Intensive surveillance including a dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) exam every six months was far more effective in detecting breast cancer in younger women with a high-risk genetic profile than an annual mammogram, according to a research team based at the University of Chicago Medicine and the University of Washington, Seattle.
"This study demonstrates, for the first time, that aggressive breast cancers can be caught early, without excessive recalls or biopsies," said Olufunmilayo Olopade, director of the University of Chicago's Center for Clinical Cancer Genetics. "Because of intensive surveillance and high-quality care, the majority of high-risk women in this study–most of whom had highly penetrant genetic mutations–have not developed breast cancer."
The study was designed to evaluate psychosocial distress levels and quality of life in women undergoing intensive surveillance. The researchers recruited 305 women, who had to have a lifetime breast cancer risk greater than 20%. More than half of the women enrolled (53%) had mutations in breast cancer-related genes, such as BRCA1, BRCA2 or CDH1.
After evaluation by a physician and a genetic counselor, participants were scheduled to undergo a clinical breast examination and a DCE-MRI scan every six months, and a digital mammogram every 12 months. Study subjects also had BROCA panel genetic tests looking for 12 genes associated with a predisposition to breast cancer. The researchers performed 2,111 DCE-MRIs and 1,223 mammograms. All cancers detected during the study were smaller than a centimeter.
The researchers found 17 cancers: four ductal carcinoma in situ and 13 early stage breast cancers. Fifteen of those cancers occurred in participants with pathogenic mutations. Eleven involved BRCA1, three involved BRCA2, and one involved CDH1. The mean tumor size was 0.61 centimeter. The 17 patients who developed a cancer were followed for a median of 5.3 years. All remain alive and free of systemic disease. Anxiety levels decreased over time and quality of life for the participants improved.
In this study, DCE-MRI every 6 months "performed well for early detection of invasive breast cancer in high-risk women, accomplishing the ultimate goal of breast cancer screening–detecting node-negative, invasive tumors less than 1 centimeter," said Olopade, an American Cancer Society Clinical Research professor. "These scans performed especially well in BRCA1 mutation carriers, who are at risk for aggressive subtypes of breast cancer."
"The central goal of our study was to understand the needs of the highest risk women," said study co-author Mary Claire King, professor of genome sciences and of medicine at the University of Washington. King has advocated for all women to be offered testing for BRCA1 and BRCA2 at about age 30, regardless of personal or family history of cancer, so that women with mutations can take action to prevent cancer in their futures.
"My concern is that mammography and MRI be used in ways that make sense given a woman's personal genetics," she said. "Women with mutations in BRCA1 or BRCA2 have very different needs for surveillance for breast disease than do women with no mutations in these genes. This is particularly true for healthy young women with mutations. It's truly critical to offer intensive surveillance to still-healthy women with BRCA1 or BRCA2 mutations."