Magnetic resonance imaging (MRI) appears to be much better at finding early breast cancer than traditional mammography, according to authors of a study published this week.
New research conducted over five years reveals MRIs detected 92 percent of all cases of pure ductal carcinoma in situ (DCIS). Mammography detected 56 percent of the cases. When the investigators looked specifically at high-grade cases of the disease — those most likely to develop into invasive breast cancer — MRI caught 98 percent versus just 52 percent for mammography.
Adjusting the findings to take factors like age, menopausal status, personal or family history of breast cancer, history of benign breast disease, or breast density into account didn’t change the findings.
Researchers conducted the study among more than 7,000 women screened for cancer at a large center specializing in the disease. The statistics are based on the 167 women diagnosed with DCIS who received both MRI and mammography screenings. Eighty-nine of the cases were considered high grade.
So, should more women undergo MRI for breast screening? In an accompanying comment, Dutch researchers suggest the option should be considered. They write, “These findings can only lead to the conclusion that MRI outperforms mammography in tumour detection and diagnosis. MRI should, thus, no longer be regarded as an adjunct to mammography but as a distinct method to detect breast cancer in its earliest stage.”
SOURCE: The Lancet, 2007;370:485-492, 459-460