Rate and Characteristics of Incompletely Excised Cutaneous Squamous Cell Carcinoma: A Dermatological Daily Practice Multicenter Prospective Cohort Study

BACKGROUND: Incomplete excision of squamous cell carcinoma (cSCC) is associated with an increased risk of recurrence, metastasis, and mortality. OBJECTIVE: To determine the rate and characteristics of incompletely excised cSCC in a dermatological daily practice setting. METHODS: Prospective study of all patients who gave informed consent, with a cSCC treated with standard excision (SE) at 1 of 6 Departments of Dermatology in the Netherlands between 2015 and 2017. Pathological reports were screened to detect all incompletely excised cSCCs. RESULTS: A total of 592 patients with 679 cSCCs were included, whereby most cases were low risk cSCC (89%). The rate of incompletely excised cSCC was 4% (n = 26), and the majority were high-risk cSCCs of which 24 invaded the deep excision margin. CONCLUSION: This prospective study showed that in a dermatological setting, the risk of an incompletely excised cSCC is low (4%) for a cohort that was dominated by low-risk cSCCs. Most incompletely excised cSCCs were of high risk, and incompleteness was almost always at the deep margins. These results suggest that for high-risk cSCC, one should pay attention especially to the deep margin when performing SE, and/or microscopic surgery should be considered