Basal cell carcinoma: Epidemiological impact of clinical versus histopathological diagnosis

• Published in: Journal of the European Academy of Dermatology and Venereology 2023-03, Vol.37 (3), p.521-527
• Main Authors: Backman, Eva, Oxelblom, Maria, Gillstedt, Martin, Dahlén Gyllencreutz, Johan, Paoli, John
• Format: Article
• Language: English
• Subjects: Carcinoma, Basal Cell - diagnosis; Carcinoma, Basal Cell - epidemiology; Carcinoma, Basal Cell - pathology; Dermatologi och venereologi; Dermatology and Venereal Diseases; Humans; Retrospective Studies; Skin Neoplasms - diagnosis; Skin Neoplasms - epidemiology; Skin Neoplasms - pathology; Sweden - epidemiology
• ISSN: 0926-9959; 1468-3083; 1468-3083
• DOI: 10.1111/jdv.18774

Background Low‐risk basal cell carcinomas (BCCs) are to an increasing extent diagnosed by dermatologists through dermoscopic examination only and treated with non‐surgical methods. Reports on increasing incidence as well as trends regarding subtypes, anatomical sites and differences related to gender are based solely on histopathologically verified tumours. How unreported clinically diagnosed BCCs affect the epidemiological data has not been sufficiently investigated. Objectives To analyse the tumour and patient characteristics of clinically diagnosed versus histopathologically confirmed primary BCCs and to make a gross estimate on how unreported BCCs could influence the total number of new cases. Methods We retrospectively reviewed all primary BCCs diagnosed in 2016 at the Department of Dermatology, Sahlgrenska University Hospital in Gothenburg, Sweden. We also reviewed all histopathologically verified primary BCCs at the two largest pathology laboratories in Western Sweden during the same year to estimate the proportion of BCCs diagnosed by dermatologists. Results In total, 2365 primary BCCs were diagnosed at our centre. More than half of these tumours were clinically diagnosed (55.8%). Superficial subtype (41.7%), location on the trunk (46.3%) and destructive treatment methods (60.0%) were most common. The reports from the two pathology laboratories showed that histopathologically verified BCCs (n = 5837) were more commonly of the infiltrative or nodular subtype and located in the head and neck area. Dermatologists managed 56.0% of them. Conclusions This study indicates that a substantial number of BCCs are not visualized in the official statistics which are solely based on reports from pathology laboratories. When taking clinically diagnosed tumours into account, truncal location and superficial subtype are more common than previously believed. Further, based on the regional calculations, the real burden of BCC in Sweden might be up to 70% higher than what is reported in official statistics.