Prospective validation of the breast cancer risk prediction model BOADICEA and a batch-mode version BOADICEACentre.
BACKGROUND
Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) is a risk prediction algorithm that can be used to compute estimates of age-specific risk of breast cancer. It is uncertain whether BOADICEA performs adequately for populations outside the United Kingdom.


METHODS
Using a batch mode version of BOADICEA that we developed (BOADICEACentre), we calculated the cumulative 10-year invasive breast cancer risk for 4176 Australian women of European ancestry unaffected at baseline from 1601 case and control families in the Australian Breast Cancer Family Registry. Based on 115 incident breast cancers, we investigated calibration, discrimination (using receiver-operating characteristic (ROC) curves) and accuracy at the individual level.


RESULTS
The ratio of expected to observed number of breast cancers was 0.92 (95% confidence interval (CI) 0.76-1.10). The E/O ratios by subgroups of the participant's relationship to the index case and by the reported number of affected relatives ranged between 0.83 and 0.98 and all 95% CIs included 1.00. The area under the ROC curve was 0.70 (95% CI 0.66-0.75) and there was no evidence of systematic under- or over-dispersion (P=0.2).


CONCLUSIONS
BOADICEA is well calibrated for Australian women, and had good discrimination and accuracy at the individual level.
Cancer Epidemiology Centre, Cancer Council Victoria, Victoria, Melbourne, Australia.
R J
RJ
MacInnis
A
A
Bickerstaffe
C
C
Apicella
G S
GS
Dite
J G
JG
Dowty
K
K
Aujard
K-A
KA
Phillips
P
P
Weideman
A
A
Lee
M B
MB
Terry
G G
GG
Giles
M C
MC
Southey
A C
AC
Antoniou
J L
JL
Hopper
D000328:Adult; D000368:Aged; D000465:Algorithms; D001315:Australia; D019313:BRCA1 Protein / Q000235:genetics; D024682:BRCA2 Protein / Q000235:genetics; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics; D003198:Computer Simulation; D005192:Family Health; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D012042:Registries; D018570:Risk Assessment; D011795:Surveys and Questionnaires; D055815:Young Adult
D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human