Health A-Z

Medical Content Created by the Faculty of the Harvard Medical School


What Is It?

Mammography is a series of X-rays that shows images of the soft tissues of the breast. It is a valuable screening procedure that can detect breast cancer early, as long as two years before a lump can be felt.

For women ages 50 to 74 with an average risk of breast cancer, the United States Preventive Services Task Force (USPSTF) recommends mammography once every 2 years. Other medical societies and organizations recommend yearly mammograms.

For women between ages 40 and 50, the benefits of mammography for women at average breast cancer risk continue to be debated. The USPSTF does not recommend routine screening for women in this age group. However, the Cancer Society, the American College of Radiology, and the American College of Obstetrics and Gynecology recommend that women start routine screening with mammography at the age of 40.

If a woman has a mother, sister or daughter who has had breast cancer, her doctor may recommend beginning mammograms earlier than age 40.

Mammography is a quick and generally painless test that usually takes less than 30 minutes, depending on the number of individual X-ray views required. The X-rays themselves take only a few seconds, but extra time is needed to position your breast and body correctly for each separate X-ray view.

Mammography misses breast cancer about 5% to 10% of the time. But the rate can be as high as 30% for women with dense breast tissue (usually women who have not reached menopause).

It is not uncommon to find something on a mammogram that requires additional testing. Most testing facilities will immediately take different, larger images of the area in question or do an ultrasound for a different view of the abnormal area. Most abnormalities found during a mammography are not cancer.

Sometimes, a doctor may order a fine-needle biopsy of the suspicious spot to determine if it is malignant (cancerous). In this type of biopsy, cells from the suspicious area of the breast are removed using a needle, and then spread on a slide. The slide is sent to the laboratory to be examined under a microscope.

The value of mammography is early detection. Early detection saves lives and, in many cases, also saves the woman's breast by identifying the cancer at a very early stage when it is most easily treated and is not life threatening.

Page 1 of 9     Next Page:  Mammography What It's Used For
Click here to to redeem your SparkPoints
  You will earn 5 SparkPoints
From Health A-Z, Harvard Health Publications. Copyright 2007 by the President and Fellows of Harvard College. All rights reserved. Written permission is required to reproduce, in any manner, in whole or in part, the material contained herein. To make a reprint request, contact Harvard Health Publications. Used with permission of StayWell.

You can find more great health information on the Harvard Health Publications website.