LB759 Post-operative radiation therapy to prevent local recurrence of low-risk Merkel cell carcinomas of the head and neck versus other sites

Abstract

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer with a recurrence risk of ∼40%; however, prognosis for low-risk, stage I disease is excellent with primary surgical management and wide local excision. The role of post-operative radiation therapy (PORT) is controversial. Here, we assess the efficacy of PORT on local recurrence (LR) rates in a cohort of patients with low-risk, pathological stage I MCC with primary tumors on the head/neck (HN) vs. non-head and neck (Non-HN) sites. One hundred forty-seven MCC patients treated from 2006-2020 were identified from an IRB-approved prospective registry who had ‘low risk’ disease: pathological T1 primary tumor resected with negative microscopic margins, negative pathologic node status, and no immunosuppression or prior systemic therapy.