Surveillance of <EMPH TYPE="ITAL">BRCA1</EMPH> and <EMPH TYPE="ITAL">BRCA2</EMPH> Mutation Carriers With Magnetic Resonance Imaging, Ultrasound, Mammography, and Clinical Breast Examination

TLDR

Current guidelines recommend annual mammography and biannual clinical breast examination for BRCA1/2 mutation carriers, yet many cancers are still detected at advanced stages, underscoring the need to evaluate MRI-based surveillance. The study aimed to compare the sensitivity and specificity of mammography, ultrasound, MRI, and clinical breast examination in BRCA1/2 mutation carriers. A prospective surveillance study of 236 Canadian women aged 25–65 with BRCA1/2 mutations performed annual MRI, mammography, and ultrasound, with clinical breast examinations every six months, and lesions scored 4 or 5 on BI‑RADS were biopsied. MRI detected 77% of cancers (17/22), outperforming mammography (36%), ultrasound (33%), and CBE (9.1%); sensitivities were 77%, 36%, 33%, and 9.1% respectively, and combining all four modalities yielded a 95% sensitivity versus 45% for mammography plus CBE.

Abstract

ContextCurrent recommendations for women who have a BRCA1 or BRCA2 mutation are to undergo breast surveillance from age 25 years onward with mammography annually and clinical breast examination (CBE) every 6 months; however, many tumors are detected at a relatively advanced stage. Magnetic resonance imaging (MRI) and ultrasound may improve the ability to detect breast cancer at an early stage.ObjectiveTo compare the sensitivity and specificity of 4 methods of breast cancer surveillance (mammography, ultrasound, MRI, and CBE) in women with hereditary susceptibility to breast cancer due to a BRCA1 or BRCA2 mutation.Design, Setting, and ParticipantsA surveillance study of 236 Canadian women aged 25 to 65 years with BRCA1 or BRCA2 mutations who underwent 1 to 3 annual screening examinations, consisting of MRI, mammography, and ultrasound at a single tertiary care teaching hospital between November 3, 1997, and March 31, 2003. On the day of imaging and at 6-month intervals, CBE was performed.Main Outcome MeasuresSensitivity and specificity of each of the 4 surveillance modalities, and sensitivity of all 4 screening modalities vs mammography and CBE.ResultsEach imaging modality was read independently by a radiologist and scored on a 5-point Breast Imaging Reporting and Data System scale. All lesions with a score of 4 or 5 (suspicious or highly suspicious for malignancy) were biopsied. There were 22 cancers detected (16 invasive and 6 ductal carcinoma in situ). Of these, 17 (77%) were detected by MRI vs 8 (36%) by mammography, 7 (33%) by ultrasound, and 2 (9.1%) by CBE. The sensitivity and specificity (based on biopsy rates) were 77% and 95.4% for MRI, 36% and 99.8% for mammography, 33% and 96% for ultrasound, and 9.1% and 99.3% for CBE, respectively. There was 1 interval cancer. All 4 screening modalities combined had a sensitivity of 95% vs 45% for mammography and CBE combined.ConclusionsIn BRCA1 and BRCA2 mutation carriers, MRI is more sensitive for detecting breast cancers than mammography, ultrasound, or CBE alone. Whether surveillance regimens that include MRI will reduce mortality from breast cancer in high-risk women requires further investigation.