Search

Recent studies show promising potential for artificial intelligence (AI) to assist healthcare providers (HCPs) in skin cancer care. The aim of this study is to explore the views of dermatologists and general practitioners (GPs) regarding the successful implementation of AI when assisting HCPs in skin cancer care. We performed a qualitative focus group study, consisting of six focus groups with 16 dermatologists and 17 GPs, varying in prior knowledge and experience with AI, gender, and age. An in-depth inductive thematic content analysis was deployed. Perceived benefits, barriers, and preconditions were identified as main themes. Dermatologists and GPs perceive substantial benefits of AI, particularly an improved health outcome and care pathway between primary and secondary care. Doubts about accuracy, risk of health inequalities, and fear of replacement were among the most stressed barriers. Essential preconditions included adequate algorithm content, sufficient usability, and accessibility of AI. In conclusion, dermatologists and GPs perceive significant benefits from implementing AI in skin cancer care. However, to successfully implement AI, key barriers need to be addressed. Efforts should focus on ensuring algorithm transparency, validation, accessibility for all skin types, and adequate regulation of algorithms. Simultaneously, improving knowledge about AI could reduce the fear of replacement.

Aim of the study: Cutaneous squamous cell carcinoma (cSCC) incidences are increasing but scarcely available separated. We analysed incidence rates of cSCC over three decades with an extrapolation to 2040. Methods: Cancer registries from the Netherlands, Scotland and two federal states of Germany (Saarland/Schleswig-Holstein) were sourced for separate cSCC incidence data. Incidence and mortality trends between 1989/90 and 2020 were assessed using Joinpoint regression models. Modified age-period-cohort models were applied to predict incidence rates up to 2044. Rates were age-standardised using the new European standard population (2013). Results: Age-standardised incidence rates (ASIR, per 100,000 persons per year) increased in all populations. The annual percent increase ranged between 2.4% and 5.7%. The highest increase occurred in the age groups ≥60 years, especially in men aged ≥80 years, with a three to 5-fold increase. Extrapolations up to 2044 showed an unrestrained increase in incidence rates in all countries investigated. Age-standardised mortality rates (ASMR) showed slight increases between 1.4 and 3.2% per year in Saarland and Schleswig-Holstein for both sexes and for men in Scotland. For the Netherlands, ASMRs remained stable for women but declined for men. Conclusion: There was a continuous increase of cSCC incidence over three decades with no tendency for levelling-off, especially in the older populations as males ≥80 years. Extrapolations point to a further increasing number of cSCC up to 2044, especially among ≥60 years. This will have a significant impact on the current and future burden on dermatologic health care which will be faced with major challenges.

Background Merkel cell carcinoma (MCC) is a rare tumour with neuroendocrine differentiation and high associated mortality. Studies that describe the epidemiology of MCC are often limited by small sample size, short duration of follow-up, absence of nationwide data and paucity of data on different risk factors. Objectives To determine the incidence, demographics and survival for MCC in England between 2004 and 2018. Methods This national retrospective cohort study identified all cases of MCC in England from 2004 to 2018 using national population-based data from the National Disease Registration Service. Crude counts, European age-standardized incidence rates (EASRs) and joinpoint analysis were conducted. Patient demographics and treatments received were described. Multivariable Cox regression analysis was used to study risk factors for MCC-specific mortality, by including a priori defined demographic factors, tumour characteristics and immunosuppression. Treatment data were not included in the Cox regression analysis. Results A total of 3775 MCC tumours were registered. The median age at diagnosis was 81 years (interquartile range 74–87). Overall, 96·6% of patients identified as White ethnicity, and 8·3% of patients were immunosuppressed. The most common site was the face (27·4%). Patients most often presented with stage one disease (22·8%); however, stage was unknown in 31·0%. In total, 80·7% of patients underwent surgical excision, 43·5% radiotherapy and 9·2% systemic therapy. The EASR increased from 0·43 per 100 000 person-years (PYs) to 0·65 per 100 000 person-years between 2004 and 2018, representing a significant annual percentage change of 3·9%. The EASR was greater in men than in women for all years, with an overall male-to-female ratio of 1·41 : 1. The highest EASR was in South West England. Five-year disease-specific survival was 65·6% [95% confidence interval (CI) 63·8–67·4], with a median follow-up of 767 days. MCC-specific mortality increased with age [hazard ratio (HR) 1·02, 95% CI 1·02–1·03], deprivation (HR 1·43, 95% CI 1·16–1·76), immunosuppression (HR 2·80, 95% CI 2·34–3·34) and stage at diagnosis (HR 8·24, 95% CI 5·84–11·6). Conclusions This study presents the largest national MCC dataset in Europe, and the most complete reporting of MCC incidence and survival ever published. With the EASR of MCC increasing and high associated mortality, this study encourages further research into the pathology, diagnosis and therapeutic options for MCC to support management guidelines.

Background: The COVID-19 pandemic reduced the number of skin cancer diagnoses, potentially causing a progression to unfavourable tumour stages. Objectives: To identify the impact of delayed diagnostics on primary invasive melanoma and cutaneous squamous cell carcinoma (cSCC) by comparing tumour (pT) stage, Breslow thickness and invasion depth from before to after the first and second lockdown periods. Methods: In this population-based cohort study, histopathology reports registered between 1 January 2018 and 22 July 2021 were obtained from the nationwide histopathology registry in the Netherlands. The Breslow thickness of melanomas, invasion depth of cSCCs, and pT stage for both tumour types were compared across five time periods: (i) pre-COVID, (ii) first lockdown, (iii) between first and second lockdowns, (iv) second lockdown and (v) after second lockdown. Breslow thickness was compared using an independent t-test. pT-stage groups were compared using a χ2-test. Outcomes were corrected for multiple testing using the false discovery rate. Results: In total, 20 434 primary invasive melanomas and 68 832 cSCCs were included in this study. The mean primary melanoma Breslow thickness of the prepandemic era (period i) and the following time periods (ii–v) showed no significant difference. A small shift was found towards unfavourable pT stages during the first lockdown compared with the pre-COVID period: pT1 52·3% vs. 58·6%, pT2 18·9% vs. 17·8%, pT3 13·2% vs. 11·0%, pT4 9·1% vs. 7·3% (P = 0·001). No relevant changes were seen in subsequent periods. No significant change in pT stage distribution was observed between the pre-COVID (i) and COVID-affected periods (ii–v) for cSCCs. Conclusions: To date, the diagnostic delay caused by COVID-19 has not resulted in relatively more unfavourable primary tumour characteristics of melanoma or cSCC. Follow-up studies in the coming years are needed to identify a potential impact on staging distribution and survival in the long term.

Background: Basal cell carcinoma (BCC) is the most frequently diagnosed malignancy worldwide and an ever increasing annual incidence is observed. However, nationwide registries of BCCs are very rare, and often extrapolation of the data has been necessary to estimate the absolute number of diagnoses. As of September 2016, all histopathologically confirmed BCCs are registered in the Netherlands, due to developments in automatic notification and import in the Netherlands Cancer Registry. This offers the unique possibility to assess the nationwide population-based incidence of first and multiple BCCs. Objectives: To assess the nationwide incidence and trends of first and multiple BCCs in the Netherlands and to predict incidence rates up to 2029. Methods: All patients with histopathologically confirmed BCC between 2001 and 2019 were selected from the population-based Netherlands Cancer Registry. Age-standardized incidence rates were calculated and trends were analysed with use of the estimated annual percentage change. Prediction of BCC incidence rates up to 2029 was based on a regression model. Results: In total, 601 806 patients were diagnosed with a first BCC over the period 2001–2019. The age-standardized incidence rates for both men and women with a first BCC increased over these years, from 157 to 304 and from 124 to 274 per 100 000 person-years, respectively. For male and female patients aged 30–39 years, decreases in annual incidences of −3·6% and −3·0%, respectively, were found in recent years. For patients aged 50 years or older an ever increasing trend was found. One-quarter of the patients with a first primary BCC developed one or more subsequent BCCs within 3 years. Increases in incidence of 30·4% (male) and 25·3% (female) are expected in the next 10 years. Conclusions: BCC incidence has doubled over the past two decades. Trends have seemed to stabilize in recent years for patients aged < 50 years. This might be a first sign of a decreasing trend. The incidence continues to rise in patients aged 50 years and older. In the next decade a further increase in BCC incidence is expected.

Background Cutaneous squamous cell carcinoma (cSCC) represents the most serious form of keratinocyte cancers because of its metastatic potential. Studies on nationwide incidence and disease-specific survival rates of metastatic cSCC (mcSCC) are lacking. Objective To investigate the cumulative incidence and disease-specific survival of patients with mcSCC in the Dutch population and assess patient-based risk factors. Methods We conducted a nationwide cancer registry study including all patients with the first cSCC in 2007 or 2008, using data from the Netherlands Cancer Registry, the nationwide network and registry of histopathology and cytopathology, and Statistics Netherlands. Cumulative incidence and Kaplan-Meier curves were calculated, and time-dependent Cox proportional hazards regression analyses were used. Results Of the 11,137 patients, metastases developed in 1.9% (n = 217). The median time to metastasis was 1.5 years (interquartile range 0.6-3.8 years). The risk factors were age (adjusted hazard ratio [aHR] 1.03, 95% CI 1.02-1.05), male sex (aHR 1.7, 95% CI 1.3-2.3), and immunosuppression (aHR [organ transplant recipient] 5.0, 95% CI 2.5-10.0; aHR [hematologic malignancy] 2.7, 95% CI 1.6-4.6). The 5-year disease-specific survival for patients with mcSCC was 79.1%. Limitations Only histopathologically confirmed mcSCCs were included. Conclusion About 2% of cSCCs metastasize, with higher risk for men, increasing age, and immunocompromised patients. Disease-specific survival for patients with mcSCC is high.

BACKGROUND: Sebaceous carcinoma (SC) is a rare malignant tumour whereby, comprehensive long-term data are scarce. This study aimed to assess the outcome of patients treated with resection for SC.METHODS: Patients treated at four tertiary centres were included. Cumulative incidence curves were calculated for recurrences.RESULTS: A total of 100 patients (57 males, 57%) were included with 103 SCs. The median age was 72 (range, 15-95) years with a median follow-up of 52 (interquartile range [IQR], 24-93) months. Most SCs were located (peri)ocular (49.5%). Of all SCs, 17 locally recurred (16.5%) with a median time to recurrence of 19 (IQR, 8-29) months. The cumulative incidence probability for recurrence was statistically higher for (peri)ocular tumours (p = 0.005), and for positive resection margins (p = 0.001). Two patients presented with lymph node metastases and additional seven patients (8.7%) developed lymph node metastases during follow-up with a median time to metastases of 8 (IQR, 0.5-28) months. Three patients had concurrent in-transit metastases and one patient also developed liver and bone metastases during follow-up.CONCLUSION: SC is a rare, yet locally aggressive tumour. Positive resection margins and (peri)ocular SCs are more frequently associated with local recurrence. SC infrequently presents with locoregional or distant metastases.

To provide patient-centered care, it is essential to explore what patients consider important and to adjust care accordingly. This may specifically be relevant for patients with complex skin cancer, for whom the care process is often more complicated and psychological and social problems may play a larger role. The objective was to explore the experiences and needs of patients who had undergone surgical treatment by a dermatologist for a complex skin cancer with a subsequent reconstruction by a plastic surgeon. An interview study was conducted among 16 patients who had undergone surgical treatment by a dermatologist and reconstruction by a plastic surgeon for basal cell carcinoma, cutaneous squamous cell carcinoma, or lentigo maligna. The interviews focused on patients’ experiences and needs regarding care using a predefined topic list. All interviews were audio-taped, transcribed verbatim and inductively analyzed using Atlas.ti. Patients reported a need for a skilled and friendly physician who tailors information and communication to their individual situation. A need for continuity of care and improved collaboration between healthcare providers was also emphasized. Furthermore, patients experienced complications and unmet expectations and expressed a need for shared decision-making at various steps throughout the treatment process (depending on age). Patients also considered completeness of tumor removal, follow-up visits with multiple specialists to be planned the same day and recognition of the psychological impact of the disease on the partner important. To improve patient-centered care for complex skin cancer patients, more efforts should be directed towards improving continuity of care and collaboration. Furthermore, it is advocated for physicians to be sensitive to the individual needs of patients and their partner and adjust information, communication and (supportive) care accordingly.

To facilitate nationwide epidemiological research on advanced cutaneous squamous cell carcinoma (cSCC), that is, locally advanced, recurrent, or metastatic cSCC, we sought to develop and validate a rule-based algorithm that identifies advanced cSCC from pathology reports. The algorithm was based on both hierarchical histopathological codes and free text from pathology reports recorded in the National Pathology Registry. Medical files from the Erasmus Medical Center of 186 patients with stage III/IV/recurrent cSCC and 184 patients with stage I/II cSCC were selected and served as the gold standard to assess the performance of the algorithm. The rule-based algorithm showed a sensitivity of 91.9% (95% confidence interval = 88.0‒95.9), a specificity of 96.7% (95% confidence interval = 94‒2-99.3), and a positive predictive value of 78.5% (95% confidence interval = 74.2‒82.8) for all advanced cSCC combined. The sensitivity was lower per subgroup: locally advanced (52.3‒86.2%), recurrent cSCC (23.3%), and metastatic cSCC (70.0%). The specificity per subgroup was above 97%, and the positive predictive value was above 78%, with the exception of metastatic cSCC, which had a positive predictive value of 62%. This algorithm can be used to identify advanced patients with cSCC from pathology reports and will facilitate large-scale epidemiological studies of advanced cSCC in the Netherlands and internationally after external validation.

We present two cases of plaque-type trichoblastoma with atypical foci. A rare variant of trichoblastoma is the plaque-variant, which is characterized by poor circumscription and locally infiltrative growth pattern. These lesions mostly require multiple stages of Mohs micrographic surgery. Debate still exists whether this variant should be considered as a benign entity or as 'low-grade' malignant counterpart of trichoblastoma. In this report we describe two cases of plaque-type trichoblastoma with atypical foci, which harbored somatic mutations in the Hedgehog pathway, thus should be acknowledged as intermediate malignancies. Additionally, extensive molecular workup of both the trichoblastic and atypical component in sequential lesions in the same patient was performed. This article is protected by copyright. All rights reserved.

Background: Mobile health (mHealth) applications (apps) incorporating artificial intelligence for skin cancer screening are increasingly reimbursed by health insurers. However, an in-depth exploration of the general public’s views towards these apps is lacking. Objectives: To explore the perceived barriers and facilitators towards mHealth apps for skin cancer screening among the Dutch general population. Methods: A qualitative study consisting of four focus groups with 27 participants was conducted. A two-stage purposive sampling method was used to include information-rich participants from the Dutch general population with varying experience of mHealth. A topic guide was used to structure the sessions. All focus group meetings were transcribed verbatim and analysed in thematic content analysis by two researchers using several coding phases, resulting in an overview of themes and subthemes, categorized as (sub-)barriers and (sub)facilitators. Results: Main barriers to using mHealth apps included a perceived lack of value, perception of untrustworthiness, preference for a doctor, privacy concerns, a complex user interface, and high costs. The main factors facilitating the use of mHealth among the general population were a high perceived value, a transparent and trustworthy identity of app developers, endorsement by healthcare providers and government regulating bodies, and ease and low costs of use. Conclusions: To increase successful adoption in skin cancer screening apps, developers should create a transparent identity and build trustworthy apps. Collaboration between app developers, general practitioners and dermatologists is advocated to improve mHealth integration with skin cancer care. Special attention should be given to the development of low-cost, privacy-friendly, easy-to-use apps.

Background: Quality indicators are used to benchmark and subsequently improve quality of healthcare. However, defining good quality indicators and applying them to high-volume care such as skin cancer is not always feasible. Objectives: To determine whether claims data could be used to benchmark high-volume skin cancer care and to assess clinical practice variation. Methods: All skin cancer care-related claims in dermatology in 2016 were extracted from a nationwide claims database (Vektis) in the Netherlands. Results: For over 220,000 patients, a skin cancer diagnosis-related group was reimbursed in 124 healthcare centres. Conventional excision reflected 75% of treatments for skin cancer but showed large variation between practices. Large practice variation was also found for 5-fluorouracil and imiquimod creams. The practice variation of Mohs micrographic surgery and photodynamic therapy was low under the 75th percentile, but outliers at the 100th percentile were detected, which indicates that few centres performed these therapies far more often than average. On average, patients received 1.8 follow-up visits in 2016. Conclusions: Claims data demonstrated large practice variation in treatments and follow-up visits of skin cancer and may be a valid and feasible data set to extract quality indicators. The next step is to investigate whether detected practice variation is unwarranted and if a reduction improves quality and efficiency of care.

Background Based on increased cardiometabolic comorbidities, inflammation, and an overlap in genetics with Alzheimer disease, psoriasis patients might be at risk for cognitive dysfunction and dementia. Objective To compare cognition, magnetic resonance imaging (MRI)–markers, and dementia risk in psoriasis and nonpsoriasis participants in the population-based Rotterdam Study. Methods We identified 318 psoriasis and 9678 nonpsoriasis participants (mean age 66.1 years, 58% women). The association of psoriasis with cognitive function, mild cognitive impairment, and MRI-markers of brain damage was examined by linear and logistic regression. Dementia risk was calculated using Cox regression. Models were adjusted for age, sex, education, and cardiovascular risk factors. Results Cognitive test scores and volumetric, microstructural, focal measures on brain MRI did not differ between psoriasis (28% systemic and ultraviolet treatment) and nonpsoriasis participants, and psoriasis was not associated with mild cognitive impairment (adjusted odd ratio 0.87, 95% confidence interval 0.53-1.43). During 115.000 person-years of follow-up, 810 incident dementia cases (15 among psoriasis patients) occurred. After adjusting for confounders, psoriasis was associated with a lower risk of developing dementia (adjusted hazard ratio 0.50, 95% confidence interval 0.28-0.91). Limitations Limited dementia cases among psoriasis patients. Conclusion In this population-based study, psoriasis was not associated with preclinical markers or higher dementia risk.

Background: Risk factors for cutaneous squamous cell carcinoma (cSCC) metastasis have been investigated only in relatively small data sets. Objective: To analyze and replicate risk factors for metastatic cSCC. Methods: From English and Dutch nationwide cancer registry cohorts, metastatic cases were selected and 1:1 matched to controls. The variables were extracted from pathology reports from the National Disease Registration Service in England. In the Netherlands, histopathologic slides from the Dutch Pathology Registry were revised by a dermatopathologist. Model building was performed in the English data set using backward conditional logistic regression, whereas replication was performed using the Dutch data set. Results: In addition to diameter and thickness, the following variables were significant risk factors for metastatic cSCC in the English data set (n = 1774): poor differentiation (odds ratio [OR], 4.56; 95% CI, 2.99-6.94), invasion in (OR, 1.69; 95% CI, 1.05-2.71)/beyond (OR, 4.43; 95% CI, 1.98-9.90) subcutaneous fat, male sex (OR, 2.59; 95% CI, 1.70-3.96), perineural/lymphovascular invasion (OR, 2.12; 95% CI, 1.21-3.71), and facial localization (OR, 1.57; 95% CI, 1.02-2.41). Diameter and thickness showed significant nonlinear relationships with metastasis. Similar ORs were observed in the Dutch data set (n = 434 cSCCs). Limitations: Retrospective use of pathology reports in the English data set. Conclusion: cSCC staging systems can be improved by including differentiation, clinical characteristics such as sex and tumor location, and nonlinear relationships for diameter and thickness.

Background: The current standard of care for patients without sentinel node (SN) metastasis (i.e., stage I–II melanoma) is watchful waiting, while >40% of patients with stage IB–IIC will eventually present with disease recurrence or die as a result of melanoma. With the prospect of adjuvant therapeutic options for patients with a negative SN, we assessed the performance of a clinicopathologic and gene expression (CP-GEP) model, a model originally developed to predict SN metastasis, to identify patients with stage I–II melanoma at risk of disease relapse. Methods: This study included patients with cutaneous melanoma ≥18 years of age with a negative SN between October 2006 and December 2017 at the Sahlgrenska University Hospital (Sweden) and Erasmus MC Cancer Institute (The Netherlands). According to the CP-GEP model, which can be applied to the primary melanoma tissue, the patients were stratified into high or low risk of recurrence. The primary aim was to assess the 5-year recurrence-free survival (RFS) of low- and high-risk CP-GEP. A secondary aim was to compare the CP-GEP model with the EORTC nomogram, a model based on clinicopathological variables only. Results: In total, 535 patients (stage I–II) were included. CP-GEP stratification among these patients resulted in a 5-year RFS of 92.9% (95% confidence interval (CI): 86.4–96.4) in CP-GEP low-risk patients (n = 122) versus 80.7% (95%CI: 76.3–84.3) in CP-GEP high-risk patients (n = 413; hazard ratio 2.93 (95%CI: 1.41–6.09), p < 0.004). According to the EORTC nomogram, 25% of the patients were classified as having a ‘low risk’ of recurrence (96.8% 5-year RFS (95%CI 91.6–98.8), n = 130), 49% as ‘intermediate risk’ (88.4% 5-year RFS (95%CI 83.6–91.8), n = 261), and 26% as ‘high risk’ (61.1% 5-year RFS (95%CI 51.9–69.1), n = 137). Conclusion: In these two independent European cohorts, the CP-GEP model was able to stratify patients with stage I–II melanoma into two groups differentiated by RFS.

In this survey study of over 600 US dermatologists, identical clinical scenarios (10mm primary asymptomatic BCC) were presented except for randomly varied patient characteristics including age, life expectancy, and tumor location. Most dermatologists (62%) recommended active surveillance for patients with advanced age (91 years) and a 1-year life expectancy. The odds ratio for choosing active surveillance was 20.31 (95% CI 14.10-35.30) comparing a patient with a 1-year life expectancy to a healthy patient.

Background: Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer worldwide with relatively low metastatic potential (2–5%). Developments in therapeutic options have highlighted the need to better identify high-risk patients who could benefit from closer surveillance, adjuvant therapies and baseline/follow-up imaging, while at the same time safely omitting low-risk patients from further follow-up. Controversy remains regarding the predictive performance of current cSCC staging systems and which methodology to adopt. Objectives: To validate the performance of four cSCC staging systems [American Joint Committee on Cancer 8th edition (AJCC8), Brigham and Women’s Hospital (BWH), Tübingen and Salamanca T3 refinement] in predicting metastasis using a nationwide cohort. Methods: A nested case–control study using data from the National Disease Registration Service, England, 2013–2015 was conducted. Metastatic cSCC cases were identified using an algorithm to identify all potential cases for manual review. These were 1 : 1 matched on follow-up time to nonmetastatic controls randomly selected from 2013. Staging systems were analysed for distinctiveness, homogeneity, monotonicity, specificity, positive predictive value (PPV), negative predictive value (NPV) and c-index. Results: We included 887 metastatic cSCC cases and 887 nonmetastatic cSCC controls. The BWH system showed the highest specificity [92.8%, 95% confidence interval (CI) 90.8–94.3%, PPV (13.2%, 95% CI 10.6–16.2) and c-index (0.84, 95% CI 0.82–0.86). The AJCC8 showed superior NPV (99.2%, 95% CI 99.2–99.3), homogeneity and monotonicity compared with the BWH and Tübingen diameter and thickness classifications (P < 0.001). Salamanca refinement did not show any improvement in AJCC8 T3 cSCC staging. Conclusions: We validated four cSCC staging systems using the largest nationwide dataset of metastatic cSCC so far. Although the BWH system showed the highest overall discriminative ability, PPV was low for all staging systems, which shows the need for further improvement and refining of current cSCC staging systems.

Early detection of melanoma or, even better, preventing mela-noma by educating and stimulating sun-protective behaviour,are still essential steps to reducing its global burden. However,evidence is insufficient to demonstrate the benefit of popula-tion-based screening by total body skin examination.1Poten-tially, focusing the screening on high-risk individuals may becost effective. Clinical implementation of polygenic risk scores(PRSs) is increasingly mentioned to facilitate this identificationof high-risk individuals (i.e. genetic risk stratification). [...]

Summary Background Patients with actinic keratosis (AK) are at increased risk for developing keratinocyte carcinoma (KC) but predictive factors and their risk rates are unknown. Objectives To develop and internally validate a prediction model to calculate the absolute risk of a first KC in patients with AK. Methods The risk‐prediction model was based on the prospective population‐based Rotterdam Study cohort. We hereto analysed the data of participants with at least one AK lesion at cohort baseline using a multivariable Cox proportional hazards model and included 13 a priori defined candidate predictor variables considering phenotypic, genetic and lifestyle risk factors. KCs were identified by linkage of the data with the Dutch Pathology Registry. Results Of the 1169 AK participants at baseline, 176 (15·1%) developed a KC after a median follow‐up of 1·8 years. The final model with significant predictors was obtained after backward stepwise selection and comprised the presence of four to nine AKs [hazard ratio (HR) 1·68, 95% confidence interval (CI) 1·17–2·42], 10 or more AKs (HR 2·44, 95% CI 1·65–3·61), AK localization on the upper extremities (HR 0·75, 95% CI 0·52–1·08) or elsewhere except the head (HR 1·40, 95% CI 0·98–2·01) and coffee consumption (HR 0·92, 95% CI 0·84–1·01). Evaluation of the discriminative ability of the model showed a bootstrap validated concordance index (c‐index) of 0·60. Conclusions We showed that the risk of KC in patients with AK can be calculated with the use of four easily assessable predictor variables. Given the c‐index, extension of the model with additional, currently unknown predictor variables is desirable. Linked Comment: Kim et al. Br J Dermatol 2020; 183:415–416., What's already known about this topic? Patients with actinic keratosis (AK) are at increased risk of developing keratinocyte carcinoma (KC), including both squamous cell and basal cell carcinoma.However, risk rates and predictive factors are unknown and to date no risk‐prediction model has been developed for patients with AK. What does this study add? We present a multivariable risk‐prediction model with an additional tool to calculate the absolute risk of KC development in patients with AK.The number of AKs (4–9 or ≥ 10), location of AKs (upper extremity or elsewhere except head) and coffee consumption are significant predictors with a moderate discriminative ability.This prediction model may help in the management of patients with AK but extension with additional factors is desirable before clinical implementation. Linked Comment: Kim et al. Br J Dermatol 2020; 183:415–416. Plain language summary available online

Door stijgende zorgkosten staat substitutie van zorg hoog op de politieke agenda. In dit onderzoek verkenden wij middels interviews welke opvattingen zorgverleners hebben over de verplaatsing van laagrisicohuidkankerzorg van het ziekenhuis naar de eerste lijn. Hoewel de betrokken zorgverleners over het algemeen gematigd positief waren over substitutie van huidkankerzorg, blijken substantiele barrieres een succesvolle implementatie op dit moment in de weg te staan. Maatregelen die substitutie kunnen bevorderen zijn dermato-oncologiescholing voor huisartsen en het verbeteren van de samenwerking tussen de lijnen. Huisartsen verwachten daarnaast inspanningen van dermatologen om hun vertrouwen en dat van patienten in huisartsen te verhogen, en compensatie in tijd en geld.

IMPORTANCE: The incidence rates of keratinocyte cancer are increasing globally; however, the incidence rates of cutaneous squamous cell carcinoma (cSCC) in situ and the risk of developing subsequent invasive cSCC remain unknown. OBJECTIVE: To estimate annual population-based age-standardized incidence rates of histopathologically confirmed cSCC in situ stratified by sex, age, and body site and to assess the risk of developing invasive cSCC among patients with cSCC in situ compared with the general population. DESIGN, SETTING, AND PARTICIPANTS: This nationwide epidemiological population-based cohort study used cancer registry data to identify all patients with a first incident of histopathologically confirmed cSCC in situ between January 1, 1989, and December 31, 2017. In addition, all patients with cSCC in situ who subsequently had a first incident of invasive cSCC were identified up to June 11, 2019. Data were analyzed between March 18 and November 12, 2019. MAIN OUTCOMES AND MEASURES: Age-standardized incidence rates per year for cSCC in situ, standardized to the 2013 edition of the European Standard Population, were calculated by sex, age, and body site. Cumulative risks, standardized incidence ratios, and absolute excess risks were calculated to assess the risk of invasive cSCC in patients with cSCC in situ compared with the general population. RESULTS: In this population-based cohort study of 88 754 patients with a first incident of cSCC in situ between January 1, 1989, and December 31, 2017, 58.8% were women; the median age was 75 years (interquartile range [IQR], 67-82 years) for women and 73 years (IQR, 65-80 years) for men. Increasing incidence rates were observed, with the highest incidence rates in 2017 among women in general (71.7 cases per 100 000 person-years) and among men 80 years and older (540.9 cases per 100 000 person-years). The most common body site among women was the face (15.9 cases per 100 000 person-years) and among men was the scalp and/or neck (12.3 cases per 100 000 person-years). After 5 years of follow-up, among patients with cSCC in situ, the cumulative risk of developing an invasive cSCC at any anatomic location was 11.7% (95% CI, 11.6%-11.9%) in men and 6.9% (95% CI, 6.8%-7.0%) in women (P

IMPORTANCE Until now, most studies on cutaneous squamous cell carcinoma (cSCC) incidence rates concerned only the first cSCC per patient. Given the increase in incidence rates and the frequent occurrence of subsequent cSCCs per patient, population-based data on the incidence rates of both first and multiple cSCCs are needed. OBJECTIVES To calculate annual age-standardized incidence rates for histopathologically confirmed first and multiple cSCCs per patient and to estimate future cSCC incidence rates up to 2027. DESIGN, SETTING, AND PARTICIPANTS A nationwide population-based epidemiologic cohort study used cancer registry data on 145 618 patients with a first histopathologically confirmed cSCC diagnosed between January 1, 1989, and December 31, 2017, from the Netherlands Cancer Registry and all patients with multiple cSCCs diagnosed in 2017. MAIN OUTCOMES AND MEASURES Age-standardized incidence rates for cSCC—standardized to the European Standard Population 2013 and United States Standard Population 2000—were calculated per sex, age group, body site, and disease stage. A regression model with positive slope was fitted to estimate cSCC incidence rates up to 2027. RESULTS A total of 145 618 patients in the Dutch population (84 572 male patients [58.1%]; mean [SD] age, 74.5 [11.5] years) received a diagnosis of a first cSCC between 1989 and 2017. Based on incident data, European Standardized Rates (ESRs) increased substantially, with the highest increase found among female patients from 2002 to 2017, at 8.2% (95% CI, 7.6%-8.8%) per year. The ESRs for first cSCC per patient in 2017 were 107.6 per 100 000 person-years (PY) for male patients, an increase from 40.0 per 100 000 PY in 1989, and 68.7 per 100 000 PY for female patients, an increase from 13.9 per 100 000 PY in 1989, which corresponds with a US Standardized Rate of 71.4 per 100 000 PY in 2017 for men and 46.4 per 100 000 PY in 2017 for women. Considering multiple cSCCs per patient, ESRs increased by 58.4% for men (from 107.6 per 100 000 PY to 170.4 per 100 000 PY) and 34.8% for women (from 68.7 per 100 000 PY to 92.6 per 100 000 PY). Estimation of ESRs for the next decade show a further increase of 23.0% for male patients (ESR up to 132.4 per 100 000 PY [95% prediction interval, 125.8-139.0 per 100 000 PY]) and 29.4% for female patients (ESR up to 88.9 per 100 000 PY [95% prediction interval, 84.3-93.5 per 100 000 PY]). CONCLUSIONS AND RELEVANCE This nationwide epidemiologic cohort study suggests that incidence rates of cSCC keep increasing, especially among female patients, and that the occurrence of multiple cSCCs per patient significantly adds to the current and future burden on dermatologic health care. Revision of skin cancer policies are needed to halt this increasing trend.

Background Machine learning algorithms achieve expert-level accuracy in skin lesion classification based on clinical images. However, it is not yet shown whether these algorithms could have high accuracy when embedded in a smartphone app, where image quality is lower and there is high variability in image taking scenarios by users. In the past, these applications were criticized due to lack of accuracy. Objective In this study, we evaluate the accuracy of the newest version of a smartphone application (SA) for risk assessment of skin lesions. Methods This SA uses a machine learning algorithm to compute a risk rating. The algorithm is trained on 131 873 images taken by 31 449 users in multiple countries between January 2016 and August 2018 and rated for risk by dermatologists. To evaluate the sensitivity of the algorithm, we use 285 histopathologically validated skin cancer cases (including 138 malignant melanomas), from two previously published clinical studies (195 cases) and from the SA user database (90 cases). We calculate the specificity on a separate set from the SA user database containing 6000 clinically validated benign cases. Results The algorithm scored a 95.1% (95% CI, 91.9-97.3%) sensitivity in detecting (pre)malignant conditions (93% for malignant melanoma and 97% for keratinocyte carcinomas and precursors). This level of sensitivity was achieved with a 78.3% (95% CI, 77.2-79.3%) specificity. Conclusions This SA provides a high sensitivity to detect skin cancer; however, there is still room for improvement in terms of specificity. Future studies are needed to assess the impact of this SA on the health systems and its users.

ObjectivesIn 2016, the SKINCATCH Trial, a clustered multi-centre randomised trial, was initiated to assess whether low-risk basal cell carcinomas (BCCs) can be treated by general practitioners (GPs) without loss of quality of care. The trial intervention consisted of a tailored 2-day educational course on skin cancer management. The aim of this process evaluation was to investigate GPs’ exposure to the intervention, implementation of the intervention and experiences with the intervention and trial.Research design and methodsData on exposure to the intervention, implementation and experiences were obtained at several points during the trial. Complementary quantitative components (ie, surveys, database analysis, medical record analysis) and qualitative components (ie, interviews and focus groups) were used. Quantitative data were analysed using descriptive statistics; qualitative data were summarised (barrier interviews) or audiorecorded, transcribed verbatim and thematically analysed using Atlas.Ti (focus groups).ResultsFollowing a 100% intervention exposure, results concerning the implementation of the trial showed that aside from the low inclusion rate of patients with low-risk BCCs (n=54), even less excisions of low-risk BCCs were performed (n=40). Although the intervention was experienced as highly positive, several barriers were mentioned regarding the trial including administrative challenges, lack of time and high workload of GPs, low volume of BCC patients and patients declining to participate or requesting a referral to a dermatologist.ConclusionsAlthough GPs’ participation in the highly valued training was optimal, several barriers may have contributed to the low inclusion and excision rate of low-risk BCCs. While some of the issues were trial-related, other barriers such as low patient-volume and patients requesting referrals are applicable outside the trial setting as well. This may question the feasibility of substitution of surgical excisions of low-risks BCCs from secondary to primary care in the current Dutch setting.Trial registration numberTrial NL5631 (NTR5746).

Background Immune checkpoint inhibitors (ICIs) have significantly improved the overall survival of patients with metastatic melanoma. It is unclear how the growing group of metastatic melanoma survivors resume their lives after treatment, and which needs they have regarding survivorship care (SSC). Objectives To gain an in-depth understanding of metastatic melanoma survivors’ experiences of resuming life after ICIs and their associated SSC needs. Methods A qualitative study was conducted among 20 patients with metastatic melanoma in whom ICIs had been discontinued after ongoing tumour response. One focus group (n = 9) was held, which was complemented by 11 individual interviews. Purposive sampling was used to select a variable sample in terms of sex, age, time since discontinuation of ICIs, and perceived impact of the disease. A topic guide was used to structure the (group) interviews, which were transcribed verbatim and analysed in a thematic content analysis, using several phases of coding. Results In resuming life after ICIs, the prognosis switch often caused mixed feelings among patients, mainly because of the uncertainty about the future. Demands and expectations from self and others, persistent complaints and new problems in different life domains often make it challenging to proceed with life as it was prior to metastatic cancer. Patients indicated they needed to find a new balance, which included learning to cope with uncertainty and a changed perspective on life and close relationships. In terms of SSC needs, patients particularly stressed the need for more tailored patient information, available at one location. In addition, they emphasized the need to know who to turn to in case of questions and indicated the need for psychosocial support, also for their close relatives. Conclusions Metastatic melanoma survivors face various challenges in resuming life after ICIs and are left with several unmet SSC needs. Efforts should be focused on offering psychosocial supportive care in addition to medical care, from diagnosis onwards, taking into account the patient’s close relatives. A single point of contact and personalized survivorship care plan (SCP) could be of added value in guiding them through the patient journey, which is, given its multidisciplinary nature, particularly important in melanoma care. What is already known about this topic? Since the introduction of immune checkpoint inhibitors (ICIs) the overall survival of patients with metastatic melanoma has improved significantly, leading to a growing group of melanoma survivors. Melanoma survivors may face various problems and challenges in resuming life after treatment, which may be associated with unmet survivorship care (SSC) needs. An in-depth understanding of their experiences with resuming life and the associated SSC needs is currently lacking. What does this study add? Metastatic melanoma survivors experience various challenges after immunotherapy, from the uncertain prognosis switch to the struggle of finding a new balance in life. Besides negative aspects, such as complaints in different life domains, the patient journey is often accompanied by positive outcomes, for example a changed perspective on life. They stress the need for tailored patient information and broader supportive care, also for their close relatives. What are the clinical implications of this work? In addition to medical care, efforts should be focused on offering psychosocial supportive care, including return-to-work issues, from diagnosis onwards, ideally taking into account the patient’s close relatives. To guide them through the patient journey, a single point of contact and a personalized survivorship care plan (SCP) could be of added value. The latter is particularly important in melanoma care, given its multidisciplinary nature.

Objective: To examine stage-specific trends in the incidence and survival of cutaneous melanoma in the Netherlands between 2003 and 2018, as well as the uptake of the sentinel lymph node biopsy (SLNB) and novel drugs during that period. Methods: Data were obtained from the nationwide population-based Netherlands Cancer Registry for all patients diagnosed with invasive primary cutaneous melanoma (n = 60,267). We presented age-standardized incidence rates, the proportion of patients with an SLNB, the proportion of patients who received a novel drug (for their primary diagnosis) and one- and five-year relative survival rates. Results: Between 2003 and 2018, the incidence rate increased from 10.9 to 23.9 for men and from 15.6 to 27.3 for women. This increase reflected the increasing incidence rate of patients with stage I and III. The proportion of patients with an SLNB increased from 23% to 64%. A reasonable increase was observed in the proportion of patients with a positive outcome (from 2% to 11%). For patients with stage IV, there was a shift from chemotherapy towards novel drugs as from 2013. The five-year relative survival rate increased from 81% to 92% for men and from 88% to 96% for women. This increase reflected the increasing five-year relative survival rate of patients with stage II, III, and IV. Conclusion: We observed an increase in incidence for patients with stage I and III and an improvement in survival for patients with stage II, III and IV. These trends can be partly explained by the introduction of the SLNB and the novel drugs.

Background: Mobile health (mHealth) consumer applications (apps) have been integrated with deep learning for skin cancer risk assessments. However, prospective validation of these apps is lacking. Objectives: To identify the diagnostic accuracy of an app integrated with a convolutional neural network for the detection of premalignant and malignant skin lesions. Methods: We performed a prospective multicenter diagnostic accuracy study of a CE-marked mHealth app from January 1 until August 31, 2020, among adult patients with at least one suspicious skin lesion. Skin lesions were assessed by the app on an iOS or Android device after clinical diagnosis and before obtaining histopathology. The app outcome was compared to the histopathological diagnosis, or if not available, the clinical diagnosis by a dermatologist. The primary outcome was the sensitivity and specificity of the app to detect premalignant and malignant skin lesions. Subgroup analyses were conducted for different smartphone types, the lesion’s origin, indication for dermatological consultation, and lesion location. Results: In total, 785 lesions, including 418 suspicious and 367 benign control lesions, among 372 patients (50.8% women) with a median age of 71 years were included. The app performed at an overall 86.9% (95% CI 82.3–90.7) sensitivity and 70.4% (95% CI 66.2–74.3) specificity. The sensitivity was significantly higher on the iOS device compared to the Android device (91.0 vs. 83.0%; p = 0.02). Specificity calculated on benign control lesions was significantly higher than suspicious skin lesions (80.1 vs. 45.5%; p < 0.001). Sensitivity was higher in skin fold areas compared to smooth skin areas (92.9 vs. 84.2%; p = 0.01), while the specificity was higher for lesions in smooth skin areas (72.0 vs. 56.6%; p = 0.02). Conclusion: The diagnostic accuracy of the mHealth app is far from perfect, but is potentially promising to empower patients to self-assess skin lesions before consulting a health care professional. An additional prospective validation study, particularly for suspicious pigmented skin lesions, is warranted. Furthermore, studies investigating mHealth implementation in the lay population are needed to demonstrate the impact on health care systems.

Summary Background Providing follow‐up to patients with low‐risk basal cell carcinoma (BCC) can be considered as low‐value care. However, dermatologists still provide substantial follow‐up care to this patient group, for reasons not well understood. Objectives To identify factors influencing current BCC follow‐up practices among dermatologists and suggested strategies to de‐adopt this low‐value care. In addition, views of patients regarding follow‐up care were explored. Methods A qualitative study was conducted consisting of 18 semistructured interviews with dermatologists and three focus groups with a total of 17 patients with low‐risk BCC who had received dermatological care. The interviews focused on current follow‐up practices, influencing factors and suggested strategies to de‐adopt the follow‐up care. The focus groups discussed preferred follow‐up schedules and providers, as well as the content of follow‐up. All (group) interviews were transcribed verbatim and analysed by two researchers using ATLAS.ti software. Results Factors influencing current follow‐up care practices among dermatologists included complying with patients’ preferences, lack of trust in general practitioners (GPs), financial incentives and force of habit. Patients reported varying needs regarding periodic follow‐up visits, preferred to be seen by a dermatologist and indicated a need for improved information provision. Suggested strategies by dermatologists to de‐adopt the low‐value care encompassed educating patients with improved information, educating GPs to increase trust of dermatologists, realizing appropriate financial reimbursement and informing dermatologists about the low value of care. Conclusions A mixture of factors appear to contribute to current follow‐up practices after low‐risk BCC. In order to de‐adopt this low‐value care, strategies should be aimed at dermatologists and GPs, and also patients., What's already known about this topic? Basal cell carcinoma (BCC) is the most common cancer in white individuals, and worldwide incidence rates are increasing.Providing follow‐up care to patients with low‐risk BCC is often not recommended in national guidelines and can be considered as low‐value care.Currently, dermatologists seem to provide more follow‐up care to patients with BCC than recommended, for reasons not well understood. What does this study add? Two main contributing factors reported by dermatologists to provide low‐value follow‐up care were complying with patient preferences and a lack of trust in general practitioners (GPs) to identify suspicious lesions.Patients consulting dermatologists also expressed a lack of trust in GPs, and whereas some of the patients with BCC preferred receiving periodic follow‐up care, other patients indicated finding follow‐up care unnecessary.Several strategies for de‐adoption were suggested, of which educating patients was identified as potentially effective by dermatologists and patients. What are the clinical implications of this work? Educating patients with improved disease information and instructions on self‐examination may reduce the need for follow‐up care among patients, and, in turn, result in the reduction of follow‐up visits provided by dermatologists.Educating GPs in skin cancer care, as well as realizing appropriate reimbursement, may also be effective in de‐adopting low‐value follow‐up care. https://doi.org/10.1111/bjd.17949 available online https://www.bjdonline.com/article/Factors-influencing-current-low-value-follow-up-care-after-basal-cell-carcinoma-and-suggested-strategies-for-de-adoption-a-qualitative-study/

In 2012 vismodegib (Erivedge), an oral hedgehog pathway inhibitor, was approved by the US Food and Drug Administration for the treatment of locally advanced or metastatic basal cell carcinoma (BCC).1 Marketing authorization, however, does not account for long-term obstacles as seen in daily clinical practice. For example, one dilemma is the positioning of vismodegib in the treatment of giant, locally advanced BCC, especially regarding its position as part of a palliative and curative treatment. Another issue is how to deal with tumor resistance to vismodegib in giant, locally advanced BCC in a specific group of patients who avoid health care, often because of fear of surgery or radiotherapy. Gaining insight in the treatment process of these patients is therefore urgently needed to improve decision making in these complex cases. We report on 3 patients treated with vismodegib for giant, locally advanced BCC and 1 patient treated for a metastasized BCC to illustrate and discuss the possibilities and limitations of vismodegib treatment in clinical practice.

Summary Background Despite the widespread use of Mohs micrographic surgery (MMS) for periocular basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) – together called keratinocyte carcinoma (KC) – follow‐up data regarding recurrences are limited. Objectives To investigate the recurrence rate for periocular KCs after MMS and to describe our experience with interdisciplinary collaborations. Methods Patients with periocular KCs treated with MMS between 2006 and 2016 in a tertiary MMS referral hospital were included in this retrospective cohort study. Descriptive statistics were used to describe the MMS procedure‐related characteristics. Using follow‐up data from the electronic patient records and linkage with the Dutch nationwide network and registry of histopathology and cytopathology on 30 June 2017, the recurrence rate was evaluated and calculated using a cumulative incidence curve. Results In total, 683 (93·7%) periocular BCCs and 46 (6·3%) SCCs were treated with MMS. Three‐quarters (n = 549) were primary tumours and the majority were located at the medial canthus or lower eyelid (n = 649, 89·0%). In 505 MMS procedures (69·3%) an oculoplastic surgeon participated, and in 63 patients (8·6%) a plastic surgeon performed the reconstruction. After a median follow‐up of 46 months the recurrence rate was 3·0%, based on 22 recurrences (20 BCCs and two SCCs). Conclusions MMS is an excellent treatment option for periocular KCs, with a low recurrence rate. Due to this specific anatomical location an interdisciplinary approach should pre‐eminently be considered., What's already known about this topic? Mohs micrographic surgery (MMS) is a widespread treatment for periocular basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) because of the expected high cure rate, while preserving healthy tissue.Follow‐up data on the risk of recurrence after periocular MMS are limited. What does this study add? This retrospective cohort study demonstrates that with a recurrence rate of 3·0% after almost 4 years, MMS has proven to be an excellent surgical treatment option for periocular BCC and SCC.We advise a low threshold for interdisciplinary collaborations, especially in case of recurrent BCCs, BCCs localized in the medial canthus and aggressive BCCs. Linked Comment: https://doi.org/10.1111/bjd.17736. https://www.bjdonline.com/article/

_Background_ The increasing incidence of actinic keratosis (AK) is causing a large burden on healthcare systems. The current management of patients with AK seems to vary within and between primary and secondary care; however, an in-depth understanding of healthcare providers’ management of AK is currently lacking. Objectives To gain insight into the management of AK by exploring the underlying motives of current practices among general practitioners (GPs) and dermatologists in the Netherlands. _Methods_ A qualitative study was conducted consisting of semistructured individual interviews with 22 GPs and 18 dermatologists focusing on the underlying motives regarding AK management. A predefined topic list was used. All interviews were audiotaped, transcribed verbatim and inductively analysed by two researchers drawing on elements of grounded theory. _Results_ GPs reported conducting limited proactive clinical assessments of cutaneous photodamage due to a perceived lack of value, varying in their method of diagnosing AK. They mainly applied cryotherapy or referred to secondary care due to lack of experience, varying in their applications and providing mostly patient-driven follow-up care. They also reported a great need for guidelines due to a lack of knowledge of AK management. Dermatologists indicated pursuing proactive clinical assessments of cutaneous photodamage and the goal of providing guideline-driven AK care. However, patient preferences still largely influence both treatment choices and follow-up regimens. Furthermore, dermatologists reported the need to improve AK and skin cancer management in primary care. _Conclusions_ For AK care to become more standardized and uniform in Dutch primary care, the implementation of guidelines and (continuing) education are needed to address the commonly reported barriers of lack of value, experience and knowledge among GPs. For efficient use of care among dermatologists, shared decision-making tools along with adequate (framing of) patient information may be useful.

Background: Despite the high and rising incidence rate of keratinocyte cancer (KC) and the importance of incorporating patient values into evidence-based care, few studies have focused on the perspectives of patients with KC. Objectives: To identify the needs and preferences of patients with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) regarding care. Methods: A qualitative study was conducted consisting of three focus groups with patients with BCC and three focus groups with patients with SCC. In total 42 patients participated. In each focus group, the patients’ needs and preferences regarding treatment and follow-up were discussed, using a predefined topic list. All sessions were transcribed verbatim and analysed by two researchers. Results: The following needs and preferences were identified: (i) the need to receive all relevant, tailored information; (ii) a physician who takes you seriously and communicates well; (iii) a short waiting period and the best treatment with direct results; (iv) to be seen by the same physician; a preference for a dermatologist during (v) treatment and (vi) follow-up; (vii) a general need for structured follow-up care and (viii) a full-body skin examination during follow-up. Patients with BCC additionally expressed the need for openness and transparency and wanting to participate in shared decision making. Conclusions: It is advocated to organize skin cancer care that is better tailored to the needs of patients with KC, providing patient-centred care. This should include investing in the patient–physician relationship, and personalizing the type and form of information and the follow-up schedules. Adding the patient's perspective to current guidelines could facilitate this process.

IMPORTANCE: Patients with cutaneous squamous cell carcinoma (SCC) of the head and neck may develop lymph node metastasis; therefore, additional workup of the regional lymph nodes in these patients should be considered. However, there is uncertainty regarding the value of baseline ultrasonographic imaging in addition to clinical examination for the detection of metastasis.OBJECTIVE: To assess the diagnostic accuracy of clinical examination and baseline ultrasonography for the detection of metastasis among patients with high-risk cutaneous SCC of the head and neck and to assess the accuracy of ultrasonography when baseline clinical examination produces negative results.DESIGN, SETTING, AND PARTICIPANTS: This diagnostic study was conducted among a retrospective cohort of 233 patients with 246 high-risk cutaneous SCC tumors of the head and neck. The study included all patients with high-risk cutaneous SCC of the head and neck who received clinical examination and baseline ultrasonographic imaging of their lymph nodes at the Erasmus Medical Center Cancer Institute, a tertiary referral hospital for patients with skin cancer in Rotterdam, the Netherlands, between January 1, 2015, and December 31, 2017. Data were analyzed from October 13, 2020, to September 29, 2021.MAIN OUTCOMES AND MEASURES: Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Fine-needle aspiration cytologic biopsy and 6 months of follow-up per patient were used as the reference standards.RESULTS: Among 233 patients (176 men [75.5%]; median age, 79.1 years [IQR, 71.5-83.7 years]; data on race and ethnicity were not collected) with 246 high-risk cutaneous SCC tumors of the head and neck, 20 metastases were cytologically confirmed at baseline, and 2 metastases were detected during 6 months of follow-up, yielding a 9% metastasis rate. The sensitivity of clinical examination was 50% (95% CI, 28%-72%), and the specificity was 96% (95% CI, 93%-98%). The PPV and NPV were 55% (95% CI, 36%-72%) and 95% (95% CI, 93%-97%), respectively. In the total cohort, ultrasonography had a sensitivity of 91% (95% CI, 71%-99%) and a specificity of 78% (95% CI, 72%-83%), with a PPV of 29% (95% CI, 23%-35%) and an NPV of 99% (95% CI, 96%-100%). In the group of patients with negative results at baseline clinical examination, 9 of 11 metastases were detected by ultrasonography, with 82% sensitivity (95% CI, 48%-98%); specificity was 79% (95% CI, 73%-84%), PPV was 17% (95% CI, 12%-23%), and NPV was 99% (95% CI, 96%-100%).CONCLUSIONS AND RELEVANCE: In this diagnostic study, among a cohort of patients with high-risk cutaneous SCC of the head and neck, baseline ultrasonography was more sensitive than clinical examination alone for the detection of lymph node metastasis. In the setting of a negative result at baseline clinical examination, ultrasonography had high sensitivity for detecting nodal metastases, but this sensitivity should be evaluated against the high rate of false-positive findings.