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.

Dermatofibrosarcoma Protuberans Re-excision and Recurrence Rates in the Netherlands Between 1989 and 2016.

Dermatofibrosarcoma protuberans is a rare soft tissue tumour with a very low (p < 0.5%) rate of metastasis. Rates of re-excision and recurrence were determined using data from the Netherlands Cancer Registry between 1989 and 2016. Of the 1,890 instances of dermatofibrosarcoma protuberans included, 87% were treated with excision, 4% with Mohs micrographic surgery, and 9% otherwise or unknown. Linked pathology data were retrieved for 1,677 patients. Half of all excisions (847/1,644) were incomplete and 29% (192/622) of all re-excisions were incomplete. The cumulative incidence of a recurrence was 7% (95% confidence interval (95% CI) 6-8) during a median follow-up of 11 years (interquartile range (IQR) 6-17). After Mohs micrographic surgery (n = 34), there were no recurrences during a median follow-up of 4 years (IQR 3-6). Due to the high rate of incomplete excisions and recurrences after excision, this study supports the European guideline, which recommends treating dermatofibrosarcoma protuberans with Mohs micrographic surgery in order to decrease the rate of recurrence.