For women who carry the BRCA1 or BRCA2 genetic mutations, adding MRI screening to mammography screening for breast cancer can be cost effective even though MRI is so expensive, according to Sylvia K. Plevritis, Ph.D., of Stanford (Calif.) University and her associates.
Breast MRI screening is “at least 10 times more expensive than mammographic screening.”
It also produces more false-positive results, which generate further costs for unneeded diagnostic workups.
“Because cost may be the greatest barrier to broader evaluation and dissemination of breast MRI screening, its cost-effectiveness is a critical consideration,” the investigators noted.
Currently there are no randomized clinical trials examining the cost-effectiveness of MRI screening for women at high risk of breast cancer.
And even if such a trial were initiated today, “mortality outcomes would not be available for at least 15 years,” Dr. Plevritis and her associates noted (J. Am. Med. Assoc. 2006;295:2374–84).
They estimated the cost-effectiveness of adding breast MRI screening to mammographic screening in women carrying BRCA1 and BRCA2 mutations using a computer simulation model that incorporated health benefits as well as expenses.
The model projected the long-term effects on clinical and economic outcomes of no breast cancer screening, annual mammography alone for women aged 25–69 years, and annual mammography plus MRI for specific age groups.
The model used a simulated cohort of women carrying the BRCA mutations who were aged 25 in 2005.
MRI screening was found to reduce breast cancer mortality by 23% over that obtained by mammography alone in women carrying either the BRCA1 or BRCA2 mutations.
For women with the BRCA1 mutation, “adding MRI increases the sensitivity of annual screening from 35% to 85%, the proportion of axillary lymph-node-negative cancers from 57% to 81%, the mean lead time from approximately 1.5 to 3 years, and the false-positive rate from approximately 5% to 25%.” Outcomes for women with the BRCA2 mutation were similar.
“With MRI, life expectancy increases from 71.2 to 73.3 years for BRCA1 mutation carriers and from 78.2 to 79.6 years for BRCA2 mutation carriers,” Dr. Plevritis and her associates wrote in their article.
Adding MRI to mammography was found to be cost effective for women aged 35–54 years.
It was not cost effective for the younger women in the simulation model (those aged 25–34 years) because of their lower incidence of the disease, and added MRIwas not cost effective for the older women (those aged 55 and older) because of the competing risk of death from other causes.