Current Clinical Trials

Note: Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)

Wide local excision has been recommended whenever possible for patients with stage I Merkel cell carcinoma (MCC).[1-3][Level of evidence: 3iiiDiii] Frozen section control has also been recommended, especially when the tumor is in an anatomical site that is not amenable to wide margins. Some authors have advocated the use of Mohs micrographic surgery as a tissue-sparing technique. The reported relapse rate is similar to or better than that of wide excision, but comparatively few cases have been treated in this manner and definitive clinical studies have yet to be conducted.[2,4,5]

The role of elective lymph node dissection (ELND) in the absence of clinically positive nodes is unclear. ELND has been recommended for larger tumors, tumors with more than 10 mitoses per high-power field, lymphatic or vascular invasion, and the small-cell histologic subtypes.[1-3] Sentinel lymph node (SLN) biopsy has been suggested as an alternative to complete ELND for the proper staging of MCC. SLN biopsy has lower morbidity than complete nodal dissection. Furthermore, for MCC sites with indeterminate lymphatic drainage, such as those on the back, SLN biopsy techniques can be used to identify the pertinent lymph node bed(s). Several reports have found the use of SLN biopsy techniques in patients with MCC to be reliable and reproducible.[6-9] A meta-analysis found that SLN positivity is strongly predictive of a high short-term risk of recurrence and that subsequent therapeutic lymph node dissection was effective in preventing short-term regional nodal recurrence.[10]

Because of the aggressive nature of MCC and the high incidence of locoregional recurrence after surgery alone, many authors advocate adjuvant radiation therapy to the primary site and to the regional lymph node basin.[1,2,4,11] Convincing data from prospective trials are not available; based on retrospective reviews, however, radiation therapy has been used in patients with larger tumors, tumors with lymphatic invasion, tumors approaching the surgical margins of resection, and locally unresectable tumors. Improved locoregional control has been achieved with resection followed by radiation therapy as compared to surgery alone in some retrospective nonrandomized reports.[12] Studies suggest that the appropriate total dose is about 50 Gy to the surgical bed and the draining regional lymphatics, delivered in 2 Gy fractions.[1,2,11-13] For patients with unresected tumors or tumors with microscopic evidence of spread beyond resected margins, higher doses of 56 Gy to 65 Gy have been recommended.[1][Level of evidence: 3iiiDiii]

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage I neuroendocrine carcinoma of the skin. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References

1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and treatment. Dermatol Surg 21 (8): 669-83, 1995.  [PUBMED Abstract]
   
   
2. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. J Am Acad Dermatol 29 (2 Pt 1): 143-56, 1993.  [PUBMED Abstract]
   
   
3. Yiengpruksawan A, Coit DG, Thaler HT, et al.: Merkel cell carcinoma. Prognosis and management. Arch Surg 126 (12): 1514-9, 1991.  [PUBMED Abstract]
   
   
4. Goepfert H, Remmler D, Silva E, et al.: Merkel cell carcinoma (endocrine carcinoma of the skin) of the head and neck. Arch Otolaryngol 110 (11): 707-12, 1984.  [PUBMED Abstract]
   
   
5. Nghiem P, McKee PH, Haynes HA: Merkel cell (cutaneous neuroendocrine) carcinoma. In: Sober AJ, Haluska FG, eds.: Skin Cancer. Hamilton, Ontario: BC Decker Inc., 2001., pp 127-141. 
   
   
6. Messina JL, Reintgen DS, Cruse CW, et al.: Selective lymphadenectomy in patients with Merkel cell (cutaneous neuroendocrine) carcinoma. Ann Surg Oncol 4 (5): 389-95, 1997 Jul-Aug.  [PUBMED Abstract]
   
   
7. Hill AD, Brady MS, Coit DG: Intraoperative lymphatic mapping and sentinel lymph node biopsy for Merkel cell carcinoma. Br J Surg 86 (4): 518-21, 1999.  [PUBMED Abstract]
   
   
8. Wasserberg N, Schachter J, Fenig E, et al.: Applicability of the sentinel node technique to Merkel cell carcinoma. Dermatol Surg 26 (2): 138-41, 2000.  [PUBMED Abstract]
   
   
9. Rodrigues LK, Leong SP, Kashani-Sabet M, et al.: Early experience with sentinel lymph node mapping for Merkel cell carcinoma. J Am Acad Dermatol 45 (2): 303-8, 2001.  [PUBMED Abstract]
   
   
10. Mehrany K, Otley CC, Weenig RH, et al.: A meta-analysis of the prognostic significance of sentinel lymph node status in Merkel cell carcinoma. Dermatol Surg 28 (2): 113-7; discussion 117, 2002.  [PUBMED Abstract]
    
    
11. Gollard R, Weber R, Kosty MP, et al.: Merkel cell carcinoma: review of 22 cases with surgical, pathologic, and therapeutic considerations. Cancer 88 (8): 1842-51, 2000.  [PUBMED Abstract]
    
    
12. Goessling W, McKee PH, Mayer RJ: Merkel cell carcinoma. J Clin Oncol 20 (2): 588-98, 2002.  [PUBMED Abstract]
    
    
13. Marks ME, Kim RY, Salter MM: Radiotherapy as an adjunct in the management of Merkel cell carcinoma. Cancer 65 (1): 60-4, 1990.  [PUBMED Abstract]
    
    

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