THURSDAY, May 12, 2005 (HealthDay News) -- Chemotherapy and hormonal therapy, which have been used for years to prevent the recurrence of breast cancer, have proven to be effective in keeping patients breast cancer-free over 15 years, a new British study finds.
The effectiveness of these treatments is the main reason why deaths from breast cancer have been dropping rapidly since the early 1990s in the United States, Great Britain and some other countries, according to the report in the May 14 issue of The Lancet.
"This is good news for people with breast cancer," said lead author Sarah Darby, a professor of medical statistics from the Clinical Trial Service Unit at the University of Oxford. "The breast cancer treatments that have been used in a standard way for millions of people are very effective," Darby stated.
"This is the largest analysis of randomized evidence ever done in any type of cancer," she added. "Because so many women in previous decades agreed to join these randomized trials, millions of women in future decades will benefit."
Darby said the researchers already knew these treatments were effective for five years following early breast cancer diagnosis, but now there is long-term follow-up that shows there is extra benefit going on for 15 years.
In their study, Darby and colleagues from the Early Breast Cancer Trialists' Collaborative Group looked at data on 145,000 women from 194 clinical trials of chemotherapy and hormonal therapy that had started by 1995. These trials included standard treatments, such as the chemotherapy drugs cyclophosphamide, methotrexate and fluorouracil, and hormonal therapy with tamoxifen.
The investigators found that for women who received both chemotherapy and hormonal therapy, their risk of dying from breast cancer was reduced by 50 percent over 15 years. "If a 50-year-old woman had a one-in-five risk of dying from her breast cancer, then this risk was halved to about one in 10," Darby said.
In addition, chemotherapy seemed to be effective in all age groups, and tamoxifen was effective over and above chemotherapy. "We think for women with hormone-sensitive breast cancer, both chemotherapy and hormonal therapy should be considered for most women to boost survival," Darby noted.
Breast cancer treatment is "a tremendous medical success," Darby said. "It's a very common cancer, and already 1 million women are taking tamoxifen and the prospects are good," she added.
Darby is also convinced that future treatments for breast cancer will be even better. "Breast cancer isn't the end. You can overcome it," she said. "And there is every prospect that things will continue to improve."
One expert finds the new study data impressive. "There is a benefit in terms of treatment in decreasing recurrence and improving overall survival," said Dr. Karen Gelmon, a clinical professor of medicine at the University of British Columbia. "The survival appears to be increasing."
Gelmon, who is the co-author of an accompanying editorial in the journal, noted that people once thought that chemotherapy and hormonal therapy would only delay recurrence of breast cancer, but instead there is continued improvement in survival, she said. "I think this is exciting in terms of giving validation to the treatment we have all been using," she added.
For Gelmon, the future is even brighter. She noted that this study didn't take into account any of the newest drugs -- such as aromatase inhibitors -- for breast cancer patients. "As we move into the future, we are getting more sophisticated in looking at tumors and predicting who's going to need this treatment. We are also getting more and more drugs, which are better. This is also very positive."
Breast cancer is the most common cancer among women, other than skin cancer, and is the second-leading cause of cancer death in women, after lung cancer. About 211,240 women in the United States will be diagnosed with invasive breast cancer in 2005, and about 40,410 women will die from the disease, according to the American Cancer Society.
The American Cancer Society can tell you more about breast cancer.