Presentation (CTI)

OBJECTIVES: Advanced Merkel cell carcinoma (aMCC) is a rare, highly aggressive neuroendocrine skin tumor characterized by a significant frequency of locoregional recurrence, metastasis, and poor prognosis. Despite its rarity, the rising prevalence of aMCC underscores the need for a thorough understanding of prognostic factors to inform clinical decision-making and enhance patient outcomes. The current systematic review aims to provide a comprehensive overview of prognostic factors associated with aMCC outcomes.
METHODS: Electronic databases such as Embase^® and Medline^® were searched using the combination of relevant keywords related to prognosis and aMCC. English language articles were included from the last five years. The standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) compliant two independent review and quality control process was followed during data collection.
RESULTS: A total of 12 studies were identified, conducted across the US (n=8), EU-4 (n=3), and one globally. Findings revealed that in the multivariable analysis, first-line immunotherapy (N=2), treatment at high-volume centers (N=1), and Eastern Cooperative Oncology Group score >1 (N=1) were associated with prolonged overall survival, while older age (N=4), male gender (N=2), advanced disease stage (N=2), bone metastases, high baseline neutrophil-lymphocyte ratio, positive merkel cell polyomavirus status (MCPyV) and delayed time to radiation (≥79 days) (N=1 study each) had a significant, independent, adverse impact on OS (p<0.05). Further, gender (HR: 2.08; p=0.018) and advanced stage (HR: 20.57; p<0.0001) were identified as independent predictors for shorter progression-free survival. Regional lymph node irradiation and adjuvant radiotherapy were associated with improved recurrence-free survival, disease-specific survival (DSS), and disease-free survival, while brain metastasis was associated with a threefold worse DSS.
CONCLUSIONS: This systematic review highlights that multiple patient, disease, and treatment-related factors influence outcomes in aMCC. Understanding these prognostic indicators is essential to inform clinical decision-making and improve patient management strategies in this rare but aggressive cancer.