Alternatively, if a woman worries that the 4-year screening interval is too long, screening mammography may be offered every 2 years, with MRI screening offered for the second 2-year interval, according to the findings. This strategy would still require the patient to undergo MRI breast cancer screening every 4 years.
“MRI is more effective not only for selected patients. It is actually more effective than mammography for all women,” editorialist Christiane Kuhl, MD, PhD, University of Aachen (Germany), said in an interview.
“But the superior diagnostic accuracy of MRI is more often needed for women who are at higher risk for breast cancer, and therefore the cost-effectiveness is easier to achieve in women who are at higher risk,” she added.
The study was published online Sept. 29 in the Journal of the National Cancer Institute.
DENSE trial
The simulation model used for the study was based on results from the Dense Tissue and Early Breast Neoplasm Screening (DENSE) trial, which showed that additional MRI screening for women with extremely dense breast tissue led to significantly fewer interval cancers in comparison with mammography alone (P < .001). In the DENSE trial, MRI participants underwent mammography plus MRI at 2-year intervals; the control group underwent mammography alone at 2-year intervals.
In the current study, “screening strategies varied in the number of MRIs and mammograms offered to women aged 50-75 years,” explains Amarens Geuzinge, MSc, University Medical Center, Rotterdam, the Netherlands, and colleagues, “and incremental cost-effectiveness ratios (ICERs) were calculated ... with a willingness-to-pay threshold of 22,000 euros (>$25,000 U.S.),” the investigators add.
Analyses indicated that screening every 2 years with mammography alone cost the least of all strategies that were evaluated, but it also resulted in the lowest number of quality-adjusted life years (QALYs) – in other words, it delivered the least amount of benefit for patients, coauthor Eveline Heijnsdijk, PhD, University Medical Center, Rotterdam, the Netherlands, explained to this news organization.
Offering an additional MRI every 2 years resulted in the highest costs but not the highest number of QALYs and was inferior to the other screening strategies analyzed, she added. Alternating mammography with MRI breast cancer screening, each conducted every 2 years, came close to providing the same benefits to patients as the every-4-year MRI screening strategy, Dr. Heijnsdijk noted.
However, when the authors applied the National Institute for Health and Care Excellence (NICE) threshold, MRI screening every 4 years yielded the highest acceptable incremental cost-effectiveness ratio (ICER), at 15,620 euros per QALYs, whereas screening every 3 years with MRI alone yielded an ICER of 37,181 euros per QALY.
If decision-makers are willing to pay more than 22,000 euros per QALY gained, “MRI every 2 or 3 years can also become cost effective,” the authors add.
Asked how acceptable MRI screening might be if performed only once every 4 years, Dr. Heijnsdijk noted that, in another of their studies, most of the women who had undergone MRI screening for breast cancer said that they would do so again. “MRI is not a pleasant test, but mammography is also not a pleasant test,” she said.
“So many women prefer MRI above mammography, especially because the detection rate with MRI is better than mammography,” she noted. Dr. Heijnsdijk also said that the percentage of women with extremely dense breasts who would be candidates for MRI screening is small – no more than 10% of women.
At a unit cost of slightly under 300 euros for MRI screening – compared with about 100 euros for screening mammography in the Netherlands – the cost of offering 10% of women MRI instead of mammography might increase, but any additional screening costs could be offset by reductions in the need to treat late-stage breast cancer more aggressively.