Myth: "A GIST that is found in the stomach is a form of stomach cancer, while a GIST found in the colon is a form of colon cancer."

Fact: In the diagnosis and treatment of cancer, the source of a tumor is just as important as its location. GISTs arise from a very specific cell type that is different from other tumors that grow in the GI tract. Also, and most importantly, tumors classified as GISTs usually have a particular mutation that responds very well to TKI treatment. Other GI tumors, such as stomach cancer, colorectal cancer, and liver cancer, do not, and are treated differently (see table below).

Myth: "If a GIST is metastatic at diagnosis, the cancer is too advanced to be controlled."

Fact: Even if a GIST has spread to other parts of the body, it usually responds very well to treatment with a tyrosine kinase inhibitor (TKI). In some patients, tumors that are inoperable at diagnosis can be reduced in size by TKI treatment and then removed by surgery. See neoadjuvant treatment of GISTs.

Myth: "If a GIST can be removed, no further treatment will be required."

Fact: Even when a GIST seems to have been completely removed by surgery, a few abnormal cells may remain. These cells may grow, causing a new tumor to grow in the same place or at a different location. This is why many doctors recommend treatment with a TKI after surgery, especially if the original tumor was large or fast-growing. See adjuvant treatment of GISTs.

Myth: "All cancer treatments are toxic, and often poison healthy tissues."

Fact: TKI therapies do not "poison" cells—they act by blocking a signal that causes cancer cells to keep growing. TKIs can cause side effects, but they usually can be addressed.