More Dermatologists are Turning to Mohs for Melanoma in Situ

Dermatologists have come to view melanoma in situ (MIS) as quite the challenge. This is because the margins of this form of skin cancer are usually poorly defined. Because we are witnessing an increase in the diagnosis of MIS, it is becoming increasingly necessary for doctors to stay abreast of advances in treatment options.

Currently, the primary therapy used for MIS is wide local excision. This minor surgical technique involves tissue removal that extends up to 1 cm outside of the tumor margin. More recently, Mohs micrographic surgery has been achieving successful patient outcomes. Mohs provides the surgeon with the ability to examine the entire marginal area of a tumor during the treatment process. Wide local excision removes tissue and closes the surgical site before histopathology is performed. If the pathology report determines that cancerous cell remain, the patient faces additional treatment.

In addition to increasing efficacy in terms of cancerous tissue removal, the immediate evaluation of the cutaneous margin of a tumor has demonstrated the best cosmetic outcome, specifically for head and neck tumors and MIS on the hand or foot. Wide local excision for these areas can be enormously challenging due to the complexity of vital structures such as the mouth, nose, and eyes. Mohs micrographic surgery entails a mapping technique that guides the surgeon in finding the exact location of cancerous cells among these structures.

In theory (and also clinical practice), Mohs micrographic surgery can achieve optimal tissue preservation. Using this technique, there is no need to obtain the average 0.5 to 1.0 cm margin of healthy tissue. At the same time, it remains completely possible to observe tumor cells with a high rate of accuracy, even in ill-defined skin cancers such as MIS.

For more dermatologists to gain confidence in Mohs, we have needed reputable research data to demonstrate side-by-side performance. Historically, the comparison between wide local excision and Mohs has involved patient information from varying institutions. The parameters of the studies were too wide to make an accurate comparison. Now we have new information from a single-institution retrospective review to show us more about the value of Mohs.

In the study, researchers observed 662 cases of melanoma in situ. 277 of the patients had been treated with Mohs surgery, and 385 underwent wide local excision. The average follow-up time after treatment was just over 8 ½ years. In the Mohs group, recurrence rates were 1.8%. In the wide local excision group, that rate was 5.7%. At five years, recurrence rates were 1.1% and 4.1% respectively.

A Little Training Goes a Long Way

Instances of skin cancer continue to rise. As they do, physicians must be able to meet the growing demand for reliable treatment protocols. The American Society for Mohs Surgery has established a comprehensive membership program to support professional development in this microsurgical technique. To learn more, call (800) 616-2767.

Posted in: MOHS Surgery

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American Society for Mohs Surgery
6475 East Pacific Coast Highway, Box 700
Long Beach, CA 90803-4201
Telephone: (714) 379-6262 or
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