According to a study published in the Journal of Surgical Oncology, preoperative use of magnetic resonance imaging (MRI) may clarify the extent of breast cancer in some women, and may influence decisions about type of breast surgery.
Magnetic resonance imaging (MRI) is an approach to breast imaging that detects a higher proportion of breast tumors than mammography, but also costs a great deal more and produces more false-positive test results.
Surgery to remove breast cancer may involve either a mastectomy or a lumpectomy. A mastectomy involves removal of the entire breast, whereas a lumpectomy involves removal of the cancer and a portion of surrounding tissue. Because a lumpectomy alone is associated with a higher rate of cancer recurrence than mastectomy, patients who elect to have a lumpectomy are also treated with radiation therapy. The combination of lumpectomy and radiation therapy is called breast-conserving therapy.
Accurate information about the extent of cancer is important when making decisions about type of breast surgery. And for women undergoing breast-conserving therapy, accurate information about the extent of cancer increases the likelihood that all of the cancer will be removed in a single operation.
To describe their experiences with preoperative MRI, researchers at the University of, San Diego, reviewed the records of 115 women. All the women had undergone MRI before breast surgery. The reasons for use of MRI varied, but included an indeterminate mammogram, participation in a study that required MRI, and evaluation of remaining cancer after an initial breast surgery.
- In 11 of the 115 women, MRI identified tumors that had not been detected through other means, and changed the course of treatment.
- In 10 patients with low-grade tumors, MRI overestimated the extent of cancer. MRI more accurately estimated the extent of cancer in patients with high-grade tumors.
In this study, preoperative use of MRI identified additional areas of cancer in some women, and influenced decisions about what type of surgery to perform.
The researchers note that “Breast MRI should be considered in any patient in whom mammography may be underestimating the extent of disease…”
Reference: Blair S, McElroy M, Middleton MS et al. The Efficacy of Breast MRI in Predicting Breast Conservation Therapy. Journal of Surgical Oncology. 2006;94:220-225.