Researchers from the Netherlands have reported that Moh’s micrographic surgery (MMS) for the treatment of recurrent basal cell carcinoma (BCC) of the face results in fewer recurrences than surgical excision. The initial results of this study with an 18-month follow-up were reported in the Lancet in 2004. The current report is a five-year follow-up of this study and appears in the December 2008 issue of the Lancet Oncology.[1]

Basal cell carcinoma is the most common form of skin cancer and affects 800,000 Americans each year. This also makes BCC the most common cancer occurring in humans. It has been estimated that one out of every three new cancers is a skin cancer, with the vast majority being BCC. The number of new cases has increased each year in the last few decades, but the average age of onset of the disease has steadily decreased. More men than women get BCC, but there has been an absolute increase in incidence in women. Chronic exposure to sunlight is the cause of almost all BCCs, which occur most frequently on exposed parts of the body. Treatments for BCC include surgical excision, MMS, curettage, cryosurgery, laser treatment, surgical excision with predetermined margins of clinically normal tissue, surgical excision under frozen section control, MMS, radiotherapy, immunomodulations, and chemotherapy.

In a previous review, researchers found only 25 comparative studies that covered seven therapeutic categories. They pointed out that most of the literature on BCC consists of uncontrolled reports of a single treatment. They found only one study that measured recurrence at four years. This trial showed superiority of surgery with frozen section control over treatment with radiation therapy. They also reported that radiation is associated with long-term cosmetic defects. From this review, they concluded that “surgery and radiotherapy seem to be the most effective treatments; surgery showed the lowest failure rates. Other treatments might have some use, but need to be compared with surgery.”

Moh’s micrographic surgery has been used to treat BCC for over 60 years and was developed by Frederick Moh's in the early 1940s. This technique uses curettage and real-time evaluation of the removed quadrants by frozen section to determine completeness of tumor eradication. This technique was developed because conventional surgery, which uses an arbitrary margin, did not always remove the entire viable tumor. A Google search for Moh’s micrographic surgery revealed 20,800 sites, many of which were surgeons or surgical practices claiming superiority for this technique with a “99% cure rate” for BCC.

The current study is the only randomized trial comparing surgical excision to MMS for treatment of BCC. In this study 408 patients with primary BCCs and 204 with recurrent facial BCCs were randomly allocated to receive conventional surgery or MMS. Three hundred ninety-seven patients with primary and 199 with recurrent BCCs were actually treated. At the end of 18 months of follow-up, the recurrence rate was 3% after surgical excision and 2% after MMS for primary tumors. For recurrent tumors, the recurrence rate was 3% after surgical excision and 0% after MMS. Surgical defects were slightly larger with conventional surgery than with MMS. They also reported that “a quarter of all aggressive carcinomas of 1 cm or more in diameter and about a third of all recurrent carcinomas were incompletely excised with a 3 mm margin. MMS is preferable to use for these tumors to avoid larger defects, a poor aesthetic outcome, and functional problems.” The cost of MMS was approximately twice as much as for conventional surgery, which was due to “higher staff costs due to longer operation times.” These authors stated that no conclusions could be made from this study about ultimate recurrence rates.

After five years of follow-up, 113 patients with primary BCC and 52 patients with recurrent BCC were lost to follow-up. The recurrence rate in patients with primary BCC was 4% for surgical excision and 2.5% for MMS (p=0.397). The recurrence rates for patients with recurrent BCC was 2.4% for MMS and 12.1% for MMS (p=0.015).  The researchers concluded that MMS is preferred over surgical excision for the treatment of facial recurrent BCC because it produces significantly fewer recurrences.

Comments: This is an important study since it shows that MMS has no significant advantage as primary treatment of BCC, which has been claimed for years. However, MMS was found to be more effective for recurrent BCC. The major problem with this study is the relatively large number of patients who were lost to follow-up.

Reference:

[1] Mosterd K, Krekels GAM, Nieman FHM, et al. Surgical excision of Moh’s micrographic surgery for primary and recurrent basal-cell carcinoma of the face: a prospective randomised controlled trial with 5-years’ follow-up. Lancet Oncology. 2008; 9:1149-1156.