Incomplete Excision of Squamous Cell Carcinoma of the Skin: A Prospective Observational Study

Background: Squamous cell carcinoma is the second most common cancer of the skin. It behaves differently from basal cell carcinoma. Few large-scale studies have identified risk factors for incomplete excision of cutaneous squamous cell carcinoma. The authors report the largest prospective study to identify the risk factors for incomplete excision of these lesions. Methods: A total of 517 histopathologically confirmed squamous cell carcinomas were excised from January of 2001 to December of 2002 at the Peter MacCallum Cancer Institute. Of these, 480 primary excisions were analyzed. Data pertaining to patient age, sex, lesion size, margin of excision, recurrence, previous excision, site, anesthetic choice, and repair method were collected prospectively. Results: The overall incomplete excision rate was 6.3 percent. Lesions on the ear (p < 0.003), re-excisions (p < 0.001), and invasive lesions (p < 0.001) were associated with the highest incomplete resection rates. Age (p = 0.61), sex (p = 0.075), tumor size (p = 0.521), surgeon’s experience (p = 0.092), and recurrent lesions (p = 0.408) were not statistically significant risk factors. Conclusions: Statistically significant risk factors were ear lesions, invasive lesions, and previously incompletely excised lesions referred for re-excision. The authors recommend more care with tumor markings, taking margins of at least 5 mm, using deeper margins, and referring patients to more experienced centers.