i just re-read this for a book club, and i think my initial rating still stands. although i'd probably nudge it up half a star simply because the book did keep me roped in and caring about the characters and wanting to know what would happen.
overall though, the thing that bothered me the most with this book is how emotionally manipulative it was. while cancer is never a happy-go-lucky subject, i think the way the story twists at the end was a bit too predictably un-predictable. i know that doesn't really make sense, but for me the ending just seemed tagged on almost as if the author were saying "haha, i fooled you. you thought it was going to end one way, so i ended it another."
anyway, thats just my opinion. one which was not strengthened when i read another of her books (plain truth) which i also found to be a compelling read, but in the end emotionally manipulative as well.
and that's not even getting started on the ethics (or non-ethics) of using one child to save another.