Breast cancer patients who use a drug for five years instead of two are less likely to see their cancer return, found a long-term study in Britain.
The generic drug, tamoxifen, is given to women with early stage cancer and they are recommended to take it for five years but many stop after two or three, Allan Hackshaw of the Cancer Research U.K. and University College London Cancer Trails Center, who worked on the study, said.
The study found for every 100 women with breast cancer, who took tamoxifen for five years, the cancer came back in about six fewer women than the ones who took it for two years.
3,5000 patients participated in the 10-year trial published Monday in the Journal of Clinical Oncology. The study is the first to compare five and two-year usage of the drug.
Forty percent of patients who took tamoxifen for five years had the cancer come back, while 46 percent of women who took it for two years had a relapse of cancer.
Many women stop taking the drug because of unpleasant side effects, like hot flashes, headaches, fatigue, and because of an increased risk of blood clots and cataracts. Experts say the benefits outweigh these risks and this new study found if tamoxifen is taken for five years the risk of developing or dying from heart disease is lowered.
The study reported 35 percent fewer women developing heart conditions and almost 60 percent fewer deaths.
About 75 percent of breast cancers are estrogen receptor positive and Tamoxifen is the first drug that blocks the effects of estrogen.
U.S. experts estimate five years of the drug costs $8,500 compared to $50,000-$200,000 for chemotherapy.
