Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 218

Breast cancer can be tested in many ways, including determination of whether the cancer cells are stimulated by the presence of the hormones. This type of exam measures a person’s hormone receptor (HR) status and tests for a positive or negative result which, respectively, corresponds to stimulation or lack of the cancer cell. The test uses the hormones estrogen and progesterone to test a tumor for cancer. If the test is positive for either estrogen or both estrogen and progesterone, then hormone therapy is usually the course of action for the treatment of the cancer in lieu of more intensive treatments. Hormone therapy can also be advantageous because it can help prevent the recurrence of cancer in both the breast and other parts of the body.

Another way of determining whether or not a tumor is malignant is by testing for the amount of protein in the tumor. The human epidermal growth factor receptor 2 (HER-2/neu) test can detect if there is an abnormally high amount of protein in the tumor. During the HER-2 exam, physicians use oncogene measurements to measure how quickly the cells in the tumor are growing. A positive HER-2 result indicates a higher-than-normal growth rate, which is indicative of either abnormally high levels of protein in the cancer cells or overexpression of the HER-2 gene, which causes too much protein to be produced. The treatment of tumors that test positive for the HER-2 exam utilize therapies that specifically target the HER-2 gene to reduce the amount of protein being produced, thus slowing the growth rate of the tumor.

The course of action for a cancer ultimately depends on the progression of the cancer. On a scale of I–IV, cancers in stages I–III are often treatable and the focus turns toward curing the patient of the cancer. In these stages, treatment involves a lumpectomy, the removal of a lump or small part of the breast, or a quadrantectomy, the removal of a quarter part of the breast in addition to other therapies. In the more advanced types of stage IV cancers, however, the focus turns from attempting to cure the cancer to improving the quality of life and increasing their chances of a longer survival. Treatment of stage IV cancer often leads to the patient receiving mastectomy (removal of the whole breast), in combination with chemotherapy, radiation therapy, and/or hormone therapy.

Krishna S. Vyas

University of Kentucky College of Medicine

Arthur Lemons III

Walisha Bland-Lemons

University of Kentucky

See Also: Breast: Cell Types Composing the Tissue; Breast: Development and Regeneration Potential; Breast: Existing or Potential Regenerative Medicine Strategies.