High-risk Mohs Surgery Outcomes Superior to Historical Data for cSCC, Study Shows

New data suggest that Mohs micrographic surgery (MMS) has made a significant difference in the outcomes of patients with high-risk cutaneous squamous cell carcinomas (cSCC). Investigators say the procedure lowers the risk of disease-specific death vs wide local excision (WLE) and reduces the rate of regional metastatic disease.

The study was published in Journal of the American Academy of Dermatology.

The authors noted that cSCC rates have been rising steadily, such that deaths from cSCC are expected to exceed those of melanoma within the next 5 years. That’s largely due to the prevalence of local recurrence (LR), nodal metastasis (NM), and disease-specific death among a small subset of high-risk patients, the authors said.

Still, they wrote that although patients with high-risk cSCC cases have historically faced poor prognoses, much of that pessimism is based on studies in which patients were treated with WLE.

The investigators wanted to see whether MMS might improve patient outcomes, including in cases where patients underwent salvage head/neck dissection for regional nodal metastases.

They used a pool of high-risk patients (N = 527) treated at their clinics between January 1, 2000, and January 1, 2020. Collectively, the patients had 581 high-risk primary cSCC, and follow-up data were available on 579 of those tumors. All of the patients were treated with MMS alone.

An analysis showed that the overall 5-year disease-specific survival rate was 95.7%, even though the patients were considered high risk. That translated into a mean survival time of 18.6 years.

“Importantly, these results were achieved without adjuvant therapies such as postoperative radiation, sentinel lymph node biopsy, or elective neck dissection,” the authors wrote.

Five-year LR-free survival, regional NM-free survival, and distant metastasis-free survival rates were similarly high, at 96.9%, 93.8%, and 97.3%, respectively. At 5 years, the progression-free survival rate from metastatic disease was 92.6%; at 10 years, 90.0%.

“The results of our study demonstrate excellent survival outcomes for patients with high-risk cSCCs when comprehensive margin analysis with MMS is utilized for tumor control,” the authors said.

Comprehensive margin analysis is critical, they emphasized. In the authors’ clinics, high-risk patients undergo routine clinical tumor surveillance examinations every 2 to 3 months.

“Importantly, a clinical regional lymph node exam is performed at each visit, and specific emphasis is placed on patient teaching of weekly self-palpation of the draining lymph node basins,” they said.

In the 32 patients who developed regional nodal metastases, among those who underwent salvage head and neck dissection with or without radiation, the 2-year disease-specific survival rate was 90.5%, while the 5-year disease-specific survival rate was 69.3%. Those patients had a median survival of 9.8 years following their salvage procedures.

The authors believe their study represents the largest ever cohort of high-risk cSCC cases treated exclusively with MMS. They said the data suggest MMS has led to a significant improvement in patient outcomes.

“We demonstrate that MMS confers a disease-specific survival advantage over historical WLE for high-risk tumors,” they concluded. “Moreover, by improving local tumor control, MMS appears to reduce the frequency of regional metastatic disease and may confer a survival advantage even for those patients who develop regional nodal metastases, as evidenced by our postsalvage disease-specific survival outcomes.”

Reference

Soleymani T, Brodland DG, Arzeno J, Sharon DJ, Zitelli JA. Clinical outcomes of high-risk cutaneous squamous cell carcinomas treated with Mohs micrographic surgery alone: an analysis of local recurrence, regional nodal metastases, progression-free survival, and disease-specific death. J Am Acad Dermatol. Published online June 24, 2022. doi:10.1016/j.jaad.2022.06.1169