20 | How Covid-19 pandemic influenced the diagnosis of new primary melanoma: a retrospective, multicenter study by the Italian Society of Oncological Surgery

Background: Melanoma is a severe and potentially fatal skin cancer, which is particularly sensitive to delays in diagnosis and treatment (Figure 1). It has been widely demonstrated that the diagnostic delays during COVID-19 pandemic determined higher incidence of advanced disease at presentation. Despite the fact that oncological surgery remained operative in Italy, the pandemic peak and lockdown led to reductions in the number of patient visits and diagnostic testing. This study aimed to investigate if the indirect impact of pandemic in Italy could be identified also in the second year of pandemic, analyzing the characteristics of primary melanoma at the diagnosis.Methods: It has been conducted a retrospective observational multicenter study involving 10 SICO Italian Melanoma centres. The pre-pandemic period (1st March 2019 - 28th February 2020, 1640 diagnoses) was compared to the Pandemic period (1st March 2021 – 28th February 2022, 1292 diagnoses). Melanoma Centre Units were classified into «Covid-free centres» (without Covid-19 dedicated beds) or «Covid centres» (with COVID-19 dedicated beds). Clinically relevant tumor characteristics at the diagnosis were considered: Breslow thickness, tumor stage, intratumoral and peritumoral-infiltrating lymphocytes (TILs), mitosis, and ulceration.Results: This study found that there was a statistically significant reduction in the mean interval from diagnosis to surgery between pre-pandemic and pandemic period only in COVID-19 centres (p=0.002). This is explained by the fact that they needed to change their case mix treating only oncological patients or emergencies, in order to face the demands of COVID-19 pandemic. Our results showed an indirect effect of the pandemic in Italy during the second year on melanoma features at the diagnosis (Breslow thickness p< 0.0001, tumor stage p = 0.002, ulceration p = 0.04, SNLB p = 0.03) (Table 1).Conclusions: It was confirmed an indirect impact of pandemic on tumor characteristics at the diagnosis during the second year of outbreak equally in both Covid and Covid-free centres. Politics to preserve access to dermatological visits are necessary and must be preserved in both Covid free and Covid Centers in case of pandemics, also using strategies such as teledermatology to do preliminary skin examinations when the number of specialist visits is restricted. Table 1.Summary of the outcome measures in the pre-pandemic period (from March 2019 to February 2020) and the pandemic period (from March 2021 to February 2022) stratified by COVID-19-free centers and COVID-19 centers.