Immunosuppression predicts poor outcomes in Mohs-treated SCC patients

Perineural invasion, poor differentiation, and immunosuppression are associated with poor clinical outcomes in patients with high-risk cutaneous squamous cell carcinomas (SCC), but Mohs micrographic surgery (MMS) is still an effective treatment, according to a study.

“Current SCC staging systems may be limited by inconsistent inclusion of poor differentiation,” the authors said. “Immunosuppression, especially transplant, should be considered a high-risk clinical feature.”

This single-institution, retrospective cohort analysis was conducted to determine the rates of local recurrence, metastatic disease, and disease-specific death in high-risk SCCs treated with MMS as well as patient- or tumour-related factors associated with poor outcomes. This study also addressed the limited literature on the long-term outcomes and prognostic factors of high-risk SCC treated with MMS.

Of the 882 high-risk SCC patients treated with MMS, 842 were treated with MMS alone and the rest with MMS and adjuvant therapy over a median follow-up time of 2.4 years. The rates of local recurrence, metastatic disease, and disease-specific death were 2.5 percent, 1.9 percent, and 0.57 percent, respectively.

Perineural invasion, poor differentiation, and immunosuppression significantly contributed to poor outcomes in patients. Of note, progression-free survival did not differ considerably in propensity score-matched patients treated with adjuvant therapy and controls treated with MMS alone, but matching was not perfect.

“Further study is needed on the effect of adjuvant treatment,” the authors said, adding that the study was limited by its single-institution, retrospective nature.