1432PSECOND PRIMARY MALIGNANCES (SPMS) IN PATIENTS (P) WITH GASTROINTESTINAL STROMAL TUMORS (GISTS) – A COINCIDENCE OR AN EFFECT OF IMATINIB?

Aim: GISTs are the most common mesenchymal tumors of the gastrointestinal tract. Imatinib has become the standard treatment for unresectable metastatic GISTs and as adjuvant treatment in high-risk p. A high rate of SPMs (4.5 -33.3%) has been reported in p with sporadic GISTs and a potential association between imatinib treatment and the development of SPMs has been postulated. Methods:We have retrospectively reviewed the incidence of SPMs in all p diagnosed with GIST and treated at a single institution between 1997 and 2012.