Magnetic resonance imaging improves diagnosis of ductal carcinoma in situ

Using magnetic resonance imaging (MRI) may be helpful in diagnosing ductal carcinoma in situ (DCIS), particularly cancer with a high nuclear grade, according to study findings published in the Aug. 11 issue of the Lancet.

Christiane Kuhl, MD, of the University of Bonn in Germany, and colleagues analyzed data on 7,319 women who received both MRI and mammography for diagnostic assessment and screening for breast cancer.

Among the cohort, 193 women were diagnosed with pure DCIS. In all, 167 women were tested using both methods; 93 (56%) were diagnosed by mammography and 153 (92%) were diagnosed by MRI. There were 89 cases of high-grade DCIS, of which 43 (48%) were missed by mammography and diagnosed by MRI. Only two cases were missed by MRI and detected by mammography.

Although the authors concede that MRI runs the risk of overdiagnosis, the fact that 60% of DCIS were high grade is significant. "There is broad agreement that the diagnosis of high-grade DCIS is prognostically relevant and should help prevent the development of invasive cancer," they conclude.

Kuhl CK, Schrading S, Bieling HB. MRI for diagnosis of pure ductal carcinoma in situ: a prospective observational study. Lancet. 2007;370:485-492.