Abstract
INTRODUCTION: The COVID-19 pandemic significantly disrupted healthcare systems worldwide. Prioritizing emergency responses resulted in the postponement of routine medical care, including melanoma diagnoses. We performed a systematic review and meta-analysis to quantify the pandemic's effect on diagnosis rates, Breslow thickness, stage at presentation, ulceration, histologic subtypes, and patient age. METHOD: We performed a systematic review and meta-analysis following PRISMA guidelines. PubMed, Scopus, Web of Science, and Embase were searched up to 10 September 2024 for observational studies comparing melanoma outcomes in the pre-COVID era (before March 2020) with the COVID era (March 2020 onwards). Two reviewers independently screened records, extracted data on diagnostic counts, patient age, Breslow thickness, ulceration, and histopathological subtype, and assessed study quality using the Newcastle-Ottawa Scale (NOS). Random-effects models pooled rate ratios (RRs) or odds ratios (ORs); fixed-effects models pooled mean differences (MDs). Heterogeneity was evaluated with I², and sensitivity analyses were restricted to high-quality studies (NOS ≥ 7). RESULTS: Sixty-two studies (38,676 pre-COVID and 46,846 COVID-era melanomas) met inclusion criteria. New melanoma diagnoses fell by 19% during the pandemic (RR = 0.81, 95% CI 0.75-0.86; I² = 98%). Mean age at diagnosis rose by 0.86 years (95% CI 0.58-1.14; I² = 45%). Tumors were thicker (MD = 0.24 mm, 95% CI 0.02-0.47; I² = 92%) and more frequently ulcerated (OR = 1.29, 95% CI 1.15-1.44; I² = 31%). Nodular melanoma, an aggressive subtype, became more common (OR = 1.34, 95% CI 1.08-1.67; I² = 81%), whereas superficial spreading, acral lentiginous, and lentigo-maligna subtypes showed no significant change. All the key findings persisted in good-quality-only analyses. CONCLUSION: COVID-19-related service disruptions were associated with fewer melanoma diagnoses but a shift toward older patients and biologically adverse tumor features, signaling delayed detection at the population level. Strengthening resilient, rapid-access skin cancer pathways and integrating tele-dermatology with triaged in-person assessment are public-health priorities for future crises. TRIAL REGISTRATION: PROSPERO registration number CRD42022361569.