As a family member of a loved one suffering from cancer and the treatments /medications that go along with it, suggestions can be made on how to deal with this terrible time in your lives. This perspective is suggested from a cancer patient survivor.
Regardless of what the diagnosis, to the patient it can be a true feeling of them dying, how they deal with this obviously differs from person to person. Try to be completely patient, understanding and loving. Do whatever it takes to make the patient feel loved and important. Understand that there will be times they won't want to even talk, don't take this personally. There will be days when they seem energetic and want to overdue it, be supportive in reminding them to take it slow.
Always see that they are comfortable, be cheerful in their presence and one of the most important things to remember is to create a stress free environment for them. This perhaps could be a big burden for some, but it is very important.