Routine screening mammograms contribute just as much as hormone therapy and chemotherapy in slowing the rate of death from breast cancer, a study released on Wednesday showed.
The study, based on seven statistical analyses by 43 researchers and published in The New England Journal of Medicine, 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.
Although some researchers have questioned the value of routine screening, in the United States women are urged to have regular mammograms beginning in their 40s for early detection of the disease.
Chemotherapy and hormone therapy such as tamoxifen reduced the death rate by 12 percent to 21 percent, according to the study led by Donald Berry of the University of Texas M.D. Anderson Cancer Center in Houston.
A combination of screening and other therapy reduced the death rate by an estimated 25 percent to 38 percent.
"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," Berry said.
"Screening would have no benefit if not followed by treatment, including surgery, and treatment has the potential to be more effective if cancer is detected at earlier stages by screening," he added.
The death rate from breast cancer has decreased by 24 percent from 1990 to 2000.
This year 215,000 women are expected to be diagnosed with breast cancer and the disease will kill more than 40,000, according to the American Cancer Society.