Merkel Cell Carcinoma from Molecular Pathology to Novel Therapies

Area of Science:

• Oncology
• Dermatology
• Virology

Background:

• Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer.
• It primarily affects sun-exposed skin and is associated with Merkel cell polyomavirus (MCPyV) in 60-80% of cases.
• Viral-negative MCCs exhibit high mutation burdens and UV damage signatures, with key gene aberrations in RB1, TP53, NOTCH, and the PI3K-AKT-mTOR pathway.

Purpose of the Study:

• To review the current understanding of Merkel cell carcinoma (MCC) pathogenesis, diagnosis, and treatment.
• To highlight the challenges in MCC diagnosis and staging.
• To discuss the evolving treatment landscape for advanced MCC.

Main Methods:

• Literature review of Merkel cell carcinoma (MCC) research.
• Analysis of diagnostic criteria and staging tools, including sentinel lymph node biopsy.
• Evaluation of treatment modalities, including surgery, radiation, chemotherapy, and immunotherapy.

Main Results:

• MCC is immunogenic but evades immune responses.
• Diagnosis requires expert pathological confirmation; sentinel lymph node biopsy is crucial for staging.
• Metastatic MCC has historically poor outcomes, but immunotherapy is now a standard first-line therapy.

Conclusions:

• Despite diagnostic challenges, MCC management has advanced significantly.
• Immunotherapy represents a major breakthrough for advanced Merkel cell carcinoma.
• Further research is needed to improve outcomes for all stages of MCC.