Adjuvant Therapy for Breast Cancer
Lymph Node Involvement
In cases of breast cancer, the disease may spread to the lymph nodes in the underarm. Doctors usually remove some of the underarm lymph nodes to determine whether they contain cancer cells. If cancer is found, the nodes are said to be "positive." If the lymph nodes are free of cancer, the nodes are said to be "negative." Breast cancer that is node-positive is more likely to recur than cancer that is node-negative, because if cancer cells have spread to the lymph nodes, it is more likely that they have also spread elsewhere in the body.
Hormone Receptor Status
Cells in the breast contain receptors for the female hormones estrogen and progesterone. These receptors allow the breast tissue to grow or change in response to changing hormone levels.
Research has shown that about two-thirds of all breast cancers contain significant levels of estrogen receptors. These tumors are said to be estrogen receptor-positive (ER+). About 40 to 50 percent of all breast cancers have progesterone receptors. These tumors are said to be progesterone receptor-positive (PR+).
ER+ tumors tend to grow less aggressively than ER- tumors. The result is a better prognosis for patients with ER+ tumors.
This term refers to how much the tumor cells resemble normal cells when viewed under the microscope. Tumors composed of cells that closely resemble normal breast cells and structures are called well differentiated. Tumors with cells that bear little or no resemblance to normal breast cells are referred to as poorly differentiated. Tumors that have "in between" cells are called moderately differentiated. For most types of invasive breast cancer, patients who have tumors with cells that are well differentiated tend to have a better prognosis.