Today, women with estrogen-sensitive breast cancer receive anti-hormonal therapy. Researchers now show that postmenopausal women with low-risk tumors have a long-term benefit for at least 20 years, while the benefit was more short-term for younger women with similar tumor characteristics who had not yet gone through the menopause. The results are reported in the Journal of the National Cancer Institute (JNCI).
In Sweden, 9 000 women are diagnosed with breast cancer each year, with hormone-sensitive breast cancer accounting for about 75 percent of women diagnosed with the disease. In patients with hormone-sensitive breast cancer tumor growth is mainly driven by estrogen and patients are therefore treated with estrogen-suppressing drugs, often tamoxifen. However, anti-hormonal treatment reduces quality of life and the question has been how the long-term benefit against recurrence looks like.
About a third of women diagnosed with breast cancer are younger and have yet not undergone the menopause, i.e. they are premenopausal, and are known to have an increased risk of recurrence.
"Younger women generally have a higher risk of recurrence than older postmenopausal women, but most studies on anti-hormonal therapy have mainly included postmenopausal women. We therefore wanted to compare the long-term benefit from the treatment in both groups," says Linda Lindström, associate professor and research group leader at the Department of Oncology-Pathology, Karolinska Institutet, who led .