What is the life expectancy of a 75 yr old woman whose breast cancer has spread to the spine and rib cage?

Everyone's different: Survival rates are most appropriately applied to large groups of patients; it's impossible to give such a number for one person, especially without knowing her own unique situation. As a generalization, we usually talk about "remission" rather than "cure" when cancer has spread to the bone (stage 4) yet people can live for years, especially if it is sensitive to medication.

Life expectancy : There are lot of variables but average life expectancy with treatment 1-3 years.