A guideline for the clinical management of basal cell nevus syndrome (Gorlin-Goltz syndrome)

Clinical vs. molecular diagnosis of Gorlin syndrome: relevance of diagnostic criteria depends on the age of the patients

BACKGROUND

Gorlin syndrome (GS) is an autosomal dominant disorder characterized by a predisposition to basal cell carcinoma and developmental defects. It is caused by pathogenic variants in the PTCH1 or SUFU genes.

OBJECTIVES

To ascertain the effectiveness of molecular screening in a cohort of patients with a suspicion of GS and to describe the patients' clinical and genetic characteristics.

METHODS

In total, 110 patients with a suspicion of GS were studied. The patients were seen at the genetic department of Bichat University Hospital for molecular screening. The patients' clinical and paraclinical data were collected and analysed according to Evans' diagnostic criteria and were compared with molecular information.

RESULTS

Among 110 probands, only 56% fulfilled Evans' diagnostic criteria. Overall, 75% of the patients who fulfilled those criteria carried a pathogenic variation in PTCH1 or SUFU. We compared the clinical and paraclinical data of 54 probands carrying a PTCH1 or SUFU mutation with 56 probands without identified mutations. Among patients carrying a pathogenic variation in the PTCH1 or SUFU genes, 30 years appears to be the cut-off age after which all patients have clear clinical GS. Indeed, after age 30 years, all patients carrying a PTCH1 or SUFU mutation fulfilled the diagnostic criteria of Evans (82% met the clinical criteria, reaching 100% with complementary examinations such as X-rays and ultrasound). Before 30 years of age, only 37% of patients with mutated genes fulfilled the clinical diagnostic criteria, reaching only 62% with simple complementary exams. We also report 22 new mutations in PTCH1.

CONCLUSIONS

Molecular screening of patients with GS who do not fulfil Evans' diagnostic criteria should only be offered in the first instance to patients under 30 years of age. After age 30 years, careful clinical examination and complementary radiological exams should be enough to eliminate the diagnosis of GS among patients who do not fulfil the diagnostic criteria.

Use of Anti-PD1 Blockade After Hedgehog Inhibitors or as First-Line Therapy for Gorlin Syndrome

This case series examines treatment with anti–programmed cell death 1 (PD1) immunotherapy for patients with basal cell nevus syndrome.

Clinicopathological and molecular insights into odontogenic tumors associated with syndromes: A comprehensive review

The association between genetic syndromes and odontogenic tumors encompasses several entities, reflecting the intricate interplay between genetic factors and the development of these lesions. The present study aimed to comprehensively investigate the associations between genetic syndromes and odontogenic tumors. We delineated the diverse spectrum of syndromic connections, including key syndromes such as Gardner syndrome, Gorlin syndrome, Schimmelpenning syndrome, and others. Our findings underscore the clinical significance of recognizing odontogenic tumors associated with genetic syndromes as diagnostic indicators for early intervention. We advocate for multidisciplinary collaboration among clinicians, geneticists, and researchers to deepen our understanding of the underlying mechanisms driving these syndromic associations. In light of this, our study contributes to the growing body of knowledge in dentistry and medical genetics, offering insights that may inform clinical practice and enhance patient care for individuals affected by genetic syndromes and odontogenic tumors.

Incidence and trends of first basal cell carcinomas in France between 1980 and 2019: a regional population-based registry study

BACKGROUND

Basal cell carcinoma (BCC) is the most frequent malignancy reported in populations with fair skin. In most countries, BCCs are only partially or not at all recorded, and incidence data are lacking.

OBJECTIVES

This study assessed the current incidence rates and trends in the only two French départements where BCCs have been recorded for several decades.

METHODS

This regional population-based study thus used data from two French cancer registries (Doubs and Haut-Rhin) where first-time BCC diagnoses were recorded. The European age-standardized incidence rates (EASR) were calculated per 100 000 person-years (PY). The trends and the annual percentages of change were assessed using joinpoint analysis.

RESULTS

In all, 48 989 patients were diagnosed with a first BCC in the study period. The median age at diagnosis was 69 years and the BCCs were mainly located on the head and neck (68.8%). In the Doubs area between 1980 and 2016, the EASR of BCC increased from 59.9 to 183.1 per 100 000 PY. The annual increase for men was 5.73% before 1999 and 1.49% thereafter, and among women 4.56% before 2001 and 1.31% thereafter. In the Haut-Rhin area, the EASR increased from 139.2 in 1991 to 182.8 per 100 000 PY in 2019. Among men, the EASR increased annually by 2.31% before 2000, and by 0.29% after 2000; among women, it increased by 0.95% over the entire period (1991-2019). In the most recent period and for these two départements, the age-specific incidence rates of BCC for men and women were close before the age of 60 years, except for the 40-49-year age group, where the rates were significantly higher among women. For patients aged 60 years and over, men had much higher rates of BCC.

CONCLUSIONS

BCC incidence has increased since 1980 and is still rising, particularly among men and the elderly. A slowing was observed from 2000, which could be explained by a shift in the management of BCCs and by the possible efficacy of prevention actions. This study provides insight into the BCC burden in France and highlights the need to maintain effective prevention strategies, as incidence is still increasing.

Conservative management of multiple odontogenic keratocysts in a child with nevoid basal cell carcinoma syndrome: A case report

BACKGROUND

Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant multisystemic disorder characterized by the presence of multiple odontogenic keratocysts (OKC), which are a hallmark feature of the syndrome. The treatment of these OKC poses challenges due to their high recurrence rates and the myriad of management options available.

CASE REPORT

We describe here a case of NBCCS diagnosed in an 11-year-old girl who presented with multiple OKC in the jaws. Chest and cranial radiographs showed no abnormalities in the ribs and the cerebral falx, respectively. Cephalometric analysis indicated mandibular retrusion, a skeletal class II relationship, and a convex profile. The treatment approach involved a personalized strategy tailored for each cyst, comprising marsupialization followed by enucleation. This approach aimed to minimize surgical trauma and to reduce the risk of recurrence. The patient underwent regular follow-up appointments, demonstrating successful outcomes with no signs of recurrence or de novo OKC observed over a 32-month period.

CONCLUSION

Clinicians should consider lesion characteristics and patient cooperation when determining treatment strategies for the optimization of outcomes for children and adolescents with NBCCS and multiple OKC.

Further Expanding the Mutational Spectrum of Gorlin Syndrome in Three Unrelated Families

Introduction

Gorlin syndrome is a rare, autosomal dominant multi-systemic disorder with a predisposition to the development of cancers such as medulloblastoma and nevoid basal cell carcinoma. Heterozygous pathogenic variants in PTCH1 are responsible for 90% of Gorlin syndrome cases. Pathogenic variants in PTCH1 cause overstimulation of the sonic hedgehog signaling pathway, which plays a role in the development of embryonic structures and tumorigenesis. Clinical major and minor diagnostic criteria for Gorlin syndrome have been determined. Odontogenic keratocyst (OKC) is the most common reason for medical admission in Gorlin syndrome. In this article, it is aimed to draw attention to the fact that patients with Gorlin syndrome are not very rare in our country and the variability in phenotypic and dysmorphic findings may be a clue for the diagnosis.

Methods

Exome sequencing was performed on the Illumina NextSeq550 System platform by using the Ion Ampliseq exome RDY kit for Illumina. Sanger sequencing was performed accordingly for the other affected individuals in both families.

Results

In this study, the clinical and molecular findings of 9 Gorlin syndrome patients from three unrelated families are presented. Macrocephaly, calcification of falx cerebri, palmar-plantar pits, rib anomalies, and OKC were detected in decreasing order in more than half of the patients. A novel heterozygous frameshift PTCH1 variant in family 1, a nonsense previously reported PTCH1 variant in family 2, and a novel heterozygous splice-site PTCH1 variant in family 3 were detected.

Conclusion

Gorlin syndrome should be kept in mind in patients presenting with macrocephaly, palmoplantar pits, and OKC history. Careful examination of all family members is essential in the timely diagnosis of other affected individuals with minor phenotypic findings.

18F-FDG PET/CT findings in nevoid basal cell carcinoma syndrome: a systematic review and a new case report

BACKGROUND

To demonstrate and analyze the 18F-FDG positron emission tomography/computed tomography (PET/CT) findings in this rare nevoid basal cell carcinoma syndrome (NBCCS).

CASE PRESENTATION

A 71-year-old woman with the left invasive breast cancer was treated with hormone therapy for six months and underwent the 18F-FDG PET/CT examination for efficacy evaluation. 18F-FDG PET/CT revealed the improvement after treatment and other unexpected findings, including multiple nodules on the skin with 18F-FDG uptake, bone expansion of cystic lesions in the bilateral ribs, ectopic calcifications and dilated right ureter. She had no known family history. Then, the patient underwent surgical excision of the all skin nodules and the postoperative pathology were multiple basal cell carcinomas. Finally, the comprehensive diagnosis of NBCCS was made. The patient was still in follow-up. Additionally, we have summarized the reported cases (n = 3) with 18F-FDG PET/CT from the literature.

CONCLUSIONS

It is important to recognize this syndrome on 18F-FDG PET/CT because of different diagnoses and therapeutic consequences.

Hedgehog pathway inhibitors for locally advanced and metastatic basal cell carcinoma: A real-world single-center retrospective review

Basal cell carcinoma (BCC) is highly curable by surgical excision or radiation. In rare cases, BCC can be locally destructive or difficult to surgically remove. Hedgehog inhibition (HHI) with vismodegib or sonidegib induces a 50-60% response rate. Long-term toxicity includes muscle spasms and weight loss leading to dose decreases. This retrospective chart review also investigates the impact of CoQ10 and calcium supplementation in patients treated with HHI drugs at a single academic medical center from 2012 to 2022. We reviewed the charts of adult patients diagnosed with locally advanced or metastatic BCC treated with vismodegib or sonidegib primarily for progression-free survival (PFS). Secondary objectives included overall survival, BCC-specific survival, time to and reasons for discontinuation, overall response rate, safety and tolerability, use of CoQ10 and calcium supplements, and insurance coverage. Of 55 patients assessable for outcome, 34 (61.8%) had an overall clinical benefit, with 25 (45.4%) having a complete response and 9 (16.3%) a partial response. Stable disease was seen in 14 (25.4%) and 7 (12.7%) progressed. Of the 34 patients who responded to treatment, 9 recurred. Patients who were rechallenged with HHI could respond again. The median overall BCC-specific survival rate at 5 years is 89%. Dose reductions or discontinuations for vismodegib and sonidegib occurred in 59% versus 24% of cases, or 30% versus 9% of cases, respectively. With CoQ10 and calcium supplementation, only 17% required a dose reduction versus 42% without. HHI is highly effective for treating advanced BCC but may require dosing decreases. Sonidegib was better tolerated than vismodegib. CoQ10 and calcium supplementation can effectively prevent muscle spasms.

Gorlin Syndrome: A Comprehensive Evaluation of Skin Findings

OBJECTIVE

Although Gorlin syndrome has rich skin findings, there is limited information about their subtypes, features specific to this genodermatosis, and relationships with each other.

MATERIALS AND METHODS

The demographic characteristics as well as cutaneous and extracutaneous findings of consecutive Gorlin syndrome patients diagnosed during 23 years were evaluated retrospectively. The relationship between palmoplantar pitting and basal cell carcinoma (BCC) in this localization and the relationship between odontogenic keratocysts (OKCs) and epidermoid cysts were investigated.

RESULTS

A total of 30 patients were diagnosed with Gorlin syndrome of whom 36.7% were children. BCC was the most common finding (90%) followed by OKCs (83.3%), skeletal system anomalies (76.7%), and palmoplantar pitting (76.7%). While classical BCC (63.3%) lesions were the predominant clinical subtype among all patients, acrochordon-like or small-sized papular BCCs were seen in 45.4% of pediatric patients. Three patients, 2 of whom were children, had BCC lesions in the palmoplantar region in association with palmoplantar pitting. Epidermoid cysts presenting clinically as solitary (n = 12) or a few nodules (n = 4) without punctum, located more commonly in acral areas (n = 10) were seen in 16 (53.3%) patients of whom 7 were children. Epidermoid cysts were seen in 60% of patients with OKCs, and the relationship between epidermoid cysts and OKCs was not statistically significant (P = .15). Extracutaneous tumors such as medulloblastoma (n = 3), cardiac fibroma (n = 1), and ameloblastoma (n = 1) were also recorded.

CONCLUSION

The awareness of papular or acrochordon-like BCCs, palmoplantar BCCs, and acral epidermoid cysts without punctum may facilitate early diagnosis of Gorlin syndrome in children.

Detection of PTCH1 Copy-Number Variants in Mosaic Basal Cell Nevus Syndrome

Basal cell nevus syndrome (BCNS) is an inherited disorder characterized mainly by the development of basal cell carcinomas (BCCs) at an early age. BCNS is caused by heterozygous small-nucleotide variants (SNVs) and copy-number variants (CNVs) in the Patched1 (PTCH1) gene. Genetic diagnosis may be complicated in mosaic BCNS patients, as accurate SNV and CNV analysis requires high-sensitivity methods due to possible low variant allele frequencies. We compared test outcomes for PTCH1 CNV detection using multiplex ligation-probe amplification (MLPA) and digital droplet PCR (ddPCR) with samples from a BCNS patient heterozygous for a PTCH1 CNV duplication and the patient's father, suspected to have a mosaic form of BCNS. ddPCR detected a significantly increased PTCH1 copy-number ratio in the index patient's blood, and the father's blood and tissues, indicating that the father was postzygotic mosaic and the index patient inherited the CNV from him. MLPA only detected the PTCH1 duplication in the index patient's blood and in hair and saliva from the mosaic father. Our data indicate that ddPCR more accurately detects CNVs, even in low-grade mosaic BCNS patients, which may be missed by MLPA. In general, quantitative ddPCR can be of added value in the genetic diagnosis of mosaic BCNS patients and in estimating the recurrence risk for offspring.

Headache as the presenting manifestation of Gorlin-Goltz syndrome with diastematomyelia: A case report

Gorlin-Goltz syndrome (GGS) is an autosomal dominant multisystemic disease with high penetrance. Headache heralding GGS has been previously reported but without discussing potential sources. We report a patient with headache and a novel association (diastematomyelia), which helped with the diagnosis. A 46-year-old woman presented with persistent holocranial headache. On examination, countless hyperpigmented basal cell nevi over the face, pits over the palmar/plantar surface, and palmar and plantar keratosis were observed. A magnetic resonance imaging (MRI) of the spinal cord revealed diastematomyelia. Diagnosis of GGS was finally made. Headache and diastematomyelia should be included in the clinical picture of GGS.

Bilateral ovarian fibromas as the sole manifestation of Gorlin syndrome in a 22-year-old woman: a case report and literature review

BACKGROUND

Nevoid basal cell carcinoma syndrome (NBCCS, Gorlin syndrome) is a rare autosomal dominantly inherited disorder that is characterized by multisystem disorder such as basal cell carcinomas, keratocystic odontogenic tumors and skeletal abnormalities. Bilateral and/or unilateral ovarian fibromas have been reported in individuals diagnosed with NBCCS.

CASE PRESENTATION

A 22-year-old female, presented with low back pain, and was found to have bilateral giant adnexal masses on pelvic ultrasonography, which had been suspected to be malignant ovarian tumors. Positron emission tomography/computed tomography showed multiple intracranial calcification and skeletal abnormalities. The left adnexa and right ovarian tumor were resected with laparotomy, and pathology revealed bilateral ovarian fibromas with marked calcification. We recommended the patient to receive genetic testing and dermatological examination. No skin lesion was detected. Germline testing identified pathogenic heterozygous mutation in PTCH1 (Patched1).

CONCLUSIONS

The possibility of NBCCS needs to be considered in patients with ovarian fibromas diagnosed in an early age. Skin lesions are not necessary for the diagnosis of NBCCS. Ovarian fibromas are managed with surgical excision with an attempt at preserving ovarian function. Follow-up regime and counseling on options for future fertility should be offered to patients.

European consensus-based interdisciplinary guideline for diagnosis and treatment of basal cell carcinoma-update 2023

Basal cell carcinoma (BCC) is the most common malignant tumour in white populations. Multidisciplinary experts from European Association of Dermato-Oncology (EADO), European Dermatology Forum, European Society for Radiotherapy and Oncology (ESTRO), Union Européenne des Médecins Spécialistes, and the European Academy of Dermatology and Venereology developed updated recommendations on diagnosis and treatment of BCC. BCCs were categorised into 'easy-to-treat' (common) and 'difficult-to-treat' according to the new EADO clinical classification. Diagnosis is based on clinico-dermatoscopic features, although histopathological confirmation is mandatory in equivocal lesions. The first-line treatment of BCC is complete surgery. Micrographically controlled surgery shall be offered in high-risk and recurrent BCC, and BCC located on critical anatomical sites. Topical therapies and destructive approaches can be considered in patients with low-risk superficial BCC. Photodynamic therapy is an effective treatment for superficial and low-risk nodular BCCs. Management of 'difficult-to-treat' BCCs should be discussed by a multidisciplinary tumour board. Hedgehog inhibitors (HHIs), vismodegib or sonidegib, should be offered to patients with locally advanced and metastatic BCC. Immunotherapy with anti-PD1 antibodies (cemiplimab) is a second-line treatment in patients with a progression of disease, contraindication, or intolerance to HHI therapy. Radiotherapy represents a valid alternative in patients who are not candidates for or decline surgery, especially elderly patients. Electrochemotherapy may be offered when surgery or radiotherapy is contraindicated. In Gorlin patients, regular skin examinations are required to diagnose and treat BCCs at an early stage. Long-term follow-up is recommended in patients with high-risk BCC, multiple BCCs, and Gorlin syndrome.

A novel de novo canonical splice site mutation in the PTCH1 gene in a male patient with mild psychomotor retardation and autistic traits: a case report

Basal cell nevus syndrome (BCNS), or Gorlin syndrome, is a rare autosomal dominant disorder caused by mutations in the tumor suppressor gene PTCH1 with complete penetrance and variable expressivity characterized by a broad spectrum of developmental anomalies and a predisposition to neoplasms. Herein, we report a novel de novo splice site mutation in the PTCH1 gene related to mild developmental delay and autistic traits in a 4-year-old male patient.

Personalized Systemic Therapies in Hereditary Cancer Syndromes

Hereditary cancer syndromes are inherited disorders caused by germline pathogenic variants (PVs) that lead to an increased risk of developing certain types of cancer, frequently at an earlier age than in the rest of the population. The germline PVs promote cancer development, growth and survival, and may represent an ideal target for the personalized treatment of hereditary tumors. PARP inhibitors for the treatment of BRCA and PALB2-associated tumors, immune checkpoint inhibitors for tumors associated with the Lynch Syndrome, HIF-2α inhibitor in the VHL-related cancers and, finally, selective RET inhibitors for the treatment of MEN2-associated medullary thyroid cancer are the most successful examples of how a germline PVs can be exploited to develop effective personalized therapies and improve the outcome of these patients. The present review aims to describe and discuss the personalized systemic therapies for inherited cancer syndromes that have been developed and investigated in clinical trials in recent decades.

Genetic predisposition to cancers in children and adolescents

PURPOSE OF REVIEW

Childhood cancer is rare, but it remains the leading cause of disease-related mortality among children 1-14 years of age. As exposure to environmental factors is lower in children, inherited genetic factors become an important player in the cause of childhood cancer. This review highlights the current knowledge and approach for cancer predisposition syndromes in children.

RECENT FINDINGS

Current literature suggests that 10-18% of paediatric cancer patients have an underlying genetic susceptibility to their disease. With better knowledge and technology, more genes and syndromes are being discovered, allowing tailored treatment and surveillance for the probands and their families.Studies have demonstrated that focused surveillance can detect early malignancies and increase overall survival in several cancer predisposition syndromes. Various approaches have been proposed to refine early tumour detection strategies while minimizing the burden on patients and families. Newer therapeutic strategies are being investigated to treat, or even prevent, tumours in children with cancer predisposition.

SUMMARY

This review summarizes the current knowledge about different cancer predisposition syndromes, focusing on the diagnosis, genetic counselling, surveillance and future directions.

Defining patient-centered research priorities in pediatric dermatology

BACKGROUND/OBJECTIVES

Patient and caregiver perspectives are critical in understanding dermatologic disease impact, presentation, and management in children. The Pediatric Dermatology Research Alliance (PeDRA) Patient Advisory Committee (PtAC), a group of patient representatives and parents of children with cutaneous disease, pursued a multistep, iterative, consensus-building process to identify comprehensive, high-priority research needs.

METHODS

Building on discussions at the 2020 PeDRA Annual Conference, a research prioritization survey was developed and completed by PtAC members. Survey themes were aggregated and workshopped by the PtAC through a series of facilitated calls. Emerging priorities were refined in collaboration with additional PeDRA patient community members at the 2021 PeDRA Annual Conference. Subsequently, a final actionable list was agreed upon.

RESULTS

Fourteen PtAC members (86.7% female) representing patients with alopecia areata, atopic dermatitis, vascular birthmarks, congenital melanocytic nevi, ectodermal dysplasias, epidermolysis bullosa, Gorlin syndrome, hidradenitis suppurativa, ichthyosis, pemphigus, psoriasis, Sturge-Weber syndrome, and pachyonychia congenita completed the survey. Following serial PtAC meetings, 60 research needs were identified from five domains: psychosocial challenges, health care navigation/disease management, causes/triggers, treatments to preserve or save life, and treatments to preserve or save quality of life.

CONCLUSIONS

Many pediatric dermatology research priorities align across affected communities and may drive meaningful, patient-centric initiatives and investigations.

Dental Screening Including Panoramic Radiograph for Gorlin-Goltz Syndrome in Patients With Multiple Basal Cell Carcinomas

PURPOSE

To answer the following clinical research question: "Among patients with multiple basal cell carcinomas (mBCCs), can panoramic radiograph (PaR) facilitate the diagnosis of Gorlin-Goltz syndrome (GGS)?"

METHODS

This retrospective study enrolled mBCCs subjects who presented to a German tertiary care center between 1 January 2015 and 31 December 2021. The primary predictor was presence of syndromic mBCCs, and the main outcomes were jaw cysts and odontogenic keratocysts (OKCs). Descriptive, bi- and multivariate statistics, diagnostic test evaluation, and number needed to screen (NNS) were computed at α = 95%.

RESULTS

The sample comprised 527 mBCCs patients (36.1% females; 6.8% GGS; 5.5% OKCs; mean age, 74.5 ± 15.8 years [range, 15-102]). There was a significant association between syndromic mBCCs and jaw cysts (P < .0001; NNS = 2 [95% CI, CI, 1.1 to 1.4]). In the adjusted logistic model, PaR identified GGS via radiographic diagnosis of jaw cysts in case of 1) age ≤ 35 years, 2) ≥ 5 BCCs, and 3) ≥ 1 high-risk BCCs. Nearly every jaw cyst identified by PaR was OKCs (P = .01; 95% CI, 3.1 to 3,101.4; NNS = 1.3 [95% CI, .9 to 2]). The post hoc power was 100%.

CONCLUSIONS

Dental screening with the use of PaR for mBCCs patients, especially those aged ≤35 years, or with ≥5 BCCs, or ≥1 high-risk BCCs, may be helpful in detection and identification of GGS through recognition of OKCs.

Patient and caregiver perspectives on delayed childhood Gorlin syndrome diagnoses

The diagnostic trends of Gorlin syndrome (GS) in the pediatric population are not well understood. In an international survey conducted by the Gorlin Syndrome Alliance, 118 individuals who were diagnosed with GS when aged 18 years and under provided information about their diagnosis. Oral surgeons and dermatologists were the most commonly reported physicians involved in diagnosis for 48.3% and 28% of cases, respectively. For 50% of children, the diagnosis was made within a year from presenting sign(s), while 27% report over 4 years to receive GS diagnosis. Of individuals who reported >4 years between presenting signs and diagnosis, 81.3% attributed the delay to insufficient medical team knowledge and 65.6% attributed to lack of personal awareness that presenting signs were related to GS, emphasizing the need for patient and physician education of GS for prompt diagnosis.

Molecular mechanism of extracutaneous tumours in patients with basal cell nevus syndrome

Basal cell nevus syndrome (BCNS) is a rare genetic disorder accompanied by a broad variety of tumours, of which basal cell carcinomas and odontogenic keratocysts are the most common. BCNS is caused by a germline or postzygotic mutation in either PTCH1 or SUFU As BCNS is a rare disease, it is difficult to establish whether less frequently occurring tumours are actually part of the syndrome. In this study, the molecular mechanism behind four extracutaneous tumours in patients with BCNS was elucidated. A leiomyoma of the testis and meningioma were confirmed to be associated with BCNS in two patients by presence of a second mutation or loss of heterozygosity in PTCH1 In a meningioma of a patient with a mosaic postzygotic PTCH1 mutation an association could not be conclusively confirmed. SUFU was probably not involved in the development of a thyroid carcinoma in a patient with a germline SUFU mutation. Hence, we have proven that meningioma and leiomyoma of the testis are rare extracutaneous tumours that are part of BCNS.

Tumor predisposition: what's the skin got to do with it?

PURPOSE OF REVIEW

Recognition of skin findings associated with tumor predisposition syndromes can prompt early evaluation and surveillance and improve management. Additionally, knowing when to test and when to defer performing genetic testing can streamline management. This article reviews tumor predisposition syndromes with recently characterized skin findings and disorders for which early recognition and counseling can impact the course of disease.

RECENT FINDINGS

Café au lait macules (CALMs) are important in many tumor predisposition syndromes, and 'atypical' CALMs are associated with constitutional mismatch repair deficiency and Fanconi anemia. Melanoma predisposition syndromes caused by pathogenic variants in POT1 and BAP1 are more recently described, and both are associated with Spitzoid tumors. Somatic pathogenic variants can cause segmental nevoid basal cell carcinoma syndrome and a mosaic form of Peutz-Jeghers syndrome. Patients with PTEN hamartoma syndrome have increased risk for melanoma but this might not occur until adulthood.

SUMMARY

The cutaneous manifestations of tumor predisposition syndromes can aid diagnosis. Early photoprotection is key to modifying a main risk factor for skin cancer in many of these syndromes. Implementing surveillance guidelines facilitates early detection of tumors.

Skin Cancer Research Goes Digital: Looking for Biomarkers within the Droplets

Skin cancer, which includes the most frequent malignant non-melanoma carcinomas (basal cell carcinoma, BCC, and squamous cell carcinoma, SCC), along with the difficult to treat cutaneous melanoma (CM), pose important worldwide issues for the health care system. Despite the improved anti-cancer armamentarium and the latest scientific achievements, many skin cancer patients fail to respond to therapies, due to the remarkable heterogeneity of cutaneous tumors, calling for even more sophisticated biomarker discovery and patient monitoring approaches. Droplet digital polymerase chain reaction (ddPCR), a robust method for detecting and quantifying low-abundance nucleic acids, has recently emerged as a powerful technology for skin cancer analysis in tissue and liquid biopsies (LBs). The ddPCR method, being capable of analyzing various biological samples, has proved to be efficient in studying variations in gene sequences, including copy number variations (CNVs) and point mutations, DNA methylation, circulatory miRNome, and transcriptome dynamics. Moreover, ddPCR can be designed as a dynamic platform for individualized cancer detection and monitoring therapy efficacy. Here, we present the latest scientific studies applying ddPCR in dermato-oncology, highlighting the potential of this technology for skin cancer biomarker discovery and validation in the context of personalized medicine. The benefits and challenges associated with ddPCR implementation in the clinical setting, mainly when analyzing LBs, are also discussed.

Basal Cell Carcinoma: Pathology, Current Clinical Treatment, and Potential Use of Lipid Nanoparticles

Skin cancer is the most common type of carcinoma diagnosed worldwide, with significant morbidity and mortality rates among Caucasians, in particular basal cell carcinoma (BCC). The main risk factors of BCC are well-identified, and there are many chemotherapeutic drugs available for its treatment. The effectiveness of therapeutic options is governed by several factors, including the location of the tumor, its size, and the presence of metastases (although rare for BCC). However, available treatments are based on non-targeted approaches, which encounter a significant risk of systemic toxicity in several organs. Site-specific chemotherapy for BCC has been proposed via the loading of anticancer drugs into nanoparticles. Among various types of nanoparticles, in this review, we focus on potential new regimens for the treatment of BCC using classical anticancer drugs loaded into novel lipid nanoparticles. To meet patient aesthetic expectations and enhance the effectiveness of basal cell carcinoma treatment, new therapeutic topical strategies are discussed, despite a limited number of reports available in the literature.

Update on Hedgehog Pathway Inhibitor Therapy for Patients with Basal Cell Naevus Syndrome or High-frequency Basal Cell Carcinoma

Some patients with basal cell carcinoma develop a large number of basal cell carcinomas during their lives. The most common underlying genetic disease that causes multiple basal cell carcinomas is basal cell naevus syndrome. Basal cell naevus syndrome is caused by a germline mutation in patched-1 (PTCH1), a tumour suppressor gene of the hedgehog signalling pathway. However, in a significant portion of patients with multiple basal cell carcinomas, no underlying genetic cause is found. Nevertheless, these patients can experience a treatment burden comparable to that of patients with basal cell naevus syndrome. They are referred to as high-frequency basal cell carcinoma patients. Hedgehog pathway inhibitors were the first group of targeted therapy for basal cell carcinomas. This study reviews the literature on hedgehog pathway inhibitor therapy for patients with basal cell naevus syndrome and high-frequency basal cell carcinoma, to provide an overview on efficacy, safety, dosing regimens, tumour resistance and reoccurrence, and health-related quality of life.