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Study Finds Many Women Over 40 Do Not Get Annual Mammograms (dateline February 12, 2002)


Despite the increased focus on mammography from non-profit organizations, healthcare professionals, and the media, a new study finds that many women who should be getting yearly screening mammograms are still not doing so. The American Cancer Society and several other organizations recommend that all women 40 years of age and older receive annual mammograms to help detect breast cancer in its earliest stages when the chances for successful treatment and survival are the greatest. According to researchers, the increased use of mammography would lead to a substantial reduction in the size of breast cancer tumors typically diagnosed by physicians.

The American Cancer Society recommends:

  • All women between 20 and 39 years of age should practice monthly breast self-exams and have physician performed clinical breast exams at least every three years.
  • All women 40 years of age and older should have annual screening mammograms, practice monthly breast self-exams, and have yearly clinical breast exams. The clinical breast exam should be conducted close to and preferably before the scheduled mammogram.
  • Younger women with a family or personal history of breast cancer should talk to their physicians about beginning annual mammograms before age 40.

To determine whether women were following the American Cancer Society’s mammography screening recommendations, James Michaelson, PhD, and his colleagues analyzed mammograms results from 59,899 women who received 196,891 mammograms at the Massachusetts General Hospital Breast Imaging Division from January 1, 1990 to March 1, 1999. They found 604 cases of invasive breast cancer, and 206 of these cases were among women who had not had a previous mammogram at the facility.

Further results of the study:

  • 50% of the women did not begin having yearly mammograms until age 50, even though a full 25% of the invasive breast cancer cases detected by the researchers were among women younger than 50.
  • Only 50% of women who had a mammogram returned for their next mammogram within 1.5 years of their previous exam.
  • 25% of the discovered breast cancer cases were among women who had not had a previous mammogram (these breast cancer tumors were also found to be larger than the cases detected among women who received regular mammograms).

Note: 30% of the 604 cases of breast cancer were detected by exams other than mammography (such as breast ultrasound or clinical breast exams). However, Dr. Michaelson and his team note that only 3% of these 604 tumors were found by methods other than mammography within six months of the previous "negative" mammogram, and only 12% were found within one year.

"Far too many women did not comply with the American Cancer Society recommendation of prompt annual screening from the age of 40 years," according to Dr. Michaelson and his colleagues. "Consequently, almost 50% of the invasive tumors emerged as larger and, thus, potentially more lethal, palpable masses." (Palpable masses are tumors that are large enough to be felt by hand).

According to Dr. Michaelson, a large portion of the public still does not understand the importance of yearly screening mammograms and the potential risks involved if mammograms are not performed. Dr. Michaelson also noted that tools such as reminding women of their mammogram appointments (via phone or mail) may help increase mammography usage.

Physicians and healthcare professionals should encourage their patients who are 40 years of age and older to receive their yearly mammograms. The table below summarizes the benefits of mammography:

Benefits of Mammography

  • Detects small breast cancers at early stages, greatly improving chances for successful treatment and survival.
  • Clinical studies in the U.S., Sweden, the Netherlands, and elsewhere have suggested that deaths from breast cancer could be reduced if screening mammography were performed annually on all women in their forties.
  • The FDA reports that mammography can find 85% to 90% of breast cancers in women over 50 and can discover a lump several years before it can be felt.
  • Breast cancers found by screening mammography in women in their forties are generally smaller and less advanced, with less spread to lymph nodes or other organs, than cancers found in women not having annual mammograms.

Additional Resources and References