Mohs Micrographic Surgery Versus Wide Local Excision in the Treatment of Merkel Cell Carcinoma: A Systematic Review.

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive neoplasm with high rates of recurrences. Current guidelines recommend wide local excision (WLE) with 1 to 2 cm margins. However, Mohs micrographic surgery (MMS) offers a potential advantage over WLE because of its ability of sparing healthy tissue and assessing 100% of margins.

OBJECTIVE

To systematically evaluate the surgical modalities for the treatment of MCC.

MATERIALS AND METHODS

Eligible articles were identified using MEDLINE, Scopus, EMBASE, and Cochrane Library. All available studies investigating surgical treatment of MCC with WLE or MMS were considered.

RESULTS

Forty studies met the inclusion criteria. Thirty-one studies described patients treated with WLE, 3 with MMS, and 6 with either WLE or MMS. Subgroup analysis of Stage I MCC showed recurrence rates similar in both surgical modalities with local recurrence rate of 6.8% for WLE versus 8.5% for MMS (p = .64) and a regional recurrence rate of 15.2% for WLE versus 15.3% for MMS (p = .99).

CONCLUSION

Overall WLE cases were at a higher stage at presentation. Subgroup analysis showed that MMS is not inferior to WLE excision for the treatment of Stage I MCC and is a reasonable option for anatomic locations where tissue sparing is important.