If you have a disease, you are meant to have it — its is what you need in this incarnation. Steiner did not rule out treating diseases any more than he ruled out charity to the poor. But “helping” the ill or the poor needs to be done with full consciousness of the possible karmic harm that may be inflicted. If a person needs to experience a certain illness in this life, we probably should not thwart this cosmic, karmic need. Trying to balance benign neglect with compassion gets complicated, of course.
Little or nothing happens entirely by accident
and here is more.