One set to collect them all? The development of a core domain set for medium‐to‐giant congenital melanocytic naevi
Authors: M.V. Heppt, T. Steeb, C. Berking
Journal: British Journal of Dermatology (2021)

Linked Article: Oei et al. Br J Dermatol 2021; 185:371–379. Large, giant or multiple congenital melanocytic naevi (CMN) are associated with an increased risk of developing melanoma or symptomatic neurocutaneous melanocytosis.1, 2 In addition to close clinical observation, treatment options comprise laser ablation, curettage or surgery, with which complete excision is often difficult to achieve. While surgical removal improves the cosmetic appearance,3-5 the risk of malignant transformation cannot be completely eliminated, as melanomas may arise in deeper dermal or extracutaneous sites such as the central nervous system. Treatment recommendations are still controversial due to lack of evidence-based guidelines and due to the heterogeneity of outcome assessment in patient care and trial reporting. To this end, it is increasingly recognized that harmonization of outcomes has widely been neglected. To promote the standardization of outcomes and their use in dermatology, the Core Outcome Measures in Effectiveness Trials (COMET) and the Cochrane Skin – Core Outcome Set Initiative (CS-COUSIN) were established.6 Currently, 63 dermatology-related projects are registered, including studies on 34 different skin conditions.7 In this issue of the BJD, Oei and colleagues present the development of an internationally and interdisciplinary-derived core domain set (CDS) for the care and research setting of CMN as a first step towards standardized reporting.8 A CDS defines the ‘what to measure’ aspects of a given condition but does not yet specifically tell how to assess them. Thus, the CDS presented by the Outcomes for Congenital Melanocytic Nevi (OCOMEN) project represents an initial framework for the future development of a core outcome set. Importantly, the study distinguished the CDS for domains that should be addressed for either routine care or the research setting. The authors strictly adhered to the guidelines of the COMET and CS-COUSIN initiatives to identify all relevant outcomes reported in the literature through a systematic review.9 This step was followed by a qualitative appraisal deploying focus group studies with patient representatives to also incorporate relevant patient-reported outcomes. After grouping of the outcomes, an e-Delphi survey was performed by an online consensus meeting to narrow down the list of possible candidates to a set of six domains. Thus, the authors ensured that each relevant domain and the views of all relevant stakeholder groups were included. Consensus was reached on six domains, four of which applied to both care and research: ‘quality of life’, ‘neoplasms’, ‘nervous system’ and ‘anatomy of skin’. In contrast, the domains ‘adverse events’ and ‘pathology’ were consented specifically for care and research, respectively. The domains ‘neoplasm’ and ‘nervous system’ are critical to reflect the risk of melanoma development and neurocutaneous melanocytosis, while ‘quality of life’ is an important global indicator for the subjective wellbeing of patients with medium-to-giant CMN. It remains to be determined how and into which domains other important outcomes such as cosmesis and efficacy of treatment can be categorized within this CDS. Nevertheless, the proposal of the CDS is an important step on the road towards a harmonization of outcomes for medium-to-giant CMN. It will enable better comparisons across distinct interventions, facilitate evidence synthesis and, ultimately, improve patient care. Markus V Heppt: Conceptualization (equal); Visualization (equal); Writing-original draft (equal); Writing-review & editing (equal). Theresa Steeb: Conceptualization (equal); Investigation (equal); Methodology (equal); Validation (equal); Writing-original draft (equal); Writing-review & editing (equal). Carola Berking: Conceptualization (equal); Supervision (equal); Validation (equal); Writing-original draft (equal); Writing-review & editing (equal). Open Access funding enabled and organized by Projekt DEAL.