Abstract
Advanced gastrointestinal stromal tumour (GIST) is one of the rarer gastrointestinal system tumours. Its advanced form has been successfully treated with imatinib mesylate for a number of years.
Failing initial imatinib dose (400mg/day) does not constitute a reason for discontinuation of the agent, but the dose is most commonly increased; second-line therapy with sunitinib is only administered in patients with further progression. Data have already been obtained for third-line therapies - nilotinib; as part of clinical trials higher-line agents ae being tested.
Importantly, the risk of reoccurrence of radically removed more advanced tumours in higher-risk cases is reported to exceed 80%!Increasing size and mitotic index of the tumour are associated with growing c-KIT-positive moderate- to high-risk GISTs. There is also growing relevance of the primary location of GISTs - the risk of reccurence is increasing especially in primary duodenal and rectal GISTs!Clinical trails, U.S.Intergroup Phase II ACOSOG Z9000 and North American Intergroup Phase III ACOSOG Z9001, have confirmed the anticipated benefit of one-year adjuvant therapy with imatinib, and the drug has become recommended standard for one-year adjuvant therapy in higher-risk, radically resected GISTs.
Another shift in the recommendations of adjuvant imatinib therapy has been due to the results of SSGXVIII/AIO, a randomized phase III trial that confirmed the benefit not only in terms of reduced relapse rates, but also in the sense of extended overall survival of patients treated with adjuvant imatinib for 36 months compared with standard 12-month adjuvant therapy.