Use of breast MRI increased dramatically in the last decade, much of it involving women who did not meet high-risk criteria for use of advanced imaging, analyses of two large databases showed.
One study showed a 20-fold increase in the rate of breast MRI from 2000 to 2009, followed by a decline and stabilization. In 2011 the rate remained 16 times higher than in 2000.
The second found that use of breast MRI almost tripled from 2005 through 2009.
The studies, reported online in JAMA Internal Medicine, showed that breast MRI was used appropriately in 20% to 30% of cases, and one of the studies found that half of women with high-risk characteristics did not undergo breast MRI.
"Our data suggest that the majority of women who underwent screening for breast MRI did not meet the recommended criteria for appropriate use, whereas many who did meet the criteria did not undergo screening breast MRI," Natasha K. Stout, PhD, of Harvard, and co-authors concluded. "However, to clearly understand appropriateness of use, better documentation of breast cancer risk is needed.
"Understanding who is receiving breast MRI and the downstream consequences of this use should be a high research priority to ensure that the limited healthcare funds available are used wisely to maximize population health."
Both the American Cancer Society and the National Comprehensive Cancer Network have published guidelines that recommend limiting use of breast MRI to women who have a greater than 20% lifetime risk of breast cancer, the authors of an accompanying editorial noted.
"Routine breast MRI screening is not recommended for a new cancer diagnosis or for cancer surveillance," said E. Shelley Hwang, MD, of Duke University, and Isabelle Bedrosian, MD, of MD Anderson Cancer Center in Houston. "Nevertheless, MRI remains frequently used for these other indications."
Despite coming from different patient populations and use of different methodology, the findings of the two studies "are remarkably consistent," Hwang and Bedrosian added.
A planned multicenter prospective study should provide information needed to define MRI's role in evaluation and management of patients with newly diagnosed cancers, they concluded.
The two studies add to a growing volume of evidence related to overuse and inappropriate use of breast MRI. There's no doubt that MRI has greater sensitivity for breast cancer detection than mammography. However, breast MRI has lower specificity and substantially higher cost. And no randomized trials have been conducted to determine whether breast MRI improves breast cancer survival or other outcomes.
Because of uncertainty surrounding the role of MRI in diagnosis, evaluation, and management of breast cancer, expert opinions have recommended limiting the imaging modality's use to women with a high risk of breast cancer. Analogous to prostate cancer screening, no data exist to show that the benefits of breast MRI outweigh the potential risks for women with lower risk.
Information about use of breast MRI in the community remains sparse, particularly as it relates to long-term trends. To address the issue, Stout and colleagues reviewed records for 10,518 patients who had at least one breast MRI from January 2000 through December 2011. The study population came from a not-for-profit health plan and a multispecialty group practice, both located in New England.
Breast MRI usage was determined from claims data, and the appropriateness of the imaging was determined by a risk prediction model derived from electronic medical records (EMRs) of a subset of patients.
The analysis showed that use of breast MRI increased 46% annually from 2003 through 2008, increasing the usage rate from 6.5 per 10,000 women in 2000 to 130.7/10,000 by the end of 2008. The rate declined by 10% annually from 2009 to 2011, ending at a rate of 104.8/10,000 in 2011. Age-specific trends followed a similar pattern.
With respect to indications for breast MRI, the authors found that 30.1% of women had a claims-documented personal history of breast cancer, 51.7% had a family history, and 3.5% had a high-risk genetic mutation.
In the subset of women with risk derived by EMRs, just 21.0% met ACS criteria for breast MRI. On the other hand, a minority (48.4%) of women with high-risk genetic mutations underwent breast MRI.
The second study involved participants in the five geographically divergent Breast Cancer Surveillance Consortium registries and encompassed 2005 through 2009. The analysis involved 8,931 breast MRI exams and 1,288,924 screening mammograms.
The rate of breast MRI increased from 4.2 per 1,000 women in 2005 to 11.5/1,000 in 2009, reported Karen J. Wernli, PhD, of the Group Health Research Institute in Seattle. The most commonly documented indication for breast MRI was diagnostic evaluation (40.3%), followed by breast cancer screening (31.7%).
As compared with women who did not have breast MRI, those who did were younger than 50, non-Hispanic whites, nulliparous, and had a personal or family history of breast cancer or dense breast tissue (P<0.001 for all). The proportion of the breast MRI group that had a high lifetime risk of breast cancer increased from 9% in 2005 to 29% in 2009.
"Use of breast MRI for screening in high-risk women is increasing," the authors concluded. "However, our findings suggest that here is a need to improve appropriate use, including among women who may benefit from screening breast MRI."
The study by Stout et al. was supported by the American Cancer Society and the National Cancer Institute.
Stout and co-authors reported no relevant disclosures.
The study by Wernli et al. was supported by the National Cancer Institute and by the Agency for Healthcare Research and Quality.
Wernli reported no relevant disclosures. One or more co-authors disclosed relationships with GE Medical Systems and Philips Healthcare.
Hwang and Bedrosian reported no relevant disclosures.
- Reviewed by F. Perry Wilson, MD, MSCE Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner
JAMA Internal MedicineSource Reference: Stout NK, et al "Rapid increase in breast magnetic resonance imaging use trends from 2000 to 2011" JAMA Intern Med 2013; DOI: 10.1001/jamainternmed.2013.11958.
JAMA Internal MedicineSource Reference: Wernli KJ, et al "Patterns of breast magnetic resonance imaging use in community practice" JAMA Intern Med 2013; DOI: 10.1001/jamainterned.2013.11963.
JAMA Internal MedicineSource Reference: Hwang ES, Bedrosian I "Patterns of breast magnetic resonance imaging use: An opportunity for data-driven resource allocation" JAMA Intern Med 2013; DOI: 10.1001/jamainternmed.2013.11958.