In the past eight months my father's had bowel cancer (surgery worked: currently in remission) and my wife had uterine cancer (surgery worked: hopefully a complete cure). And the cat went blind.

Anyone saying "everything happens for a reason" to me would probably wind up with a black eye. (At the very least, they'd go on my personal do-not-call list.)

Which is to say: you shouldn't say things to immediate relatives that you shouldn't say to the patient, either.