The most important predictors of survival are the size of the invasive component of the tumor, and the status of the regional lymph nodes. When there is no invasive tumor present (i.e. only ductal carcinoma in-situ, or DCIS), the survival rate is 100%. When the invasive tumor is less than 11 mm in diameter and the nodes are negative, the 10-year survival approaches 95%, and if you make it to ten years, consider yourself cured.
As the tumor enlarges and the number of involved lymph nodes increases, the potential for cure is reduced. However, dramatic improvements have been made in the medical treatment of breast cancer (i.e. chemotherapy and hormone therapy), and many new treatments are on the horizon. There is now reason for optimism in even the most advanced cases.
The time that elapses before a woman is informed about the details of her prognosis is typically 7-14 days after the removal of the tumor and the under arm lymph node(s). It usually takes this long to analyze the tumor and to receive a pathology report on the various tumor markers that also influence prognosis (see link to understanding your pathology report). A woman and her family will usually have a detailed consultation with the oncologist to discuss her prognosis, and more importantly, what steps should be taken to maximize her chances of survival. After this detailed discussion, a woman chooses the option that is best for her.