Radiology: BRCA1 carriers should be screened with MRI + mammography
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Researchers from the Department of Radiology, Division of Hematology/Oncology at Massachusetts General Hospital in Boston estimated the number of QALYs--a measure of both the quantity and quality of life--gained by screening, along with lifetime costs, and found that the annual combined screening method for women considered to be high-risk for developing breast cancer was best at detecting early stage cancers and provided the greatest relative mortality reduction in this patient-population.
“Women with BRCA1 or BRCA2 gene mutations have a substantially increased lifetime risk of developing breast cancer,” explained Janie M. Lee, MD, the lead author of the study. “Although screening mammography is the current clinical standard for breast cancer screening in the general population, it aids in the detection of less than one half of prevalent and incident breast cancers in high-risk women.”
Lee and colleagues utilized a simulation model to compare a hypothetical cohort of 25-year-old BRCA1 mutation carriers for their study. The cohort was divided into three groups; screen-film mammography screening only, MR imaging only and combined MR imaging and screen-film mammography (combined screening).
The simulation model was used to estimate QALYs as well as lifetime costs by way of Medicare reimbursement rates and the medical literature. Incremental cost-effectiveness ratios were also calculated, noted the researchers.
Annual combined screening was determined to be most effective in providing the most QALYs (44.62 years) than annual MR imaging (44.50 years) and annual mammography (44.46 years) alone. In addition, the combined method was also found to have the highest overall cost ($110,973), compared to MR imaging alone ($108,641) and annual mammography alone ($100,336), wrote the authors.
Despite carrying the highest cost, Lee and colleagues determined that combined screening became more cost-effective as breast cancer risk increased and less cost-effective as risk decreased. Moreover, the researchers noted that commonly cited threshold values range from $50,000 to $100,000 per QALY, and adding annual MRI to annual mammography screening cost $69,125 for each additional QALY gained.
According to the authors, the study’s finding also highlight a potential concern in regard to MRI, as the screening method has been associated with an increase in false-positive test results. While annual mammography resulted in 37 false-positive findings for every breast cancer death averted, the addition of annual MRI increased this number to 137 false-positives for each breast cancer death averted.
However, the researchers said, “[t]he benefits of screening with increased intensity for these women are likely to outweigh the effects of false-positive screening results.”
“For women at the highest risk of breast cancer, using both breast MRI and mammography together for screening will likely reduce their chances of dying from breast cancer and help them live longer, healthier lives,” said Lee.
The findings of this study support current American Cancer Society screening recommendations for breast cancer.