.

Malignant epithelial tumors: Part I. Pathophysiology and clinical features

Epithelial skin cancer is a major burden for western societies. In the 21(st) century there will be a steady increase in the incidence of these tumors in the elderly population. The article summarizes the pathophysiology of epithelial tumors and gives a systematic outline of the different clinical features of keratinocytic tumors. Furthermore, the article gives an overview of inherited syndromes that predispose to malignant epithelial tumors.

Congenital hypotrichosis, eruptive milia, and palmoplantar pits: a case report with review of literature

We report a ten-month-old male infant, presenting with congenital hypotrichosis of scalp, absence of eyebrows and eyelashes. He also had multiple milia over face and extremities along with palmoplantar pits. The infant was born to third degree consanguineous marriage. None of the family members had similar disease. Histopathology was consistent with milia. Based on these findings, a diagnosis of unclassified ectodermal dysplasia was made.

Basal Cell Carcinoma: A Retrospective Clinicopathological Analysis of 100 Cases Derived from the Histopathological Registry of the Institute of Pathology in Niš / Bazocelularni karcinom: retrospektivna kliničko-histološka analiza 100 slučajeva na osnovu Histopatološkog registra Instituta za patologiju u Nišu

Basal cell carcinoma (BCC) is the most common malignant tumor of the skin. This study was conducted to analyze patients with BCC, their age and sex distribution, occupation, site distribution of tumors, clinical types, and histopathological characteristics of lesions. Based on the data obtained from the Histopathological Registry, a clinical and histopathological analysis of the surgically excised BCCs was performed.

The study included 100 randomly selected patients out of 263 consecutive patients with histopathologically diagnosed BCC at the Institute of Pathology of the Clinical Center in Niš in the period of 15 months. The sex ratio was 1.4:1 in favor of men (p<0.05). Two thirds of patients were over the age of 60 (p<0.0001). The average age of patients was 66.6 ± 12.2 years (range 23 - 90). In agreement with the age distribution, 53 patients were retired (mostly retired farmers), 12 were workers, 14 farmers, 12 without permanent employment, 5 were housewives, and 4 clerks. A substantial majority of 61% of examinees lived in the country (p<0.001). The employment status was related to the age of examinees, but also with the altered demographic structure in the country: many workers lived in the country, or returned to the country after retirement.

BCC was commonly found on the face (77%), and rarely on the trunk (11%) and extremities (2%).

There were no data about exposition to X-rays or chemicals (except for pesticides and insecticides), scars resulting from burns or genodermatoses. In 87% of cases, BCC was significantly most often found at sites continually exposed to the sun (head including face and scalp, and neck). The most commonly diagnosed was the nodular type (57%), then the superficial (7%), ulcerative (5%), ulcero-sclerotic (4%), pigmented (1%), and morpheaform (1%). In 27% of cases, there were no data about the histopathological type of BCC in the Histopathological Registry, based on which accurate histological type of BCC could have been established. Based on histopathological analysis, apart from the nodular (40%), other types were rarely diagnosed, like the adenoid (12%) (p<0.0001), mixed types (nodular-adenoid, nodular-adenoid-fibroblastic and mixed) (9%), superficial (7%), fibroblastic (2%), infiltrative (1%), pigmented (1%), and morpheaform (1%). Surgical excision is the gold standard in the treatment of BCC: conventional, conducted in our patients, and Mohs micrographic surgery, which takes an important place in the treatment of high-risk BCCs. In 6% of cases, the tumor process was found in the margins of the excision.

In conclusion: Basal cell carcinoma was more common in males than in females. Significantly more patients with excised basal cell carcinoma lived in the country. An age-related increase in the number of patients with BCC has been established, and most patients with excised basal cell carcinomas belonged to the age group of 61 to 81 years of age. In most patients the tumor site was on the face, whereas clinically and histopathologically, nodular type was the most common.

Hereditary tumour syndromes featuring basal cell carcinomas

Basal cell carcinoma (BCC) is the most frequent cutaneous malignancy worldwide. This skin tumour is characterized by a broad phenotypic variability and distinct histopathological subtypes. It shows slow, locally invasive growth and only rarely metastasizes. BCCs can occur either sporadically or in the context of genetic syndromes, including Gorlin syndrome, Bazex-Dupré-Christol syndrome, Rombo syndrome, Oley syndrome and xeroderma pigmentosum. Different genes and signalling routes have been shown to play an important role in the development and growth of these tumours, including the hedgehog and Wnt/β-catenin pathway. In some of the aforementioned hereditary disorders the underlying genetic defect is still unknown whereas in others several genes have been demonstrated to be involved. Currently, most therapeutic approaches are based on surgical measures. In the case of superficial BCCs, photodynamic therapy, 5-fluorouracil cream, imiquimod or radiotherapy also may be an option. Elucidation of the molecular mechanisms governing the manifestation of BCCs in monogenetically inherited tumour syndromes will not only contribute to a better understanding of the complex pathogenesis of these tumours but might pave the way to the development of noninvasive, specific and molecule-based therapeutic strategies in the near future.