In Islam it's your duty to preserve life as much as you can. Refusing treatment is comparable to suicide. It doesn't necessarily mean prolonging suffering either, some people just give up too easily.

And I just realized that may have come across as a little insensitive concerning your family situation.. I'm sorry, didn't mean it to come across that way.

No worries jmatts.

Treatment is all well and good but when it reaches the point where the cure is worse than the disease and it's terminal then I would say it was time to make your peace with your God and however you worship. But to just give up is wrong.