Fast Five Quiz: How Much Do You Know About Merkel Cell Carcinoma?

Elwyn C. Cabebe, MD


May 31, 2017

The 2015 European guidelines on the diagnosis and management of MCC included the following regarding treatment:

  • The primary tumor should be excised with 1- to 2-cm margins

  • In patients with regional lymph node involvement, radical lymphadenectomy is recommended

  • Adjuvant radiation therapy may be considered in patients with multiple affected lymph nodes of extracapsular extension

  • In unresectable metastatic MCC, monochemotherapy or polychemotherapy achieves high remission rates; however, responses are usually short-lived

  • Treatment within clinical trials is regarded as a standard of care in disseminated MCC

Aggressive, wide local excision is the treatment of choice for the primary tumor. A 2-cm to 3-cm margin is recommended because it is thought to decrease the risk of recurrence. All margins should be confirmed with frozen sections.

Because the definitive treatment of cutaneous melanoma is surgery, medical management is reserved for adjuvant therapy of patients with advanced melanoma. Chemotherapy is generally not currently advocated for stage II disease. Less than one half of patients with deep primaries (>4 mm) or regional lymph node involvement have long-term disease-free survival; consequently, these patients are classified as high risk and should be considered for adjuvant therapy.

No combination chemotherapy regimen has proven to be significantly better than single-agent dacarbazine, which yields only a 10%-15% response rate.

The development of distant metastases portends a poor prognosis, with a mean life expectancy of 5 months. Many types of chemotherapeutic agents have been used with brief success in treating stage III disease, with no increase in the survival rate. Pharmacologic agents most commonly used are doxorubicin and cyclophosphamide. Other agents are cisplatin, vincristine, etoposide, methotrexate, bleomycin, and 5-fluorouracil. However, reports of these treatments to date have consisted of small studies and anecdotal evidence. No chemotherapeutic protocol has notably increased survival rates in patients with stage III MCC.

For more on the treatment of MCC, read here.


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