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Garneski, K. M. & Nghiem, P. Merkel cell carcinoma adjuvant therapy: current data support radiation but not chemotherapy. J. Am. Acad. Dermatol. 57, 166-169

University of Washington Seattle, Seattle, Washington, United States
Journal of the American Academy of Dermatology (Impact Factor: 5). 08/2007; 57(1):166-9. DOI: 10.1016/j.jaad.2007.03.011
Source: PubMed

ABSTRACT Merkel cell carcinoma (MCC) is a skin cancer with 30% mortality and an incidence that has tripled in the past 15 years. There is agreement that surgical excision with negative margins is an appropriate therapeutic first step and that sentinel lymph node biopsy is a powerful prognostic indicator. After excision of detectable cancer, optimal adjuvant therapy is not well established. A role for adjuvant radiotherapy is increasingly supported by observational data. These data suggest that a regimen of surgery plus adjuvant radiotherapy is associated with both a lower loco-regional recurrence rate and longer overall survival when compared with surgery alone. In contrast, a role for adjuvant chemotherapy is not well supported. The rationale for chemotherapy in this disease is based on small-cell lung cancer, a more common neuroendocrine tumor for which chemotherapy is the primary treatment modality. Several issues call into question the routine use of adjuvant chemotherapy in MCC: lack of evidence for improved survival; the associated morbidity and mortality; important differences between small-cell lung cancer and MCC; and rapid development of resistance to chemotherapy. Importantly, chemotherapy suppresses immune function that plays an unusually large role in defending the host from the development and progression of MCC. Taken together, these arguments suggest that adjuvant radiation may be indicated for many MCC patients while adjuvant chemotherapy should largely be restricted to clinical trials.

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Available from: Paul Nghiem, Aug 28, 2015
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    • "Whether chemotherapy in the setting of metastatic disease improves survival is not established [4,5]. Furthermore, the retrospective analyses that have been conducted do not indicate that adjuvant chemotherapy improves overall survival [6,7]. "
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    ABSTRACT: Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer. The Merkel cell polyomavirus (MCPyV) is implicated in its pathogenesis. Immune mechanisms are also implicated. Patients who are immunosuppressed have an increased risk. There is evidence that high intratumoral T-cell counts and immune transcripts are associated with favorable survival. Spontaneous regressions implicate immune effector mechanisms. Immunogenicity is also supported by observation of autoimmune paraneoplastic syndromes. Case reports suggest that immune modulation, including reduction of immune suppression, can result in tumor regression. The relationships between MCPyV infection, the immune response, and clinical outcome, however, remain poorly understood. Circulating antibodies against MCPyV antigens are present in most individuals. MCPyV-reactive T cells have been detected in both MCC patients and control subjects. High intratumoral T-cell counts are also associated with favorable survival in MCPyV-negative MCC. That the immune system plays a central role in preventing and controlling MCC is supported by several observations. MCCs often develop, however, despite the presence of humoral and cellular immune responses. A better understanding on how MCPyV and MCC evade the immune response will be necessary to develop effective immunotherapies.
    03/2013; 5(1):234-54. DOI:10.3390/cancers5010234
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    • "chemotherapy suppresses immune function that may play a large role in defending the host from the development and progression of MCC [106]. "
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    ABSTRACT: The role of surgeons in the treatment of Merkel cell carcinoma (MCC) of the skin is reviewed, with respect to diagnosis and treatment. Most of the data in the literature are case reports. Surgery is the mainstay of treatment. A wide local excision, with sentinel node (SLN) biopsy, is the recommended treatment of choice. If SLN is involved, nodal dissection should be performed; unless patient is unfit, then regional radiotherapy can be given. Surgeons should always refer patients for assessment of the need for adjuvant treatments. Adjuvant radiotherapy is well tolerated and effective to minimize recurrence. Adjuvant chemotherapy may be considered for selected node-positive patients, as per National Comprehensive Cancer Network guideline. Data are insufficient to assess whether adjuvant chemotherapy improves survival. Recurrent disease should be treated by complete surgical resection if possible, followed by radiotherapy and possibly chemotherapy. Generally results of multimodality treatment for recurrent disease are better than lesser treatments. Future research should focus on newer chemotherapy and molecular targeted agents in the adjuvant setting and for gross disease.
    01/2013; 2013(2):850797. DOI:10.1155/2013/850797
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    • "The poor life expectancy observed in patients with MCC is a result of the aggressive nature of the disease and the high rate of metastases. Though no randomized trials have been conducted, observational data supports postoperative adjuvant radiotherapy [39]. Clark et al. showed that although adjuvant radiotherapy did not confer an improvement in disease-free survival in all stages, subset analysis showed that stage II patients demonstrated both improved DFS and DSS with adjuvant radiotherapy. "
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    ABSTRACT: Introduction. Merkel cell carcinoma is a rare form of non-melanoma skin cancer of neuroendocrine origin. Optimal management of patients is controversial and the role of radiotherapy is unclear. Purpose. The purpose of this study was to review the efficacy of RT in the treatment of both local and distant metastatic disease from MCC. Methods. A literature search was conducted in MEDLINE (1946—January Week 1 2012) and Embase (1980–2012 Week 2). Articles of interest analyze the efficacy of radiotherapy for treatment of metastatic MCC and did not exclude case reports. Results. All articles except one focusing on the role of radiotherapy were of retrospective origin or case series. Significant limitations applied in all studies due to limited sample sizes and the retrospective nature of these studies. Radiotherapy improves locoregional control in the adjuvant setting, and many series suggest an improvement in overall survival. In cases where surgery is not possible, definitive radiotherapy may be an as-efficacious alternative. The radiosensitive nature of MCC coupled with existing reports suggests that treatment via current protocols for other primary tumors is adequate. Conclusion. Further studies should be conducted prospectively to clarify the true role of radiotherapy in metastatic MCC.
    07/2012; 2012(2090-2905):654981. DOI:10.1155/2012/654981
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