A study conducted in Denmark reports that women age 60 or older who have small, low-grade, hormone receptor-positive breast cancers may not need adjuvant (post-surgery) treatment with hormone therapy or chemotherapy. These results were published in the Journal of the National Cancer Institute.
The majority of breast cancers are hormone receptor-positive. These cancers are stimulated to grow by the circulating female hormones estrogen and/or progesterone. Treatment of hormone receptor-positive breast cancer often involves hormonal therapies that suppress or block the action of estrogen. These therapies include tamoxifen as well as agents known as aromatase inhibitors.
Hormonal therapy reduces the risk of cancer recurrence among women with hormone receptor-positive breast cancer, but also has side effects. Side effects of aromatase inhibitors include joint pain and bone loss. Side effects of tamoxifen include an increased risk of endometrial (uterine) cancer. If some women can safely forgo hormonal therapy after breast cancer treatment, they could avoid these side effects.
To explore outcomes among breast cancer patients who do not receive adjuvant hormonal therapy or chemotherapy, researchers in Denmark conducted a study among 3,197 women between the ages of 35 and 74. All of the women had node-negative, hormone receptor-positive breast cancer. None had received adjuvant therapy. Survival in these women was compared to age-matched women in the general population.
- Overall, mortality rates were higher among the women with breast cancer than among women in the general population. There were 970 deaths among the women with breast cancer. A similar group of women in the general population would have experienced 737 deaths.
- Factors that were linked with an increased risk of death among the women with breast cancer were larger tumor size and younger age (age 35-59).
- In the subset of women age 60-74, those with small (10 mm or less), low-grade tumors had a risk of death that was similar to women in the general population.
These results suggest that older women with low-risk, hormone receptor-positive breast cancers have a good prognosis (similar to that of women in the general population) even when they do not receive any adjuvant therapy. Decisions about adjuvant therapy need to be individualized, however; an accompanying editorial notes “Clearly, patient preferences regarding risks and benefit of endocrine therapy play a critical role in decision making…”
 Christiansen P, Bjerre K, Ejlertsen B et al. Mortality rates among early-stage hormone receptor-positive breast cancer patients: a population-based cohort study in Denmark. Journal of the National Cancer Institute. Early online publication August 31, 2011.