Improvement in DCIS detection rates by MRI over time in a high-risk breast screening study.
Although magnetic resonance imaging (MRI) is much more sensitive than mammography for detecting early invasive breast cancer, in many high-risk screening studies MRI was less sensitive than mammography for detecting ductal carcinoma in situ (DCIS). We reviewed our experience detecting DCIS in our single center study of annual MRI, mammography, ultrasound and clinical breast examination (CBE) for screening very high-risk women. All cases of DCIS±microinvasion and invasive cancer were compared in two time frames: before (period A) and after (period B) July 2001-when we acquired expertise in the detection of DCIS with MRI-with respect to patient demographics, method of detection, and rates of detection of invasive cancer and DCIS. In period A there were 15 cases (3.1% of 486 screens) in 223 women, of which 2 (13%) were DCIS-one with microinvasion-neither detected by MRI. In period B there were 29 cases (3.3% of 877 screens) in 391 women, of which 10 (34%) were DCIS±microinvasion (p=0.04), all 10 detected by MRI but only one by mammography. No DCIS cases were detected by ultrasound or CBE. Specificity was lower in period B than in period A but acceptable. The ability to detect DCIS with screening MRI improves significantly with experience. MRI-guided biopsy capability is essential for a high-risk screening program. In experienced centers the increased sensitivity of MRI relative to mammography is at least as high for DCIS as it is for invasive breast cancer.
Division of Medical Oncology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. ellen.warner@sunnybrook.ca
Ellen
E
Warner
Petrina A
PA
Causer
John W-N
JW
Wong
Frances C
FC
Wright
Roberta A
RA
Jong
Kimberley A
KA
Hill
Sandra J
SJ
Messner
Martin J
MJ
Yaffe
Steven A
SA
Narod
Donald B
DB
Plewes
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics / Q000473:pathology*; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006801:Humans; D008279:Magnetic Resonance Imaging; D008327:Mammography; D008875:Middle Aged; D009154:Mutation; D009361:Neoplasm Invasiveness; D010808:Physical Examination; D012189:Retrospective Studies; D018570:Risk Assessment; D014463:Ultrasonography