INTRODUCTION
Nonmelanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is the most common malignancy in Caucasian populations worldwide. However, because NMSC are typically not reported to national and state registries, the exact incidence rates are unknown and are likely underestimated. In the United States, it is estimated that over 5.4 million cases of NMSC are treated in more than 3.3 million people annually and that the incidence is increasing each year.1 A significant increase in NMSC diagnosed in patients younger than 40 years, particularly in women diagnosed with BCC, has been reported.2-4 Yet, little is known about this patient population beyond age and gender. Additionally, as many of these patients are being treated with Mohs micrographic surgery (MMS), the surgical implications of both patient and tumor characteristics in this patient population become of greater clinical interest. The purpose of this study was to further investigate patient demographics and tumor characteristics in patients younger than 50 years undergoing MMS for NMSC at a large, referral-based practice. Differences in tumor characteristics based on gender, age range, smoking status, immunosuppression, and hormonal influence in this patient population were also considered. In particular, this study aimed to elucidate patient characteristics that may predispose to high-risk tumor characteristics or more extensive surgical intervention.
METHODS
After institutional review board approval, a retrospective chart review was performed on consecutive patients younger than 50 years treated with MMS for BCC or SCC from January 2009 to December 2013. This population was treated at the Laser & Skin Surgery Center of New York, a referral-based, private practice, outpatient surgical center, where nearly 3,000 MMS are performed annually. Given the relative infrequency of NMSCs such as dermatofibrosarcoma protuberans (DFSP), merkel cell carcinoma, and atypical fibroxanthoma, patients undergoing MMS for treatment of these tumors were excluded. Data were collected on patient age, gender, Fitzpatrick skin type (FST), personal and family history of NMSC or malignant melanoma, and smoking, immunosuppression, and hormonal status at the time of initial presentation for MMS within the study period. Family history was considered positive if the patient reported a parent with NMSC or MM. Patients were considered immunosuppressed if they