August 10, 2007 (Insidermedicine) Using MRI to diagnose intraductal breast cancer could help prevent the development of invasive cancer, according to a study published in The Lancet.

Breast cancer the second leading cause of cancer deaths in women today, and in the US approximately one in eight women will develop breast cancer and about 20% of those under age 40 will die from the disease.

•    Annual mammograms are recommended for women starting at age 40
•    MRI in addition to mammogram is recommended for women with a lifetime breast cancer risk of 20% or more
•    Monthly breast self-exams and annual screening by a physician are recommended for all women starting in their 20s

A benefit of MRI is its increased sensitivity at detecting early breast cancers that may be missed by mammography. However, because this increased sensitivity can also lead to false positive results, which requires breast biopsy procedures, MRI screening is not currently recommended for all women.

In the present study, more than 7,000 women received MRI in addition to conventional mammography screening over a five-year period, with the aim of discovering the sensitivity of each method for diagnosing intraductal breast cancer.

The researchers found that of the 167 women who were diagnosed with early-stage breast cancer, 92% were detected with MRI, but only 56% were diagnosed with mammography; there was no difference in the false positive rate: the positive predictive value was 59% for MRI and 55% for mammography.

Further research may support the use of MRI as a distinct method to detect breast cancer in its earliest stages. In the meantime, women should be encouraged to perform monthly self breast exams starting in their 20s and undergo an annual mammogram at age 40. Women at high risk of breast cancer should receive an annual mammogram and MRI to help detect early-stage cancer.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.