Women with the most common and least aggressive subtype of breast cancer luminal A tumors remained at an increased risk of death from the disease more than 10 years after diagnosis, according to a study.
Consistent with findings from previous studies, women with HER2-enriched and luminal B tumors had roughly twice the risk of dying from breast cancer compared with women diagnosed with luminal A tumors.
“The findings of this study indicate that it is important to consider breast cancer molecular subtypes in determining the optimal treatment for women with breast cancer,” Reina Haque, PhD, MPH, the studys lead author and an investigator in Kaiser Permanente Southern Californias Department of Research & Evaluation, said in a news release.
“Women with luminal A tumors could benefit from extended treatment to improve their chances for long-term survival.”
Breast cancer tumors often are divided into four molecular subtypes: luminal A, which tends to have the best prognosis with fairly high survival rates; luminal B, with typically occurs in younger women and has a poor prognosis; the basal-like subtype, which tends to occur in younger women and African-American women and has a poor prognosis; and the HER-2 enriched subtype, which has a fairly poor prognosis and is prone to early and frequent recurrence and metastases.
The researchers said future breast cancer studies should focus on identifying factors that are associated with longer survival in women with luminal A tumors and how the association between breast cancer molecular subtypes and survival varies by race and ethnicity — especially in minority women who are more likely to have aggressive tumor subtypes.
The study appeared Sept. 18 on the website of Cancer Epidemiology, Biomarkers and Prevention. The study abstract is available at http://cebp.aacrjournals.org/content/early/2012/09/17/1055-9965.EPI-12-0474.abstract.