Staging and treatment of Merkel cell carcinoma
- Patricia Tai, MB, BS, DABR, FRCR, FRCPC
Patricia Tai, MB, BS, DABR, FRCR, FRCPC
- Clinical Oncologist
- Clinical Professor
- University of Saskatchewan
- Canada Department of Radiation Oncology
- Allan Blair Cancer Center
- Section Editors
- Robert S Stern, MD
Robert S Stern, MD
- Section Editor — Nonmelanoma Skin Cancer
- Professor of Dermatology
- Harvard Medical School
- June K Robinson, MD
June K Robinson, MD
- Section Editor — Nonmelanoma Skin Cancer
- Professor of Clinical Dermatology
- Northwestern University Feinberg School of Medicine
- Michael B Atkins, MD
Michael B Atkins, MD
- Section Editor — Malignant Melanoma and Other Cutaneous Neoplasms; Cancer of the Kidney
- Deputy Director
- Georgetown Lombardi Comprehensive Cancer Center
Merkel cell carcinoma (MCC) of the skin is a rare, aggressive cutaneous malignancy that predominantly affects elderly Caucasians and has a propensity for local recurrence and regional lymph node metastases. Other terms used to describe this tumor include neuroendocrine or primary small cell carcinoma of the skin, trabecular cell carcinoma, and anaplastic cancer of the skin.
The staging and treatment of MCC are discussed here. The clinical features and initial diagnosis of MCC are reviewed separately. (See "Pathogenesis, clinical features, and diagnosis of Merkel cell (neuroendocrine) carcinoma".)
TNM STAGING SYSTEM
The eighth (2017) edition of the tumor, node, metastasis (TNM) staging system provides important information for both management and prognosis of patients with Merkel cell carcinoma (MCC). The TNM system is recommended by both the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) and is presented in detail in the tables (table 1 and table 2) . In contrast to the seventh TNM staging system, the eighth edition has separate criteria for clinical and pathological staging.
Based upon the TNM information, patients are assigned to prognostic stage groups. These can be summarized as follows:
●Stage I – Primary tumors ≤2 cm maximum tumor dimension, without evidence of regional lymph node involvement.
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- TNM STAGING SYSTEM
- APPROACH TO STAGING AND MANAGEMENT
- Initial staging procedures
- Initial management
- PRIMARY TUMOR
- Radiation therapy
- REGIONAL LYMPH NODES
- Clinically negative nodes
- Clinically positive nodes
- ADJUVANT THERAPY
- Radiation therapy
- Chemotherapy or chemoradiotherapy
- Adjuvant immunotherapy
- HEAD AND NECK LESIONS
- UNKNOWN PRIMARY
- SURVEILLANCE AFTER INITIAL THERAPY
- Second primary cancers
- RECURRENT DISEASE
- METASTATIC DISEASE
- - Avelumab
- - Pembrolizumab and nivolumab
- Targeted therapy
- Somatostatin receptor-based therapy
- Experimental approaches
- SUMMARY AND RECOMMENDATIONS
- Initial evaluation and management of locoregional disease
- Recurrent and metastatic disease