Factors Influencing Squamous Cell Carcinoma In Situ Recurrence and Implications for Treatment Choice

BACKGROUND Numerous treatment modalities have been reported for squamous cell carcinoma in situ (SCCIS). Risk factors for recurrence have not been systematically reviewed. OBJECTIVE To systematically review and summarize the data on risk factors that contribute to recurrence of SCCIS. MATERIALS AND METHODS A PubMed search was completed using the terms “SCCIS,” “Bowen's disease,” “Bowen's disease and recurrence,” and “Bowen's disease and Mohs.” These sources were cross-referenced for the terms “treatment,” “management,” “therapy,” “recurrence,” and “margins.” Studies were selected on the basis of relevance and applicable treatments. RESULTS Immunosuppression was the only variable with a statistically signficant association with progression or recurrence of SCCIS. Although there were no data directly correlating subclinical lateral extension or invasive squamous cell carcinoma within SCCIS with recurrence, evidence supports both of these as common features of SCCIS. Other potential recurrence risk factors for which there are limited supporting data included tumor size, depth of follicular extension, and location. CONCLUSION Immunosuppression was the only risk factor associated with increased risk of tumor recurrence. Subclinical tumor extension and occult invasive squamous cell carcinoma are relatively common features that theoretically could increase recurrence risk. These factors should be considered when deciding upon treatment for SCCIS. Further study is required to quantify variables that influence recurrence and to identify optimal treatment options.