Breast cancer therapies' side effects vary by age

By Amy Norton

NEW YORK (Reuters Health) - Even among relatively young women with early-stage breast cancer, the side effects of therapy can vary by age, according to a new study.

Past research has found that for some premenopausal women, breast cancer treatment with standard chemotherapy or a hormonal therapy with goserelin is equally effective. This includes women with early-stage cancers that are positive for estrogen receptors; in these cancers tumor growth is fueled by estrogen.

Goserelin treats breast cancer by blocking the action of estrogen on tumor cells, while chemotherapy directly kills cancer cells, as well as some healthy cells in process.

Since the two treatments are equally effective for certain women, the side effects are likely to be a prime factor in treatment decisions, according to the authors of the new study, published in the Journal of Clinical Oncology.

To compare the quality of life after each treatment, the researchers followed 874 women randomly assigned to receive chemotherapy, goserelin, or both for early-stage breast cancer. All of the women were either premenopausal or just beginning menopause.

Those on goserelin alone received monthly injections of the hormone for 2 years, while chemotherapy patients were on a three-drug combination administered every 28 days for 6 months.

The researchers, led by Dr. Jurg Bernhard of the International Breast Cancer Study Group Coordinating Center in Bern, Switzerland, found that women on goserelin generally reported better quality of life -- including less fatigue, less nausea, and a greater sense of well-being -- in the 6 months after starting therapy.

They did, however, have hormonal side effects, including loss of menstrual periods (amenorrhea) and hot flashes, sooner and more often than women on chemotherapy.