Swiss Novartis AG announced that the Food and Drug Administration cleared marketing of blockbuster Gleevec to be used after surgery, reducing risk of relapse on patients with gastrointestinal stromal tumor (GIST).

Gleevec is the the most important drug in the market to treat chronic myeloid leukemia and had sales of 2.780 million dollars for the first 9 months of 2008.

The most frequent form of cancer in the gastrointestinal tract is known as gastrointestinal stromal tumor (GIST) is a rare tumor of the gastrointestinal tract (1-3 percent of all gastrointestinal malignancies). They are a type of mesenchymal tumor and typically defined as tumors whose behavior is driven by mutations in the Kit gene or PDGFRA gene, and may or may not stain positively for Kit

When GIST is suspected—as opposed to other causes for similar tumors—the pathologist can use immunohistochemistry (specific antibodies that stain the molecule CD117 (also known as c-kit) 95 percent of all GISTs are CD117-positive (other possible markers include CD34, desmin, vimentin and others). Other cells that show CD117 positivity are mast cells.

GIST is a life-threatening cancer of the gastrointestinal tract. After initial removal, GIST tumors can return in as many as one of two patients. Recurrent GISTs are often more aggressive than primary tumors, with relapses associated with lower survival rates.

The incidence of GIST is estimated to be 4,500 - 6,000 new cases per year in the US (15-20 cases per million population), of which more than 90 percent are Kit-positive