Effects of COVID-19 Pandemic on the Diagnosis of Melanoma and Keratinocyte Carcinomas: a Systematic Review and Meta-analysis Díaz Calvillo, Pablo Muñoz Barba, Daniel Ureña Paniego, Clara Amanda Maul, Lara Valeska Cerminara, Sara Kostner, Lisa Martínez López, Antonio Arias Santiago, Salvador Antonio Melanoma Squamous cell carcinoma Basal cell carcinoma Since December 2019, the COVID-19 pandemic has profoundly affected healthcare. The real effects of the COVID-19 pandemic on skin cancer are still unclear, more than 3 years later. This study aims to summarise the pandemic’s impact on skin cancer diagnosis and outcome. A systematic review and meta-analysis was conducted, selecting studies comparing skin cancer diagnosis and prognosis post-pandemic with pre-pandemic data. A total of 27 papers were reviewed including 102,263 melanomas and 271,483 keratinocyte carcinomas. During the initial pandemic months (January– July 2020), melanoma surgeries dropped by 29.7% and keratinocyte carcinomas surgeries by 50.8%. Early pandemic tumours exhibited greater thickness and stage. In a long-term period beyond the initial months, melanoma surgeries decreased by 9.3%, keratinocyte carcinomas by 16.6%. No significant differences were observed in the Breslow thickness of melanomas after the start of the pandemic (mean difference 0.06, 95% confidence interval –0.46, 0.58). Melanomas operated on post-pandemic onset had an increased risk of ulceration (odds ratio 1.35, 95% confidence interval 1.22–1.50). Keratinocyte carcinomas showed increased thickness and worsened stage post-pandemic. However, studies included were mostly retrospective and cross-sectional, reporting diverse data. This review indicates that the pandemic likely caused delays in skin cancer diagnosis and treatment, potentially impacting patient outcomes. 2024-06-03T09:56:50Z 2024-06-03T09:56:50Z 2024-03-14 journal article Díaz-Calvillo P, Muñoz-Barba D, Ureña-Paniego C, Maul LV, Cerminara S, Kostner L, Martínez López A, Arias-Santiago S. Effects of COVID-19 Pandemic on the Diagnosis of Melanoma and Keratinocyte Carcinomas: a Systematic Review and Meta-analysis. Acta Derm Venereol. 2024 Mar 14;104:adv19460. doi: 10.2340/actadv.v104.19460 https://hdl.handle.net/10481/92255 10.2340/actadv.v104.19460 eng http://creativecommons.org/licenses/by-nc/4.0/ open access Atribución-NoComercial 4.0 Internacional MJS Publishing