Risk factors for positive margins after wide local excision of cutaneous squamous cell carcinoma

Background and objectives: The standard treatment for cutaneous squamous cell carcinoma (cSCC) is wide local excision (WLE). Incomplete tumor excision is associated with increased recurrence rates and mortality risk. Risk factors for positive margins after WLE of cSCC has been examined in only a few studies. We sought to assess the influence of several clinicopathological factors on margin status in the largest cSCC population to date.Methods: We performed a retrospective review of records at two skin cancer clinics identifying patients with biopsy-proven cSCC who underwent WLE. We mined clinicopathological information for eligible subjects including age, gender, lesion location, immunosuppression, previous treatment, lesion size, biopsy type, tumor subtype, tumor thickness, degree of differentiation, ulceration and perineural invasion.Results: A total of 1468 patients were eligible and 117 (8%) had positive margins after WLE. Older age at diagnosis (p=.011), lesion location on the head and neck (p<.001), previous treatment (p<.001), increased lesion diameter (p<.001), invasive subtype (p=.020) or increased tumor thickness (p<.001) were statistically significant risk factors for positive surgical margins.Conclusions: Our results present an opportunity to stratify cSCC patients into low- or high-risk for incomplete tumor clearance after WLE based on several clinicopathological factors. These findings should educate and inform the dermatologic surgeon's choice of primary management of cSCC.