Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2025 Jul;27(7):822-832.
doi: 10.1007/s11912-025-01693-z. Epub 2025 Jun 3.

Merkel Cell Carcinoma: Current Treatment Landscape and Emerging Therapeutic Targets

Kelly Pan  1 , A Maria Vromans  1 , Liang Cheng  2 , Jane M Grant-Kels  3 , Steven C Katz  4 , Matthew J Hadfield  5
Affiliations
Review

Merkel Cell Carcinoma: Current Treatment Landscape and Emerging Therapeutic Targets

Kelly Pan et al. Curr Oncol Rep. 2025 Jul.

Abstract

Purpose of review: Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine carcinoma that is primarily driven by Merkel cell polyomavirus (MCPyV) and ultraviolet radiation. Due to its rarity and innocuous appearance on clinical exam, MCC diagnosis is often delayed and therefore diagnosed at advanced stages. Overall survival outcomes are poor and notably worse than melanoma, with an estimated five-year survival ranging from 35 to 60% for stage I or II disease to < 15% for metastatic disease. Our review examines the diagnostic workup, prognostic markers, and current and emerging treatments of MCC.

Recent findings: For local disease in which surgical resection is feasible, tumor removal with potential adjuvant radiation therapy is the primary treatment modality. Immunotherapy with PD-1 / PD-L1 inhibitors is now standard for advanced disease where complete resection is not feasible. Additionally, there are many ongoing clinical trials examining novel immune checkpoint inhibitors, immunomodulators, targeted therapies, cellular therapies, vaccines, and oncolytic virus therapies with the goal of improving outcomes for patients with advanced disease or those who experience recurrence after first-line immunotherapy. MCC is an aggressive disease with a rapidly evolving treatment landscape, and emerging therapies hold the potential to improve prognosis in advanced disease.

Keywords: Checkpoint inhibitor; Immunotherapy; Merkel cell carcinoma; Merkel cell polyomavirus (MCPyV); PD-1; PD-L1.

PubMed Disclaimer

Conflict of interest statement

Declarations. Competing Interests: The authors declare no competing interests.

References

    1. Lee T, Oka T, Demehri S. High-Risk Non-Melanoma skin cancers: biological and therapeutic advances. Hematol Oncol Clin North Am. 2024;38(5):1071–85. https://doi.org/10.1016/j.hoc.2024.05.004 . - DOI - PubMed
    1. Harms PW, et al. The biology and treatment of Merkel cell carcinoma: current Understanding and research priorities. Nat Rev Clin Oncol. 2018;15(12):763–76. https://doi.org/10.1038/s41571-018-0103-2 . - DOI - PubMed - PMC
    1. Tetzlaff MT, Harms PW. Danger is only skin deep: aggressive epidermal carcinomas. An overview of the diagnosis, demographics, molecular-genetics, staging, prognostic biomarkers, and therapeutic advances in Merkel cell carcinoma. Mod Pathol. 2020;33(Suppl 1):42–55. https://doi.org/10.1038/s41379-019-0394-6 . - DOI - PubMed
    1. Paulson KG, et al. Merkel cell carcinoma: current US incidence and projected increases based on changing demographics. J Am Acad Dermatol. 2018;78(3):457–63. https://doi.org/10.1016/j.jaad.2017.10.028 ..e2. - DOI - PubMed
    1. Pacaud M, et al. Merkel cell carcinoma from renal transplant recipients are mostly MCPyV-negative and are frequently associated with squamous cell carcinomas or precursors. J Eur Acad Dermatol Venereol. 2023;37(8):e1014–8. https://doi.org/10.1111/jdv.19076 . - DOI

MeSH terms

Substances

LinkOut - more resources