There have been no head-to-head trials comparing the two treatment strategies, and in the absence of this, surgeons tend to most commonly perform excisional biopsy prior to referring for radiation therapy to eradicate MCC. MCC is exquisitely radiosensitive. The conclusion amongst published studies in the Radiation Oncology community is that MCC should be managed ideally with radiation therapy alone. Chemotherapy
Because of its significant adverse effects, traditional chemotherapy has been saved for late-stage highly metastasized cases of MCC. While some chemotherapeutic regiments have been shown to have transient effects, studies have not found any significant long-term effect on recurrence rate or life expectancy. As of 2015, there were no FDA-approved standard chemotherapy regimens for MCC treatment. The most recent American guidelines do not recommend adjuvant chemotherapy, citing a lack of evidence to suggest improved outcomes. Instead, consideration of the need for chemotherapy on a case-by-case basis is recommended. Drug therapy
Immunotherapies, namely inhibitors of the PD1-PDL1 checkpoint signaling pathway, are novel anticancer agents that have shown benefit in advanced-stage MCC or chemotherapy-resistant MCC. The PD-1 pathway is responsible for regulating the balance between T-cell activation and over-activation leading to T-cell exhaustion or autoimmunity. However, over-expression of PD-1 ligands (PDL1) have been observed in tumors as a method of evading immune attack. PD-1 inhibition therefore enhances the bodys immune response, enabling it to target cancer cells for destruction.
It is a rare type of skin cancer, with a 2013 incidence of only 0.7 per 100,000 persons in the U.S. As of 2005, roughly 2,500 new cases of MCC are diagnosed each year in the United States, as compared to around 60,000 new cases of malignant melanoma and over 1 million new cases of nonmelanoma skin cancer. Similar to melanoma, the incidence of MCC in the US is increasing rapidly. Worldwide, MCC is most commonly found in regions with increased sun exposure. Australia is the country with the highest incidence of MCC but has a lower incidence of MCV-positive MCC than observed in other countries.Since 2006, it has been known that other primary cancers increase the risk of MCC significantly, especially in those with the prior multiple myeloma, chronic lymphocytic leukemia, and malignant melanoma. Immunosuppression including HIV infection or immunosuppressant therapy following organ transplant or for autoimmune disease can also increase the odds of developing MCC. History
Friedrich Sigmund Merkel (1845–1919) was a German anatomist and histopathologist who first described the Tastzellen (touch cells) in the skin in 1875. In 1878 the term Merkel cell was coined by the anatomist Robert Bonnet (1851–1921). Merkel-cell carcinoma was first described in 1972 by Cyril Toker. He reported five cases of trabecular carcinoma of the skin.