Despite the outcry after a government task force recommended changes to mammography screening guidelines in 2009, only about half of women whose insurance covers mammograms have annual screening, researchers reported at the CTRC-AACR San Antonio Breast Cancer Symposium.
"We are reporting a lower than expected prevalence of mammography based on the loud outcry after the US Preventive Services Task Force recommendations," said Milayna Subar, MD, Vice President and National Practice Leader for Oncology at Medco Health Solutions, Inc. in Franklin Lakes, NJ.
"We often listen to the loudest and forget about those who aren't shouting. We have to look at the actual data, not what people say when they are speaking out."
The review of medical claims in the study included some 1.5 million women age 40 and older between 2006 and 2009. Among women 40 to 49, 47% had an annual screen. About 54% of women aged 50 to 64 and 45% of those 65 and older had an annual mammogram.
The findings are particularly alarming because all the women had health insurance, said AACR President-lect Judy E. Garber, MD, MPH, Leader of the Center for Cancer Genetics and Prevention at Dana-Farber Cancer Institute.
She compared the situation to that also observed with colon cancer screening- "We have the same data that colonoscopies are beneficial, but we have a hard time getting people to do them."
Contributors to Noncompliance
While the researchers did not look at contributors to lack of compliance, Dr. Subar speculated that conflicting guidelines may be confusing to patients. For example, among the various guidelines:
* American Cancer Society: Ages 40 to 49, screen every one to two years; annual if 50 or older.
* American Congress of Obstetricians and Gynecologists: Annual for age 40 and older while in good health.
* National Cancer Institute: Every one to two years age 40 and older, if at average risk.
* National Comprehensive Cancer Network: Annual for age 40 and older, if at average risk.
* Society of Breast Imaging/American College of Radiology: Annual for age 40 and older, if at average risk, until life expectancy is less than five to seven years.
That was until November 2009, when the US Prevention Services Task Force complicated things further, saying that women in their 40s at average risk for breast cancer do not need routine mammograms and that women 50 and older need them only every two years. The resulting outcry led Congress to include a provision in the health care reform legislation for insurers to cover annual mammography starting at age 40.
No matter which guidelines are followed, however, the numbers are dismally low, Dr. Subar said.
Among women 40 and older, only 60% had two or more mammograms over four years, and even in the 50 to 64 age group, the age group that most benefits from the screens, only 65% did.
Other possible contributors to the low screening rates are concerns regarding procedure-related discomfort and a shortage of easily accessible screening centers in some areas, Dr. Subar said, adding that even among this group of women who do have insurance, cost can be a factor.
Other Surveys
Dr. Subar noted that other datasets also suggest poor compliance with mammography screening guidelines.
The US Department of Health and Human Services' "Healthy People 2010" goal of achieving 70% compliance with a mammogram within the past two years for women age 40 and over was not met when last reported as 67% in 2005-"and this study now shows that, as of 2009, the goal has still not been achieved," she said.
Dr. Garber said that although some other mammography surveys have reported rates of compliance as high as 80%, they relied on self-reported data and are therefore less reliable than this new study.
Concluded Dr. Subar: "Continued public education and access to mammography are of utmost importance to reaching target goals for breast cancer screening."
False-Positive Mammogram Result Found as Risk Factor for Breast Cancer
In another study reported at the meeting, a prior false-positive result on a mammogram was found to be a risk factor for breast cancer.
The study, by Danish researchers, involved nearly 60,000 women participating in a mammography program in Copenhagen, where all women aged 50 to 69 in the city get an invitation to come in for a mammogram every two years.
Results showed that women who had false-positive results were 73% more likely to develop breast cancer in the two years before their next mammogram and 33% more likely to develop breast cancer over the next 17 years, compared with women who did not have false positives.
Still, only 22 of the 5,080 women who had false-positive results developed breast cancer in the next two years, reported My von Eular-Helpin, PhD, Assistant Professor of Public Health at the University of Copenhagen.
Physicians may want to monitor patients who have false positives closely, perhaps with more frequent mammograms, she said.
Some Lesions May be Missed
Although the researchers did not investigate the reasons, Dr. Eular-Helpin said she suspects that some benign lesions turned malignant. Also, some lesions are so small they may be missed, especially by a less experienced radiologist, she theorized.
Claudine J. Isaacs, MD, Director of the Clinical Breast Cancer Program at Georgetown Lombardi Comprehensive Cancer Center, noted that having a prior biopsy is a risk factor in the Gail model for predicting breast cancer risk, "so this is not dissimilar."
"The increased risk [associated with a prior false-positive result or a prior biopsy] is very minimal over the long-term, so this should not cause alarm," she said.