Back in the 90's there was a movie with 4 girlfriends that went away for the weekend and at the end of the movie one of them died from cancer. I think JoBeth Williams was in it but not sure. Does anyone know what that movie is called?:

The only movie I can think of like that is Beaches... but it's only 2 girls. Then there's the Virgin Suicides and it's about 4 sisters... but they all die at the end.

Boys on the Side (1995) (http://imdb.com/title/tt0112571/)
This is the only thing I can think of at the moment

Boys on the side only had 3 girlfriends... but yeah, one dies in the end. It definitely relates.