My 79 year old friend has breast cancer since 2004. is she at the end now? she fefused all treaments. and not eating ! living on vitimin water.

Depends: If your friend has disease that has spread extensively, then the fact that she is not eating may reflect end of life. However, she should be evaluated for other problems that maybe treatable , such as depression , even if her disease is advanced. When someone with cancer becomes bedbound and stops eating, generally the life expectancy is less then 3 months, and less then 2 weeks if not hydrating.

Sorry to hear this: Each person can decide what treatments they may or may not want. See if she needs assistance, or contact a local hospice nursing care facility is she wants some help at home.