Carolina Nätterdahl -Institutionen för kliniska vetenskaper, Lund

Title: Improving Skin Cancer Diagnosis and Management in Teledermoscopy and Mohs Surgery

Main supervisor: Åsa Ingvar, MD, PhD

Reviewers: Magnus Falk, MD, PhD and Katrine Karmisholt, MD, PhD

Abstract

Background

The incidence of skin cancer is increasing worldwide. This poses a burden on the already strained healthcare system due to a rising demand for skin lesion assessments. Hence, there is a need to streamline the referral, triage and management of skin lesions.

Research questions

Q1) What risk factors are associated with complicated Mohs micrographic surgery (defined as ≥3 surgical stages)?

Q2) What is the diagnostic accuracy of single reader evaluations in teledermoscopic assessments and when should an additional intervention be employed? 

Q3) Can artificial intelligence-generated diagnostic support improve the accuracy and efficiency of diagnosing and managing skin lesions in teledermoscopy?

Q4) Can artificial intelligence-based image analysis improve the accuracy of basal cell carcinoma subclassification in teledermoscopy?

Preliminary results

Study 1 (published): Retrospective cohort study based on data collected from 612 patients that underwent Mohs micrographic surgery (MMS) for basal cell carcinoma at Skåne University Hospital, Lund, between 2009 and 2020. In adjusted multivariate analyses, age (odds ratio (OR) 1.02; confidence interval (CI) 95% 1.00–1.04), previous cryotherapy (OR 2.3; CI 95% 1.1–4.8), and >1 previous surgery (OR 3.4; CI 95% 1.5–7.7) were significantly associated with risk of complicated MMS (defined as ≥3 surgical stages).

Study 2 (published): This retrospective cohort study involved 1997 TDS referrals sent from general practitioners to dermatologists in Stockholm, Sweden, selected based on dermoscopic diagnoses. Single reader evaluations achieved a benign-malignant sensitivity and specificity of 84% (95% CI: 81-87% and 82-86%, respectively). The risk of misdiagnosis correlated strongly with assessors’ decreasing diagnostic confidence. 

Study 3: Data has been collected and is currently being analyzed.

Study 4: The study design is being finalized. 

Significance

Understanding the risk factors associated with complicated Mohs surgery is crucial to optimize preoperative planning. This is important not only to conserve the limited resources available for MMS but also for providing patients with accurate expectations regarding the procedure and its outcome. In teledermoscopy, diagnostic accuracy strongly correlates with assessors' confidence in their diagnosis.When diagnostic confidence is perceived as moderate or low, additional interventions, such as double reader evaluations, should be employed to maintain high-quality care.

Published studies

1. Nätterdahl C, Kappelin J, Persson B, Lundqvist K, Ahnlide I, Saleh K, Ingvar Å. Risk factors for complicated Mohs surgery in the South Sweden Mohs Cohort. J Eur Acad Dermatol Venereol. 2022 Jul;36(7):1113-1117. doi: 10.1111/jdv.18124. Epub 2022 Apr 12. PMID: 35366359; PMCID: PMC9324151.
2. Nätterdahl C, Kristensson H, Persson B, Lapins J, Ivert LU, Radros N, Schultz K, Sand C, Lundgren S, Pahlow Mose A, Ingvar J, Dizdarevic A, Nielsen K, Ingvar Å. When Are Single Reader Evaluations Insufficient in Teledermoscopic Assessments? Analyses of a Retrospective Cohort Study. Telemed J E Health. 2025 Jan 27. doi: 10.1089/tmj.2024.0532.