Skin cancer in his brain is forcing Jimmy Carter to slow down, but the 90-year-old former president won't give up yet on the humanitarian work that sustained him since losing re-election as president 35 years ago.

Carter said Thursday that his work isn't done yet. He plans to keep up with The Carter Center's progress reports on eradicating Guinea worm disease and other previously neglected tropical maladies.

Former aides say that is no surprise from Carter, whose work ethic hasn't ebbed.

Still, Carter acknowledged that he will have to scale back his usual routine for intravenous drug treatments and more targeted radiation if needed. That may include having his family represent him at a planned trip to Nepal to build houses in November with Habitat for Humanity.