MRI cost-effective for some BRCA1/2 carriers

NEW YORK (Reuters Health) - Annual breast screening using MRI plus annual mammogram is cost-effective for some women with a high risk of breast cancer because they carry the BRCA1 or BRCA2 mutation, investigators in California report.

MRI, used with contrast dye, can detect breast cancer earlier than mammography in high-risk women, Dr. Sylvia K. Plevritis and her associates report in the Journal of the American Medical Association. However, MRI also increases the rate of false-positive test results and costs about 10 times more than mammography.

To evaluate the cost-effectiveness of screening BRCA1/2 mutation carriers with MRI in addition to mammography, Plevritis, from Stanford University School of Medicine, and her team constructed a model using health and economic outcomes for women between the ages of 25 to 69 years.

The model simulated the life histories of individual mutation carriers, incorporating the effects of mammographic and MRI screening. In their model, patients who developed breast cancer received chemotherapy and women with estrogen receptor-positive disease also received tamoxifen treatment.

Plevritis's team points out that MRI may be more important in screening BRCA1 mutation carriers because these women have a higher risk and their cancers are more aggressive, compared with cancers in BRCA2 mutation carriers.

The researchers found that using both screening methods annually has a cost per quality-adjusted life-year (QALY) gained ranging from less than $45,000 to more than $700,000, with variation in risk having the largest effect on the cost-effectiveness of screening.

At a cost-effectiveness threshold of $100,000 per QALY gained, adding annual MRI to mammography for BRCA1 mutation carriers between the ages of 35 and 54 years was cost-effective. Women younger than 34 have a lower risk, Plevritis and her associates note, while in women who are 55 or older, MRI is not cost-effective because of a declining quality of life and risk of death from other causes.

For BRCA2 carriers, adding MRI to screening is generally not cost-effective. However, MRI screening every other year is just within the cost-effectiveness threshold for patients with mammograms that are difficult to interpret due to breast density.

The authors add that cost-effectiveness may change as digital mammography replaces film-based mammography; if the cost of MRI screening declines; if more women undergo premenopausal surgery to remove the ovaries to lower estrogen levels; or receive tamoxifen.

SOURCE: Journal of the American Medical Association, May 24/31, 2006.