cancerGenentech’s Avastin is approved for lung, colon and breast cancer, but it’s used off-label for a bunch of other types of the disease. Now Genentech is trying to turn one of those off-label uses — for brain cancer — into an FDA approval.

The company said today that it has submitted an application to the FDA for approval of Avastin for the most aggressive form of brain cancer, a use that got some attention around the time Sen. Edward Kennedy was diagnosed with brain cancer.

The application is for an accelerated timeline that would allow provisional approval of the drug based on preliminary evidence. That evidence comes from a mid-stage study of Avastin that showed patients who had already been treated for glioblastoma survived longer than would typically be expected, and went longer without disease progression. But the study didn’t include a group of patients who didn’t get the drug, making it hard to draw firm conclusions. (See more on off-label use of Avastin for brain cancer in this NYT article, which notes that the drug costs tens of thousands of dollars per patient.)

In the first half of 2009, Genentech expects to start a late-stage study of the drug in patients with newly diagnosed glioblastoma.

Update: Genentech tells us the estimated cost for a course of treatment for this type of cancer is $39,600.