Living With Cancer
Does tamoxifen help?
Oct. 30, 2000 -- The day that forever changed Bonnie McDonald's life started out like any other. It was a typically hectic Monday morning last spring when the 37-year-old decided to grab a quick shower. She'd gone for a run after dropping her son off at school and was about to rush off to her part-time catering job when she felt a pea-sized lump in her left breast. Tests later that week showed that she had found a cancerous tumor. "It was so frightening," she says. "I'd always been athletic and healthy. That was my first glimpse of mortality."
McDonald underwent a lumpectomy and eight weeks of radiation. Then her oncologist suggested she begin taking tamoxifen, an anticancer drug that has been playing a substantial role in the fight against the return of breast cancer. Tamoxifen works by blocking the estrogen that breast cancer cells need to grow. Her doctor explained that, as a side effect of the treatment, she might go through a temporary menopause and could experience hot flashes, mood swings, and all of the other symptoms associated with the change of life. He also said that taking tamoxifen could increase her risk of developing endometrial cancer -- cancer of the lining of the uterus or womb.
His prescription, he said, was based on a balance of risks and benefits and, like many other medical decisions these days, the choice was ultimately up to the patient. McDonald got on the Web and did her own research, talked to women in similar circumstances, and finally decided that she would take tamoxifen.
McDonald's choice is one that many women are making. About one million women worldwide take tamoxifen, according to a review article in the May 27 British Medical Journal, and medical research backs up the choice. In May, a Lancet article reported that breast cancer death rates in the United States and Britain have dropped dramatically -- between one quarter and one third -- in the past decade. Sir Richard Peto, a leader of the international Early Breast Cancer Trialists' Collaborative that produced this new report, calls this news "the best decrease in national death rates that has ever been seen with any common cancer." Surely earlier diagnosis, better surgery, chemotherapy, and radiotherapy all play a part in improved survival rates, Peto says, but he is convinced that the widespread and prolonged use of tamoxifen may be the most important factor. However, women on tamoxifen must cope with the side effects of taking the drug -- some of them quite severe.