Cumulative incidence and risk factors for cutaneous squamous cell carcinoma metastases in organ transplant recipients: The Skin Care in Organ Transplant Patients in Europe-International Transplant Skin Cancer Collaborative metastases study, a prospective multicenter study.

INTRODUCTION: Solid organ transplant recipients (SOTRs) are believed to have an increased risk of metastatic cutaneous squamous cell carcinoma (cSCC), but reliable data are lacking regarding the precise incidence and associated risk factors. METHODS: In a prospective cohort study, including 19 specialist dermatology outpatient clinics in 15 countries, patient and tumor characteristics were collected using standardized questionnaires when SOTRs presented with a new cSCC. After a minimum of 2 years of follow-up, relevant data for all SOTRs were collected. Cumulative incidence of metastases was calculated by the Aalen-Johansen estimator. Fine and Gray models were used to assess multiple risk factors for metastases. RESULTS: Of 514 SOTRs who presented with 623 primary cSCCs, metastases developed in 37 with a 2-year patient-based cumulative incidence of 6.2%. Risk factors for metastases included location in the head and neck area, local recurrence, size > 2 cm, clinical ulceration, poor differentiation grade, perineural invasion, and deep invasion. A high-stage tumor that is also ulcerated showed the highest risk of metastasis, with a 2-year cumulative incidence of 46.2% (31.9%-68.4%). CONCLUSIONS: SOTRs have a high risk of cSCC metastases and well-established clinical and histologic risk factors have been confirmed. High-stage, ulcerated cSCCs have the highest risk of metastasis.

Defining the Validity of Skin Self-Examination as a Screening Test for the Detection of Suspicious Pigmented Lesions: A Meta-Analysis of Diagnostic Test Accuracy.

BACKGROUND: Skin self-examination (SSE) is widely promoted for the detection of suspicious pigmented lesions. However, determining screening accuracy is essential to appraising the usefulness of SSE. OBJECTIVES: The aim of this work was to pool estimates from studies of SSE diagnostic accuracy in the detection of suspicious pigmented lesions. METHODS: This study was registered with PROSPERO (CRD42021246356) and conducted in accordance with PRISMA-DTA guidelines. A systematic search of Medline (PubMed) EMBASE, CINAHL, and The Cochrane Library was conducted to identify relevant studies. We included studies that examined the accuracy of SSE, either whole-body or site-specific, for detecting change in individual pigmented lesions or detecting an atypical naevus. A univariate random-effects model, based on logit-transformed data, was used to calculate a summary diagnostic odds ratio (DOR) as well as pooled sensitivity and specificity. Cochran's Q test and the I2 statistic were calculated to assess heterogeneity. A proportional hazards model was used to calculate the area under the curve (AUC) and plot the summary receiver operator characteristic curve. We used the Quality Assessment of Diagnostic Accuracy Studies-2 tool to grade study quality. RESULTS: We identified 757 studies, of which 3 met inclusion criteria for quantitative synthesis. The pooled sensitivity and specificity based on 553 included participants was 59 and 82%, respectively. The summary DOR was 5.88 and the AUC was 0.71. There were some concerns regarding risk of bias in all 3 studies. CONCLUSIONS: SSE can detect suspicious pigmented lesions with reasonable sensitivity and relatively high specificity, with the AUC suggesting acceptable discriminatory ability.

Reproducible Naevus Counts Using 3D Total Body Photography and Convolutional Neural Networks.

BACKGROUND: The number of naevi on a person is the strongest risk factor for melanoma; however, naevus counting is highly variable due to lack of consistent methodology and lack of inter-rater agreement. Machine learning has been shown to be a valuable tool for image classification in dermatology. OBJECTIVES: To test whether automated, reproducible naevus counts are possible through the combination of convolutional neural networks (CNN) and three-dimensional (3D) total body imaging. METHODS: Total body images from a study of naevi in the general population were used for the training (82 subjects, 57,742 lesions) and testing (10 subjects; 4,868 lesions) datasets for the development of a CNN. Lesions were labelled as naevi, or not ("non-naevi"), by a senior dermatologist as the gold standard. Performance of the CNN was assessed using sensitivity, specificity, and Cohen's kappa, and evaluated at the lesion level and person level. RESULTS: Lesion-level analysis comparing the automated counts to the gold standard showed a sensitivity and specificity of 79% (76-83%) and 91% (90-92%), respectively, for lesions ≥2 mm, and 84% (75-91%) and 91% (88-94%) for lesions ≥5 mm. Cohen's kappa was 0.56 (0.53-0.59) indicating moderate agreement for naevi ≥2 mm, and substantial agreement (0.72, 0.63-0.80) for naevi ≥5 mm. For the 10 individuals in the test set, person-level agreement was assessed as categories with 70% agreement between the automated and gold standard counts. Agreement was lower in subjects with numerous seborrhoeic keratoses. CONCLUSION: Automated naevus counts with reasonable agreement to those of an expert clinician are possible through the combination of 3D total body photography and CNNs. Such an algorithm may provide a faster, reproducible method over the traditional in person total body naevus counts.

Omega-3 fatty acid intake and decreased risk of skin cancer in organ transplant recipients.

PURPOSE: Organ transplant recipients have over 100-fold higher risk of developing skin cancer than the general population and are in need of further preventive strategies. We assessed the possible preventive effects of omega-3 polyunsaturated fatty acid (PUFA) intake from food on the two main skin cancers, squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in kidney and liver transplant recipients. METHODS: Adult kidney or liver transplant recipients transplanted for at least 1 year and at high risk of skin cancer were recruited from the main transplant hospital in Queensland, 2012-2014 and followed until mid-2016. We estimated their dietary total long-chain omega-3 PUFAs and α-linolenic acid intakes at baseline using a food frequency questionnaire and ranked PUFA intakes as low, medium, or high. Relative risks (RRsadj) of skin cancer adjusted for confounding factors with 95% confidence intervals (CIs) were calculated. RESULTS: There were 449 transplant recipients (mean age, 55 years; 286 (64%) male). During follow-up, 149 (33%) patients developed SCC (median 2/person; range 1-40) and 134 (30%), BCC. Transplant recipients with high total long-chain omega-3 PUFA compared with low intakes showed substantially reduced SCC tumour risk (RRadj 0.33, 95% CI 0.18-0.60), and those with high α-linolenic acid intakes experienced significantly fewer BCCs (RRadj 0.40, 95% CI 0.22-0.74). No other significant associations were seen. CONCLUSION: Among organ transplant recipients, relatively high intakes of long-chain omega-3 PUFAs and of α-linolenic acid may reduce risks of SCC and BCC, respectively.

Prevalence of Perineural Invasion in keratinocyte cancer in the general population and among organ transplant recipients.

BACKGROUND/OBJECTIVES: Basal cell carcinomas (BCCs) and cutaneous squamous cell carcinomas (SCCs) are the most commonly encountered cancers in fair-skinned populations worldwide. Perineural invasion is associated with worse outcomes for patients with BCC or SCC. Estimates of perineural invasion prevalence range widely, likely reflecting non-representative patient samples. We sought to determine the prevalence of perineural invasion in BCC and SCC in the general population, as well as among cancers arising in solid organ transplant recipients. METHODS: We retrospectively analysed histopathology reports of BCC and SCC from patients enrolled in the QSkin Study (a population-based cohort of 43 794 Queensland residents recruited 2010-2011) and the Skin Tumours in Allograft Recipients (STAR) study (a cohort of 509 high-risk kidney or liver transplant recipients at the Princess Alexandra Hospital, Brisbane, recruited 2012-2014.) We estimated the prevalence of perineural invasion (and 95% confidence interval) in BCC and SCC, respectively, and identified clinical factors associated with perineural invasion. RESULTS: In QSkin, we observed 35 instances of perineural invasion in 9850 histopathologically confirmed BCCs (0.36%) and 9 instances of perineural invasion in 3982 confirmed SCC (0.23%) lesions. In the STAR cohort, we identified 4 lesions with perineural invasion in 692 BCCs (0.58%) and 16 reports of perineural invasion in 875 SCC lesions (1.9%). CONCLUSIONS: These data suggest that the overall prevalence of perineural invasion in keratinocyte cancer is low, although perineural invasion prevalence may be slightly higher among organ transplant recipients when compared to the general population.

Unscheduled Visits of Patients with Familial Melanoma to a Pigmented Lesion Clinic: Evaluation of Patients' Characteristics and Suspicious Lesions.

Approximately 10% of all melanomas occur in subjects with a family history of melanoma. This retrospective follow-up study investigated the characteristics of patients with familial melanoma who made unscheduled visits to our pigmented lesions clinic, and the diagnosis of excised lesions. A total of 110 (9%) out of 1,267 patients made at least one unscheduled visit between May 2011 and February 2016. Histopathology was taken from 59 patients. Thirty-four naevi, 7 melanomas and 3 basal cell carcinomas were detected. All patients with melanoma were CDKN2A carriers and all melanomas were discovered at a very early stage. In this patient population it appears to be safe to limit visits to once or twice yearly, provided patients are easily able to make an unscheduled extra visit if they have a worrisome lesion. We recommend supporting patients' self-reliance by stimulating them to carry out self-examination of their skin.

Metastasis Risk of Cutaneous Squamous Cell Carcinoma in Organ Transplant Recipients and Immunocompetent Patients.

Organ transplant recipients (OTRs) have a high incidence of cutaneous squamous cell carcinoma (cSCC), and immunosuppression has been reported to be an important risk factor for metastasis. The aim of this study was to identify the metastasis risk over a 10-year period for 593 patients with cSCC, of whom 134 were OTR and 459 were immunocompetent. Metastasis incidence rate was 1,046 (95% confidence interval (95% CI) 524-2,096) per 100,000 person years in OTR and 656 (95% CI; 388-1,107) in immunocompetent patients, yielding an incidence rate ratio of 1.6 (95% CI 0.67-3.81). In OTRs head/neck location, older age at transplantation and older age at diagnosis of first cSCC were associated with metastatic risk, and 7 out of 8 metastasized tumours were smaller than 2 cm. In immunocompetent patients tumour size and tumour depth were associated with metastasis. In conclusion, we were not able to demonstrate an increased incidence rate of metastasis in OTRs compared with immunocompetent patients. However, OTRs and immunocompetent patients differed with regard to risk factors for metastasis.