A recent study has reported that postmenopausal women newly diagnosed with breast cancer, including those aged 70 years or older, should undergo MRIs to detect possible breast cancer in the apparently cancer-fee breast. The authors reviewed the cases of 425 women newly diagnosed with breast cancer at the Mayo Clinic in Florida between February 2003 and November 2007 who underwent bilateral breast MRIs after undergoing mammograms and breast exams that found no cancer. Of the women evaluated, 129 (30%) were aged 70 years or older. The rate of bilateral invasive breast cancer diagnosed only by MRI was assessed and analyzed, taking into account breast density, age, family history of breast cancer, menopausal status, and characteristics of the primary tumor.

A biopsy was recommended and performed in the opposite breast solely on the basis of MRI in 72 of the 425 women (17%). Sixteen of these 72 women had pathologically confirmed carcinoma of the breast, including seven of the older women. The prevalence of contralateral carcinoma found only by MRI was 3.8% overall and 5.4% in the older women. Of the risk factors examined, postmenopausal status was the only one that was found to be a significant predictor of contralateral cancer detected by MRI. The authors conclude that contralateral breast screening with MRI should be considered in postmenopausal women who are diagnosed with breast cancer, including women aged 70 years or older at diagnosis.

Implications of the study results

This study reports that bilateral breast cancer found solely by MRI may be more common in elderly women. This finding makes sense since most of the factors that may have contributed to breast cancer in one breast will also be present in the other. More time will have elapsed in older women during which cancer could develop.

Many women who have reached their seventies can expect to live into their nineties. Detecting cancer in the opposite breast upon initial diagnosis could spare these women from having to have two sets of surgery and other cancer treatments, in addition avoiding the shock and distress of learning of cancer in the second breast at a later date (at which time it will not be clear whether the tumor represents a new primary breast cancer or recurrence of the original cancer). The authors commented in an interview that there should be no age cutoff in use of MRI in these breast cancer patients.