Triple Negative Breast Cancer Disease - Is it a Negative Disease for African American Women?
- Created on September 21st, 2008
- By Sharon T. Wilks, MD FACP
Breast Cancer is an uncommon disease amongst African Americans but of those who do get diagnosed, the outcomes can be poor with an observation that stage for stage, African American women do less well as measured by recurrence and mortality rates when compared to women from other ethnic groups.
Many have proposed that poorer outcomes amongst African American women is due to social issues such as a poorer/limited access to existing screening methods for early breast cancer detection which could lead to diagnosis at later stages but one form of breast cancer known as triple negative disease appears to occur often amongst African American women. Individuals diagnosed with triple negative breast disease experience poorer outcomes suggesting that intrinsic tumor biology may lead to higher recurrence and death rates. Many studies have shown that women with this biology experience poorer outcomes when formal analysis is done including studies in Atlanta, North Carolina, California and Europe.
Triple negative breast tumors are so named because they mark the absence of estrogen, progesterone receptor (ER/PR-) and human epidermal growth factor receptor (HER2/Neu) on special testing. These tumors tend to be high grade with the presence of high levels of proliferation related genes observed. These tumors are referred to as basal-like cancers which are tumors that have genes that are found in the normal basal/myoepithelial regions of the breast.
Triple negative breast cancer accounts for 10-20% of all breast cancers. These tumors affect younger women and are more prevalent among African American women (appears that it occurs 2 times more commonly than among Caucasians-some have reported an incidence of 40% or more). If these tumors recur, they recur early prior to the fifth year post diagnosis.
Triple negative breast cancers are challenging for management. Today, there is an interest to select chemotherapy based upon a feature of the tumor that a drug can target, as there are no such targets due to the lack of receptor expression in triple negative disease, reliance on chemotherapy that works even if there are no targets remains the standard approach. Most experts recommend use of the current best types of chemotherapy utilized in breast cancer which usually involves administration of anthracyclines and taxanes. Despite use of these active agents, some patients with triple negative disease remain resistant and reoccur. Some models suggest that basal tumors mimic changes in women with BRAC1/2 mutations which may be more sensitive to platinum forms of treatment. These high-risk tumors appear to be sensitive to these agents that induce cross-linking of the DNA within tumors.
It is important to emphasize that triple negative breast cancers are a heterogeneous type of disease where some types of this cohort enjoy a more indolent or benign course and some patients do present at older ages-they are not all young and not all women recur. Understanding tumor biology will lead to new areas of research and hope for this very serious form of breast cancer.
- Filho, JS and Tutt, AN. Triple Negative Tumours: a Critical Review. Histopathology 52: 108-18, 2008.
- Bowen, RL et al. Early Onset of Breast Cancer in a Group of British Black Women. British Journal of Cancer 98: 277-81, 2008.
- Lund, MJ et al. Race and Triple Negative Threats to Breast Cancer Survival: A Population-Based Study in Atlanta, Ga.
- Kang, et al. Triple Negative Breast Cancer: Current Understanding of Biology and Treatment Options. Curr Opin Obstet Gynencol 20:40-46, 2008.