Millions of women worldwide receive combined estrogen and progestin hormone replacement therapy to counter the unwanted effects of menopause. Yet studies are increasingly suggesting the use of such treatment may increase the risk of breast cancer. A new study shows that luteolin, present in vegetables such as celery, could counter this risk.
Scientists from the University of Missouri in Columbia claim that luteolin, which occurs naturally in herbs and vegetables, can slow the development of breast cancer caused by the combination of natural estrogen and synthetic progestin used in hormone replacement therapy.
The research was led by Salman Hayder, the Zalk Endowed Professor in tumor angiogenesis and professor of biomedical sciences in the College of Veterinary Medicine and the Dalton Cardiovascular Research Center, and published in Springer Plus.
Hyder explains that while the majority of older women normally have benign lesions in breast tissue, "these lesions typically don't form tumors until they receive the 'trigger' - in this case progestin - that attracts blood vessels to cells, essentially feeding the lesions, causing them to expand."
Hyder's team has found that "as human breast cancer cells develop, they take on stem cell-like properties, which can make them harder to kill."
How can luteolin help?
In the study, breast cancer cells were exposed to varying concentrations of luteolin in vitro for 24 or 48 hours.
The result was a markedly reduced cell viability, in terms of both time and dose. The blood vessels that were feeding the cancer cells decreased, causing them to die, and the stem cell-like properties of the cells, which normally promote cancer cell development, were reduced. Overall, luteolin was found to produce an anti-tumor effect.
Having established these results, Hyder tested luteolin on laboratory mice with breast cancer and discovered that there, too, blood vessel formation and stem cell characteristics were reduced.
Fast facts about breast cancer
- There will be around 231,840 new cases of breast cancer diagnosed in the US this year
- More than 40,000 women in the US will die from breast cancer in 2015
- There are more than 2.8 million survivors of breast cancer in the US.
It would appear that luteolin has the potential to prevent or disrupt the growth of tumors in a variety of ways. The team is hopeful that further research, if successful, may lead to a new drug that could be used to treat some of the more "aggressive and hard-to-treat types of breast cancer." It could be used in the form of a supplement that is injected directly into the bloodstream.
Meanwhile, Hyder calls upon women to continue consuming a healthy diet with fresh fruit and vegetables. Luteolin is present in thyme, parsley, celery and broccoli.
After skin cancer, breast cancer is the most commonly diagnosed form of cancer and the second leading cause of cancer-related death in American women.
HRT is also one of the most widely used treatments in the US. A drug that allows women to continue taking this highly effective treatment, without the potentially fatal long-term side effects, would surely be welcome.
For some time, the presence of the BRCA gene has been thought to imply a high risk of breast cancer. A recent article in Medical News Today suggested that very few women benefit from BRCA gene testing, as it may not be a strong predictor for breast cancer after all.