SAN ANTONIO – Compliance with mammographic screening guidelines is considerably less than would be expected based upon the public sound and fury that greeted the U.S. Preventive Services Task Force’s November 2009 updated guidelines recommending a cutback from annual to biennial screening in 50- to 74-year-olds and dropping the routine screening of women aged 40-49.
"When the U.S. Preventive Services Task Force guidelines came out, there was a large outcry. We heard, ‘Don’t take away our right, our ability, to have a mammogram regularly.’ So we thought we’d take a look at our database and see what women are actually doing, what the compliance is with the guidelines," Dr. Milayna Subar explained at the San Antonio Breast Cancer Symposium.
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Her study involved nearly 1.6 million American women aged 40 or older with full health insurance coverage and no history of breast cancer. It showed that only 50% got annual mammograms during the study years 2006-2009, as was widely recommended by most major guidelines during that period, including the since-revised USPSTF guidelines.
Moreover, 40% of insured women with access to the full range of preventive health care services did not even get the biennial mammographic screening as recommended in the USPSTF guidelines operative today, reported Dr. Subar, vice president and national practice leader for oncology at Medco Health Solutions.
Of note, the widely cited American Cancer Society guidelines still recommend annual mammography in women aged 40 or older, and American College of Obstetricians and Gynecologists guidelines recommend annual mammography in women aged 50 and older, and every 1-2 years in 40- to 49-year-olds. The reality demonstrated by the Medco study is that compliance with these more-stringent guidelines falls even further short of adherence to the cutback USPSTF guidelines, she observed.
During 2006-2009, the rate of annual screening mammography remained fairly constant over the years at 47% among women aged 40-49 years, compared with 54% in 50- to 64-year-olds, and 45% among those women aged 65 or older.
Screening every 2 years was obtained by 57% of women aged 40-49, 65% of those aged 50-64 years – the age when all of the guidelines (despite their other differences) agree on screening at a minimum of every 2 years – and in 53% of insured women aged 65 or older.
This study didn’t examine reasons for noncompliance with mammographic guidelines among insured women. But Dr. Subar offered several theories as to the low screening rates: fear, procedure-related discomfort, simple forgetfulness, the declining number of mammographic facilities, and the inconsistency of the guidelines.
"I think there could be some confusion about what to do," she said.
Some women may have been put off by debate among experts as to the net benefit of screening mammography. For Dr. Alan Coates, that issue has been well answered by a recent published analysis of the Norwegian breast cancer screening program experience.
The Norwegian investigators found that during a recent 20-year period mortality due to breast cancer declined by 28% in that country, as has also been true in most other Western countries. Since the Norwegian national mammographic screening was introduced in stages regionally, the investigators were able to determine that of the 28% drop in breast cancer mortality, 18% was attributable to improved patient management, most notably the introduction of adjuvant tamoxifen and better multidisciplinary care, while the other 10% was due to the effects of earlier diagnosis through mammographic screening (N. Engl. J. Med. 2010;363:1203-10), noted Dr. Coates of the University of Sydney in his conference-closing summary of the year’s highlights in early breast cancer.
Dr. Subar’s study was sponsored by Medco Health Solutions.