Cancer Research Lab

Pooled data from numerous studies indicate that contrast-enhanced magnetic resonance (MR) imaging has a high specificity in detection of breast cancer in patients with breast lesions, Dutch researchers report in the January issue of Radiology.

However, lead investigator Dr. Nicky H. G. M. Peters told Reuters Health that “MR mammography can improve diagnosis and treatment of patients with breast cancer, but biopsy remains necessary to definitively characterize lesions.”

Dr. Peters and colleagues at University Medical Center, Utrecht conducted a meta-analysis of 44 studies carried out over a 10-year period among patients suspected of having breast cancer who also underwent biopsy.

The number of patients involved in each study ranged from 14 to 821, with a mean of 128. The mean cancer prevalence was 54% and the mean patient age was 51 years.

The number of criteria used to differentiate benign from malignant lesions was unknown in 11 of the studies and ranged from 1 to 3 in the remainder.

The team calculated that the overall sensitivity of MR imaging was 0.90 and the overall specificity was 0.72. Specificity, they write, “varied across the individual studies more than sensitivity did, and it varied with or across cancer prevalence and number of criteria used to differentiate benign from malignant lesions.”

In fact, the researchers note that they were unable to explain fully why specificity was higher (0.81) when two criteria were used, than was the case for one (0.74) or for three (0.67).

They call for further studies in patients with nonpalpable breast lesions, but point out that the approach has high sensitivity and a lower specificity in patients referred for biopsy of a breast lesion.

“We concluded that MR cannot yet replace biopsy for definitive characterization of breast lesions,” Dr. Peters added.