An evidence-based, peer-reviewed journal for practicing clinicians in the field of dermatology
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38 JCAD journal of clinical and aesthetic dermatology April 2017 • Volume 10 • Number 4 r E v i E W of genetic syndromes), and key tumor characteristics predictive of future recurrence. 2 While many surgical and oncological organizations have established guidelines for the treatment of NMSC, great variations exist between the societies. Developing a collaborative consensus between organizations can help alleviate mounting frustration associated with these common cancers. This article provides a comprehensive global review of the current guidelines on surgical excision margins for basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), dermatofibrosarcoma protuberans (DFSP), and Merkel cell carcinoma (MCC). DISCUSSION Basal cell carcinoma. BCC and cSCC are recognized as the most common malignant skin cancer worldwide. Of the estimated 5.4 million BCC and cSCC diagnosed each year, approximately 80 percent are BCC. 2 Sun exposure is a well- established, leading risk factor, with 85 percent of BCC lesions affecting sun-exposed areas and the nose accounting for approximately 25 to 30 percent. 3 Micronodular, infiltrative, and morpheaform patterns have greater tendencies toward aggressive behavior. Collectively, however, among the BCC subtypes, the risk of metastasis is low. 3 Primary lesions in the head and neck have greater tendencies toward recurrence, while those affecting the ears, genitalia, and other mucosal surfaces carry higher risk of metastasis. Early recognition is key in preventing onset of advanced disease. 4 National Comprehensive Cancer Network. The National Comprehensive Cancer Network (NCCN) guidelines on surgical margin selection of BCC are categorized as low and high risk, based on risk of recurrence. Low- risk BCC describes primary lesions with well-defined borders, less than 20mm in Area L, less than 10mm in Area M, less than 6mm in Area H, and of the nodular or superficial subtype (Table 1). High-risk lesions include those that are recurrent, have poorly defined margins, are greater than or equal to 20mm in Area L, greater than or equal to 10mm in Area M, or greater than or equal to 6mm in Area H. This includes more aggressive patterns, such as morpheaform, basosquamous, sclerosing, mixed infiltrative, or micronodular subtypes. Hosts with history of immunosuppression and/or radiation, as well as those with existing perineural or bone involvement, are additionally considered high risk. 3 NCCN recommendations stem from a large study by Wolf and Zitelli involving 117 cases of BCCs which were either less than or greater than 2cm in diameter and excised via a MMS approach. 4,5 For BCCs less than 2cm, complete removal of the lesion was achieved in 95 percent of cases via SE with 4mm peripheral surgical margins. 4,5 For BCCs greater than 2cm, margins greater than 4mm are recommended. Alternatively, MMS is considered first-line treatment in high- risk BCCs. 4 Per the NCCN, biopsy should target a depth to the deep reticular dermis if there is concern for local invasion, though deep margin recommendations during excision are not specified. 4 [Abstract continued] margin selection for d ermatofibrosarcoma protuberans and Merkel cell carcinoma. Conclusion: Although guidelines exist, there is a need for international collaboration and consensus to determine a more unified and evidence-based approach to surgical excision as a treatment for nonmelanoma skin cancer. J Clin Aesthet Dermatol. 2017;10(4):37–46.