Breast cancer is the second leading cause of cancer deaths among US women. Mammography screening may be associated with reduced breast cancer mortality but can also cause harm.
Guidelines recommend individualizing screening decisions, particularly for younger women.
Researchers reviewed the evidence on the mortality benefit and chief harms of mammography screening and what is known about how to individualize mammography screening decisions, including communicating risks and benefits to patients.
Mammography screening is associated with a 19% overall reduction of breast cancer mortality ( approximately 15% for women in their 40s and 32% for women in their 60s ).
For a 40- or 50-year-old woman undergoing 10 years of annual mammograms, the cumulative risk of a false-positive result is about 61%.
About 19% of the cancers diagnosed during that 10-year period would not have become clinically apparent without screening ( overdiagnosis ), although there is uncertainty about this estimate.
The net benefit of screening depends greatly on baseline breast cancer risk, which should be incorporated into screening decisions.
Decision aids have the potential to help patients integrate information about risks and benefits with their own values and priorities, although they are not yet widely available for use in clinical practice.
To maximize the benefit of mammography screening, decisions should be individualized based on patients’ risk profiles and preferences.
Risk models and decision aids are useful tools, but more research is needed to optimize these and to further quantify overdiagnosis.
Research should also explore other breast cancer screening strategies.
Breast cancer is the most common non-cutaneous cancer and the second leading cause of cancer death among women in the United States. About 40 000 women die of breast cancer in the United States each year.
For decades, there has been strong interest in screening strategies that will detect early cancers before they progress, thereby reducing mortality.
Some trials have demonstrated that mammography is associated with decreased breast cancer mortality, but these data and increasing evidence about the harms of mammography screening have generated controversy.
In 2009, in light of evidence that the benefit-risk ratio is higher among women older than 50 years and with less frequent screening, the US Preventive Services Task Force ( USPSTF ) reversed its previous recommendation of mammography every 1 to 2 years beginning at age 40 years and recommended routine screening every 2 years starting at age 50.
This was consistent with recommendations in many European countries but contrasted with several other US organizations, revitalizing the recurring debate in both the medical community and mainstream media about mammography policy and practice.
Recent evidence suggests that use of mammography in the United States has not changed following the USPSTF 2009 recommendations.
The USPSTF stated that the decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take into account patient context, including the patient’s values regarding specific benefits and harms.
The central issue for clinicians, which is infrequently addressed in the medical literature, is how to individualize mammography recommendations and foster informed decisions by patients.
To accomplish this, clinicians must assess a patient’s individual risk for breast cancer, effectively communicate the risks and benefits of screening, identify how a patient’s characteristics might modify those risks and benefits, and elicit patients’ personal preferences and values. ( Xagena )
Source: Journal of American Medical Association, 2014