[Basal cell nevus syndrome: the interface between dentistry and dermatology]

Basal cell nevus syndrome is a rare, autosomal dominant disorder, predominantly caused by a mutation in the PTCH1 gene. As basal cell carcinomas and keratocysts are the most common abnormalities, dermatologists, orofacial maxillary surgeons, and dentists play a key role in patient care. From the age of 8, screening for odontogenic keratocysts with an orthopantomogram or MRI is recommended every other year. The intensity increases to annual screening after the development of the first odontogenic keratocyst. If BCNS is caused by an underlying SUFU mutation, screening is not indicated since there are no reports of odontogenic keratocyst in these patients to date. Radiation exposure by, for example, computed tomography, should be minimized as it induces new BCCs. Regular follow-up by a dermatologist for early diagnosis and treatment of (multiple) BCC's is recommended for life.

The application of artificial intelligence in the detection of basal cell carcinoma: A systematic review

Basal cell carcinoma (BCC) is one of the most common types of cancer. The growing incidence worldwide and the need for fast, reliable and less invasive diagnostic techniques make a strong case for the application of different artificial intelligence techniques for detecting and classifying BCC and its subtypes. We report on the current evidence regarding the application of handcrafted and deep radiomics models used for the detection and classification of BCC in dermoscopy, optical coherence tomography and reflectance confocal microscopy. We reviewed all the articles that were published in the last 10 years in PubMed, Web of Science and EMBASE, and we found 15 articles that met the inclusion criteria. We included articles that are original, written in English, focussing on automated BCC detection in our target modalities and published within the last 10 years in the field of dermatology. The outcomes from the selected publications are presented in three categories depending on the imaging modality and to allow for comparison. The majority of articles (n = 12) presented different AI solutions for the detection and/or classification of BCC in dermoscopy images. The rest of the publications presented AI solutions in OCT images (n = 2) and RCM (n = 1). In addition, we provide future directions for the application of these techniques for the detection of BCC. In conclusion, the reviewed publications demonstrate the potential benefit of AI in the detection of BCC in dermoscopy, OCT and RCM.

2021 international consensus statement on optical coherence tomography for basal cell carcinoma: image characteristics, terminology and educational needs

BACKGROUND

Despite the widespread use of optical coherence tomography (OCT) for imaging of keratinocyte carcinoma, we lack an expert consensus on the characteristic OCT features of basal cell carcinoma (BCC), an internationally vetted set of OCT terms to describe various BCC subtypes, and an educational needs assessment.

OBJECTIVES

To identify relevant BCC features in OCT images, propose terminology based on inputs from an expert panel and identify content for a BCC-specific curriculum for OCT trainees.

METHODS

Over three rounds, we conducted a Delphi consensus study on BCC features and terminology between March and September 2020. In the first round, experts were asked to propose BCC subtypes discriminable by OCT, provide OCT image features for each proposed BCC subtypes and suggest content for a BCC-specific OCT training curriculum. If agreement on a BCC-OCT feature exceeded 67%, the feature was accepted and included in a final review. In the second round, experts had to re-evaluate features with less than 67% agreement and rank the ten most relevant BCC OCT image features for superficial BCC, nodular BCC and infiltrative and morpheaphorm BCC subtypes. In the final round, experts received the OCT-BCC consensus list for a final review, comments and confirmation.

RESULTS

The Delphi included six key opinion leaders and 22 experts. Consensus was found on terminology for three OCT BCC image features: (i) hyporeflective areas, (ii) hyperreflective areas and (iii) ovoid structures. Further, the participants ranked the ten most relevant image features for nodular, superficial, infiltrative and morpheaform BCC. The target group and the key components for a curriculum for OCT imaging of BCC have been defined.

CONCLUSION

We have established a set of OCT image features for BCC and preferred terminology. A comprehensive curriculum based on the expert suggestions will help implement OCT imaging of BCC in clinical and research settings.

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

The overall objective of this guideline is to provide up-to-date, evidence-based recommendations for the diagnosis and surveillance of all symptoms of children and adults with either basal cell nevus syndrome (BCNS), a clinical suspicion of BCNS, or a parent with BCNS. In the last two groups the guidelines should be followed until the diagnosis of BCNS can be rejected with certainty. The guideline aims to: - Update and expand on the previous guidelines by an appraisal of all relevant literature from January 2011 up to January 2021 - Address important, practical, clinical questions relating to the primary guideline objective - Provide guideline recommendations - Discuss potential developments and future directions.

Measuring aesthetic results after facial skin cancer surgery by means of the FACE-Q

Background

Skin cancer is the most commonly occurring type of cancer. However, the influence of facial skin cancer surgery on patients’ perceived aesthetic appearance is poorly understood. The objective of this study was to provide an insight into how patients perceive the aesthetic outcome of facial skin cancer surgery by means of a specialised patient-reported outcome measure designed for the aesthetic evaluation of the face: the FACE-Q.

Methods

A total of 47 patients with non-melanoma skin cancer who were scheduled for Mohs’s micrographic surgery (MMS) or standard surgical excision (SE) were included. These patients filled out three different FACE-Q questionnaires: satisfaction with facial appearance, social function, and satisfaction with outcome. Follow-up was conducted after baseline at 1 month and 3 months post-surgery.

Results

No significant differences were detected between baseline and follow-up regarding social function and satisfaction with facial appearance. However, after 3 months, patients were significantly more satisfied with the result of surgery when compared with the 1-month post-surgery follow-up.

Conclusions

The perceived aesthetic appreciation of patients does not seem to be significantly influenced by facial skin cancer SE or MMS surgery in this 3-month follow-up study.

Level of evidence: Not ratable.

A trial-based cost-effectiveness analysis of topical 5-fluorouracil vs. imiquimod vs. ingenol mebutate vs. methyl aminolaevulinate conventional photodynamic therapy for the treatment of actinic keratosis in the head and neck area performed in the Netherlands

BACKGROUND

Actinic keratosis (AK) is a common premalignant skin condition that might have the ability to progress into squamous cell carcinoma. Due to the high incidence of AK, treatment of this disease significantly impacts healthcare spending.

OBJECTIVES

To determine which commonly prescribed field-directed treatment is the most cost-effective, when comparing 5-fluorouracil (5-FU) 5%, imiquimod (IMQ) 5%, ingenol mebutate (IM) 0·015% and methyl aminolaevulinate photodynamic therapy (MAL-PDT) for AK in the head and neck region.

METHODS

We performed an economic evaluation from a healthcare perspective. Data were collected alongside a single-blinded, prospective, multicentre randomized controlled trial with 624 participants in the Netherlands. The outcome measure was expressed as the incremental cost-effectiveness ratio, which is the incremental costs per additional patient with ≥ 75% lesion reduction compared with baseline. This trial was registered at ClinicalTrials.gov, number NCT02281682.

RESULTS

The trial showed that 5-FU was the most effective field treatment for AK in the head and neck region. Twelve months post-treatment, the total mean costs for 5-FU were significantly lower (€433) than the €728, €775 and €1621 for IMQ, IM and MAL-PDT, respectively. The results showed that 5-FU was a dominant cost-effective treatment (more effective and less expensive) compared with the other treatments, 12 months post-treatment.

CONCLUSIONS

Based on these results, we consider 5-FU 5% cream as the first-choice treatment option for multiple AKs in the head and neck area. What's already known about this topic? Due to the increasing incidence of actinic keratosis (AK), the recommended treatment results in a considerable socioeconomic burden for (dermatological) healthcare. Although cost-effectiveness modelling studies have been performed in which different treatments for AK were compared, a prospective clinical trial comparing four frequently prescribed treatments on effectiveness and resource consumption within a time horizon of 12 months has never been conducted. What does this study add? This is the first study examining the cost-effectiveness of 5-fluorouracil 5% cream, imiquimod 5% cream, ingenol mebutate 0·015% gel and methyl aminolaevulinate photodynamic therapy, with data collected in a randomized controlled trial over a time horizon of 12 months. We found that 5-fluorouracil was a dominant cost-effective treatment (more effective and less costly), based on data from the Netherlands. Linked Comment: Steeb et al. Br J Dermatol 2020; 183:612.

Genetic profiling of basal cell carcinomas detects postzygotic mosaicism in basal cell naevus syndrome

Basal cell naevus syndrome (BCNS) is associated with germline mutations in the PTCH1 gene. Postzygotic mosaicism can also cause BCNS. Here we describe two patients, one with multiple basal cell carcinomas (BCCs) and one with clinical BCNS, who had no PTCH1 mutation in DNA extracted from blood. In both patients, we performed genetic analysis on different BCCs, revealing the presence of a shared PTCH1 mutation in all tumours. Our findings show that in patients with symptoms of BCNS and initial absence of a PTCH1 mutation in blood, genetic profiling of BCCs can detect postzygotic mosaicism. What's already known about this topic? Basal cell naevus syndrome (BCNS) is associated with germline mutations in the PTCH1 gene, but it can also be caused by low-grade postzygotic mosaicism in PTCH1. What does this study add? In patients suspected of having BCNS or patients with multiple basal cell carcinomas (BCCs) with a special distribution on the body and no mutation detected in blood, it is worthwhile to search for a shared PTCH1 mutation in their BCCs as this can detect postzygotic mosaicism. This information is important to ensure proper surveillance programmes, choose the right therapy and provide adequate genetic counselling.

Postzygotic mosaicism in basal cell naevus syndrome

Basal cell naevus syndrome (BCNS) is an autosomal dominant disorder most commonly caused by a germline mutation in the Drosophila homologue of patched-1 gene (PTCH1). Here we describe a patient with clinical signs of BCNS, caused by postzygotic mosaicism of a PTCH1 mutation. We performed restriction fragment length polymorphism analysis and Droplet Digital polymerase chain reaction to determine the degree of mosaicism in different tissues of this patient. Our case shows that a relatively low-grade mosaicism can lead to clinical signs reminiscent of those caused by a germline mutation. This finding has important implications for genetic counselling and therefore is pivotal to recognize for dermatologists, as well as for clinical geneticists and clinical laboratory geneticists.

[Complete treatment of basal cell carcinoma; cost effectiveness of Mohs micrographic surgery versus conventional excision]

OBJECTIVE

To investigate whether Mohs micrographic surgery (MMS) in accordance with the indications in the revised guideline on basal cell carcinoma (BCC) more often leads to complete treatment than conventional excision (CE) and whether the costs are comparable, and to analyse whether this also applies to all primary BCC of the face.

DESIGN

Retrospective analysis.

METHOD

We gathered data on 3374 MMS procedures and calculated per localisation, subtype and size: the percentage of CE that would have been incomplete after applying the recommended surgical margin; the surgical margin necessary to achieve complete excision in > 90% of cases; the final defect after CE and after MMS; the cost of MMS and the cost of CE with postponed reconstruction or, in the case of incomplete CE, subsequent MMS.

RESULTS

For the new MMS indications we can show that using MMS seems to prevent incomplete CE in 12-45% of cases. CE will also lead to incomplete excision in ≥ 10% of cases in most subgroups of primary facial BCC, with the exception of some small superficial or nodular BCCs in the H-zone. The final defect was always smaller after MMS than after CE. MMS can be used with comparable costs for primary BCCs > 5 mm in the H-zone and > 20 mm elsewhere in the face.

CONCLUSION

The surgical margins recommended in the guidelines are inadequate to achieve complete excision rates in > 90% of facial CEs. MMS is an efficient alternative for CE for primary BCCs > 5 mm in the H-zone and > 20 mm elsewhere in the face.

[Vismodegib for basal cell carcinoma: targeted therapy in case of locally advanced or metastasised disease]

The development of the hedgehog pathway inhibitor vismodegib provides a new treatment option for metastasised and locally advanced basal cell carcinoma in which surgical excision or radiotherapy is contraindicated. Only a fraction of patients with basal cell carcinoma are eligible for this therapy, but it is effective in the majority of those who do receive vismodegib. However, development of tumour resistance is quite common and adverse events frequently lead to discontinuation of therapy. Intermittent treatment or combination therapy could reduce the occurrence of tumour resistance and diminish toxicity. We present three patients who were successfully treated with vismodegib: a 73-year-old man with locally advanced basal cell carcinoma, an 82-year-old man with basal cell carcinoma that had metastasised to the lungs, and a 42-year-old man with Gorlin syndrome.

Fractionated 5-aminolaevulinic acid-photodynamic therapy vs. surgical excision in the treatment of nodular basal cell carcinoma: results of a randomized controlled trial

BACKGROUND

Skin cancer incidence rates have been increasing for decades and this increase is expected to continue. Surgical excision (SE) is the treatment of first choice for nodular basal cell carcinoma (nBCC). Photodynamic therapy (PDT) has proven to be an effective treatment for superficial basal cell carcinoma. Its long-term efficacy in nBCC has not yet been established.

OBJECTIVES

Prospectively compare the efficacy of 5-aminolaevulinic acid (ALA)-PDT and SE in terms of failure rates with long-term follow-up. Determinants of failure in the study population, such as the effect of tumour depth, were analysed retrospectively.

METHODS

A randomized controlled trial in 173 primary nBCCs in 149 patients. Primary nBCCs were randomly assigned either to PDT (n = 85) or to SE (n = 88). Tumours treated with PDT were illuminated twice on the same day, 4 h after application of ALA cream, 3 weeks after debulking. SE was performed under local anaesthesia with a 3-mm margin, followed by histological examination. An intention-to-treat analysis was performed.

RESULTS

In total, 171 primary nBCCs in 149 patients were treated. A 3-year interim analysis revealed that the cumulative incidence of failure was 2.3% for SE and 30.3% for PDT (P < 0.001). Tumour depth and other analysed determinants of failure were not significantly related to treatment failure.

CONCLUSIONS

SE proved to be significantly more effective than treatment with fractionated illumination ALA-PDT. Therefore, in the treatment of primary nBCC, SE is preferred over PDT following this treatment regimen.