New Hampshire Mammography Network: Years of Data Add Up
October 15, 2008
October is Breast Cancer Awareness Month, a good time to recognize that each year 800 to 900 women in New Hampshire are diagnosed with breast cancer. Many women fill out a familiar, detailed questionnaire each time they get a mammogram. Over fifteen years, the NH Mammography Network (NHMN) has collected data on almost a million mammograms in New Hampshire. Women who have been filling out the NHMN questionnaire over the years can take credit for contributing to valuable discoveries that may affect breast cancer detection nationwide.
Mammography is the most commonly used screening technique for cancer in women who have no symptoms. The NHMN data shows that 36% of New Hampshire women either never had a mammogram previously or had an irregular schedule of screening. Older women (80 years and older) are the least likely to be screened. And 35% of women have one or two mammograms and then do not return for at least 27 months.
The NHMN data also shows that women who are screened every year for ten years have a 50% chance of being asked back for more imaging that turns out to show no cancer. Higher recall rates do not result in higher cancer detection rates. They also discovered that the presence of breast implants decreases the ability of mammography to detect breast cancer.
NHMN is looking at ways to deal with the impact of their results. They have tried out two different ways to encourage New Hampshire women who were not receiving routine mammograms to get screened. They are also testing ways to improve radiologists' mammography interpretation skills and are assessing new technologies, like digital mammography.
NHMN's continued collection of data is essential to gauging the impact of mammography on cancer detection, to evaluating new mammography technologies, and to finding ways to encourage women to get screened. The NH Mammography Network, which is managed at Dartmouth's Norris Cotton Cancer Center, is one of only five mammography registries nationwide, which comprise the Breast Cancer Surveillance Consortium, funded by the National Cancer Institute. The combined data from the five registries contains information about 6.5 million mammograms.