MRI breast cancer screening

The word ‘mammogram’ is synonymous with dread and discomfort for many women who would prefer anything to having a mammogram.

Increasing numbers of women are therefore asking their doctors to order a Magnetic Resonance Imaging (MRI) test as an alternative to a mammogram.

MRI is an imaging test that uses magnetic fields to produce detailed cross-sectional images of tissue structures, providing very good soft tissue contrast. It has none of the discomfort traditionally associated with mammography.

The vast majority of women seeking a MRI for routine breast cancer screening mammogram are told, ‘no’, but why this answer? One reason is the high cost of MRI testing but there are other more scientific reasons for this answer as well.

The test has a high ‘sensitivity’ but low ‘specificity’ for breast cancer detection so what does this mean? Simply put, MRI can detect many abnormalities in the breast tissue (high sensitivity), necessitating further investigative and often invasive follow-up for what turns out to be a benign (non-cancerous) condition (low specificity for breast cancer).

The consensus of the medical professionals is that MRI is not an effective tool to screen most women for breast cancer.

However, the medical community appears united in recommending MRI be used as a adjunct to mammography screening in certain groups of women. These groups of women have been identified as high risk and include those who have BRCA gene mutations or other unusual genetic syndromes; have a lifetime risk for breast cancer of at least 20 per cent according to predictive models based on family history; have a strong family history of breast and ovarian cancer; or have received chest radiation for conditions such as Hodgkin’s disease between ages 10 and 30 years.

It is recommended that women at high-risk for breast cancer discuss with their doctor beginning annual screening with mammogram and MRI as early as age 30.

For other women, the advice is still to have a mammogram every two years beginning at the age of 40 or as recommended by your doctor.

For more information call the Cayman Islands Cancer Society at 949-7618.