<b>Ckit or CD117, should be done if tumor's primary site was abdominal.</b> This test is done on the paraffin block tumor.

If the tumor is Ckit positive, it might respond to Gleevec [Glivec, STI-571], the molecular targeted drug.  If it is a gastrointestinal tumor, and is CKit positive, you may have been misdiagnosed as LMS, and really have a GIST [gastrointestinal stromal tumor].  In that case, you should contact the Life Raft Group online, the patient advocacy and educational group for people with GIST.  GISTs are notoriously resistant to most chemotherapy, but are often very sensitive to Gleevec, and there is another drug, SU 11248, which has also shown good effect in GIST.  

Some LMS tumors are also positive for ckit.  Most of these do not respond to Gleevec, however some have.  It is postulated that what is going on in these LMS tumors is that PDGFr, and not CKit, is the marker that indicates Gleevec sensitivity.  However, at this time there is no commercial test available for testing tumors for PDGFr.  So use of Gleevec in LMS with or without ckit positivity is a hit or miss chance.  However, one study showed that 8 out of 9 LMS tumors tested was positive for PDGF.  But of the 8 Ckit positive nonGIST LMS patients in the Gleevec clinical trial, none of them responded to Gleevec.

this section was updated October 2003
doctordee