"The American Cancer Society is in complete disagreement with conclusions drawn by the Danish team," says Harmon J. Eyre, MD, Chief Medical Officer for the American Cancer Society (ACS). "In the early 1980s, when only 13 percent of American women were getting mammograms, the average size of breast tumors at diagnosis was 3.2 centimeters (about 1 1/4 inch). By the late 1990s, 60 percent of women in the United States were having regular mammograms and the average tumor size had dropped to 2 centimeters. Also, in most cases diagnosed today, the cancer has not spread to the underarm lymph nodes; decades earlier this was not the case.

"Evidence in the United States – where mammography has been done for a longer period of time than in Europe and where women are generally screened at shorter intervals using better quality equipment – shows vastly improved diagnosis and prognosis," said Dr. Eyre. "Most significantly, the death rate from breast cancer has been falling steadily over the past 10 years, in part due to mammography."

The ACS recommends that women 40 and older have an annual mammogram, annual clinical breast examination (CBE) by a health care professional, and should perform monthly breast self-examination. The CBE should be conducted close to the scheduled mammogram. Women ages 20 to 39 should have a clinical breast examination by a health care professional every three years and should perform monthly breast self-examination.

According to Robert J. Smith, PhD, Director of Cancer Screening for ACS, randomization is designed to ensure the comparability of study groups. "Because randomization is an integral part of any study design, the issue raised in the current study is not a new one. The method of randomization has been scrutinized extensively in all the mammography trials conducted in the past several decades," he said.

"Ironically, the randomization method used in one of the two trials championed by the Danish investigators has been under the darkest cloud. Numerous investigators have analyzed and re-analyzed these data and have demonstrated that the original findings show a benefit for mammography in finding breast cancer early. Mammography is beneficial, and it is beneficial because it finds breast cancer early, when a women has more treatment options."