Postoperative Defect Size as a Criterion for Upstaging High-Risk Cutaneous Squamous Cell Carcinoma Treated With Mohs...

Area of Science:

• Dermatology
• Surgical Oncology
• Cancer Staging

Background:

• Brigham and Women's Hospital (BWH) criteria classify cutaneous squamous cell carcinoma (cSCC) ≥2 cm preoperatively as high-risk.
• The significance of postoperative histologic size in cSCC staging after Mohs micrographic surgery (MMS) is not well-defined.

Purpose of the Study:

• To compare outcomes of cSCCs treated with MMS based on clinical size (<2 cm vs. ≥2 cm) and histologic size (≥2 cm).
• To evaluate the utility of postoperative defect size for cSCC risk stratification.

Main Methods:

• Retrospective analysis of cSCC cases treated with MMS at a tertiary academic center.
• Follow-up of at least 33 months postoperatively.
• Multivariable logistic regression analysis of recurrence, nodal involvement, metastasis, and disease-specific mortality.

Main Results:

• Out of 517 cSCCs, 216 were clinically ≥2 cm and 301 were histologically ≥2 cm.
• No significant differences in recurrence or lymph node spread were observed between histologically ≥2 cm and clinically ≥2 cm cSCCs.
• Histologically ≥2 cm cSCCs showed lower rates of disease-specific death (p=.010) and metastasis (p=.042); however, multivariable analysis indicated no significant difference in overall poor outcomes (OR [95% CI] = 0.37 [0.15-1.39]).

Conclusions:

• Postoperative defect size following MMS is a reliable metric for upstaging cSCC according to BWH criteria.
• Histologic size after MMS should be considered in the risk assessment and staging of cSCC.