Evaluation of the Vitamin D role in cutaneous melanoma risk: An umbrella review of systematic reviews and meta-analyses

comparative data of clinical and laboratory melanoma characteristics at diagnosis, in groups of patients from European countries diagnosed before (Pre-Covid), during and immediately after the pandemic and its individual public health phases (Post-Covid) were included in the analysis.The quality of studies was evaluated using the Cochrane ROBINS-I tool.Meta-analysis was conducted utilizing a random effects model to synthesize the data.Results: A total of 25 studies containing 32231 patients were included in the data analysis models.Evidence from a pool of 19 studies and 29,329 patients marked a statistically significant increase in mean Breslow thickness [0.29 mm (0.03-0.55 mm)] in the Post Covid group.The sensitivity analysis of 16 studies further supported the derived outcome of thicker tumors, by reducing the overall observed heterogeneity.A total of 12 studies investigated the tumors' ulceration rates and yielded a significant rise for the patients in the PostCovid group [OR=1.66(1.29-2.13)].Also, the resulting tumor staging in the Post Covid group showed a notable increase in the rates of clinically advanced stage III melanomas and, on the other hand a discernible decrease in stage 0 and I tumors.Finally, the subgroup analysis revealed that the lockdown derived data was responsible for the trends witnessed on all outcomes of interest.Conclusions: This meta-analysis highlighted the negative impact of COVID-19 restrictions on the management of patients with primary melanoma in Europe, which reflected in the increased incidence of more clinically advanced forms of the disease at diagnosis.The evidence presented herein has implications for the future, as it shows the need for the continuation of screening procedures for the prompt diagnosis of melanoma, even in the case of emergency healthcare adaptations.