Journal Article Comparative Study Ppublish
PubMed: 42476365 DOI: 10.1016/j.jaad.2026.07.041
One dose of adjuvant 8 Gray postoperative radiotherapy for Merkel cell carcinoma excised with narrow margins: Low toxicity and comparable efficacy to conventional radiotherapy.
J Am Acad Dermatol 95(5):1352-1361
Authors: Emily T Huynh, Peter Y Ch'en, Daniel S Hippe, Xinyi Fan, Peter H Goff, Kate Biese, Alex Fu, Ankita Menon, Nikhil Harikrishnan, Kristina Lachance, Kent Wallner, Neil Panjwani, Upendra Parvathaneni, Yolanda D Tseng, Tomoko Akaike, Lisa C Zaba, Paul Nghiem
Affiliations
- Department of Dermatology, University of Washington, Seattle, Washington; Pacific Northwest University of Health Sciences, College of Osteopathic Medicine, Yakima, Washington.
- Department of Dermatology, University of Washington, Seattle, Washington; Albert Einstein College of Medicine, Bronx, New York.
- Clinical Research Division, Fred Hutch Cancer Center, Seattle, Washington.
- Department of Radiation Oncology, University of Washington, Seattle, Washington.
- Department of Dermatology, University of Washington, Seattle, Washington.
- Department of Radiation Oncology, The University of Texas Medical Branch, Galveston, Texas.
- Department of Dermatology, Stanford University, Palo Alto, California.
- Department of Dermatology, University of Washington, Seattle, Washington.
Abstract
BACKGROUND
Merkel cell carcinoma (MCC) recurs in 17% to 30% of patients with stage I to II disease, with local recurrence rates between 2% and 27%. Per established guidelines, conventional postoperative radiotherapy (cPORT; ∼50 Gray across 25 fractions) should be considered for localized MCC when risk factors are present. cPORT can be morbid and logistically challenging. Single-fraction radiotherapy (SFRT) of 8 Gray has utility and low toxicity for palliation but remains underexplored postoperatively.
OBJECTIVE
Evaluate postoperative SFRT for stage I to II MCC, compared to observation and cPORT.
METHODS
Local recurrences were assessed for observation (n = 108 patients), cPORT (n = 156), or SFRT (n = 43) groups.
RESULTS
Observation patients had fewer per-patient risk factors (mean: 1.2 vs 1.6 for SFRT [P = .020] and 1.6 for cPORT [P = .001]). Despite this, 3-year local control was better for cPORT (97.4%; P < .001) and SFRT (100%; P = .012) groups than observation (91.0%), particularly in patients with narrow surgical margins (≤1 cm). Adverse events occurred in 21% of SFRT patients (all grade 1).
LIMITATIONS
Single-center retrospective study.
CONCLUSIONS
The SFRT group experienced improved local control relative to observation and had comparable local control to the cPORT group. For early-stage narrowly excised MCC, SFRT is feasible, well tolerated, and warrants exploration in a prospective multicenter study.
MeSH
Radiotherapy, Cells, Quality Of Life, Merkel Cells, Risk Factors, Dermatology, Carcinoma, Merkel Cell