Clinical course of Merkel cell carcinoma: A DeCOG multicenter study of 1049 patients

Georg C Lodde ¹, Ulrike Leiter ², Anja Gesierich ³

¹Department of Dermatology, University Hospital Essen, Essen, Germany.
²Centre for Dermatooncology, Department of Dermatology, University Hospital Tübingen, Tübingen, Germany; German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany.
³Department of Dermatology, Venereology and Allergology, University Hospital Wuerzburg, Würzburg, Germany.
⁴Centre for Dermatooncology, Department of Dermatology, University Hospital Tübingen, Tübingen, Germany; German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany; Department of Dermatology, Venereology and Allergology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität, Berlin, Germany.
⁵Department of Dermatology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
⁶Department of Dermatology, Saarland University Medical School, Homburg/Saar, Germany.
⁷Department of Dermatology, Ruhr-University Bochum, Bochum, Germany; Department of Dermatology, Dortmund Hospital, University Witten-Herdecke, Germany.
⁸Department of Dermatology, Helios Klinikum Erfurt, Erfurt, Germany.
⁹German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany; Department of Dermatology, University Hospital Dresden, Dresden, Germany.
¹⁰German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany; Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany.
¹¹German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany; Department of Dermatology, University Hospital Freiburg, Freiburg, Germany.
¹²Department of Dermatology, Elbe-Kliniken, Buxtehude, Germany.
¹³Department of Dermatology, UKSH Campus Lübeck, Lübeck, Germany.
¹⁴Departments of Dermatology, Venereology, Allergology and Immunology, Städtisches Klinikum Dessau, Germany; Faculty of Health Sciences, Brandenburg Medical School Theodor Fontane, Dessau, Germany.
¹⁵Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, Homburg, Germany.
¹⁶Institute for Medical Informatics, Biometry and Epidemiology, University Medicine Essen, Essen, Germany.
¹⁷Department of Dermatology, Bielefeld University, Medical School and University Medical Center OWL, Klinikum Bielefeld Rosenhöhe, Bielefeld, Germany.
¹⁸Department of Dermatology, University Hospital Essen, Essen, Germany; German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany; Department of Dermatology, Bielefeld University, Medical School and University Medical Center OWL, Klinikum Bielefeld Rosenhöhe, Bielefeld, Germany.
¹⁹Department of Dermatology, University Hospital Essen, Essen, Germany; German Cancer Consortium (DKTK), Deutsches Krebsforschungsinstitut, Heidelberg, Germany; Translational Skin Cancer Research (TSCR), Department of Dermatology and West German Cancer Center, University of Medicine Duisburg-Essen, Essen, Germany.

⁰Department of Dermatology, University Hospital Essen, Essen, Germany.

European Journal of Cancer +

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April 14, 2025

View abstract on PubMed

Summary

Optimal Merkel cell carcinoma (MCC) treatment involves 1-2 cm surgical margins and early adjuvant radiotherapy. Wider margins or complete lymph node dissection in stage IIIA do not improve survival outcomes for this aggressive skin cancer.

Area Of Science

Oncology
Dermatology
Surgical Oncology

Background

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer known for frequent recurrences.
Existing large databases lack detailed analysis of MCC recurrence patterns linked to patient and tumor characteristics or interventions.

Purpose Of The Study

To analyze associations between patient/tumor characteristics, locoregional interventions, and recurrence patterns in Merkel cell carcinoma (MCC).
To identify optimal treatment strategies for improving progression-free probability (PFP) and disease-specific survival (DSS) in MCC patients.

Main Methods

Retrospective analysis of 1049 histopathologically confirmed MCC patients from the DeCOG MCC registry (1998-2017).
Evaluation of patient/tumor characteristics, surgical margins, radiotherapy timing, and lymph node dissection on PFP and DSS.
Statistical analysis of progression-free probability (PFP) and disease-specific survival (DSS) rates.

Main Results

Surgical margins of 1-2 cm significantly improved PFP and DSS compared to smaller or larger margins.
Early adjuvant radiotherapy (within 8 weeks) improved PFP (HR 1.36) and DSS (HR 1.79).
Complete lymph node dissection in stage IIIA patients and expanded radiotherapy fields did not enhance survival outcomes.

Conclusions

Optimal surgical margins for MCC are 1-2 cm, with no additional benefit from wider resection.
Timely adjuvant radiotherapy is crucial for improving MCC patient outcomes.
Certain interventions like complete lymph node dissection in stage IIIA and extended radiation fields do not improve survival.

Keywords:

Complete lymph node dissection Locoregional treatment Merkel cell carcinoma Radiotherapy Safety margins

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