Abstract
BACKGROUND: There are no clear treatment guidelines for solid organ transplantation (SOT) patients with Merkel cell carcinoma (MCC) despite increased incidence rates. OBJECTIVE: To review treatment outcomes of MCC patients with prior SOT. METHODS: A systematic review (Prospective Register of Systematic Reviews CRD42024569200) of studies that reported treatment modalities and outcomes for MCC patients with SOT were selected. Databases screened included PubMed, Web of Science, Scopus, and Embase. RESULTS: Thirty articles comprising 21 case reports, 8 cohort studies, and 1 clinical trial were included. Treatment modalities reported in case reports and clinical trials included surgery (77.7%), radiotherapy (62.9%), and chemotherapy (25.9%), with 3 patients receiving immune checkpoint inhibitors and 1 patient receiving an oncolytic virus. Cohort studies reported varying usage of surgery, radiotherapy, chemotherapy, and immunosuppression regime modifications. LIMITATIONS: Heterogeneity in methodologies and data reporting of studies included impeded meaningful comparisons. Lack of stratification of immunosuppressed populations in the excluded studies reduced the available patient data for comparison. CONCLUSION: Oncolytic virotherapy has the potential to mediate a localized, targeted response with minimal side effects in SOT patients. Inclusion of SOT patients with MCC into future clinical trials involving immunotherapy and immunosuppression combination therapies is needed to establish future treatment guidelines.