The researchers say that mammograms contribute just as much as hormone therapy and chemotherapy in slowing the rate of death from breast cancer.
The study, which is based on seven statistical analyses by 43 researchers, found that screening as practiced in the United States reduced the rate of death from breast cancer by 7 percent to 23 percent, depending on the analysis.
Some researchers have previously questioned the value of routine screening, but in the United States and other countries, women are encouraged to have regular mammograms beginning in their 40s for early detection of the disease.
According to the study led by Donald Berry of the University of Texas M.D. Anderson Cancer Center in Houston, chemotherapy and hormone therapy such as tamoxifen, reduced the death rate by 12 percent to 21 percent, while a combination of screening and other therapy reduced the death rate by an estimated 25 percent to 38 percent.
Berry says all seven groups concluded that the decline in the rate of death from breast cancer is a combination of screening and therapy, and not restricted to one or the other.
As he states screening would have no benefit if not followed by treatment, including surgery.
The treatment, he says, has the potential to be more effective if cancer is detected at earlier stages by screening.
The death rate from breast cancer has decreased by 24 percent from 1990 to 2000.
The American Cancer Society estimates that this year alone, 215,000 women are expected to be diagnosed with breast cancer and the disease will kill more than 40,000.
The study is published in The New England Journal of Medicine.
Another new monoclonal antibody, bevacizumab has recently completed Phase III clinical trials for the treatment of locally advanced or metastatic breast cancer. Bevacizumab is a monoclonal antibody to vascular endothelial growth factor (VEGF) and acts to inhibit tumour angiogenesis (process of diverting nutrients to the tumour).
The randomised Phase III trial was coordinated by the Eastern Cooperative Oncology Group to compare the efficacy and safety of paclitaxel with or without bevacizumab as first line therapy in patients with locally advanced or metastatic breast cancer. 722 patients were recruited between December 2001 and May 2004 and were divided into two groups receiving either paclitaxel alone or the combination of paclitaxel and bevacizumab. The primary endpoint was progression-free survival (PFS).
The results were positive and indicated that the combination of paclitaxel and bevacizumab improved overall survival of patients than receiving paclitaxel alone (no final data available yet). Importantly the progression-free survival was improved with combination therapy, 10.97 months vs 6.11 months for paclitaxel alone. In addition, the investigators noted that combination therapy did not cause significant toxicity effects.
Speaking at ECCO 13, Dr Kathy Miller from the Indiana University Cancer Centre, USA, commented, ???This is the first study to confirm the benefit of anti-angiogenic therapy in patients with breast cancer. Importantly, the improvements in response rate and progression-free survival were obtained with minimal increase in side effects. Given the benefit of bevacizumab in patients with metastatic disease, we look forward to initiating trials in the adjuvant setting.???
toniclc