Stage I Merkel Cell Carcinoma
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).[1,2,3][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.[1,2,3] 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.[6,7,8,9] 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.[1,2,11,12,13] 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]
WebMD Public Information from the National Cancer Institute
Today in Cancer
WebMD Special Sections
Health Solutions From Our Sponsors
©2005-2012 WebMD, LLC. All rights reserved.
WebMD does not provide medical advice, diagnosis or treatment. See additional information.