The use of Mohs micrographic surgery (MMS) alone in patients with high-risk squamous cell carcinoma (hrSCC) provides excellent marginal control and may lower the rate of local recurrence, nodal metastasis, and disease-specific death, according to the results of a retrospective chart review published in the Journal of the American Academy of Dermatology.
The investigators sought to report on the rate of poor outcomes in patients with hrSCC treated with MMS alone and to ascertain whether any specific clinical factors may be more predictive of these outcomes. They identified all cases of primary cutaneous SCC (cSCC) treated at their clinic between October 1, 2011 and December 1, 2015.
A total of 647 hrSCC tumors met study inclusion criteria. The mean patient age at the time of treatment was 74.8±11.2; 78.7% of the patients were men and 10.5% were immunocompromised. The median follow-up was 36 months (range, 12 to 192 months). The median size of the tumors was 2.1 cm; 57.7% of the SCCs were ≥2 cm in diameter.
During the follow-up period, 2.9% (19 of 647) of hrSCCs exhibited local recurrence, 4.8% (31 of 647) of tumors had nodal metastases, 1.1% (7 of 647) of hrSCCs exhibited distant metastases, and 1.1% (7 of 647) of tumors resulted in disease-specific death. Multivariate analysis demonstrated that poor histologic differentiation and invasion beyond the subcutaneous fat were both positively associated with local recurrence, nodal metastasis, and disease-specific death.
The investigators concluded that poor outcomes are most likely associated with tumors that have spread beyond subcutaneous fat and tumors with poor histologic differentiation. Continued elucidation of what constitutes hrSCC will help clinicians recognize which tumors might benefit from adjuvant prognostic testing, such as sentinel node biopsy or genetic expression profiling. These results should prove important to dermatologists because they can help guide the selection of treatment modalities for hrSCC.
Marrazzo G, Zitelli JA, Brodland D. Clinical outcomes in high-risk squamous cell carcinoma patients treated with Mohs micrographic surgery alone [published online September 19, 2018]. J Am Acad Dermatol. doi:10.1016/j.jaad.2018.09.015