Microscopically, most GISTs
demonstrate 3 main histologic subtypes: spindle cell type (most common), epithelioid type, and mixed spindle and epithelioid type.
This insight into the way GISTs
develop has already helped to identify new treatments for this sarcoma.
Activating mutations of Kit or PDGF receptors are critical to the pathogenesis of more than 90 percent of GIST
One approach classified all mesenchymal tumors of the GI tract as GISTs
, regardless of the immunohistochemical profile.
5) Because of immunophenotypic and ultrastructural similarities, investigators (2,5-8) have postulated that GISTs
are derived from the interstitial cells of Cajal.
Besides, the tumor cells showed mostly positive reactions in CD117; the c-kit proto-oncogene protein, which includes a tyrosine kinase component, is expressed in and is a useful marker of GISTs
Use of Gleevec after surgery shows significant benefit for gastrointestinal stromal tumor (GIST
) patients, dramatically reducing risk of relapse -- GIST
, a life-threatening cancer, recurs in as many as one of two patients; recurrent tumors are often more aggressive than primary tumors -- For GIST
patients who were assigned to Gleevec, more than nine out of
The purpose of the present investigation is to test the hypothesis that GISTs
originate from CD34-positive stem cells and differentiate toward an ICC phenotype by immunohistochemical studies using selected lineage-directed monoclonal antibodies for ICCs (c-kit), smooth muscle (desmin), Schwann cells (S100 protein), stem cells (CD34), myofibroblasts ([Alpha]-actin), and proliferative cells (MIB-1).
The logical first step would be testing for the specific c-Kit mutations present in GISTs
, before the start of treatment.
This study entailed analysis of the spectrum of mutations identified in a series of GISTs
from more than 1,000 patients, coupled with assessment of the impact of various mutations on sensitivity/resistance to imatinib.
However, many GISTs
cannot be surgically removed, because they are too large or have already spread to other parts of the body before diagnosis.
Each year approximately 900 people in the UK are diagnosed with GISTs
, and today's positive recommendation means around 250 of these people whose tumours have spread to other parts of their bodies, or are unsuitable for surgery, can now receive Glivec - the only effective treatment for GISTs
- on the NHS.