Annual mammograms help detect breast cancer in its earliest stages, according to a new report presented at the annual meeting of the American Society for Therapeutic Radiology and Oncology.

A study of 1,591 women over age 40 with newly diagnosed breast cancer, seen between 1995 and 2001 at the Breast Evaluation Center at Fox Chase Cancer Center in Philadelphia, supports annual mammograms to increase the chances of finding early-stage, non-invasive breast cancer, the researchers said.

The women in the study were put into one of three groups: those who had never had a mammogram prior to their diagnosis (group 1); those who had mammograms on average less than once a year (group 2); and those who had mammograms on average yearly or more often (group 3).

The method of cancer detection was by mammogram alone in only 33 percent of the women in group 1, 49 percent in women in group 2 and 59 percent of women in group 3. Fifteen percent of patients in group 1 had ductal carcinoma in situ, the most curable form of breast cancer, compared with 21 percent of patients in group 2 and 26 percent of patients in group 3.

Researchers also found a link between mammography and whether women were offered the option of breast-conserving surgery. For women in group 1, doctors offered 41 percent of them breast-conserving surgery and radiation, but recommended mastectomy to 41 percent of their patients. For the women in groups 2 and 3, 60 percent were eligible for breast conservation, with only 29 percent receiving a recommendation for a mastectomy.

"Regular mammograms are recommended for women over the age of 40 for early detection of breast cancer. Whether there is a survival benefit to screening mammograms and exactly how often these women should have mammograms, however, has been open to debate," said Dr. Gary M. Freedman, lead author of the study.

"This study demonstrates that regular screening is linked to an early stage of breast cancer when it is diagnosed. We know that patient survival is better with earlier stage of disease," said Freedman. "If women want to increase their odds of detecting breast cancer early and decrease the likelihood that they would need a complete mastectomy, they should make sure they have a mammogram at least once a year."

Other sources: American Society for Therapeutic Radiology and Oncology