Basic Information about Breast Cancer
Start with the most basic information here, here, here, here and here and nursing instructions sheets here.
Most breast cancers are invasive (or infiltrating ) ductal carcinoma. The seriousness of the cancer is based on the size of the tumor, the grade of the cancer (how mutated the cells are) whether the cancer is sensitive to hormone therapy (estrogen receptors) and the status of the lymph nodes.
For more specific details about the natural history of breast cancer (nodes, histology, hormone receptors, prognosis and survival rates etc.) and other topics like genetics, screening and prevention go here and here.
The most accurate way to predict cure rates is to go here.