MRI-based screening detected cancers at an earlier stage than mammography in women with a familial risk of breast cancer, according to a recent study published in Lancet Oncology. However, the study warns about over-diagnosis resulting in false-positive in women with high breast density.
A cohort of 1,355 women with a familial predisposition to breast cancer were involved in the study. Of these, 675 were randomized to receive annual MRI and clinical breast examination plus biennial mammography (MRI group) and 680 were allocated to receive annual mammography and clinical breast examination (mammography group).
More breast cancers were detected in the MRI group (40) than in the mammography group (15), reported Madeleine M.A. Tilanus-Linthorst, MD, of Erasmus University Medical Center, in Rotterdam, the Netherlands, and colleagues in the article.
According to the Dutch FaMRIsc trial, the 24 invasive cancers in the MRI-detected group were smaller than the eight found in the mammography group. They were also less frequently node-positive: four (17%) of 24 compared with five (63%) of eight.
Additionally, tumour stages in the MRI group were significantly earlier with 12 (48%) of 25 tumours identified as T1a and T1b compared with one (7%) of 15 in the mammography group. One (4%) of 25 in the MRI group and two (13%) of 15 in the mammography group were stage T2 or higher.
“We conclude that in real-life practice, MRI screening can result in an important and favourable shift in tumour stage at the time of breast cancer detection compared with mammography screening, reducing the incidence of late-stage cancers and thus reducing the need for adjuvant chemotherapy and the risk of mortality,” the researchers revealed in the article.