CHICAGOIn a screening program for young women with a high
susceptibility for developing breast cancer, magnetic resonance
imaging (MRI) proved more effective than mammography or ultrasound in
detecting cancers, German researchers reported at the 85th Annual
Meeting of the Radiological Society of North America (RSNA).
The Screening Program
In 1996, researchers at the University of Bonn began a multicenter
trial on the identification and care of women who carry gene
mutations associated with breast cancer or who have a strong personal
or family history of breast cancer.
These women were entered into a screening program that consists of a
clinical visit and ultrasound twice a year, and two-view mammography
and MRI once a year.
Of 262 women in the study, 105 have undergone the full screening
protocol and been followed for 3 years. Fifteen have been diagnosed
with breast cancer, nine asymptomatic and six symptomatic.
Christiane K. Kuhl, MD, reported that breast MRI was the only imaging
modality to detect and correctly classify cancer in all nine of the
asymptomatic women and all six of the symptomatic patients.
Mammography and ultrasound combined detected cancer in only four of
the nine asymptomatic women and four of six symptomatic individuals.
Breast MRI also produced fewer false-positive findings than
mammography or ultrasound. Mammography had 7 false-positive biopsy
calls, ultrasound had 19, and MRI had 5.
MRI maintained a consistent positive predictive value and high
specificity (see Table) despite a
high prevalence of patients with MRI contrast enhancement that was
classified as insignificant, benign, or cyclical-phase induced (52%).
In these high-risk women, MRI is able to identify breast cancer
that is occult on both mammography and ultrasound, Dr. Kuhl said.