Elderly women diagnosed with early hormone-positive breast cancer and treated with hormone therapy are more likely to die from causes not related to breast cancer than from breast cancer itself. These results were recently published in the Journal of the National Cancer Institute.
Early breast cancer refers to cancer that has not spread beyond the breast or lymph nodes under the arm. Cure rates for early breast cancer have steadily improved with advances in screening methods and treatments. The majority of breast cancers are hormone-positive, meaning they are stimulated to grow from exposure to the circulating female hormones estrogen and/or progesterone. Patients with hormone-positive breast cancer are treated with hormone therapy, which reduces the amount of estrogen or progesterone produced by the body or blocks the growth-stimulatory effects of these hormones on cancer cells.
Elderly women with early hormone-positive breast cancer are often treated with hormone therapy only, as they may not be able to tolerate side effects of chemotherapy. Hormone therapy also provides long-term survival for a significant portion of these patients.
Researchers affiliated with the National Cancer Institute of Canada Clinical Trials Group previously conducted a large clinical trial called the MA. 17 trial. The hormone agent Femara® (letrozole) was compared to placebo (inactive substitute) following five years of treatment with tamoxifen (Nolvadex®) among postmenopausal women with early hormone-positive breast cancer. Researchers from the United States and Canada recently evaluated data from this trial to assess causes of death among participants.
- 60% of deaths were caused by reasons other than breast cancer.
- Among patients who were 70 years of age or older, 72% of deaths were caused by reasons other than breast cancer.
- Patients with cardiovascular disease and osteoporosis had significantly higher rates of death from causes other than breast cancer.
The researchers concluded that elderly women with early hormone-positive breast cancer treated with hormone therapy are more likely to die from causes other than breast cancer. These results may also provide further evidence that hormone therapy without chemotherapy may be an appropriate treatment approach for these patients. However, all patients are encouraged to discuss their individual risks and benefits of available treatment options with their physician.
Reference: Chapman J-A, Meng D, Shepherd L, et al. Competing causes of death from a randomized trial of extended adjuvant endocrine therapy for breast cancer. Journal of the National Cancer Institute [early online publication]. February 12, 2008. DOI: doi:10.1093/jnci/djn014.