Epidemiology and Outcome of Squamous Cell Carcinoma in Epidermolysis Bullosa in Australia and New Zealand.

We investigate the epidemiology and outcomes of squamous cell carcinoma (SCC) in recessive dystrophic epidermolysis bullosa (RDEB) from the Australasian EB registry cohort. Seventeen out of 49 (34.6%) RDEB patients developed at least one SCC. Data detailing SCC was obtainable from 16/17 RDEB-SCC patients. A total number of 161 primary SCCs occurred in 16 RDEB-SCC patients with a mean of 10 SCCs per person. The earliest age of first SCC development was 16 years. Eleven out of 16 RDEB-SCC patients eventually developed metastatic SCCs. The majority of the tumours were well and moderately differentiated. The cumulative risk of SCC development by age 35 was 76.1% for RDEB-Generalized Severe (RDEB-GS) and 10% for RDEB-Generalized Intermediate (RDEB-GI). Amongst those who developed SCCs, their median time to death after first SCC was 5 years for RDEB-GI and 4 years for RDEB-GS. This is the first retrospective study of RDEB-SCC in Australasia.