After Lumpectomy, Mammogram Plus MRI Detects More New Breast Cancers

According to a recent study, young women who have a lumpectomy for early-stage breast cancer could benefit from annual screenings with both mammography and MRI.

The study was conducted at six medical centers in South Korea and published in JAMA Oncology.

Background and Goals

Mammograms are imaging tests that help look for breast cancer. Women who have had breast cancer and a lumpectomy, also called breast-conserving surgery, along with radiation therapy are advised to have yearly mammograms after breast cancer treatment. That’s because they have a higher risk of developing a second cancer in either breast compared to the risk of breast cancer for women who have never had the disease.

But mammograms may be less able to pick up signs of breast cancer in women who were diagnosed at age 50 or younger. Mammograms also have a harder time finding breast cancers because of dense breast tissue or changes that have been caused by surgery or radiation. As a result, these women are more likely to have a new breast cancer discovered between annual screenings by a self-exam or noticing a lump or other difference in the breast.

To screen for cancer or breast changes after a lumpectomy, some women at a high risk of breast cancer returning receive ultrasound or MRI screenings in addition to mammograms. But how well recommending such screenings in addition to mammography has not been studied enough for them to be added to routine follow-up guidelines for women who do not have genetic mutations that put them at even higher risk.

In this study, the researchers compared what happens when young women who had lumpectomy have annual cancer screenings with

• mammogram and MRI
• mammogram and ultrasound
• mammogram alone

They wanted to see if adding another screening method improved cancer detection. They also wanted to know the tumor characteristics of breast cancers found with combined screenings.

Design

The study included 754 women diagnosed with early-stage breast cancer at age 50 or younger and who had a lumpectomy and radiation. It did not include women who have the highest risk of recurrence due to having positive margins after surgery or who did not receive radiation.

The women in the study were screened each year with mammograms, ultrasounds and MRIs of both breasts for 3 years. Participants also received clinical breast exams every 6 months.

Different radiologists looked at the results from the mammogram, ultrasound and MRI for each woman, without seeing images from the other methods. They then compared which methods had identified specific breast cancers.

Results

The 754 women had a total of 2,065 screenings. The screenings found new breast cancers in 17 women. Of those 17

• 2 were found by mammogram alone
• 3 were found by MRI alone
• 1 was found by mammogram and MRI
• 5 were found by ultrasound and MRI
• 0 were found by mammogram and ultrasound
• 6 were found by all three imaging methods
• 0 were found by ultrasound alone

Mammography detected only 9 of the cancers found in this study. But mammography and MRI together detected all 17 of the cancers diagnosed. No cases were found by ultrasound alone or by clinical exams.

Limitations

Participants received all screening methods. The study did not include a control group that only received mammograms. The study was able to show that MRI caught cancers that mammograms missed, but without a control it does not show if the breast cancers would be at a later stage when found or how that might affect survival.

What This Means for You

It’s important to have the recommended yearly breast screenings for your ongoing care if you had lumpectomy and radiation treatment. The findings in this study could help you and your oncologist make decisions about which screening method or methods are best for you.

You may want to talk with your doctor about your situation — your age, breast density and treatments — and whether you should consider having MRI screenings in addition to mammograms.

There are some drawbacks to using MRI for breast screenings. Compared with mammography, it can increase the number of “false positive” findings — results that suggest breast cancer but turn out not to be cancer. Women who get false-positives still experience the anxiety of having a biopsy and other tests to find out if they have cancer.

MRI is more costly than other screening methods and might not be available in your area. MRI also requires an injection. If MRI is not an option, the researchers said, adding ultrasound with annual mammograms could also be considered.

Cho, N, Han, W, Han B-K, 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 Oncology 2017; doi: 10.1001/jamaoncol.2017.1256.

This article was supported by the Grant or Cooperative Agreement Number 1 U58 DP005403, funded by the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention or the Department of Health and Human Services.