Over the past 20 years, the approach to evaluating and treating breast cancer has changed considerably. Most women with newly diagnosed breast cancer are now candidates for breast conserving surgery (lumpectomy), which may be followed by radiation and adjuvant systemic therapy.
Types Breast cancers are divided generally into two types: invasive cancers and non-invasive or in situ cancers. Invasive cancers are generally divided into lobular and ductal cancers. Lobular cancers start in the many small sacs in the breast that produce milk. The much more common ductal cancers start in the tubes that carry milk from the lobules to the nipple. Within these broad categories, there are over 30 different types as seen under the microscope. About half are infiltrating ductal cancers, meaning that they spread through the duct wall. Another 28 percent are combinations of infiltrating ductal cancers and other types, including mucinous, papillary and lobular.
Infiltrating lobular carcinoma (5 to 10 percent of breast cancers), which is often detected as a thickening of the breast tissue rather than as a lump, may often be found in many places at the same time, not only in the same breast but also in the opposite one.
Other infiltrating cancers include Paget's disease, a cancer that involves the nipple and is associated with bleeding, redness, itching and burning (this is not the same as Paget's disease of bone, which is a chronic benign process), and inflammatory breast cancer, which shows up as a hot, red, swollen area having the appearance of an infection or inflammation .
