Differences between first and subsequent rounds of the MRISC breast cancer screening program for women with a familial or genetic predisposition.
BACKGROUND
Within the Dutch MRI Screening (MRISC) study, a Dutch multicenter screening study for hereditary breast cancer, the authors investigated whether previously reported increased diagnostic accuracy of magnetic resonance imaging (MRI) compared with mammography would be maintained during subsequent screening rounds.


METHODS
From November 1999 to October 2003, 1909 eligible women were included in the study. Screening parameters and tumor characteristics of different rounds were calculated and compared. The authors defined 3 different types of imaging screening rounds: first round in women never screened by imaging before, first round in women screened by imaging (mainly mammography) before, and subsequent rounds.


RESULTS
The difference in sensitivity for invasive cancers between mammography and MRI was largest in the first round of women previously screened with mammography (20.0 vs. 93.3%; P=.003), but also in subsequent rounds, there was a significant difference in favor of MRI (29.4 vs. 76.5%; P=.02). The difference in false-positive rate between mammography and MRI was also largest in the first round of women previously screened with mammography (5.5 vs. 14.0%; P<.001), and it remained significant in subsequent rounds (4.6 vs. 8.2%; P<.001). Screen-detected tumors were smaller and more often lymph node negative than symptomatic tumors in age-matched control patients, but no major differences in tumor stage were found between tumors detected at subsequent rounds compared with those in the first round.


CONCLUSIONS
In subsequent rounds, a significantly higher sensitivity and better discriminating capacity of MRI compared with mammography was maintained, and a favorable tumor stage compared with age-matched symptomatic controls. As results of these subsequent screening rounds were most predictive for long-term effects, the authors expect that this screening program will contribute to a decrease of breast cancer mortality in these high-risk women.
Kriege
Mieke
M
The Rotterdam Family Cancer Clinic, Department of Medical Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, Netherlands.
Brekelmans
Cecile T M
CT
Boetes
Carla
C
Muller
Sara H
SH
Zonderland
Harmine M
HM
Obdeijn
Inge Marie
IM
Manoliu
Radu A
RA
Kok
Theo
T
Rutgers
Emiel J T
EJ
de Koning
Harry J
HJ
Klijn
Jan G M
JG
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000235:genetics; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000175:diagnosis / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008279:Magnetic Resonance Imaging; D008327:Mammography; D008403:Mass Screening; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity