Basal Cell Carcinoma around the Eyes: to Mohs or not Mohs, that is the question ! (Skin Surgery)

Basal Cell Carcinoma (BCC) is the most frequent skin cancer. It is a keratinocyte carinoma (KC) and is related to chronic cumulative sun exposure.
-It can appear anywhere on the body except non-follicular area such as the glabrous skin of the palms and soles.
-In areas BCC can be rapidly growing such as around the eyes (click HERE to read more)
-When doing a treatment, tissue is precious and a curative excision needs to take into account volume loss in the final result.

Treatment can be done by normal surgical excision, but Mohs micrographic surgery is the Gold standard: however this procedure is very costly (To read more about Mohs surgery, click HERE)

–Normal surgery = excision of the tumor without histological examination during the procedure. The tumor is visually removed completely and a small surrounding amount of tissue is removed (called an “Excision Margin“)
–Mohs Micrographic Surgery = the edge of the tumor is examined “during” the treatment session and additional tissue is removed until the tissue is free of tumoral tissue.

-In this Canadian Study, all patients attending the Mohs Surgery Unit of the University of Ottawa between 2011 and 2015 were included.

Results found were that:

Surgical excision of BCC with a 2mm excision margin is not enough*:
-in 75% of cases, tumor extends past the excision limit

Surgical excision of BCC with a 4mm excision margin is insufficient
-indeed in this group 35% had a larger Mohs excision size (and in 10% of cases, the difference was more than 1cm) (In NODULAR BCC, the results were 66% and 17% respectively)
-however there was no statistically significant difference between the 4mm and Mohs groups

Conclusions of the study
–Mohs surgery remains the best treatment for excision of BCC around the eyes. Limitations is that this procedure is costly and time consuming
-Where this is not possible, 4mm margins or more should be used, although there remains a risk of recurrence
-BCC of nodular histologic type behaves in a more aggressive way around the eyes, and Mohs surgery should be the only surgical treatment

*Even though previous studies have shown that treatment with 2mm margins may be a safe and efficient alternative, especially for nodular basal cell carcinomas.

Reference: Poster 2336  – Chan S et al. Comparison between 2mm margin excision, 4mm margin excision, and Mohs excision, in periorbital basal cell carcinomas. AAD Annual Meeting 2016, Washington DC, USA (United States of America)