American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes

Featured Commentary

The online formats of SRGS include access to What You Should Know (WYSK): commentaries on articles published recently in top medical journals. These commentaries, written by practicing surgeons and other medical experts, focus on the strengths and weaknesses of the research, as well as on the articles' contributions in advancing the field of surgery.

Below is a sample of one of the commentaries published in the current edition of WYSK.

Lehman CD, Lee JM, DeMartini WB, et al. Screening MRI in Women With a Personal History of Breast Cancer. J Natl Cancer Inst. 2016;108(3). pii: djv349.

Cho N, Han W, Han B, et al. Breast Cancer Screening with Mammography Plus Ultrasonography or Magnetic Resonance Imaging in Women 50 Years or Younger at Diagnosis and Treated with Breast Conservation Therapy. JAMA Oncol. 2017; 3(11):1495–1502. Free Full Text

Commentary by: H. Colleen Silva, MD, FACS

Screening MRI (magnetic resonance imaging) after breast cancer may find small, node-negative breast cancers not seen by mammography. However, the overall number of secondary cancers is quite low, (ranging from 1.7 to 2.3 percent in these two studies). It would be necessary to perform one thousand MRIs to find four additional cancers. As there are currently no established guidelines for MRI as a screening tool after breast cancer, decisions regarding MRI use should be based on a discussion of potential benefits with your patient (finding recurrent cancer) versus harms (false positives and additional biopsies) and your patient's personal level of risk tolerance and anxiety.

Although the use of MRI is supported by the American College of Surgeons and the National Comprehensive Cancer Network to screen women with greater than a 20 percent lifetime risk of cancer based on familial and genetic models, the current guidelines neither recommend for nor against MRI screening after breast cancer treatment, and the American Society of Clinical Oncology recommends against surveillance MRI.

Lehman and colleagues set out to assess the diagnostic performance of MRI in women with a personal history (PH) of treated breast cancer compared to women with a genetic or family history (GFH) in order to establish the best methods of surveillance after breast cancer treatment. The authors performed a retrospective review of approximately 3000 breast MRIs performed at their institution from 2004 to 2011 in 1521 women (915 women with a personal history of breast cancer and 606 women with genetic/family history of breast cancer).

Along similar lines, Cho and colleagues sought to compare outcomes of combining mammography with MRI or ultrasound screening in women 50 or younger following breast conserving surgery for cancer. This was a multicenter prospective nonrandomized study, and 754 women completed 2065 screenings. The women received three annual breast MRI screenings in addition to mammograms and ultrasounds.

In the Lehman study, the majority of women were between 40 and 60. Mammographic density distribution was similar across the two groups, with the majority being heterogeneously or extremely dense. Cancer detection rate by screening MRI was 1.7 percent and 1.8 percent, respectively, in the PH and GFH groups. A total of 34 of 1521 women were diagnosed with breast cancer: 27 after a positive MRI and seven after a negative MRI. Four of the seven false negatives (FN) were DCIS, which presented as calcifications on mammography. The remaining three FN cases were assessed as BI-RADS 3, with invasive cancer diagnosed within one year.

For Cho and company, the cancer detection rate was 2.3 percent (17 women) in the three years of the study. None of these cancers were found on clinical exam. No interval cancers were found. The majority were early stage. The cancer detection rate (CDR) of mammography plus MRI was higher than mammography alone (8.2 versus 4.4 per 1000).

One of the drawbacks of MRI is its high false positive rate and subsequent increased costs and morbidity. Lehman et al had recall rates of 18 percent, and 11 percent were recommended for biopsy. Both age and prior MRI history decreased the risk of a false-positive interpretation on screening MRI.

In the Cho study, the addition of MRI to mammography increased the recall rate from 4.4 percent to 13.8 percent and the biopsy rate from 0.5 to 2.7 percent; however, 8 of the 17 cancers might have been missed with mammography alone. In the Lehman study, 16 PH women were diagnosed with a secondary breast cancer by screening MRI, and 13 had a recent negative mammogram.