Mohs Surgery for the Treatment of Skin Cancer: A Review of Guidelines [Internet]

Excerpt

Skin cancer is an abnormal growth of skin cells – usually caused by exposure to ultraviolet radiation. The two most common types of skin cancers basal cell carcinoma and squamous cell carcinoma (usually grouped under non-melanoma skin cancers - NMSC).^, Melanoma, a less common but the most deadly form of skin cancer lead to 1,250 Canadian deaths in 2017.^, Other less common types of skin cancer include Merkel cell carcinoma, dermatofibrosarcoma protuberans, atypical fibroxanthoma and sebaceous carcinoma. Skin cancers can be invasive (invading through the basement membrane) or in situ (confined to the epidermis), and tumour characteristics such as size, location, and pathology influence the risk for deep tumour invasion and recurrence after treatment.

Treatment for non-melanoma skin cancer usually includes surgical removal of the tumour, while treatment for melanoma may include surgery, radiation therapy, chemotherapy, and immunotherapy. Surgery for small skin cancer lesions can include simple excision, electrodesiccation and curettage, or cryosurgery; surgery for larger or recurrent lesions may include conventional wide excision of the tumour, or Mohs surgery. Mohs surgery, also known as Mohs micrographic surgery (MMS) is a surgical procedure in which thin layers of the tumour are progressively removed and examined until only cancer-free tissue remains, and can be done in a single visit at an outpatient clinic.^, The increased precision of MMS can also decrease scarring and reduces the likelihood for needing additional treatment or surgeries. Clinical evidence up to date showed that, compared with conventional surgical excision, MMS led to a significant higher cure rate for treatment of recurrent NMSC, and may have a role in the treatment of melanoma in situ and some other unusual skin cancers such as Merkel cell carcinoma and dermatofibrosarcoma protuberans.^,

With a noticeable increase in use of MMS and associated expenditures in Canada, this Rapid Response report aims to review the evidence-based guidelines associated with the use of Mohs surgery for the treatment of skin cancer.