Cancer Blood Test Improves Therapy14 years, 1 month ago
Posted on Feb 10, 2005, 4 a.m.
By Bill Freeman
Researchers now say breast cancer is not one disease, but many different diseases. Even when tumors are classified together based on their appearance, they can act differently because of different genetic makeup. Only recently have researchers begun to understand this and to use it in predicting how a disease will progress.
HER2 DISEASE: HER-2-positive disease is one type of breast cancer. Characterized by aggressive growth and a poor prognosis, it is caused by the presence of excessive numbers of a gene called HER-2 (human epidermal growth factor receptor-2) in tumor cells. In about 25 percent of women with advanced breast cancer, there is a genetic alteration in the HER-2 gene that produces an increased amount of the growth factor receptor protein on the tumor cell surface. This overexpression can cause cells to divide, multiply and grow more rapidly than normal. Research has shown that women with HER-2 positive advanced breast cancer have a more aggressive disease, greater likelihood of recurrence, poorer prognosis and approximately half the life expectancy of women with HER-2- negative breast cancer.