For women with genetic risk, MRI twice a year beats mammography

The results, presented for the first time on December 8, 2017 at the annual Breast Cancer Symposium in San Antonio and now available online in Clinical research on cancer, suggest that for women with high-risk genetic mutations, intensive efforts to find small, early cancers can be crucial to improving outcomes.

"This study demonstrates for the first time that aggressive breast cancers can be detected quickly without excessive recall or biopsies," said Olufunmilayo Olopade, MD, distinguished professor of Walter L. Palmer and associate dean of the University of California. Chicago Medical. Center.

Due to intensive monitoring and high quality care, the majority of high-risk women in this study did not develop breast cancer, despite the fact that most of these women had genetic mutations such as BRCA1.

For their study, "intensive two-year dynamic magnetic resonance imaging enhanced contrast monitoring minimizes breast cancer in BRCA1 mutation carriers," researchers recruited 295 women in a clinical trial. The average age at entry was 43.3 years old.

To participate in the trial, volunteers had to have a breast cancer risk of more than 20% in their lifetime. More than half (53%) of the women enrolled had one of the 11 known genetic abnormalities related to breast cancer. Seventy-five of these 157 women had BRCA1 gene mutations and 61 mutations in the BRCA2 gene.

The study also included women diagnosed with breast cancer or ductal carcinoma in situ by the age of 35 or a mother or sister diagnosed with breast cancer before the age of 35. Age 50 (before age 40 for people of African descent). All subjects in the study had a panel of genetic tests looking for genes associated with a predisposition to breast cancer.

After evaluation by a physician and genetic counselor, participants were required to undergo a clinical breast examination and dynamic magnetic resonance imaging (DCE-MRI) exam every six months, as well as a digital mammogram every 12 months. month. People with high-risk mutations who completed five years of the study protocol were offered ongoing screening.

During the study, the researchers performed 2,111 MRIs (approximately seven for each participant on average) and 1,223 mammograms (four per participant). They found 17 cancers: four ductal carcinomas in situ and 13 early breast cancers.

Fifteen of these cancers occurred in participants with pathogenic mutations. Eleven involved BRCA1, three involved BRCA2 and one involved CDH1. None of the cancers have spread to the lymph nodes. The average tumor size was 0.61 cm (about 1/4 inch). All cancers detected during the study were less than one centimeter.

The 17 patients who developed cancer were followed continuously for a median of 5.3 years (range 0.5 to 11 years). All are alive and free from systemic diseases. Patient anxiety levels have decreased over time and the quality of life reported by patients has improved. The authors of the study recommend "other interventional studies evaluating this new screening approach to personalize the assessment and prevention of breast cancer risk".

In this study, DCE-MRI every 6 months "is well behaved for the early detection of invasive breast cancer in high-risk genomically stratified women," said Gregory Karczmar, professor of radiology at the University of Toronto. University of Chicago. "It's the ultimate goal of breast cancer screening," he added, "by detecting invasive tumors at less than 1 centimeter.

"For these patients, the annual mammogram did not bring any additional benefit to dynamic biannual MR exams with enhanced contrast," the authors agreed.

Mammograms are commonly used to screen for breast cancer, but they are "not the best option for about 40% of women," said Karczmar. "This includes those with dense breasts as well as those with significant genetic risks."

"MRI is much more sensitive than mammography," he added. "He may find invasive breast cancers earlier than mammograms and he can eliminate abnormalities that seem suspicious during a mammogram.Unfortunately, MRI is far too expensive for routine screening."

Mammograms will remain important for most women, but for high-risk women who receive a MRI-DCE every six months, "annual mammograms can be eliminated," said Olopade.

"The central objective of our study was to understand the needs of the most at-risk women," said Mary Claire King, Ph.D., co-author of the study, a professor of genomic sciences and research. medicine at the University of Washington and at American Cancer. Professor of Breast Cancer Research.

King proposed that all women be screened for BRCA1 and BRCA2 by the age of 30, regardless of their personal or family history of cancer, so that women with mutations could act to prevent cancer in women. their future.

"I hope mammography and MRI will be used in a logical way considering the woman's personal genetics," she said. "Women with mutations in BRCA1 or BRCA2 have very different needs in breast disease surveillance, but especially in young, healthy women with mutations BRCA1 or BRCA2 mutations."

A number of patients withdrew from the study within five years. The main reasons for their departure were the cost of health insurance or other payment problems, 27%; prophylactic mastectomy, 16%; and moved or changed health care provider, 11%.

The American Cancer Society (ACS) currently recommends an annual MRI as well as an annual mammogram for high-risk women, typically starting at age 30.

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For women at genetic risk, bi-annual MRI beats mammograms

More information:
Rodrigo Santa Guindalini et al., Two-year dynamic contrast-enhanced magnetic resonance imaging contrast-enhanced downstream breast cancer in BRCA1 mutation carriers, Clinical research on cancer (2018). DOI: 10.1158 / 1078-0432.CCR-18-0200