Unresectable Primary Gastrointestinal Stromal Tumors
Therapy with neoadjuvant imatinib is under evaluation. It may be used for patients with very large primary gastrointestinal stromal tumors (GIST) or poorly positioned small GIST (considered unresectable without the risk of unacceptable morbidity or functional deficit) until surgical therapy is feasible, which can take as long as 6 to 12 months.[1,2] There are no controlled trials addressing the benefits of imatinib in this setting, so the impact of neoadjuvant imatinib on overall survival (OS) is unclear. Even the conversion rate from inoperability to operability with neoadjuvant therapy is ill-defined. Therefore, any advantages of neoadjuvant therapy are currently theoretical.
Mutational analysis may help to exclude nonsensitive mutations prior to imatinib cytoreduction therapy or to determine whether a tumor harbors a KIT exon 9 mutation, potentially requiring an increase in initial imatinib dosing.[1,3] Follow-up is performed at close intervals, possibly with 18fluoro-deoxyglucose-positron emission tomography (18FDG-PET), to assess response to therapy.[1,4]
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with gastrointestinal stromal tumor. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
- Demetri GD, Benjamin RS, Blanke CD, et al.: NCCN Task Force report: management of patients with gastrointestinal stromal tumor (GIST)--update of the NCCN clinical practice guidelines. J Natl Compr Canc Netw 5 (Suppl 2): S1-29; quiz S30, 2007. [PUBMED Abstract]
- Bonvalot S, Eldweny H, Péchoux CL, et al.: Impact of surgery on advanced gastrointestinal stromal tumors (GIST) in the imatinib era. Ann Surg Oncol 13 (12): 1596-603, 2006. [PUBMED Abstract]
- Debiec-Rychter M, Sciot R, Le Cesne A, et al.: KIT mutations and dose selection for imatinib in patients with advanced gastrointestinal stromal tumours. Eur J Cancer 42 (8): 1093-103, 2006. [PUBMED Abstract]
- Gayed I, Vu T, Iyer R, et al.: The role of 18F-FDG PET in staging and early prediction of response to therapy of recurrent gastrointestinal stromal tumors. J Nucl Med 45 (1): 17-21, 2004. [PUBMED Abstract]