abstract: RAS Mutations Are Associated With the Development of Cutaneous Squamous Cell Tumors in Patients Treated With RAF Inhibitors (vemurafenib/sorafenib/secondary malignancies)

"Purpose 

RAF inhibitors are effective against melanomas with BRAF V600E mutations but may induce keratoacanthomas (KAs) and cutaneous squamous cell carcinomas (cSCCs). The potential of these agents to promote secondary malignancies is concerning. We analyzed cSCC and KA lesions for genetic mutations in an attempt to identify an underlying mechanism for their formation.

Methods
Four international centers contributed 237 KA or cSCC tumor samples from patients receiving an RAF inhibitor (either vemurafenib or sorafenib; n = 19) or immunosuppression therapy (n = 53) or tumors that developed spontaneously (n = 165)........."

Muir-Torre syndrome-is it really a new syndrome? Am J Dermapathology

Note: that there is an overlap here with Lynch Syndrome

"This syndrome is defined as the coexistence of sebaceous adenomas, sebaceus carcinomas, keratoacanthomas, and pedunculated tumors, some with lobulated structure. The cutaneous involvement (sebaceous gland tumor) is associated with at least a single internal malignancy; mostly colonorectal or genitourinary malignancies."