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Recent studies compare Mohs micrographic surgery with wide local excision for melanoma, showing Mohs for melanoma may be promising in specific clinical scenarios.
The controversy surrounding the use of Mohs micrographic surgery (MMS) in treating patients with melanoma stems from concerns about tumor upstaging risk, increased costs of the procedure, and failure of care coordination for sentinel lymph node biopsy (SLNB). Recent studies explored these concerns and compared MMS with wide local excision (WLE), the traditional melanoma surgical intervention. The results suggest there is promise in using MMS rather than WLE in certain clinical scenarios.
To provide clarity and guidance, Matthew LeBoeuf, MD, PhD, and colleagues developed a clinical review of 71 studies that compared MMS and WLE for the treatment of melanoma, including melanoma in situ and invasive melanoma. They published their findings in the Journal of the American Academy of Dermatology.
The literature review showed a lower local recurrence rate with MMS intervention (<1%) when compared with WLE (<10%). The results were similar when the reviewers specified for head and neck melanoma. Both surgical interventions yielded similar long-term survival outcomes for patients with cutaneous melanoma.
Melanoma in situ
The research team also explored the inclusion of immunohistochemistry in applying MMS in data examining the lentigo maligna (LM) and non-LM subtypes of MIS. At a median 60 months of follow-up, 1.4% of patients experienced local recurrence after MMS with immunohistochemistry versus 2.6% without immunohistochemistry.
Another study involved a 9-year follow-up on patients with melanoma in situ. Patients who underwent MMS had a local recurrence rate of 1.8%, compared with 5.7% for those who underwent WLE. A review of the data showed that patients with melanoma in situ who underwent MMS experienced benefits such as lower tumor recurrence, which limited the number of follow-up procedures needed, reduced delay of positive margins (a delay which could result in repeat excisions), resections that spared tissue in critical anatomical locations, and the opportunity for same-day reconstruction.
Invasive Melanoma
Although the National Comprehensive Cancer Network does not recommend using MMS in treating patients with invasive melanoma, the data in Dr. LeBoeuf’s review support its use in invasive melanoma at all depths, with specific efficacy in the head and neck regions. A systematic review of patients with invasive melanoma in the head and neck showed the local recurrence rate was 0.6% (n=926) in patients who underwent MMS compared with 7.7% (n=4,255) in patients who underwent WLE.
For melanoma of the trunk and extremities, efficacy data show that MMS and WLE yield similar results over 5 years of follow-up. The local recurrence rate was 1.3% for those treated with MMS and 1.4% for those treated with WLE. The melanoma-specific survival rates were 99.8% versus 99.8%, respectively, and the OS rates were 94.8% and 95%, respectively.
Cost Effectiveness
Because WLE is performed in an office setting, it is associated with a lower price point than MMS, which is sometimes performed in an operating room. A study outlining the cost of these procedures on patients with head and neck melanoma estimated an MMS operating room procedure at $5,122, an office-based MMS procedure at $2,882, and an office-based WLE procedure at $1,434. However, because MMS has benefits such as same-day and simpler reconstruction and a lower local recurrence rate, the long-term cost-effectiveness of MMS may be more advantageous than WLE.
Other major hurdles to adapting MMS in clinical protocols are the risk of upstaging and challenges with SLNB coordination. A literature review showed that upstaging risk with MMS was low, and major consequences due to changes in disease management were insignificant. As for SLNB, the researchers noted that multidisciplinary coordination in eligible cases is possible, but conclusive evidence is lacking and needs to be developed through further study.
“As use of MMS expands for melanoma with emerging long-term evidence, cases with greatest potential benefit from MMS should be prioritized given the high associated resource burden,” Dr. LeBoeuf and colleagues concluded. “Prioritization efforts should consider risk of subclinical tumor spread, local recurrence, patient mortality, comprehensive healthcare costs, and coordination of SLNB, if eligible.”
