Surgical delays of less than 1 year in Mohs surgery associated with tumor growth in moderately- and poorly-differentiated squamous cell carcinomas but not lower-grade squamous cell carcinomas or basal cell carcinomas: A retrospective analysis

Background: Evidence is controversial and limited concerning whether surgical delays are associated with tumor growth for cutaneous squamous cell carcinomas (SCCs) and basal cell carcinomas. Objective: Identify tumor subpopulations that may demonstrate an association between tumor growth and surgical delay. Methods: We retrospectively analyzed 299 SCCs and 802 basal cell carcinomas treated with Mohs surgery at a single institution. Time interval from biopsy to surgery represented surgical delay. Change in major diameter (Delta MD) from size at biopsy to postoperative defect represented tumor growth. Independent predictors of Delta MD were identified by multivariate analysis. Linear regression was then utilized to assess for whether the Delta MD from these independent predictors trended with surgical delay. Results: Surgical delays ranged from 0 to 331 days. Among SCCs, histologic subtype and prior treatment were identified as independent predictors of Delta MD. Significant associations between Delta MD and surgical delay were found for poorly- and moderately-differentiated SCCs, demonstrating growth rates of 0.28 cm and 0.24 cm per month of delay, respectively. The Delta MD for SCCs with prior treatment and basal cell carcinoma subgroups did not vary with surgical delay. Limitations: Retrospective design, single center. Conclusion: Surgical delays of less than a year were associated with tumor growth for higher-grade SCCs, with effect sizes bearing potential for clinical significance.