New Jersey’s breast density legislation was successful in publicizing the potential masking effect of dense breasts, according to a recent study published by the Journal of the American College of Radiology. Supplemental screening ultrasounds and MRI examinations both became more common in the state after the law went into effect in May 2014.
“The New Jersey breast density law (NJBDL) mandates that mammography reports acknowledge the masking effect of breast density; however, it does not require that patients be specifically informed of their mammographic density,” wrote lead author Linda M. Sanders, MD, Barnabas Health Ambulatory Care Center in Livingston, N.J., and colleagues. “Provisions regarding insurance coverage for supplemental screening vary by state; the NJBDL requires insurers to cover supplemental imaging.”
For their study, Sanders et al. examined data from patients with core biopsy-proven malignancy at an outpatient breast center in New Jersey from November 2012 to October 2015. Data was divided into two time periods: the 18 months before implementation of the NJBDL and the 18 months after implementation.
Jumps in utilization
Overall, the number of screening ultrasounds increased from more than 1,500 before implementation of the NJBDL to more than 11,400 after implementation, which represented a jump of 651 percent. This leap in utilization certainly caught the research team’s attention.
“Although breast ultrasound is the modality favored by referring physicians for supplemental screening, such increased utilization has tremendous economic ramifications for insurance providers and the health care system overall,” the authors wrote. “In the present study, screening ultrasound was requested even for patients without dense breast tissue. Although the NJBDL specifically stated its intent not to alter standard of care, the dramatic increase in screening ultrasound utilization at this facility, even among patients without dense breasts, suggests that clinicians feel obligated to order additional imaging to prevent legal liability.”
MRI utilization increased by more than 59 percent after implementation of the NJBDL. Mammography volume, meanwhile, decreased by 6 percent after implementation.
Sanders and colleagues also looked at cancer diagnosis by modality. Screening-detected cancers increased by 11 percent overall, they found, with some modalities showing significant changes after implementation of the NJBDL.
“Cancers found by screening mammography did not change significantly: 242 versus 235,” the authors wrote. “Cancers found by screening ultrasound and screening MRI increased by 600 percent and 189 percent, respectively.”
Ultrasound vs breast MRI
The researchers also wrote about the value of breast MRI, especially when the patient has dense breasts.
“Breast MRI is the most efficient modality for excluding or diagnosing breast cancer and should be considered in patients with dense breasts regardless of risk,” the authors wrote. “Negative results on ultrasound do not reliably exclude malignancy, particularly when performed by technologists; however, negative findings on MRI reliably confirm the absence of malignancy.”
Speaking of negative results on ultrasound: According to the data, breast MRI diagnosed 56 cancers, and in 28 of those instances, there had been a negative ultrasound within the last three months. Also, of the 26 breast cancers detected by screening MRI, 11 had recent screening ultrasound results that had come back negative.
State by state
Sanders and colleagues concluded that, as breast density legislation grows in popularity, it remains an issue states must explore on its own.
“Each state should determine its need for breast density legislation,” the authors wrote. “We encourage all health care providers to discuss with patients the risk of increased breast density and the importance of annual screening mammography beginning at 40 years of age. We recommend all breast imagers specifically inform patients of their breast density and suggest supplemental imaging when appropriate.”