Eating carotenoid-rich fruit and vegetables, such as leafy greens, may reduce the risk of developing breast cancer
Results from a new Cancer Research UK-funded trial have brought interesting – and positive – news on the use of tamoxifen. The ATLAS (Adjuvant Tamoxifen: Longer Against Shorter) trial, published in the Lancet, has found that taking this drug for double the amount of time currently standard, can roughly halve the number of deaths.
About 65% to 85% of breast cancers in women in Great Britain are oestrogen receptor positive (ER+). This means that their cancer is driven by oestrogen. After treatment such as surgery, radiotherapy, or chemotherapy, many women are for some years given endocrine treatment with a drug such as tamoxifen, or with an aromatase inhibitor, to prevent any cells that may have been left behind, being re-charged by oestrogen.
The standard length of treatment with tamoxifen is currently five years. The protection this treatment gives continues for another 10 years after the treatment finishes. And the results are positive – this treatment reduces death rates by about one third for the first 15 years following diagnosis.
The ATLAS study, co-founded by the Medical Research Council, recruited almost 7,000 women with ER+ breast cancer, who had reached the stage of completing their five years of tamoxifen treatment. Half were randomly chosen to stop treatment immediately, and half to continue with the treatment for another five years. All the women were followed for an average of another eight years.
To begin with there was little difference between the two groups. This was because both groups were protected through the first decade by their initial five years of treatment. However, after the tenth year the benefits of longer treatment became clear in the group that continued taking tamoxifen. In these women the risk of dying from breast cancer during the second decade was further reduced by about a quarter. And most of the extra protection that came from taking the drug for longer happened after the 10-year period was over.
“Around three-quarters of all UK women with breast cancer have hormone sensitive disease,” said Dr Christine Davies, a Cancer Research UK scientist at Oxford University and leader of the ATLAS study. “ATLAS shows that 10 years of tamoxifen helps save lives not just during the decade women are taking the drug, but also during the second decade after diagnosis.”
Martin Ledwick, Cancer Research UK’s head information nurse, said: “This important study adds further clarity to the question about the length of time women should take tamoxifen. Although treatment for hormone receptor positive breast cancer has become more complex in recent years with some women receiving aromatese inhibitors, these results will help in deciding the length of treatment for women who are prescribed tamoxifen alone.”
Another study, published in the Journal of the National Cancer Institute, found that women with higher levels of carotenoid have a reduced risk of breast cancer.
These micronutrients, found in fruit and vegetables, are known to have anti-carcinogenic properties. Other studies have found that they inhibit tumor progressions in both oestrogen receptor-positive (ER+) and oestrogen receptor-negative breast cancers.
The study was carried out by A.Heather Eliassen, Channing Division of Network Medicine, Department of Medicine, Brigham & Women’s Hospital and Harvard Medical School, and colleagues. They carried out a pooled analysis of eight studies, which between them contained over 80% of the world’s published data on levels of the nutrient in blood and breast cancer.
They discovered a clear link between levels of carotenoids and reduced breast cancer risks. The view of the researchers is that “A diet high in carotenoid-rich fruits and vegetables offers many health benefits, including a possible reduced risk of breast cancer.”
Want to increase your intake of carotenoids? Make sure you include carrots, dark green leafy vegetables and orange-coloured fruit and veg such as mangoes, apricots and sweet potatoes in your diet.
In post-menopausal women taking tamoxifen increases the risk of endometrial -or womb – cancer. However, the ATLAS results show that the reduction in deaths from breast cancer when taking tamoxifen, far outweigh the risks of death from womb cancer.
NHS Choices - www.nhs.uk
British Nutrition Foundation - www.nutrition.org.uk