Side effects vary by breast cancer maintenance therapy

Wed Nov 14, 5:13 PM ET
Among postmenopausal women receiving adjuvant therapy for early breast cancer, exemestane is associated with fewer hot flashes than is tamoxifen, but it also causes more sleep problems, according to a study published the Journal of Clinical Oncology.
"Hormonal breast cancer treatment increases menopausal symptoms in women," note Dr. Stephen E. Jones and colleagues from US Oncology Research Inc., Houston.
The investigators used questionnaires, completed by more than 1,500 women to assess 10 common symptoms in the first year of a clinical trial of tamoxifen or exemestane. Tamoxifen is sold under the trade name Nolvadex, and exemestane is sold under the trade name Aromasin.
The patients had completed surgery and chemotherapy for early breast cancer. All of the women had hormone receptor-positive cancers, which respond to these two agents.
The prevalence of the initial symptoms ranged from 2 percent (for vaginal bleeding) to 75 percent (for fatigue).
Patients who received tamoxifen experienced significantly more vaginal discharge than those who received exemestane. Those who received exemestane had more bone and muscle aches, vaginal dryness, difficulty sleeping and decreased libido.
In both treatment groups, hot flash scores peaked at about 3 months and decreased thereafter. As mentioned, patients in the tamoxifen group had a significantly higher mean hot flash score at 12 months than those in the exemestane group.
"These are common complaints and the treatments used make some worse," Jones commented to Reuters Health. "Oncologists and other oncology health professionals need to be aware of the commonplace nature (of these side effects) and attempt to help wherever possible," he said. For example, he suggested it may be necessary to treat the hot flashes if they are affecting the patient's of life.
SOURCE: Journal of Clinical Oncology, October 20, 2007.