Primary Finding
The Digital Mammographic Imaging Screening Trial (DMIST) showed that, for the entire population of women studied, digital and film mammography had very similar screening accuracy.

Who would benefit from digital screening mammograms?
Women who fit ANY of these three categories:

• under age 50 (no matter what level of breast tissue density they had)
• of any age with heterogeneously (very dense) or extremely dense breasts
• pre- or perimenopausal women of any age (defined as women who had a last menstrual period within 12 months of their mammograms).

Who would not benefit from digital screening mammography?
Women who fit ALL of the three categories:

• over age 50
• those who do not have dense or heterogeneously (very dense) breast tissue
• those who are not still menstruating.

Should all women get a digital mammogram?
No. At present, only 8 percent of the mammography units in the U.S. are digital systems, whereas approximately 40 percent of women undergoing screening mammography have dense breasts.

Given these results, should women move up or skip their next regularly scheduled mammogram?
Women should have their next mammogram when they are scheduled for it. It would be better to have a film mammogram when a woman is supposed to have her next mammogram than for her to delay her screening in order to get a digital mammogram. No woman should defer screening with mammography just because of a lack of access to digital mammography. Film mammography has been successfully used as a screening tool for breast cancer for over 35 years.

There is no reason for any woman to receive an extra mammogram because of these trial results. That is, if a woman has had a mammogram in the last year, and she has no breast signs or symptoms, she should undergo her next screening mammogram only when she is due for one, not earlier than she would ordinarily be scheduled.

Multiple exposures to obtain an accurate view of a portion of the breast may be necessary with digital mammography. Is additional dose an issue? Increasing the number of images per view does not increase the dose dramatically because not all breast tissue is exposed in each view. For example, taking two digital images of the breast instead of one film mammogram does not double the dose overall, since only a portion of the breast is exposed twice. On average, the larger number of digital images required is more than offset by the lower doses delivered by digital mammography for women with thicker and denser breasts.

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