Abstract LB-245: Loss of function of the TGFβRI receptor leads to the spontaneously regressing squamous carcinoma condition, multiple self-healing squamous epithelioma (Ferguson-Smith disease)

A re-examination has been carried out of the region on chromosome 9 containing the locus responsible for Ferguson-Smith disease, or multiple self-healing squamous epithelioma (MSSE/FSD); this is a rare autosomal dominant inherited condition first identified in the west of Scotland, that presents with multiple squamous cell skin carcinomas which grow, invade locally and then spontaneously regress. Approach: A 4Mb locus on chromosome 9 was earlier identified by genetic mapping in a cluster of families. In this study a wider region encompassing 24Mb around this earlier identified locus was examined using high-throughput sequencing with exon capture, followed by Sanger sequencing. Result: This effort identified mutations in the TGFBR1 gene in 18 out of 22 families diagnosed as affected by MSSE/FSD. These include 11 different mutations. The tumours occur in sun-exposed areas of the skin, and loss-of-heterozygosity in tumours is frequently seen. The sequence variants disturb the function of the TGFβRI receptor such that although heterozygous carriers are asymptomatic during development, loss of the second (wild-type) allele ablates the receptor function and leads to local cancer susceptibility. Conclusions: The nature of the mutations sets the mechanism apart from that involved in Marfan syndrome-related disorders, in which developmental defects in vasculature are also caused by mutations in this gene. The involvement of TGFβ receptors in this condition is intriguing as TGFβ pathway effects are known to be biphasic and opposing at different stages of cancer development. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-245. doi:10.1158/1538-7445.AM2011-LB-245