by Craig Weatherby
According to the National Cancer Institute, more than 175,000 women receive a breast cancer diagnosis annually, and 50,000 die from the disease each year in the United States.
While heart disease kills many more women, breast cancer inspires more anxiety and can involve traumatic treatments and a longer-term struggle.
Some cases stem from genetic factors, but most are linked to diet, lifestyle, and exposure to environmental triggers.
Previous studies suggest that chronic activation of a pro-inflammatory gene switch (transcription factor) called Nf-KappaB or NFKB is key to cancer cell survival.
NFKB has also been found to play important roles in all stages of breast cancer development, from initiation to promotion.
And as we report in this issue, a study in mice supports the so-far persuasive hypothesis that chronic over-activation of NFKB is essential to formation of breast cancer… and other malignancies (See “Breast Cancer Linked to Inflammation”).
Now, a study in isolated female breast cells shows that omega-3 fatty acids from fish oil suppress activation of NFKB, and do it in a way relevant to breast cancer creation and promotion.
The study also found evidence suggesting that omega-3 fatty acids may help prevent luminal A, B and basal breast cancer subtypes… but not the subtype caused by over-expression of the HER2 gene.
Previous studies have found omega-3s able to affect tumor growth in animals and cells, and some epidemiological studies link lower breast cancer risk to higher intake of fish or fish oil.
Linda Ann deGraffenried, Ph.D., and her colleagues from the University of Texas at Austin and the University of Kansas suspected that omega-3s might be more effective against certain subtypes of breast cancer than others.
In their study, the researchers tested fish oil rich in omega-3s in four lines of breast cancer cells representing the four principal subtypes, called luminal A, luminal B, basal, and HER2 over-expressors.
The researchers found the omega-3s suppressed NFKB activity in the cell lines of the luminal A, luminal B and basal subtypes… which represent three out of four cases.
But the omega-3s did not exert a suppressive effect on the aggressive HER2 over-expressing cell lines.
About one in four women with breast cancer suffers from a genetic alteration in the HER2 gene… a fault that can cause cells to divide, multiply, and grow more rapidly than normal.
Women with HER2-positive breast cancer have a more aggressive disease and reduced survival rates, compared with women with the three other types of breast cancer.
The researchers said results from clinical trials currently in process should show whether any of the four subtypes of breast cancer are actually curbed by omega-3s.
As they wrote, “These [ongoing clinical] studies are some of the first to use molecular profiles to identify potential responders and non-responders for dietary intervention and may provide better direction for future clinical studies evaluating the efficacy of diet and lifestyle in the preventive setting” (Chen C et al. 2010).
The study results were presented at the 33rd Annual San Antonio Breast Cancer Symposium held in San Antonio, Texas, from December 8 through 12.
The paper has not yet been published in a peer-reviewed journal, so the findings should be considered preliminary.
- Chen CH et al. [P1-06-01] Omega-3 Fatty Acids for Chemoprevention: NF-Kb as a Molecular Target in Both Pre and Post Menopausal High-Risk Breast Cancer Models. Thursday, December 9, 2010 5:30 PM. Poster Session 1: Epidemiology, Risk, and Prevention: Prevention - Nutritional Studies (5:30 PM-7:30 PM). 33rd Annual San Antonio Breast Cancer Symposium (SABCS), Dec. 8-12, 2010, San Antonio, Texas.