Primary Tumor Site for Localized Merkel Cell Carcinoma Drives Different Management Strategies Without Impacting Oncologic Outcomes

Authors

Samuel Cass
Brandon Cope
Andrew J Bishop
Yi-Ju Chiang
B Ashleigh Guadagnolo
Ahsan Farooqi
William Morrison
Russell G Witt
Riyad N H Seervai
Adam S Garden
Clifton D Fuller
Ryan P Goepfert
Merrick Ross
Jeffrey E Gershenwald
Michael Wong
Phyu P Aung
Emily Z Keung
Devarati Mitra

Publication Date

11-1-2023

Journal

Radiotherapy & Oncology

Abstract

BACKGROUND AND PURPOSE: Clinically localized Merkel cell carcinoma (MCC) has been associated with high rates of disease relapse. This study examines how primary tumor anatomic site drives patterns of care and outcomes in a large cohort treated in the contemporary era.

MATERIALS AND METHODS: Patterns of care and associated outcomes were evaluated for clinically Stage I-II MCC patients treated at our institution with adjuvant radiation therapy (RT) to the primary site and/or regional nodal basin as a component of their curative intent therapy between 2014-2021.

RESULTS: Of 80 patients who met inclusion criteria, the primary tumor anatomic site was head and neck (HN) for 42 (53%) and non-head and neck (NHN) for 38 (47%). Primary tumor risk factors were similar between cohorts. Fewer patients with HN tumors had wide local excision (WLE; HN-81% vs. NHN-100% p < 0.01). Of those undergoing WLE, patients with HN tumors received higher dose adjuvant RT (>50 Gy: HN-70% vs. NHN-8%; p < 0.01). Patients with HN tumors were less likely to undergo sentinel lymph node biopsy (HN-62%vs. NHN-100%; p < 0.01) and more likely to have elective nodal RT (HN-48% vs. NHN-0%). Despite varying management strategies, there was no significant difference in local recurrence-free survival (3-yr LRFS HN-94% vs. NHN-94%; p = 0.97), nodal recurrence-free survival (3-yr NRFS HN-89% vs. NHN-85%; p = 0.71) or overall recurrence-free survival (3-yr RFS 73% HN vs. 80% NHN; p = 0.44).

CONCLUSIONS: Among patients with primary MCC who had RT as a component of their initial treatment strategy, anatomically-driven heterogeneous treatment approaches were associated with equally excellent locoregional disease control.

Keywords

Humans, Carcinoma, Merkel Cell, Male, Female, Aged, Skin Neoplasms, Head and Neck Neoplasms, Aged, 80 and over, Radiotherapy, Adjuvant, Middle Aged, Retrospective Studies, Neoplasm Recurrence, Local, Neoplasm Staging, Treatment Outcome, Merkel cell carcinoma, radiation therapy, surgery, anatomic site

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Supplementary Materials

PMID: 37659660