Mohs Treatment for Skin Cancer

Mohs micrographic surgery is a type of cancer treatment that targets a tumor in its exact location and removes it without also removing healthy tissue surrounding it. This is a very specialized surgery that is typically for patients who have a recurring tumor, have a type of cancer that is likely to recur or have a cancer that is located in very sensitive areas of the body, such as the face or hands.

Function

• Mohs surgery is particularly a skin cancer procedure, in the cases of basal and squamous cell carcinomas and, sometimes, melanoma. In determining whether a patient should be a candidate for Mohs, the doctor will check to see if the cancer is widespread, if its edges are indeterminate, if it's metastasizing rapidly, if there is scar tissue in the cancerous area, if the cancer is in a cosmetically sensitive area and if the cancer has recurred.

Advantages

• Mohs surgery targets the tumor in its precise location and eliminates it from the roots, so the healthy tissue around the tumor is spared, unlike in other types of surgeries, which can ruin healthy tissue while trying to eliminate the damaged tissue. It is highly appropriate for skin cancers, because skin cancers can be much larger than they appear to be on the surface. The roots of skin cancer can go deep into the skin, blood vessels, cartilage and nerves, and cancers can recur beneath the scar tissue of previously treated areas. Mohs can examine these hidden tumorous areas and determine exactly how much tissue to take out and where. The resulting skin defect will typically be only slighter bigger than the cancer itself, so Mohs has a cosmetic advantage for patients, especially if the cancer is on the face, hands, feet or genitals.

Procedure

• Mohs is an outpatient procedure, during which the patient is fully conscious and experiences minimal discomfort. In the first part of the procedure, the surgeon anesthetizes and removes the visible cancerous area on the surface of the skin and an additional layer of tissue. The extracted tissue is sliced and diagrammed, frozen and examined under a microscope. The surgeon looks for the roots of the cancer, examines the additional layer of tissue removed to see if it is cancerous, then creates a Mohs map that diagrams the nature and location of the cancer. The surgeon uses the Mohs map as a guide to removing the cancerous tissue. He goes through this process several times to make sure that he removes all the cancer. The process usually takes only one day, often less than 4 hours.

Postsurgery

• Mohs surgery will leave a scar, as with all other types of surgery, but the scar will be fairly minimal. Patients can choose to let the wounds heal naturally. Collagen implants, laser resurfacing, chemical peeling and skin grafting are other options. The scars often become less noticeable over time. There is a chance that the cancer could recur, so patients should schedule postsurgical checkups.

Success Rate

• Statistically, in two out of five patients who have a certain type of skin cancer, recurrence happens in five years after treatment. Several medical institutions around the world, including the Mayo Clinic, have conducted studies on Mohs surgery, and they find that Mohs results in a cure rate of more than 99 percent for new cancers and 95 percent for cancers that have recurred.