Most people take their symptoms to their primary care physician, and that's a very good starting point, Sause and Choucair agree. They do a good job of assessing who needs further screening and then referring cases when it's appropriate.

Sause says early detection is important for certain benign tumors because they can be removed when they're relatively small, but for most malignant brain tumors, "it's not clear how well it works."

The brain is different than some parts of the body, because every cell in the brain has the potential to become malignant, although the most common brain cancers are those involving connective tissue and the glial cells, which are not surprisingly also the most abundant cells in the brain. Also different from some cancers, most brain cancers stay in the brain and don't metastasize elsewhere.

Brain cancers are sorted by grades. Grade 1 is more common in the younger age group, says Choucair. "They tend to be very, very slow growers." Grade 2 also usually grows quite slowly. Grade 3 is faster; if left untreated, a tumor could double in size in about three months, while grade 4 could double in as little as two. As a brain tumor grows, it displaces or infiltrates normal brain tissue.

The higher-grade tumors have much lower cure rates. But that, too, depends on the type of tumor.

Tomorrow: Treating brain cancer

---

E-mail: lois@desnews.com