A new study has reported that magnetic resonance imaging (MRI) and mammography both find tumors not found by the other method in women with lobular carcinoma in situ (LCIS). To conduct the study, the authors reviewed 670 screening breast MRIs performed between January 2003 and September 2008 in 220 women with a history of LCIS. The women's' mammograms were also examined. The number of cancers diagnosed, method of detection, and tumor characteristics were reviewed.

Biopsy was recommended in 63 lesions found in 58 (9%) of the 670 screening MRIs. Eight additional lesions were identified as a result of short-term follow-up MRIs, for a total of 71 lesions detected by MRI in 59 patients. Twelve breast cancers were identified in 60 lesions sampled. Biopsy was recommended in 26 additional lesions identified using mammography. Biopsy was performed in 25 of these lesions and malignancy was found in five (20%). In summary, a total of 17 cancers were found in 14 patients during the study period, of which 12 were found with MRI alone and five were found with mammography alone. Of the 12 cancers detected with MRI, nine were invasive cancers and three were ductal carcinoma in situ (DCIS). Of the five cancers detected with mammography, two were invasive and three were DCIS. The authors conclude that breast MRI is a useful method for screening women with a history of LCIS (and therefore at high-risk of developing breast cancer), resulting in a 4.5% incremental cancer detection rate. Sensitivity in the detection of breast cancers with a combination of MRI and mammography was higher than sensitivity of either method alone.

Please see our article on LCIS and lobular breast cancer more information.