{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T21:27:46Z","timestamp":1789680466469,"version":"4.0.1"},"reference-count":20,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2024,7,3]],"date-time":"2024-07-03T00:00:00Z","timestamp":1719964800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004339","name":"Sanofi","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100004339","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Acad Dermatol Venereol"],"published-print":{"date-parts":[[2025,3]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>There is currently no staging system for cutaneous squamous cell carcinoma (cSCC) that is adapted to decision\u2010making and universally used. Experts have unconscious ability to simplify the heterogeneity of clinical situations into a few relevant groups to drive their therapeutic decisions. Therefore, we have used unsupervised clustering of real cases by experts to generate an operational classification of cSCCs, an approach that was successful for basal cell carcinomas.<\/jats:p><\/jats:sec><jats:sec><jats:title>Objectives<\/jats:title><jats:p>To generate a consensual and operational classification of cSCCs.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Unsupervised independent clustering of 248 cases of cSCCs considered difficult\u2010to\u2010treat. Eighteen international experts from different specialties classified these cases into what they considered homogeneous clusters useful for management, each with freedom regarding clustering criteria. Convergences and divergences between clustering were analysed using a similarity matrix, the K\u2010mean approach and the average silhouette method. Mathematical modelling was used to look for the best consensual clustering. The operability of the derived classification was validated on 23 new practitioners.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Despite the high heterogeneity of the clinical cases, a mathematical consensus was observed. It was best represented by a partition into five clusters, which appeared a posteriori to describe different clinical scenarios. Applicability of this classification was shown by a good concordance (94%) in the allocation of cases between the new practitioners and the 18 experts. An additional group of easy\u2010to\u2010treat cSCC was included, resulting in a six\u2010group final classification: easy\u2010to\u2010treat\/complex to treat due to tumour and\/or patient characteristics\/multiple\/locally advanced\/regional disease\/visceral metastases.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Given the methodology based on the convergence of unguided intuitive clustering of cases by experts, this new classification is relevant for clinical practice. It does not compete with staging systems, but they may complement each other, whether the objective is to select the best therapeutic approach in tumour boards or to design homogeneous groups for trials.<\/jats:p><\/jats:sec>","DOI":"10.1111\/jdv.20209","type":"journal-article","created":{"date-parts":[[2024,7,4]],"date-time":"2024-07-04T02:50:48Z","timestamp":1720061448000},"page":"612-621","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Operational classification of cutaneous squamous cell carcinomas based on unsupervised clustering of real cases by experts"],"prefix":"10.1111","volume":"39","author":[{"given":"C.","family":"Gaudy\u2010Marqueste","sequence":"first","affiliation":[{"name":"Dermatology and Skin Cancer Department Aix\u2010Marseille University, APHM  Marseille France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. J.","family":"Grob","sequence":"additional","affiliation":[{"name":"Dermatology and Skin Cancer Department Aix\u2010Marseille University, APHM  Marseille France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8530-780X","authenticated-orcid":false,"given":"C.","family":"Garbe","sequence":"additional","affiliation":[{"name":"Centre for Dermatooncology, Department of Dermatology Eberhard Karls University  Tuebingen Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P. A.","family":"Ascierto","sequence":"additional","affiliation":[{"name":"Department of Skin Cancer, Cancer Immunotherapy and Development Therapeutics Istituto Nazionale Tumori IRCCS Fondazione Pascale  Naples Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Arron","sequence":"additional","affiliation":[{"name":"Peninsula Dermatology  Burlingame California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N.","family":"Basset\u2010Seguin","sequence":"additional","affiliation":[{"name":"Dermatology Department Saint\u2010Louis Hospital  Paris France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. S.","family":"Bohne","sequence":"additional","affiliation":[{"name":"Department of Dermatology University Hospital Schleswig\u2010Holstein (UKSH), Campus Kiel  Kiel Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-5174-9932","authenticated-orcid":false,"given":"C.","family":"Lenoir","sequence":"additional","affiliation":[{"name":"Department of Dermatology, H\u00f4pitaux Universitaires de Bruxelles Universit\u00e9 Libre de Bruxelles  Brussels Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2279-6906","authenticated-orcid":false,"given":"R.","family":"Dummer","sequence":"additional","affiliation":[{"name":"Skin Cancer Centre at University Hospital Zurich  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7249-2556","authenticated-orcid":false,"given":"M. C.","family":"Fargnoli","sequence":"additional","affiliation":[{"name":"Dermatology, Department of Biotechnological and Applied Clinical Sciences University of L'Aquila  L'Aquila Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Guminski","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology Royan North Shore Hospital  Sydney New South Wales Australia"},{"name":"Northern Clinical School University of Sydney  Sydney New South Wales Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Hauschild","sequence":"additional","affiliation":[{"name":"Department of Dermatology University Hospital Schleswig\u2010Holstein (UKSH), Campus Kiel  Kiel Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1614-694X","authenticated-orcid":false,"given":"R.","family":"Kaufmann","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Venereology and Allergology Frankfurt University Hospital  Frankfurt Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7193-0964","authenticated-orcid":false,"given":"A.","family":"Lallas","sequence":"additional","affiliation":[{"name":"First Department of Dermatology, School of Medicine, Faculty of Health Sciences Aristotle University  Thessaloniki Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"V.","family":"del Marmol","sequence":"additional","affiliation":[{"name":"Department of Dermatology University Hospital Erasme, Universite'Libre de Bruxelles  Brussels Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Migden","sequence":"additional","affiliation":[{"name":"Departments of Dermatology and Head and Neck Surgery UT MD Anderson Cancer Center  Houston Texas USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Penicaud","sequence":"additional","affiliation":[{"name":"Department of Oto\u2010Rhino\u2010Laryngology and Head and Neck Surgery APHM, La Conception University Hospital  Marseille France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Rembielak","sequence":"additional","affiliation":[{"name":"Department of Clinical Oncology The Christie NHS Foundation Trust  Manchester UK"},{"name":"Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health The University of Manchester  Manchester UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Stratigos","sequence":"additional","affiliation":[{"name":"1st Department of Dermatology\u2010Venereology Andreas Sygros Hospital, National and Kapodistrian University of Athens  Athens Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"Tagliaferri","sequence":"additional","affiliation":[{"name":"Dipartimento di Diagnostica per Immagini e Radioterapia Oncologica Fondazione Policlinico Universitario A. Gemelli\u2010IRCCS  Rome Italy"},{"name":"Universit\u00e0 Cattolica del Sacro Cuore  Rome Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"I.","family":"Zalaudek","sequence":"additional","affiliation":[{"name":"Dermatology Clinic, Maggiore Hospital University of Trieste  Trieste Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Arance","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology and IDIBAPS Hospital Cl\u00ednic  Barcelona Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Badinand","sequence":"additional","affiliation":[{"name":"Department of Radiotherapy Oncology Hospital La Timone  Marseille France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0135-0224","authenticated-orcid":false,"given":"P.","family":"Bossi","sequence":"additional","affiliation":[{"name":"Department of Biomedical Sciences Humanitas University  Milan Italy"},{"name":"IRCCS Humanitas Research Hospital  Milan Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3683-9583","authenticated-orcid":false,"given":"A.","family":"Challapalli","sequence":"additional","affiliation":[{"name":"Department of Oncology, Bristol Haematology and Oncology Centre UHBW  Bristol UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Clementi","sequence":"additional","affiliation":[{"name":"Department of Biotechnological and Applied Clinical Sciences University of L'Aquila  L'Aquila Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Di Stefani","sequence":"additional","affiliation":[{"name":"UOC Dermatologia, Dipartimento di Scienze Mediche e Chirurgiche Addominali ed Endocrino Metaboliche Fondazione Policlinico Universitario A. Gemelli \u2013 IRCCS  Rome Italy"},{"name":"Dermatologia, Dipartimento di Medicina e Chirurgia Traslazionale Universit\u00e0 Cattolica del Sacro Cuore  Rome Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C.","family":"Ferr\u00e1ndiz\u2010Pulido","sequence":"additional","affiliation":[{"name":"Department of Dermatology University Hospital Vall d'Hebron  Barcelona Spain"},{"name":"Facultad de Medicina Universitat Aut\u00f2noma de Barcelona  Bellaterra Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5492-3033","authenticated-orcid":false,"given":"R.","family":"Giuffrida","sequence":"additional","affiliation":[{"name":"Department of Clinical and Experimental Medicine Dermatology \u2013 University of Messina  Messina Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G. L.","family":"Gravina","sequence":"additional","affiliation":[{"name":"Department of Biotechnological and Applied Clinical Sciences, Radiotherapy and Radiobiology Unit University of L'Aquila  L'Aquila Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"Ha","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology Head and Neck Surgery University of California San Francisco  San Francisco California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"Heinzerling","sequence":"additional","affiliation":[{"name":"Department of Dermatology and Allergy Ludwig\u2010Maximilian University Hospital, LMU  Munich Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Mallet","sequence":"additional","affiliation":[{"name":"Dermatology and Skin Cancer Department Aix\u2010Marseille University, APHM  Marseille France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Paradisi","sequence":"additional","affiliation":[{"name":"UOC Dermatologia, Dipartimento di Scienze Mediche e Chirurgiche Addominali ed Endocrino Metaboliche Fondazione Policlinico Universitario A. Gemelli \u2013 IRCCS  Rome Italy"},{"name":"Dermatologia, Dipartimento di Medicina e Chirurgia Traslazionale Universit\u00e0 Cattolica del Sacro Cuore  Rome Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"Mohr","sequence":"additional","affiliation":[{"name":"Department of Dermatology Elbe\u2010Kliniken Buxtehude  Buxtehude Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1734-7310","authenticated-orcid":false,"given":"A.","family":"Piccerillo","sequence":"additional","affiliation":[{"name":"UOC Dermatologia, Dipartimento di Scienze Mediche e Chirurgiche Addominali ed Endocrino Metaboliche Fondazione Policlinico Universitario A. Gemelli \u2013 IRCCS  Rome Italy"},{"name":"Dermatologia, Dipartimento di Medicina e Chirurgia Traslazionale Universit\u00e0 Cattolica del Sacro Cuore  Rome Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Rutkowski","sequence":"additional","affiliation":[{"name":"Department of Dermatology Manchester Foundation Trust  Manchester UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"Saiag","sequence":"additional","affiliation":[{"name":"Department of General and Oncologic Dermatology, Ambroise Par\u00e9 Hospital, APHP, &amp; EA 4340 \u201cBiomarkers in Cancerology and Hemato\u2010Oncology\u201d UVSQ, Universit\u00e9 Paris\u2010Saclay  Boulogne\u2010Billancourt France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"Sollena","sequence":"additional","affiliation":[{"name":"UOC Dermatologia, Dipartimento di Scienze Mediche e Chirurgiche Addominali ed Endocrino Metaboliche Fondazione Policlinico Universitario A. Gemelli \u2013 IRCCS  Rome Italy"},{"name":"Dermatologia, Dipartimento di Medicina e Chirurgia Traslazionale Universit\u00e0 Cattolica del Sacro Cuore  Rome Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4312-6557","authenticated-orcid":false,"given":"M.","family":"Trakatelli","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology Aristotle University Medical School, Papageorgiou General Hospital  Thessaloniki Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"Wojcieszek","sequence":"additional","affiliation":[{"name":"Brachytherapy Department Maria Sklodowska\u2010Curie National Research Institute of Oncology (MSCNRIO)  Gliwice Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. S.","family":"Yom","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology University of California San Francisco  San Francisco California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9276-3627","authenticated-orcid":false,"given":"E.","family":"Zelin","sequence":"additional","affiliation":[{"name":"Institute of Dermatology Santa Maria Della Misericordia University Hospital  Udine Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1957-6600","authenticated-orcid":false,"given":"K.","family":"Peris","sequence":"additional","affiliation":[{"name":"UOC Dermatologia, Dipartimento di Scienze Mediche e Chirurgiche Addominali ed Endocrino Metaboliche Fondazione Policlinico Universitario A. Gemelli \u2013 IRCCS  Rome Italy"},{"name":"Dermatologia, Dipartimento di Medicina e Chirurgia Traslazionale Universit\u00e0 Cattolica del Sacro Cuore  Rome Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"Malvehy","sequence":"additional","affiliation":[{"name":"Dermatology Department, Hospital Clinic of Barcelona IDIBAPS, University of Barcelona and CIBER de enfermedades Raras, ICIII  Barcelona Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,7,3]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaad.2010.08.033"},{"key":"e_1_2_10_3_1","doi-asserted-by":"publisher","DOI":"10.3322\/caac.21389"},{"key":"e_1_2_10_4_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1610-0387.2012.07896.x"},{"key":"e_1_2_10_5_1","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2012.48.5326"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.21037\/atm.2019.03.13"},{"key":"e_1_2_10_7_1","doi-asserted-by":"publisher","DOI":"10.1111\/bjd.20909"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1111\/jdv.17466"},{"key":"e_1_2_10_9_1","doi-asserted-by":"publisher","DOI":"10.1111\/jdv.17467"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.3115\/980845.980859"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10791-008-9066-8"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.1177\/001316446002000104"},{"key":"e_1_2_10_13_1","first-page":"768","article-title":"Cluster analysis of multivariate data: efficiency versus interpretability of classifications","volume":"21","author":"Forgy EW","year":"1965","journal-title":"Biometrics"},{"key":"e_1_2_10_14_1","doi-asserted-by":"publisher","DOI":"10.1080\/01621459.1963.10500845"},{"key":"e_1_2_10_15_1","first-page":"226","volume-title":"Proceedings of the 2nd international conference on knowledge discovery and data mining","author":"Ester M","year":"1996"},{"key":"e_1_2_10_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/0377-0427(87)90125-7"},{"key":"e_1_2_10_17_1","first-page":"207","volume-title":"Modern multidimensional scaling: theory and applications","author":"Borg I","year":"2005"},{"key":"e_1_2_10_18_1","doi-asserted-by":"publisher","DOI":"10.6004\/jnccn.2021.0059"},{"key":"e_1_2_10_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejca.2023.113252"},{"key":"e_1_2_10_20_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF02833890"},{"key":"e_1_2_10_21_1","doi-asserted-by":"publisher","DOI":"10.1111\/bjd.21291"}],"container-title":["Journal of the European Academy of Dermatology and Venereology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/jdv.20209","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,19]],"date-time":"2025-10-19T14:42:55Z","timestamp":1760884975000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/jdv.20209"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,7,3]]},"references-count":20,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2025,3]]}},"alternative-id":["10.1111\/jdv.20209"],"URL":"https:\/\/doi.org\/10.1111\/jdv.20209","archive":["Portico"],"relation":{},"ISSN":["0926-9959","1468-3083"],"issn-type":[{"value":"0926-9959","type":"print"},{"value":"1468-3083","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,7,3]]},"assertion":[{"value":"2024-01-22","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-06-07","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-07-03","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}